Rachel Clarkson: This way of living is actually going to encourage those good genes to be turned on and bad genes to be turned off and what that means is you may have genes that are going to predispose you to a disease for instance, like cancer or Alzheimer's let's say. If you live in a way that's healthy, you can ensure or at least try to ensure that those good genes are going to be switched on and the bad genes switched off.
Dr Rupy: Welcome to the Doctor's Kitchen podcast, the show about food, lifestyle, medicine and how to improve your health today. My name is Dr Rupy. I'm a medical doctor, I also study nutrition and I'm a firm believer in the power of food and lifestyle as medicine. Join me on this podcast where we explore multiple determinants of what allows you to live your best life. And remember you can sign up to the doctorskitchen.com for the newsletter where we give weekly recipes plus tips and hacks on how to improve your lifestyle today. On this episode, I'm delighted to welcome Rachel Clarkson, who is a leading nutrigenomic specialist dietitian. And we're going to be talking about eating with your genes. She uses next generation technology and expert analysis to create personalised wellness programs for her clients under the name of The DNA Dietitian, very catchy. She's also a guest lecturer for St Mary's University's Masters in Genetics and Nutrition and sits on the scientific advisory board of two health tech platforms. On today's podcast, we're going to be talking about her background in dietetics and why she decided to specialise specifically in personalised nutrition. The basics of what we mean by nutrigenomics. This is something I spoke about in my, wrote about rather, in my first book and I continue to talk about the impact of food and lifestyle on the expression of our genes. And we're going into a bit more detail on that today. We're talking about epigenetics and how that relates to food and environmental changes. The differences between nutrigenetic tests and deterministic gene investigations that we do within the healthcare service. I think it's really important this part of the podcast because it really does delineate between the different types of testing that there are out there, as well as the unsavoury practices of some profit maximising companies that are there sort of preying on people's fear of not knowing exactly what their genomic analysis is and whether it's actually even robust enough to give personalised insights. And this is why I think it's very important to have someone talk about this quite honest and openly as Rachel does. We talk about Rachel's approach to consulting with patients in clinic and how to personalise diets for things like fertility, obesity and more. And I also find some really interesting insights into caffeine and coffee in particular, things that I did not know before and you'll you'll tell I was quite surprised at some of the insights that Rachel gave me. It's an incredibly interesting area of nutrition and medicine. It's definitely something that I think will become the norm in the future. Don't forget, you can check out the recipe I made Rachel at the top end of the show on YouTube. I made a beautiful pea pasta with artichoke. She loved it. It was a delicious recipe and I'm sure you'll like it too. Make sure you listen to the end and I'll sum up the conversation that we had as well as signing up and subscribing to the Doctor's Kitchen podcast and the newsletter on the doctorskitchen.com where we give you recipes every single week. I'll be quiet now and I hope you enjoy this pod. I'm going to be cooking you a very simple meal. It's a pasta and I'm not ashamed to say it's basically made up of all the leftovers in my fridge.
Rachel Clarkson: That's fine. It's the end of the week.
Dr Rupy: Exactly. It's Friday. I'm sure you're the same as well when you make. Actually, what's your go to when you when you've got stuff in your fridge?
Rachel Clarkson: My go to is basically just make a sheet pan meal. So I'll just basically put all the veggies onto a large pan. Probably have like a piece of fish, bit of olive oil, some herbs, pop it in the oven and it'll be done.
Dr Rupy: Brilliant. I should have done that. Anyway, I'm going to make you a pasta. We're doing simple. Yeah, we're doing simple. I'm going to use some of these beautiful artichokes that I used earlier in the week from a jar. You like jarred artichokes as well in water?
Rachel Clarkson: I love artichokes. High fibre.
Dr Rupy: Beautiful. Yeah. High fibre, prebiotics. And we've got peas, a bit of broccoli stem, some mushrooms, a little bit of parsley to finish off with, all in the pan. I've already made this pea pasta. I don't know if you've come across this before, but it's
Rachel Clarkson: Is it gluten free?
Dr Rupy: It is. Yeah. It's made out of 100% pea, but the texture is brilliant and the flavour is there as well and it just it holds itself quite nicely. And it's really high in both protein and fibre as well. So I'm a big fan of that. But then, you know, you could use regular gluten pasta as well. I'm going to start off with this and why don't you start by telling us about your background and how you got into dietetics because I find your chosen field at the moment absolutely fascinating and I know that I'm going to learn so much on this podcast.
Rachel Clarkson: Yeah, so I started in Manchester doing an undergraduate in biomedical science and that almost gave me a, well, exposure to the world of genetics, molecular biology, biochemistry, basically everything you need as a foundation to start. As you, you know, I'm sure you did it in your first year at university as a doctor. So that then took me into the area of inflammation where I did a research project looking at inflammation and disease. And then realised that's the underlying cause of all disease. So instead of treating disease, thinking about how do we prevent. That then took me to do a masters in nutrition at King's in London and during that time we basically learned all about the molecular biology, biochemistry to do with nutrients at an almost molecular level. And that then took me to a research project in something called epigenetics where I researched how something called DNA methylation can actually cause differences in the homeostasis of iron. And really what that means in simple terms is do turning genes on and off in the body alter the way that we function, I guess.
Dr Rupy: In simple terms. Yeah, for both positive and negative outputs of your genetic sequence, which is fixed, we can't change that, but it's more about the expression of genes. And from what I understand, the heritable characteristics that aren't encoded in the actual genetic sequence itself, which I find absolutely fascinating because it's the thought that you can change the phenotype or the physical appearances that are passed off in offspring without a change in the actual sequence is just mind boggling for me. When I first came across that, I was like, wow. And that's why I feel like, you know, we're going to have to go back to basics quite a bit when we go into the second bit after I've finished cooking here because it's like a journey for me and I want to take sort of like the listener on a journey as well. I just, as people are probably listening to this right now, I've just popped the artichokes in a large saucepan with some olive oil and I'm just going to go in with all the mushrooms. It's kind of like a one pan wonder sort of meal where you just throw everything in it with a little bit of seasoning. So when you were doing your masters at King's, how long was it firstly?
Rachel Clarkson: It was around 18 months.
Dr Rupy: Okay.
Rachel Clarkson: Yeah, 18 around 18 months, I think.
Dr Rupy: 18 months.
Rachel Clarkson: Yeah, because that was the first one. And then I really thought about the importance of being able to actually apply my nutritional knowledge to a patient in order to treat medical disease and also healthy individuals. So then I went on to do another course at King's in dietetics. And I learned exactly that along with clinical placements in a few of London's really great hospitals. You probably, I'm sure you've probably worked in them.
Dr Rupy: Like St Thomas's, Imperial.
Rachel Clarkson: Yeah, Royal Marsden.
Dr Rupy: No, I've never worked in St Thomas's. I've I've been there to Royal Marsden as a medical student. We did some oncology placements there. Imperial I've done a bit. I mean, I still work in West London and stuff, so, so yeah, oh nice. So you were all over when you were doing your masters and stuff.
Rachel Clarkson: Yeah, I was very lucky. I got placed in some of the most local and some of the most well regarded when it comes to research and teaching. So I was very happy.
Dr Rupy: And when you were doing your research in inflammation, how was that, how is that still influenced like the way you practice now in terms of like, you know, what you see as the root cause of?
Rachel Clarkson: Yeah, so the research was really looking at inflammatory pathways and I guess the literature that was needed in order to put it together, definitely has an impact in the way that I feel regarding lifestyle and how we should be really looking to move more, eat more plants, get more sleep, de-stress and the effect that inflammation or anti-inflammatory really can have on the body and disease progression.
Dr Rupy: Yeah, yeah. Because I think like inflammation is this really misunderstood, bandied around term that people get quite fearful of and it's kind of perpetuated this like supplement industry that's designed to capitalise on people's fear of being inflamed or having, you know, anything that's kind of regarded as detrimental to their health. Whereas in reality, inflammation is one of the most important processes and we have to respect the fact that we need inflammation in our bodies to survive, to respond to stresses, as a means of communicating with our immune system and signalling to the cells that that need to come and, you know, clot blood or fight pathogens and, you know, a whole host of other issues. But inflammation in its excess is something that is the root cause of a whole host of different conditions. And that was really like for me pretty special when I realised, oh, there's an underlying link to all these things that we're seeing in clinic.
Rachel Clarkson: And it's that chronic inflammation that we really see the progression of disease. It's not the acute that like you said, we need in order to function in a healthy state day to day. So.
Dr Rupy: Amazing. And so like your background, like how, like why did, why did you go into dietetics? I'm always fascinated into like finding out the back stories behind people and like why they ended up, you know, into the professions that they're in.
Rachel Clarkson: I guess being very honest, when I started as a student in Manchester, I really fell into the student lifestyle of maybe not cooking a lot, eating maybe quite a few takeaways, maybe having a few too many drinks.
Dr Rupy: It's a right of passage though, isn't it?
Rachel Clarkson: It's the, it's the norm. And then I realised, wow, my body's changing, my energy levels aren't great. I didn't have great focus. And so I thought, along with doing the research project in kind of inflammation and thinking about the association between lifestyle and and really health, I thought I must do something about this. So I became quite obsessive regarding my diet and active lifestyle. But unfortunately, I wasn't educated in nutrition. I'd just read a few books. I'd read a blog, I'd read blogs, I'd kind of looked to these people who I thought were experts for advice and I really followed that. And that meant restricting quite a lot of the things that we should be eating. And actually, when I look back at what that resulted in, I was low in energy, I was low in weight. I looked and felt as I was, which was malnourished. So that wasn't good.
Dr Rupy: What were you cutting out, sorry, before?
Rachel Clarkson: So, I mean, I cut out dairy, I cut out gluten, I cut out animal products. I didn't think about the importance of incorporating nutrients in other sources of food that I would be naturally missing. And, you know, it was crazy. I was listening to my personal trainer who told me that I had to eat steak for breakfast sometimes. So that was the initial thing. And then I was like, I don't feel good eating steak for breakfast. So then I looked elsewhere that said that I couldn't eat meat and animal products. So I cut everything out. It was, it was a crazy time.
Dr Rupy: So a proper yo-yoing from like different.
Rachel Clarkson: It was just exactly that, a yo-yo. And I think that that's what many people really suffer with, that yo-yo dieting, kind of jumping on anything that is selling them health and wellness. And unfortunately, it can really have detrimental effects unless you do it in a, in a healthy way with a trusted individual.
Dr Rupy: So how did you break out of that pattern then?
Rachel Clarkson: So then I applied for a nutrition masters and that's when I actually realised, first of all, that a masters in nutrition was not going to tell you what to eat to get healthy. I actually, you know, ended up in London, first day and we were given the syllabus, which was all about molecular biology, biochemistry, you know, everything that I'd basically been doing in biomedical science, but in a nutritional basis. But yeah, it was then when I realised the importance of nutrients for the body, normal body functioning, and really started to eat in a way that was healthy and recommended for the population. So I was, you know, eating more plants, I was incorporating lots of different proteins, whether that be plant proteins and also animal proteins, just thinking about moderation really. And yeah, I felt really great.
Dr Rupy: So that's kind of what spurred you on into like, you know, digging into nutrition at a deeper level and looking into genomics as well, which I, I find fascinating, but it's a bit of a murky field, right?
Rachel Clarkson: Yeah. So towards the end of the nutrition masters, we were encouraged to find a topic that we were interested in where we would carry out a research project in the laboratory and write up a paper. So naturally, I was very interested in genetics because I'd already done it in my undergraduate during the biomed. And so that's when I looked into the epigenetic modification of the iron sensing genes and really looked at genes turning on and off for that was my first exposure.
Dr Rupy: Was that your paper on hepcidin?
Rachel Clarkson: Yes.
Dr Rupy: Is that right? Okay.
Rachel Clarkson: Yeah. So we published that, which was pretty exciting.
Dr Rupy: I had a quick read of it. I, I, I got to admit, I haven't finished the paper. I pretty much just read the abstract, but I don't know if you could summarise it because it sounded really interesting.
Rachel Clarkson: We determined that further research needed to be taken into the methylation of genes that encoded the iron sensing pathway, which basically means when we think about homeostasis of iron, so when somebody has low levels, they will sense that they have low levels in the body and hepcidin is a hormone that is released into the body. And basically, we just worked out that lifestyle modifications would cause methylation of these genes that encode for the iron. It's very complicated and I don't expect anyone to understand.
Dr Rupy: It's a simple explanation. So hepcidin is found in the gut, if I'm correct.
Rachel Clarkson: Yeah. I mean, it's all to do with the sensing actually occurs in the liver.
Dr Rupy: So, so when you have low iron levels, your hepcidin is upregulated and that changes the absorption of iron.
Rachel Clarkson: Yeah, turns kind of things on, like you need to absorb more. And then when it's too high, we don't, we don't absorb as much because our body knows that we're sensing we've got enough.
Dr Rupy: Exactly. And so what were the lifestyle factors that you found were particularly detrimental to iron? Because I don't think this is talked about enough. We think of iron in a very binary sense in terms of the different types of iron, the pathological causes for women, it's like, you know, menstruation loss, heavy menstruation. For a whole bunch of other causes, it could be dietary, but actually there's a lot more to the story that I think we as practitioners are giving credit for.
Rachel Clarkson: So we specifically looked at cancer liver cells and our recommendation for future research was to find out exactly which lifestyle modifications need to be taken in order to turn things on and off. We weren't exactly sure what, we just knew that methylation was the mechanism that caused things to be turned on and off. So future research will tell.
Dr Rupy: Pretty much the conclusion of every paper I've ever read. We need to do more research on this. Exactly. Okay, fine. We're going to switch gears and go back to cooking now. As you've seen, I've just piled in all the veg, the mushrooms, a bit of the artichoke, the stems of the parsley actually, I forgot to mention, I threw in there as well because the stems are a bit woody. You don't want to eat them raw. Put it, put the, the green pea pasta in that I cooked, a little bit of olive oil. And as you like some heat, I'm going to put some red chilli flakes on top. Not flakes, sorry, slices. And you can give me your honest opinion of this. I honestly won't be offended if any constructive criticism will be really appreciated. So.
Rachel Clarkson: Always honest.
Dr Rupy: Always honest. Yeah. I'm excited for the broccoli.
Rachel Clarkson: You were telling me before that broccoli has been shown to increase the detox, well, to basically turn genes on that are to do with detoxification in the body.
Dr Rupy: Yeah, it's really interesting that I came across a paper based in China where they actually used broccoli sprout extract and I think it's because of sulforaphane changing the methylation factors. But I think a lot of people think in too much of a reductionist when it comes to detoxification. It's a very important natural mechanism, but it's supported by micronutrients found in food, those phase one and phase two enzymes that we can talk about a bit later if you like.
Rachel Clarkson: Thank you.
Dr Rupy: Getting into it. You can dive in. Here you go.
Rachel Clarkson: Ladies first.
Dr Rupy: Yeah. Okay, I'll try to get a bit of everything.
Rachel Clarkson: Honest opinion.
Dr Rupy: Okay.
Rachel Clarkson: I need some artichoke, obviously.
Dr Rupy: Yeah, yeah, definitely, definitely. What does it need? Is it balanced? Is it need something? Is it lacking?
Rachel Clarkson: It's really good.
Dr Rupy: Good? Good. She loves it. Great. How is your lunch?
Rachel Clarkson: It was delicious. Thank you.
Dr Rupy: Good. Right answer.
Rachel Clarkson: I'm feeling very full with all the fibre.
Dr Rupy: Yes, a lot of fibre. Yeah. Hopefully like a light lunch. So I wanted to get back to the reason why I asked you to come on the pod because like you said earlier, you've done training, your BSc, you've done a masters in nutrition, you've done some extra training with Monash University, University of Toronto in the subject of nutrigenomics. You're also a lead educator in Europe for nutrition professionals and you're a guest lecturer for all these different nutrition and genetics conferences. You are the perfect person that I want to talk to about this subject, which is marred by a bit of, it's a bit murky and we talked about that in the break about how it's an unregulated industry. It's very new. People are often afraid of new industries. And I'll be honest, I was sceptical of the idea of nutrigenomics initially, perhaps due to the practices of some companies that are there to maximise on people's fear of, you know, what they should be doing or what's lacking from their diet. But the way you practice, I think is exceptionally responsible and it's the way we should be using this incredible tool. Before we go into that, I think I want to take the user on a journey because a lot of people would assume that I know absolutely everything about nutrigenomics in the same way people expect general practitioners to know everything about gynaecology, psychiatry, gastroenterology, cardiology, etc, etc. And I am just as ignorant as most people when it comes to the subject matters of gene, nutrigenomics and epigenetics. I know a bit, perhaps not enough to practice in the same way you do. So why don't we take the user on a journey and just go way back. Go way back. And we can start off with like, what do we mean with the terminology of a gene and epigenetics?
Rachel Clarkson: Yeah. So, good question and I always like to start from the beginning because you're absolutely right. We're not expected to know these things. It's not language that we use on a day to day basis, but from a health point of view, when we're talking about genetics and nutrition, I think that it's important to think about, well, what is a gene? So a gene is a part of your DNA that basically has information that tells your body what to do, what to make, what protein it should be making. And we all actually have around 99% of the same genes as human beings. And 1% of that is actually different, which is what makes me and you look very different. I was going to say black hair, is it black?
Dr Rupy: I'd say dark brown.
Rachel Clarkson: Dark brown. I'm light brown. You know, you've got brown eyes, I've got blue eyes. Great in some lights. But these are, you know, physical traits that are passed down from our parents. Now, these physical traits make us look different on the outside. We also have traits on the inside that are very different and that's really what the study of nutrigenomics looks at, the different variations of the same genes which alter the way that we respond to nutrients and the food. So we just ate the same pasta with artichokes, mushrooms, broccoli. Well, me and you have eaten the same meal in maybe different quantities, but similar. If we were to look at how much of each nutrient has been absorbed, metabolised and utilised, say an hour, two hours, three hours from now, we'd actually have different levels in our, in our blood and that's all to do with our variants of these genes. Sorry if I went on a bit of a tangent.
Dr Rupy: No, that's perfect because I think intuitively, when I'm listening to you explain that, it's obvious. It's like, yeah, 100%, there's so many different reasons as to why I might metabolise something completely differently to you, both environmentally and both at a genetic level as well, right? So, uh, so when we talk about like, you know, heritable traits and traits that are influenced by the environment, what do we mean by environmental factors? Like what are those sort of different and in how we, how we express our genes? Like what do we mean by environmental factors?
Rachel Clarkson: So, as you know, you have this podcast, you have Instagram, you write books all around how we should be eating and living in a healthier way. And really, when it comes to genetics, it's the part that epigenetics has to play. So environmental factors around how we eat, how we sleep, our stress, how much we move, how much sunlight we get, the pollutants in the city, these are all environmental factors which will have a huge impact on how our genes are expressed. And that can come from a few ways. We like to talk about DNA methylation. So the adding of methyl group, as you probably know, or histone modification. These are all epigenetic modifications of genes which can turn things on and off. So the methylation, if you imagine a, like a plastic, a rubber band on a pencil, literally on one section of the pencil, it would be covering part of the pencil. So that part of the pencil wouldn't be able to be expressed. If you imagine the pencil as your gene. And the histone modification, well, our DNA is actually wrapped around those histones and that's why it's able to be in such a condensed shape. And it's tightly bound. Now, the histones actually, well, epigenetic modification can relax these histones in order that the gene can actually be expressed because it's actually shown.
Dr Rupy: Okay, so I love that analogy of the pencil. It's making me think about it a little bit clearer. So the pencil is the gene. The rubber band are the histones.
Rachel Clarkson: Like a methyl group.
Dr Rupy: The methyl group, sorry. And those will essentially when they're covering that bit of the pencil, that tiny bit of the pencil, that's either turning the gene expression on or off.
Rachel Clarkson: Yeah, because it's covering it.
Dr Rupy: Got you. Okay, fine.
Rachel Clarkson: Yeah. So if you just think about all of the healthy recommendations around sleeping, you know, seven to nine hours a night, eating a diet that's, well, we could go into that for days, but you know, high in plants, adequate hydration, just a varied healthy diet, moving more, decreased stress. This way of living is actually going to encourage those good genes to be turned on and bad genes to be turned off. And what that means is you may have genes that are going to predispose you to a disease, for instance, like cancer or Alzheimer's, let's say. If you live in a way that's healthy, you can ensure or at least try to ensure that those good genes are going to be switched on and the bad genes switched off.
Dr Rupy: Exactly. So I, I remember writing a chapter on this in my first book where we were talking about food as information and how the information encoded in, in food interacts with our very existence, the very core of our existence. And the impression I had at the time was, you know, largely plants, lots of fibre, plenty of things like sunlight, and the lifestyle 360 factors that I talk about, social cohesion, a clean environment, sleep hygiene, etc. These all have been shown in studies and G mapping studies to turn the positive expressions of genes on and the negative ones like tumour promoting genes off. If we know what the positive lifestyle factors are and the positive dietary traits are, what is the utility of genetic counselling in terms of genetic, in terms of nutrigenomics specifically? And perhaps we should take one step back and actually talk about the different types of genetic testing available out there.
Rachel Clarkson: Yeah, that's a really good question. I'm probably going to take it back even a little step regarding why look at genetics, you know, over the last 10, 20, 30 years, there's been a huge rise in these chronic diseases. And so many would say, well, our genetics haven't changed. So why look at genetics? It's actually environmental factors that have changed or maybe around us. So maybe we're living in an unhealthy way. Now, yes, that is true. Environmental factors have probably increased the likelihood of people developing these diseases. And that maybe is shown with these increases, but some people aren't getting these diseases. And so that sheds a light on, well, maybe we have to look at genetics and the sense that maybe these environmental changes have actually unmasked the genetic capability or risk factor of someone developing these diseases. And and I suppose you could also look at it in the sense that if you look at observational studies that are looking at nutrients associated with a health outcome. If you look at enough of these, you'll see that there are almost different outcomes depending on the different studies that you look at. So literally, if you have enough observational studies looking at nutrient versus health outcome, you will basically see that some are saying that say, for instance, caffeine is going to increase your risk of a heart attack and then others are going to say that it's not. You've got saturated fat, it's going to kill you. You've got others saying it's, it's not. Same, you know, there's so many studies out there. And really, initially, we thought that those people were outliers and scientists would think, how do we, you know, get around publishing this maybe. Some actually in a quite a biased way wouldn't publish outlying results. But what we do know is that these aren't just outliers. It's actually just taking things back to genetics. So when you look at whether something, whether a nutrient is increasing or decreasing a risk of a disease, when you look at the genetics, these people have different variations of genes that are actually coding for the metabolism of these nutrients, which alter the the health outcome.
Dr Rupy: Got you. Okay. And so when we talk about the different types of testing now specifically to reveal the differences in metabolism as one example, the way we treat different elements in our lifestyle and our environment, what are the the different types?
Rachel Clarkson: Yeah, good question. So it's easy for people to get almost confused with genetic tests or for people to think of a genetic test as one test. But actually, it's really important to define the difference between a disease risk gene and a modifier or metabolic gene. So there are some companies out there that are testing to see if you have a risk of developing a disease for instance. So a disease risk association. Now, you know Angelina Jolie, I'm sure. Yeah. Uh, I don't know her personally, unfortunately. But if Angelina is listening. So, yeah, I'm sure she is. She will enjoy the shout out. So if you remember back, she actually was in the press because she tested positive for the BRCA one gene for breast cancer. And it was quite public that she ended up taking a precaution and actually having both breasts removed in order to minimize the risk of her developing the disease. And that meant that quite a lot of, well, the world really, women went and got tested for this BRCA one gene. And if they tested positive, they maybe took precaution. Now, and maybe took those precautions similar to Angelina Jolie. But if they didn't test as positive, they initially thought that they hadn't got a risk of developing the breast cancer. But what most people don't realize and most of those women didn't realize is that BRCA one is only really representative of 10% of all breast cancer cases. So the other 90% of risk is to do with many other genetic factors amongst other things. And so it's almost, almost false reassurance. And so I think it really has to be taken into consideration when testing for a disease risk, whether it's warranted. I think for rare diseases that we can test for genetic predisposition or kind of risk, 100%. But when it comes to these, you know, non-communicable diseases, the the evidence isn't robust enough in order to to make these predictions. And so that's really important to understand and also, we were talking about the anxiety that could be caused for individuals and families around, you know, how would it make you feel if you were told that you're at increased risk of, you know, such and such cancer or, you know, Alzheimer's and Yeah. So that's really got to be taken into consideration and a lot of these testing companies don't have genetic counsellors who can really explain what that means and, yeah, counsel people through the the hard emotions that they and their families may experience. So that's really important to distinguish that as a a disease risk test. But then the exciting test comes in and that's regarding modifier genes. These are metabolic genes that you can actually make actionable recommendations from. So these genetic tests are basically, if I bring you back to the studies looking at whether a nutrient has a positive or negative effect on a health outcome. We're looking at those variations of the genes which cause this positive or negative effect depending on the person. The nutrigenomic analysis can really identify what variation of a gene somebody has in order to predict how they'll respond to a certain nutrient. So, do you want me to talk about?
Dr Rupy: Please do.
Rachel Clarkson: So I mentioned caffeine before, first of all because I love coffee and I think that, you know,
Dr Rupy: I'm a big fan of coffee. Like ever since I came back from Sydney, you know, where I was, I I basically became a coffee snob and I learned to love the process, the ritual, the taste, the history behind it. Before that, I was just drinking regular mocha, which I, I mean, nothing against mocha drinkers, but I just, I look back at it now and I'm the kind of person who enjoys the long black, the just purest sort of coffee with, you know, where you can taste the notes and everything. It sounds pretty pretentious, but that's, that's me and coffee.
Rachel Clarkson: Correct me if I'm wrong. Is a long black not just an Americano? Please teach me the difference because somebody did ask me to order a long black the other day and the waitress said, oh, Americano. And I said, I don't know. So please.
Dr Rupy: So it depends which coffee store you go to. If you go to a proper like Australian coffee place, they will know the difference. An Americano has got slightly more hot water in than a long black. A long black is like a double shot of espresso topped up with hot water. Sounds similar, very different. If you order an,
Rachel Clarkson: I mean, it sounds like an Americano to me.
Dr Rupy: I mean, it does sound like an Americano, but it's, there is a clear difference because Americanos, they tend to be served in like big, big cups. And a long black is in a shorter cup. It's like an eight ounce cup or something like that.
Rachel Clarkson: Okay, next time.
Dr Rupy: Next time. Yeah, yeah.
Rachel Clarkson: You can make me one.
Dr Rupy: And I'm definitely sensitive to caffeine. So that was the last thing I wanted to say. Like I know without having to have my, my genes analysed that I, if I drink coffee after 12pm, I definitely struggle to fall asleep and the quality of my sleep changes.
Rachel Clarkson: This is really interesting. So, I'm glad you brought this one up because when people find out that I'm in this field, especially, you know, if I'm out for dinner or, you know, just anywhere, they'll say, oh, I know that I'm really sensitive to caffeine because of exactly that. And it's interesting because the jittery effect that caffeine gives or even the ability to not be able to sleep, so that kind of high stimulant effect actually doesn't have anything to do with how well you metabolise caffeine. It actually has to do with a receptor in the brain. Okay. So depending on the variant of this receptor, of the gene that encodes for the receptor, the caffeine, for instance, in yourself, will most probably be bound really tightly to that and so you're going to have that stimulating effect for much longer. Now, that doesn't actually translate into whether caffeine is good or bad for you from a health point of view. So we're talking about caffeine specifically now. This can be in coffee or tea or wherever you find caffeine. Now, it's interesting. This was one of the first nutrients that was studied in nutrigenomics, probably because it's the world's most widely consumed stimulant, I think. Well, they first of all found that caffeine intake had a almost J or U shaped curve when it came to kind of health outcomes. So it was recommended that a moderate amount of caffeine was okay and actually, if you consume more than that, maybe not. So the, you know, the recommendation around the world, I think it's 400 micrograms. I know that it is similar to that in the UK as well. So that's around four cups of coffee is the safe limit.
Dr Rupy: Which to me sounds like a lot.
Rachel Clarkson: Yeah. I think really important to note, 400 micrograms is not the same as four cups of coffee from the coffee shop. It's almost like the maybe instant coffee or a espresso, let's say. So, I like to say that 100 micrograms is around one espresso and that's how you can kind of do the math in your head.
Dr Rupy: Two long blacks.
Rachel Clarkson: Two long blacks. Okay. So when the researchers actually looked into this further from a genetic point of view, they actually found out that it really depended which variation of the gene you had. And to break that down even more, caffeine is consumed and it's broken down by an enzyme. Okay. Now, an enzyme is a protein and the protein in particular is coded by a gene. Okay. Now, it's the variation of that gene which alters how much of the enzyme you have. So we like to put people into groups. So if you have one variation of this of this gene, you're a fast metabolizer and if you have the other genetic variation, you're a slow metabolizer. So this study actually showed that the fast metabolizers of caffeine were actually breaking down caffeine very, very fast and so it wasn't lingering in the body. And this meant that they didn't have an increased risk of a heart attack. They actually were protecting themselves against a heart attack by consuming caffeine, which is quite,
Dr Rupy: Oh, wow.
Rachel Clarkson: Crazy.
Dr Rupy: Yeah.
Rachel Clarkson: Is that explained what sort of that one of the explanations for the U-shaped impact of?
Rachel Clarkson: Slightly, yes, but we almost, we dissected it even further basically. And those fast metabolizers were a protective effect. And we think that's because the caffeine was metabolised quite quickly before it maybe got to the cardiovascular system. And we believe that or scientists believe that the other components found in say coffee, for instance, the polyphenols actually had the beneficial effect. Now, on the other side of the table, we have the slow metabolizers. That's me.
Dr Rupy: And I'm probably me.
Rachel Clarkson: Yeah. And the slow metabolizers, we actually struggle to break down the caffeine very quickly and so it lingers in the body and it actually has a increased risk, well, an increased effect on our blood pressure. And actually, if slow metabolizers consume more than two cups of coffee a day, they're actually putting themselves at higher risk of a heart attack. So it's really important to distinguish whether you are a high risk or a fast metabolizer or a slow metabolizer. But it's not enough to think, oh, coffee makes me jitter and keeps me up at night because like I said, it's a different mechanism.
Dr Rupy: Yeah. Well, that's fascinating because I think, I mean, for, if I'm honest, slightly scared about the heart attack element. But, um, I think it definitely puts into, uh, it it it makes me understand a little bit more about why nutrigenomics is quite important because I think, you know, I wouldn't have thought of, you know, CVD risk and heart attack risk on the basis of those things. And I think there's a lot more to the story beyond just the impact on that particular enzyme. But, um, that is interesting.
Rachel Clarkson: And when you look at the study, I think it was around, you know, 2,000 people. It was a Harvard professor that actually was involved as well with this. And they determined the amount of coffee that people were drinking from food frequency questionnaires. But they also took into consideration other lifestyle factors like smoking, physical activity, amongst other things. So it was a very, very high quality study. And researchers also replicated this in Europe and found that it didn't just increase risk of heart attack, it increased risk of blood pressure, which you can imagine obviously is the the first. And then other researchers actually looked at how it can also have a huge impact on your kidney function as well, which was really exciting research.
Dr Rupy: I can send you that paper. Yeah, please do. I'd love to to share that on the podcast notes. I mean, so we're talking a bit about like health outcomes for the individual. What about like things like fertility? Are we there yet with any genomic predictions or things that you can actually heighten people's likelihood of conception?
Rachel Clarkson: Yeah, it's a really good question. So you probably know as a doctor, we link blood biomarkers to fertility outcomes. Yeah, we know that. We also know that nutrition and genetics, as we talked about today, have a huge impact on blood biomarkers of your nutrient status. And what the University of Toronto are doing at the moment, I'm actually involved in a review paper, is we're trying to link the nutrition, genetics, the blood biomarkers and the fertility outcomes together to create a paper. We've finished the female, we're onto the male now. And it's really exciting because, yes, nutrition, genetics, nutrigenomics has a huge part to play in someone's fertility capability, not just women, but also men. I think there's a, I don't know the exact percentage, like 20 or 30% of all, you know, fertility cases are like or lack of fertility. Yeah. are based upon men and their sperm motility. Yeah. Um, so for instance, just, just to put things simply, something so simple as B12. Well, some people have a genetic variation, men and women, which means that they don't transport it very well between the cells and they are predisposed to low levels. And really B12 works with folate to control homocysteine levels. And high levels of homocysteine can actually have a negative impact on chance of getting pregnant from a sperm and egg perspective. So, yeah, really exciting area.
Dr Rupy: I didn't know that about homocysteine. I'm aware of homocysteine levels being potentially causative in stroke and cardiovascular risk, but the fertility element, I didn't realize at all.
Rachel Clarkson: And that's just one marker that we look at in our fertility test, which I also do with with clients. I also work with fertility and we can make personalized dietary recommendations for both men and women in order to for them to basically have optimal nutritional status and and have their best chance of getting pregnant.
Dr Rupy: So I, I find this whole area fascinating because it's giving us some more insights on how simple changes, not just the ones that are free, the lifestyle changes, but even simple supplementation regimes for people who are trying to conceive, which is, you know, emotionally draining. The number of parents or potential parents I've, you know, come across in general practice that are struggling and in some cases, I'm not too sure if you have any clarity on like how many are suffering on the basis of something that we potentially have insights into and could, uh, alleviate with a supplementation regime is quite, is is just for me phenomenal. And I think, yes, it's definitely in the future, but I think there is a premise for responsibly introducing this now with the appropriate, um, support mechanisms. What I'm also interested in is, um, behaviour change and we touched on this earlier about how, you know, a simple test that will demonstrate whether you're at high risk of inflammation or your, um, ability to exercise might be marred if you go too high intensity or your ability to recover or something like that. Like, how have you in your own personal practice noticed, um, the genomic testing, the nutrigenomic testing has changed someone's behaviour? And is there evidence to support that as well?
Rachel Clarkson: Yeah, good question. So, yes, it has. Short answer. When people come to me, it's not something that is compulsory to do the nutrigenomic test.
Dr Rupy: Oh, I'm glad you said that because I think most people would just expect like straight away, saliva, spit in this pot and then I'll see you next week.
Rachel Clarkson: I mean, you know, I've branded myself as the DNA dietitian and it's because I am an expert in the area, but it's by all means not something that's compulsory. And it's really important when working with patients, first of all, to get verbal consent and explain the kind of the testing procedure, etc. But when it comes to, I mean, people come to me for it, let's be honest. That's what I'm known for. They come for those personalized recommendations. And so immediately, people who come to me for this are more motivated to make a change. They want to find out about themselves, how best to live a life according in accordance with their genes. They're sick of the fad diets, not knowing how to eat or at least wanting just recommendations that are right for them. So, personally, from an anecdotal point of view, I've seen huge benefits for people, you know, when it comes to specifically weight, that's the most visible sign of change from day one when you take the the saliva test to getting the report back within three, four weeks, giving those recommendations and then following up with that person, seeing how much weight they've lost based upon your personalized recommendations is something that, you know, it's so exciting. But I guess from a more holistic point of view of energy, of overall health, I think people who are coming to me with cardiometabolic disorders, so, you know, high blood pressure, um, risk of of heart disease, I've had huge, huge improvements with my patients when I've been able to give them that panel of cardiometabolic markers to say, listen, if you decrease your salt to 13 milligrams a day based around this genetic marker, you're more likely to have a lowered, um, you know, blood pressure. Uh, we need to decrease saturated fat, we need to think about GI index and your caffeine intake. In fact, one guy actually didn't really drink much caffeine at all in his diet and he was of a variant that would be cardioprotective if he drank between 300 and 400 micrograms a day. So we actually slowly increased, sorry, incorporated caffeine into his diet day to day and his, you know, his blood biomarkers improved and his blood pressure improved and his cardiologist was over the moon. You know, what have you been doing? And I, you know, I said I told him to drink some coffee. No, he didn't like coffee. So we had to do it with teas, but, um, yeah, I've had some really great success stories, let's say. And also myself.
Dr Rupy: Yeah.
Rachel Clarkson: You know, I explained, you know, we talked about how at the beginning of my university years, I was highly restrictive, then I started learning about nutrition and started eating in a way of general dietary guidelines, which, you know, we all try to do. When I got into the field of nutrigenomics, naturally, I started eating according to my genes in a personalized way that was right for me, right for my health and was going to prevent disease in the future. So from a micronutrient point of view, I was actually predisposed to low levels of vitamin C, of B12, of calcium. I mean, that micronutrient wise, that's all I was predisposed to low levels in. So actually day to day, I consciously ensure that I get my adequate or personalized requirements in those nutrients, you know, this isn't just from an energy or, you know, point of view right now to feel great. It's from that place of, I don't want osteoporosis in the future because my, you know, I've only been having the 800, 900 micrograms of calcium a day that's recommended. I need 1300 micrograms right now. And and and that has changed myself.
Dr Rupy: Absolutely. And I think like, you know, one thing I think is quite refreshing is that you're not of the mindset like, oh, you need X amount and we'll just give you the supplement and then we'll just figure it out. Like you take a food focused approach, which definitely resonates with me. I think we can get a lot of the micronutrients that we might be predisposed to lacking through food, but in some cases, you'll need to use supplementation again responsibly and with, you know, the intuition and the understanding that we want to try and optimize nutrition as much as much as possible alongside lifestyle as well.
Rachel Clarkson: Food first, every time. That's, as a dietitian, that's what we're taught. And so if someone comes into clinic, the first thing I'll say is, are you taking your 10 micrograms of vitamin D a day? Great. Okay. Well, in a month's time when you get your nutrigenomic report back, depending on your variation, maybe we need to increase that to 25 micrograms. But you're absolutely right. It's always food first and it's important that people also realize that coming to me, you're not just going to get a list of supplements that you need to take based on your genetic report because everything is advised around food unless you can't meet those requirements and then you would potentially need to supplement. I also just want to mention here about food intolerances because there, I know you've had some great people on the podcast before regarding gut health and who've probably talked about the lack of validity of food intolerance tests. I don't know whether. Yeah. And I have to say, I completely agree and don't do it. However, the nutrigenomic test, we only test for genetic predisposition of risk for gluten intolerance and lactose intolerance because those are the only two that we actually have snips to prove robust evidence for. And that's not to say that when you are told that you have a slightly elevated risk of a lactose intolerance, like me, I stop eating dairy, I don't have symptoms. So that means I don't need to make, I don't need to take measures to, you know, cut that out.
Dr Rupy: I think a lot of people are quite intuitive about whether they're reacting to different foods these days as well. And if not, like I try and encourage people to just think about symptoms in terms of doing like a seven day food diary and, you know, just being a bit more sort of aware of like what you're putting in and what might be triggering you. Obviously, I don't have the time in the NHS to go into it in any significant detail. Um, and it's more about empowering people. Um, what I find interesting is like the future of this technology and where it's going and the current skepticism and how you deal with that because I can imagine given that you're pioneering this, you're one of the only like registered practitioners of this doing it in a responsible way. Um, it must be, uh, conflicting for some people who don't really understand what you do on a day to day basis.
Rachel Clarkson: You hit the nail on the head there. It is an area that is almost taboo or a touchy subject for people who don't necessarily understand or haven't seen the evidence. I think first of all, what people don't realize is that before I was a dietitian, I did a quite intensive nutritional science masters, then before then I did a biomedical science BSc. We touched, didn't just touch upon genetics, but you know, we did a huge module on it. I then published a paper in genetics. I did all this, you know, further continual professional development afterwards. And that is what's required. You do ideally need training in dietetics or nutrition and genetics to be able to safely practice this. And and you're absolutely right. This isn't an area that people understand and rightly so. Why would people know about genetics if they were in nutrition? It's not something that we're taught. And maybe it's complex and maybe it's a whole new world, but this is a fairly new area, you know, it's 10, 15 years old. But we shouldn't be shying away from it. And I'm sure people would prefer for someone like me who is trained in this field and also I'm not just trained in the field to a high level, I've been, I'm also now educating other people at universities. Um, surely you would prefer me to be dealing with patients safely translating genetic material amongst all of the other assessment that I've done than others.
Dr Rupy: I like how you said others. It's very diplomatic of you, but let's say, you know, the a young person who has a print out degree by doing a three month course online and then suggesting genomic tests on the basis of a weekend course.
Rachel Clarkson: And, you know, yeah, you're absolutely right. And to be very honest, it hasn't been widely, it hasn't been widely accepted and I haven't had warm receptions from fellow colleagues or people in the area. It's not something that has has been accepted and yes, I do feel slightly alone in the industry. But I guess I'm doing something that's not in that box that we're told to stay in. But if we're not going to, if I'm not going to do it, then unqualified professional, sorry, unqualified non-professionals are going to take the stand and I don't want that to happen because that means that the public's safety is at risk.
Dr Rupy: The the courses that you run and the guest lectures that you do, who are they geared at? Are they geared at other healthcare professionals or they lay person or?
Rachel Clarkson: Good question. So at the moment, I, we touched on it before, I actually was trained by a leader in research, a professor at the University of Toronto. He trained me in nutrigenomics along with Monash University. At the moment, I'm a guest lecturer at St Mary's University in London and that is basically teaching applied personalized nutrition to upcoming nutrition and genetic professionals. I've also got a upcoming online course for nutrition professionals and also medical professionals. So doctors, nurses, nutritionists, you know, dietitians, teaching them all about nutrition and genetics. And I've also got a course coming out for everyone else who wants to understand in an easy to understand, fun way about genetics, about nutrition, about nutrigenomics, about how you can start eat eating according to your genes, taking control and also be able to read a report. So I teach people how to read through their reports and make actionable lifestyle choices accordingly. So I'm really excited for that to come out.
Dr Rupy: One word of advice, I think about like, um, uh, softening the approach with colleagues that might be skeptical is holding open days, um, perhaps like a lecture series where you bring yourself and a few other guests who can actually educate on the utility, where the pitfalls are in the technology, what the future might hold and how to utilize this, um, technology responsibly because I think, um, the reason people, um, hate on each other or are skeptical is in a lot of cases out of ignorance. And if you actually welcome people into the space, I think it's a lot better. It's one thing that I've learned through doing the culinary medicine, um, nonprofit that we're running in medical schools and for qualified professionals. I knew from the get go that, you know, a doctor with no nutrition qualification who has somewhat of a presence on Instagram and has written a book is not going to be widely received, um, well received, I should say, by the wider nutrition community that I respect so highly. And so creating a collaborative organization where we work together is perhaps one of the the best things I could have done, but the most obvious thing to do if my mission is to try and, uh, help nutrition come into the curriculum in a, in a way that's actually, um, promoting of the of the different specialties in the multidisciplinary team. So my two cents and I don't like to give advice where it's unwarranted is that I think, you know, actually involving your colleagues more in terms of all the stuff that you're doing in terms of guest lecturing, but actually tailoring it more to the skeptics would be a really nice way of disarming it and actually, you know, taking your position as the the pioneer in this, um, field because it's definitely going to be the norm in the next five to 10 years, I can imagine from just what we've just told me.
Rachel Clarkson: You're, you're so right and that's really helpful advice. And I think it'll get to a point where genetic testing is also so cheap as in it'll almost be free.
Dr Rupy: It's already, it's already pretty damn cheap, right?
Rachel Clarkson: Yeah. Um, so I think that you're absolutely right. It will be used in clinical practice in most areas and I think that even the the NHS will be on board with that.
Dr Rupy: They're already on that, aren't they?
Rachel Clarkson: Yeah. I mean, someone, someone quite high up is also on the scientific advisory board of one of the companies that I work with from the NHS. So, you know, it's, it is the future. It isn't the future, it's the now. You know, is personalized nutrition the future? No, because it's now. It's here. We, we have enough to start giving recommendations. We shouldn't wait any longer.
Dr Rupy: Yeah, totally.
Rachel Clarkson: Yeah.
Dr Rupy: So I think to summarize, we've talked a lot about the science, a lot about the different utility of markers and, you know, I think it's absolutely fascinating. I definitely think there's legs for it. And I think the the the technology is here now. A skeptic or someone might say, okay, well, is there, you know, is there evidence that it's actually going to lead to behavior change? Is there, you know, is this a useful tool to do now? Do we really need genetic tests like this?
Rachel Clarkson: Well, I talked to you about some of my own clients actually finding a huge benefit from having the test when it came to being motivated to make a change and, you know, maybe giving personalized recommendations based around people following them more because it's coming from a place of maybe ego. Like, oh, this is information about me, so of course I'm going to follow it because I know it's going to work. When you look at the scientific literature, there was a great study that was published comparing recommendations that were pretty standard versus personalized recommendations based around nutrigenomic analysis that were translated into easy to understand formats.
Dr Rupy: With like a counselor or something like that?
Rachel Clarkson: With a nutrition professional. And I think it was a randomized control. It was a really high quality study. And what they found was that the people who actually received the personalized nutrition and meaning the nutrigenomic information about themselves were much more engaged in the learning and took a greater interest in in their health and in their reports. But what was interesting is they were actually more likely to follow the dietary recommendations than those who were given just general recommendations based around guidelines. But also for a long period of time. So when they followed up a year later, I think it was a year or two years later.
Dr Rupy: Because that was going to be my next question. Like, okay, fair enough, they might have done it for like a month or two months, but like how long did that last?
Rachel Clarkson: Yeah. So I think at the year mark, they were kind of asked again, are you are you following this or not? And those who were following the personalized recommendations versus the standard were following it and following it for the longest. And specifically, mostly in the blood pressure and salt. So those who were told that they have a genetic predisposition to salt sensitive hypertension were more likely to be following this low sodium diet. And well, why that is important is, well, those people were the ones that needed it the most. You know, hypertension, you know, high blood pressure is a risk factor for heart disease and these people were following this advice based around their genetic report much more than those who were just being told, we should be, you know, lowering our salt to, what is it, six grams a day. But you know, that that's that's huge implications to the reason why personalized nutrition is definitely something that people should be thinking about to motivate them to make a change. You know, it's not just about them, but they've also paid money. They've invested in their health. And while these tests range in cost, people spend that on a pair of trainers, you know, or, you know, other areas of their lives.
Dr Rupy: The only issue I think with health practitioners accepting the fact that, you know, it is an investment in their health is that if it's a true investment in their health, and we've definitely talked about the validity of a lot of these tests. And I think it's going to take a bit of a rebranding of nutrigenomics in general to rid itself of the the sort of cloud of, you know, um, perhaps some unsavory, commercially motivated interests of of industry just targeting consumers directly. Um, but that being said, you know, if it's done in a responsible way, how much could someone, um, expect to pay to have a qualified genetic counselor, someone like yourself, and a genomic test? Like how much is actually this going to cost, um, someone? And I definitely see the benefits if, you know, there's evidence to suggest that people will be able to keep up with the recommendations for over a year. That's fantastic.
Rachel Clarkson: I think that for a good quality test, you can be looking from anything from say 160 to maybe 200 pounds for the test. To have that translated by a nutrition professional, depending on the, um, the type of person, whether that be a doctor in say the NHS, it could be free if that doctor has been trained in in nutrigenomics. If you were going to someone in private practice, you could pay for their consultation, their time, or you could buy it as part of a package. So a lot of the time, my clients come to me because they want to improve their health or they want to lose weight or they want to improve their, you know, their digestive health, for instance. Like I said, that will be part of the assessment phase. So I don't like to think of things as you're just coming in to find out this information. It's it's part of a holistic approach to your health or weight loss.
Dr Rupy: Yeah, and that's why I think it's fantastic that someone like yourself who is nutrition training, registered dietitian and the nutrigenomic element as well. It's just like this complete package. It's almost like, you know, having regular doctors with a nutrition training and a holistic mindset. We need more of that. And you know, you're one of many that I think are going to start populating, um, the healthcare system. So good on you, mate.
Rachel Clarkson: Thank you. Thank you so much for having me.
Dr Rupy: I really appreciate you coming on and sharing it, honestly, like sharing your story, sharing the background. I think it's going to be super useful for listeners and actually, you know, I'm tempted as well. I think I'm probably going to look through my genomic history and and see if there are any things that I can tinker with just to optimize it.
Rachel Clarkson: Maybe we can discuss it over a long black.
Dr Rupy: Is it a long black? Did I get it right?
Rachel Clarkson: It's not an Americano.
