How Your Genes Help Us Personalise Your Diet
What is Nutrigenomics?
Nutrigenomics is the study of the interaction between our genes and the foods we eat. Different foods can influence how well our genes work by virtue of the bio-active compounds they contain such as vitamins and minerals. The genes we are born with, inherited from our mother and father at the time we were conceived, are unique to us.
Genetic Variation
Genes are made up of DNA and over time some parts of the DNA get changed very slightly. These changes are what we call variations or mutations; I prefer to use the term ‘variation’ as ‘mutation’ tends to imply that all variations are bad and that is not the case. Sometimes we inherit variations from our parents or other ancestors, and sometimes the variations occur spontaneously in response to damage or a failure in our systems to repair that DNA damage.
Many variations have little or no noticeable effect, but some do. Sometimes changes increase the activity of a gene and sometimes they decrease the activity of a gene, which in turn can have a negative impact or a positive benefit. Variations which confer some advantage, potentially having an impact on survival, end up becoming more common and this is the process known as natural selection. Sometimes genetic variations in a population end up being positively ‘selected’ in regions of the world because of some environmental factors, such as greater exposure to sun, or cold. If such a person moves to a different part of the world with very different environmental conditions, this can sometimes have an impact on their health because their genetic makeup is not as well suited to new conditions.
Another commonly used term for genetic variations is SNPs, pronounced snips. SNP stands for Single Nucleotide Polymorphism. Nucleotides are the building blocks of DNA, and it is made up of very long chains of them.
What do Genes Do?
Genes are like a recipe book. Our genes carry the recipes for making all the different compounds that we need in our body for everything to run smoothly and for us to be healthy. Those compounds include proteins needed to build new cells and tissues and for complex molecules like antibodies and enzymes. Many of these compounds control how our body functions including our metabolism, our immune responses, and cellular repair.
Every compound we make needs a recipe, and the body goes to the DNA to get the recipe. Now, imagine the recipe book has been misprinted and there are some errors in the recipes, so the recipe doesn’t turn out as we would expect it to. In DNA, the misprints are the variations in the nucleotides present and the order of them in the chain, the SNPs. SNPs are given code names which usually relates to the compound the gene makes.
How our DNA works, that is which SNPs are present and whether all the necessary compounds are made as they should be, is called gene expression.
Gene Expression & Health
Gene expression is affected by both the foods we eat, and lifestyle factors such as sleep, exercise, exposure to light and how stressed we are. There are some key areas of gene expression which can affect our health and here are a few examples:
Nutrient Absorption
There are genes that influence how well we absorb, make, or use certain vitamins and minerals.
One of the most well-known is MTHFR and this gene codes for making an active form of folate in the body that is used in a process called methylation. Methylation is a critical process that is needed in many biochemical pathways so this SNP can have far-reaching consequences. If we don’t have enough of this compound it can contribute to mental health problems, how well we deal with stress, and how well we can eliminate toxins from the body to name just three.
Another is VDR and this gene codes for the receptor for vitamin D. Someone with this SNP is likely to need higher levels of vitamin D to remain healthy because their receptors are not as sensitive. When the body does not have sufficient vitamin D for their needs their immune system is likely to be compromised, and it can also affect bone health.
Metabolism
Our genes can influence how well metabolise proteins, fats and carbohydrates. FTO and PPARG genes can influence how well we burn fats and carbohydrates for energy. We may have both helpful variants and can process either well, or we may be better suited to one or the other. Understanding your predisposition can tell you whether you are better suited to diets lower or higher in carbohydrates and fats. This is often helpful for improving energy levels and can be particularly important for athletes to match their diets with both their genetic profile and the needs of their chosen sport.
Our genes also influence our appetite regulation which, in turn, may have an impact on how easy or difficult it is to lose or gain weight. If you are one of those people who struggle to maintain your desired weight, looking into your genetics may very well be helpful.
Chronic Disease
There are numerous genes which can predispose us to chronic diseases such as heart disease, diabetes and cancer but with tailored diet and lifestyle strategies we can help to prevent or better manage such conditions. The TCF7L2 gene plays a role in regulating insulin production and is associated with a higher risk of type 2 diabetes. Variants on the APOE gene influence how well we process saturated fats and our susceptibility to heart disease. Variants on the COMT gene can affect how we detoxify oestrogen and may make us more susceptible to hormone related cancers.
It must also be said that there are some genes which diet and lifestyle choices and interventions cannot have an impact on. There are very few of these, but it is important to acknowledge them. Examples are the genes that cause diseases such as cystic fibrosis, muscular dystrophy. Whilst people with these conditions may still benefit from dietary and lifestyle support, such strategies do not alter the expression of the genes that cause the disease.
The Difference Personalised Nutrition Can Make
Personalised nutrition means eating the foods that support your genes to work for you, not against you. It means avoiding foods that can inhibit your genes, foods that might be generally regarded as healthy, and will be helpful for people who have a different genetic profile from you. With some genetic variants it may be hard to get enough nutrients from your food and supplements might be needed but food and lifestyle is always our first port of call.
Whatever your health goals or challenges, knowledge of your genetics puts you back in the driving seat. With the help of skilled professional who understands the intricacies of nutrigenomics to tailor a nutrition and lifestyle plan for you, you can optimise your health.
If you are curious to learn more about your genetics and how they might impact your health now, and in the future, get in touch to find out how we can support you with testing options to suit your needs.
Relevant References
Rana S, Kumar S, Rathore N, Padwad Y, Bhushana S. “Nutrigenomics and its Impact on Life Style Associated Metabolic Diseases”. Curr Genomics. 2016;17(3):261-278. doi:10.2174/1389202917666160202220422
Vyas S.” Advances in Nutrigenomics and Applications in Public Health: A Recent Update”. Curr Res Nutr Food Sci 2022; 10(3). doi : 10.12944/CRNFSJ.10.3.23
Jenzer Helena , Sadeghi-Reeves Leila “Nutrigenomics-Associated Impacts of Nutrients on Genes and Enzymes With Special Consideration of Aromatase” Frontiers in Nutrition. 2020; 7 doi: 10.3389/fnut.2020.00037
Lorraine Brennan, Baukje de Roos, “Nutrigenomics: lessons learned and future perspectives”, American Journal of Clinical Nutrition, 2021; 113(3): 503-516, doi: 10.1093/ajcn/nqaa366