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Nutrigenomics: Personalised Nutrition for Chronic Disease, Health and Fitness Goals

Updated: Jun 12, 2023

There's nothing more unique about you than your DNA. So, when it comes to personalised nutrition, how do your genetics and diet affect one another? And how can you use genetic information to make healthier dietary choices for your body? Nutrigenomics and nutrigenetics are emerging fields exploring these questions, and unsurprisingly, they have been gradually transforming the nutritional therapy approach to chronic disease management and achieving health and fitness goals. Understanding the interplay between diet and our genetic makeup can help design ultra-individualised dietary strategies. However, making sense of this vast and intricate genetic information can be challenging. Working with a nutritional therapy practitioner can help you to tailor this cutting-edge science to your specific health needs and goals. In the UK, nutritional therapists are uniquely positioned among nutrition professionals insofar as it has been a part of everyday clinical practice for nearly two decades. By engaging enthusiastically with clinical nutrigenomic research and testing early on, nutritional therapy services with more extensive clinical experience in nutrigenomics, such as AG Nutrition,

Silhouette of a human body set against a backdrop of the letters A, T, C and G, symbolising genetic sequences.
The human genome provides the blueprint for our genetic health potential. Nutrigenomics helps us to understand how foods, dietary habits and nutrients interact with our genes to affect our health.

often benefit from broad familiarity with nutrigenomic research and real-world clinical experience of troubleshooting its application in practice.

So, What is Nutrigenomics?

Your body knows how to build, develop and maintain itself to keep you alive because of the genes passed down from your ancestors. These transgenerational messages are the instructions that your cells use to build, break down, repair and communicate. You share the essence of these messages in common with other humans. But like a story passed down through the ages, essential details can sometimes be omitted or altered, which might change how they can be interpreted and acted upon. Each gene, or message, comprises a "language of the DNA." Like any language, its sentences rely on a combination of words arranged according to rules. Depending on the word, even a minor spelling error or a substitution for a different word could affect how your cells respond to these instructions. Geneticists call these spelling errors "single nucleotide polymorphisms" (or SNP's for short), which loosely means that there is a "single 'letter' change" in a particular part of a genetic "sentence."

So, while you and I both have a gene that regulates the production of a receptor, such as a Vitamin D receptor, the details in my copy of the gene may differ slightly from yours. I may have a spelling error, or SNP, in one part of the message that you do not. Or we each have one or more misspelt words but in different parts of the sentence.

Researchers have identified at least 900 specific genetic SNP in the Vitamin D receptor gene. A few of these could affect our predisposition to chronic diseases, like diabetes [1], as well as our response to dietary supplements containing Vitamin D [2]. A nutritional therapist can use this information to understand whether you require increased vitamin D intakes and how to modify environmental factors that influence vitamin D receptor expression and activity.

Nutrigenomics and nutrigenetics form the frontier of personalised nutrition, exploring how our unique genetic makeup interacts with nutrients and influences our body's responses to food. While nutrigenomics delves into how nutrients affect our gene expression, nutrigenetics focuses on how genetic variations impact nutrient absorption and metabolism, paving the path for tailored dietary plans to optimise health.

Nutrigenetics and Nutrient Metabolism

Your body does more with dietary fats than turning it into cellular energy or storing it in fat cells. For example, the omega 3 and 6 fats from seeds and nuts can help provide structural and signalling properties in cells, regulating communication in the brain, heart and immune system.

The "Fatty Acid Desaturase 1 (FADS1)" gene influences how your cells use and transform these omega 3 and 6 fatty acids [3]. A change, or SNP, in the FADS1 gene could alter blood and tissue levels of these fats. Genetic researchers use standardised codes, like a barcode number on a book, to indicate the precise location of an SNP in a particular gene (i.e. which "word" in the genetic sentence contains the spelling variation), such as the code rs174556 in the FADS1 gene [4]. Suppose your gene includes the FADS1 rs174556 variation or SNP [4]. In that case, there may be more than one type of spelling error: substituting one letter for another, including an additional 'letter', or omitting a letter entirely. A specific spelling error is known as an "allele" in genetics. For example, in this gene location, people carrying the A-allele can have lower levels of long-chain fatty acids from omega 3 and 6 in the blood and tissues and higher levels of one particular type of omega 6, called linoleic acid [5]. Since the more extended chain types of these fats are necessary for communication in the immune and nervous systems, this might have important implications for brain health. Interestingly, the impact of being an A-allele carrier differs across the body. For example, the type or amount of fatty acids in breast milk does not appear to differ from those without this SNP in the FADS1 gene [5]. Since babies cannot produce their own long-chain omega 3 and 6 fatty acids, dietary sources such as breast milk or formula milk in the diet must provide them.

In people with inflammatory or nervous system disorders, especially those who do not consume fish due to allergy, ethical beliefs or taste aversion, genetic testing could help a nutritional therapist determine whether to use blood laboratory tests to check fatty acid levels in the blood. It could also help determine the dose and composition of dietary supplements when necessary.

You might be familiar with the importance of dietary folate or folic acid supplements in pregnancy. Numerous variations in a gene involved in folate metabolism, called MTHFR (methylene tetra-hydro folate reductase), such as the SNP rs1801133, can lead to lower blood levels of folate and higher levels of an inflammatory substance called homocysteine, which can rise as folate drops [6]. Depending on your specific allele, folate levels may increase more slowly following supplementation, even if homocysteine levels drop.

A nutritional therapist might use genetic testing to determine the type of folate supplement and the dose you need if your levels are low or you have an increased requirement.

Genetics and Nutrition for Chronic Disease

The chances of you becoming obese in childhood and adulthood may be higher if you carry specific fat mass and obesity-associated (FTO) gene variants [7, 8]. People with these SNP's may be more likely to consume foods higher in calories, fat and protein. However, they may report consumption of fewer calories [9] and be more susceptible to the effects of ultra-processed foods and Western dietary patterns [10]. Some of these FTO gene variants have also been linked to diabetes [11], polycystic ovarian syndrome [12] and arthritis [13]. In practical terms, if you carry a high-risk variant, a nutritional therapist could use this information to help devise a diet plan that helps to lose weight more effectively and mitigate the genetic risk associated with obesity and diabetes. The interplay of nutrigenomics – how nutrients influence our genes, and nutrigenetics – how genetic variations affect your response to nutrients, can be harnessed to enhance health.

However, understanding and translating this interplay into daily dietary choices requires professional expertise. A nutritional therapist can help navigate this intricate genetic map and formulate a diet that aligns with your genetic predispositions.

Nutrigenomics and Physical Fitness Goals.

Not only clients with chronic diseases could benefit from nutrigenomics-informed diet planning. Personalised nutrition could give you an edge that helps you achieve your physical fitness goals. For example, the ACTN3 gene crafts alpha-actinin-3, a key player in our fast-twitch muscle fibres, and influences muscle oxygen metabolism. Suppose you are a carrier of the R577X variant of this gene. In that case, your muscles will contain more slow-twitch fibres, a trait often seen in top endurance athletes but not often among professional sprint runners or strength-focused athletes [14]. Conversely, those built for speed and strength typically carry the standard variant, 577RR.

Let's assume that you want to improve your physical fitness. In that case, considering your genetics could help you to determine which activities to start with, as well as activities you find more difficult under abnormal physiological states, such as anaemia, when oxygen transport is compromised. For example, ~18% of Caucasians may carry two copies of the R577X variant, resulting in a complete absence of the ACTN3 protein [15]. People with this variant have fewer blood and urine markers of iron depletion and blood cell breakdown after endurance athletics, such as marathon training [16]. In contrast, those with the standard variant show more signs of iron loss and blood cell damage.

Now, if you're a 577RR (standard variant) carrier but love long-distance running, in that case, this doesn't mean you need to stop or can't improve your performance. However, understanding your genetics might help you recognise physiological limits, optimise your diet and biochemistry for event preparation, training and recovery, and balance your general fitness regime to minimise kidney stress.

While nutrigenomic and nutrigenetic testing offers powerful insights, a nutritional therapist must interpret your genetic test results within the broader context of your overall health, lifestyle, and environmental factors.

Moreover, a nutritional therapist can apply these personalised nutrition principles in the quest for sustainable weight management. Recognising that different individuals respond differently to the same food, a nutritional therapist can formulate an effective weight management plan that aligns with your genetic profile.

In conclusion, integrating nutrigenomics and nutrigenetics into personalised nutrition heralds an exciting new era in health and wellness. However, translating this genomic information into actionable dietary strategies requires the expertise of a nutritional therapist. By working with these professionals, we can unlock the potential of our unique genetic identities, creating a tailored path to manage chronic diseases effectively, achieve fitness goals, and lead healthier lives. If you're interested in learning how nutritional therapy could help you to personalise your diet based on genetic factors and more, click here to read more about the nutritional therapy approach used at AG Nutrition.



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