Nutrigenomics: Your Genes, Diet and Health

If you have ever followed a diet faithfully for weeks while a friend got results from the same plan in half the time, you already understand the central premise of nutrigenomics. The idea that one diet suits everyone is a myth — and part of the reason lies in our genes.

What is nutrigenomics?

Nutrigenomics is the study of how nutrition and genetics interact. It covers two related directions:

How your genes affect your response to food — how efficiently you metabolise caffeine, alcohol, lactose or fat
How food affects your genes — how nutrients influence which genes are switched on or off (gene expression)

The practical goal is to move beyond generic dietary advice toward guidance that accounts for individual variation.

Where the evidence is strongest

Some gene–nutrient relationships are well established:

Lactose — variants near the MCM6/LCT genes determine whether you continue producing lactase into adulthood. This is genuinely predictive.
Caffeine — CYP1A2 variants determine how quickly you clear caffeine. Slow metabolisers experience stronger, longer effects.
Alcohol — ALDH2 and ADH1B variants explain the facial flushing and nausea some people experience.
Coeliac disease — HLA-DQ2 and DQ8 genotypes are necessary (though not sufficient) for the condition to develop.
Familial hypercholesterolaemia — an inherited condition causing very high cholesterol from birth, requiring treatment regardless of diet.
Folate metabolism — MTHFR variants affect conversion of folate to its active form.

Where the evidence is weaker

Here honesty matters more than enthusiasm. The claim that genetic testing can tell you whether to follow a low-fat or low-carbohydrate diet for weight loss has been directly tested — and large randomised trials, including the DIETFITS study, found that genotype did not predict which diet worked better for weight loss. Participants lost similar amounts on either approach regardless of their genetic pattern.

Be cautious of any service promising a precise, genetically optimised meal plan that will succeed where other diets failed. The science supports meaningful insight into specific traits; it does not yet support bespoke diet prescriptions for weight loss.

Genes are one factor among many

Your response to food is shaped by the gut microbiome, sleep, physical activity, stress, medications, existing health conditions, age, and — substantially — food environment and habits. Genetics contributes, but rarely dominates.

What nutrigenomic testing is genuinely useful for

Identifying specific intolerances worth investigating properly (lactose, caffeine, alcohol)
Flagging inherited risks such as familial hypercholesterolaemia that warrant clinical follow-up
Highlighting nutrient metabolism variants, such as folate or B12, worth checking with a blood test
Providing motivation and context — for some people, seeing their own data prompts changes that general advice did not

What it should not be used for is self-diagnosing a condition, or restricting food groups long-term without dietitian input.

An important caveat about diet risk

Some restrictive diets can raise cholesterol or blood lipids in susceptible people. If you are considering a very high-fat or highly restrictive eating pattern and have a family history of high cholesterol or heart disease, get your lipids checked first and discuss it with a clinician — not after the fact.

Testing with Rightangled

Rightangled's DNA tests examine markers relating to nutrition, metabolism and intolerance, and our blood tests measure cholesterol, HbA1c and nutrient levels — which is often the more directly actionable information. Results are reviewed by our clinical team, which includes GPhC-registered independent prescribers, with medical oversight from our doctor, Dr Abdullah, so you get realistic interpretation rather than overstated promises.

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