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Advances in Personalised Nutrition & DNA Diet test controversies


DNA testing an extremely saturated market, with every man and his dog starting a company based on a ‘groundbreaking DNA diet test’. With absolutely no regulations in place, it’s no surprise that this area of nutrition has gotten a bad reputation. In this blog, we uncover the truth behind the criticism around DNA testing with a balanced and scientific approach so you can make an informed decision about elevating your health.

The massive problem

Most direct-to-consumer genetic tests are not provided by nutrition experts with a background in genetics and nutritional biochemistry. This leads to testing of genes that aren’t scientifically validated and nutrition recommendations that don’t have scientific backing and therefore don’t lead to deliver results. Unfortunately, there is no ramification for using bad or a lack of science in a DNA Diet test due to the lack of regulation in the area. This leaves you the consumer often tricked into the legitimacy of a testing company with clever marketing, scientific language, ‘scientific’ claims, and a ‘fluffy’ scientific advisory board consisting of Doctors and Professors that add social proof but have no expertise in the area and therefore cannot possibly advise on the validity of genes, locations on genes and clinical validity of dietary recommendations.

Where do the skeptics come from?

The science of DNA and Diet (Nutrigenomics), although a field based on strong scientific evidence, is often criticised as a relatively new area – beginning only after the completion of the human genome project in 2004. This groundbreaking science has progressed in leaps and bounds with a DNA diet test being at the forefront of personalised nutrition. Fortunately, we have a significant amount of robust scientific evidence to prove that these criticisms are not valid! Remember a Regulated Expert in this area will use the results from the DNA diet test as a piece of the puzzle to give you personalised dietary advice along with other information about your medical history, current diet and health goals. Below are the most common criticisms we hear about this field (excluding the ones I’ve already mentioned above).

  1. “Testing single genes are not useful”
    This comment is commonly heard from Genetic Epidemiologists, whose personal area of focus links specific genes to specific diseases. Whenever debating this criticism with a Genetic Epidemiologist, reminding them that their study of ‘Population Genetics’ is worlds apart from Nutrigenomics (the study of DNA and Diet) which requires expertise in Genetics but considerably more knowledge about Nutritional Biochemistry.These Genetic Epidemiologists know that it is not possible to predict chronic diseases such as diabetes and heart disease with a single gene as these are complex diseases that develop as a result of many different factors. Results from a DNA diet test are not used to predict any disease, these modifier genes’ help us understand the way you absorb, break down, transport, utilise and excrete nutrients. This information allows for actionable dietary recommendations that will help prevent these diseases amongst many other things.
  2. “People will never change their health behaviours”
    Many clinicians find that people’s habits and behaviors are extremely difficult to change. However, we have a  number of gold-standard designed studies that have shown us that people who receive actionable advice based on their DNA results are more likely to change their behaviours and habits compared to people who just receive general healthy eating advice when the results are interpreted by a Regulated Health professional. The British Medical Journal published a fantastic study, using the same DNA diet test used in The DNA Way and showed that this method led to enhanced long-term fat loss and enhanced motivation to make healthier food choices compared to general dietary guidelines. Individuals even find dietary recommendations based on genetics more understandable and more useful than general dietary advice (1, 2). In contrast, most direct-to-consumer tests just upload your results into an app rather than giving an in-depth interpretation by an expert which studies also show is not effective at creating behaviour change.
  3. “We do not have enough Randomised-Control Trials  to use DNA testing in practice”
    Many skeptics that highlight Randomised-Control Trials (RCTs)  in this area overlook the fact that the vast majority of dietary advice we use today is not based on RCTs. RCTs are mostly used when developing drugs and vaccines to test their efficacy and validity. When it comes to nutrition advice, we use the “totality of the evidence” to make recommendations. This means we review all the evidence there is on a nutritional factor, both positive and negative, and using all the evidence together, scientists decide the recommendation on that specific nutritional factor. Despite the countless number of RCTs conducted in the field of nutrigenomics, we look at the totality of the evidence – the same as every scientist.
  4. “Results from genetic tests are too complex”
    Yes, this is absolutely the case if you are receiving raw genetic data from a lot of these DNA diet test companies but if you seek the advice of a Regulated expert this is absolutely not the case! Individuals who make a sensible decision to take a DNA test with a trusted provider won’t ever receive long documents with complex raw data that they can’t make sense of. Individuals following The DNA Way receive an in-depth consultation with an in-house Genetic expert who translates their genetic results into simple dietary advice.
  5. “Just follow recommendations for healthy eating”
    The best example that disproves this criticism is caffeine intake. The healthy eating recommendation for caffeine intake is 400mg of caffeine which is equal to 4 espressos per day (or two coffee shop coffees). However, 50% of the population are slow metabolisers of caffeine, which means if they continuously have 4 cups of coffee every day, this will increase their risk of chronic diseases like heart attack, hypertension, prediabetes, and kidney disease (3,4). So, following healthy eating recommendations or a one-size-fits-all approach is great for a public health message but is not the best approach if you want to optimise your health.

Hopefully, you feel more well informed about genetic testing to gain a personalised diet for life and any hesitations are now cleared up nicely. If you want to unlock your genetic potential and start eating The DNA Way please book a FREE discovery call now!


(1)   Horne J, Gilliland J, O’Connor C, et alEnhanced long-term dietary change and adherence in a nutrigenomics-guided lifestyle intervention compared to a population-based (GLB/DPP) lifestyle intervention for weight management: results from the NOW randomised controlled trialBMJ Nutrition, Prevention & Health 2020;bmjnph-2020-000073. doi: 10.1136/bmjnph-2020-000073

(2)   Nielsen, D. E., & El-Sohemy, A. (2012). A randomized trial of genetic information for personalized nutrition. Genes & nutrition, 7(4), 559–566.

(3)   Cornelis et al. Coffee, CYP1A2 genotype, and risk of myocardial infarction. Journal of the American Medical Association. 2006;295:1135-41.

(4)   Palatini P et al. CYP1A2 genotype modifies the association between coffee intake and the risk of hypertension. Journal of Hypertension. 2009;27:1594-1601.


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