What is personalised nutrition?
Personalised nutrition is based on the idea that customised nutrition advice is likely to be more effective than the traditional ‘one-size-fits-all’ approach.We are all individuals with differences in our biochemistry, metabolism, genetics, and microbiota. Thus, a specifically created personalized nutritional plan can be devised to consider these factors in accordance with our personal eating habits, body measurements, weight, cholesterol levels, and lifestyle. Personalized nutrition goes by a variety of alternative names: “precision nutrition,” “individualized nutrition,” and “nutritional genomics,” and these terms can have overlapping meanings in this literature.
The complete mapping of the human genome in 2000 introduced new possibilities in medicine. For the first time, there was potential to individualise treatments specifically based on an individual’s genes, race, and personal history. As an extension to this, personalised nutrition also emerged, with the idea of taking the above information to prescribe diet recommendations, tailored to the individual.
There are now services available to the public through genetic testing companies which profile an individual’s DNA, provide a report based on their genetic makeup as it applies to their nutrition and lifestyle, and guide them to the most-likely-to succeed diet. A report may provide information such as how an individual processes and stores fat, their ability to breakdown cholesterol, their caffeine sensitivity and food intolerances as well as their risk of certain chronic diseases such as obesity and cardiovascular disease.
What are the benefits of personalized nutrition?
Personalised nutrition promises to help clients achieve optimal health and disease prevention based on their own individual genetic makeup. There is the potential to assist an individual in working towards goals such as improved body composition and exercise performance, while also informing them about chronic diseases they may be predisposed to, allowing them the opportunity to make changes to their lifestyle to reduce these risks.
Is it just another fad or is it worth its hype?
When considering the future of personalised nutrition, the key word is ‘potential’. There’s no doubt that it holds huge promise, however, we need to better understand exactly how our genes interact with the food we eat before we can be sure of the legitimacy and usefulness of lifestyle interventions based on this information.
In 2002, the Institute of the Future in Palo Alto, California, released a document titled ‘From Nutrigenomic Science to Personalized Nutrition: The Market in 2010’, where they forecasted that “at least one third of consumers will be making some changes to their nutrient intake in response to personalised nutrition by 2010”. There were clearly big hopes around personalised nutrition even 2 years after the mapping of the human genome, but despite this potential, personalised nutrition is yet to develop as a commercial service. Does this mean that personalised nutrition is just another fad, that will eventually be forgotten?
This is not the case. Whilst personalised nutrition may not have had the impact it expected, it is a genuine, credible, and promising area of research, which is gaining more and more traction. Early studies identified a role of genotypes and diet success, showing that the ‘correct’ diet, as determined by participants genetic code, led to drastically improved responses to diet, compared to those who were not on the ‘correct’ diet (Dopler Nelson et al. 2010).
It’s important to bear in the mind that analysing an individual’s genetic makeup only provides part of the picture, and it should be acknowledged that there are many other factors besides our genes that affect what we eat – emotional, economic, religious and social as well as existing health conditions.
The Food4Me study, one of the first large-scale personalised nutrition trials, also found that the effectiveness of a dietary intervention improved when tailored to the individual (Celis-Morales et al. 2016). More recently, the PREDICT trial (Berry et al. 2020) showed that individual responses to food can have large variations in glucose and triglyceride responses. Clearly, there is benefit to a personalised approach.
Personalized nutrition is an emerging area of research. Advances in technologies that enable testing and developments in our understanding of factors affecting our individual digestive and metabolic profile have given rise to novel methods for personalizing our diet.
What does this mean for healthcare professionals?
Personalised nutrition, including the use of an individual’s genotype, is not quite ready for full implementation, but this will not always be the case. As more and more funding and research focuses on elucidating the interaction of genes and food, the better we will be able to implement this area of nutrigenomics to create more targeted nutritional plans. Despite multiple companies promoting a personalised nutrition service, nutritionists and other healthcare professionals should be wary of implementing this until further work is done to shed light on gene-food interactions. Until then, nutritionists need to work with clients to offer the most personalised service possible, taking personal history, preferences, dietary habits, and culture (among various other factors) into account. There is still a level of personalising that can be achieved (Ferguson et al. 2016):
- Level 1: conventional nutrition based on general guidelines for population groups by age, gender, and social determinants.
- Level 2: individualized nutrition that adds phenotypic information about the current nutritional status of individuals
- Level 3: genotype-directed nutrition based on rare or common gene variations
However, some examples of personalized nutrition have entered the clinical setting through the implementation of the therapeutic diet for the optimization of health have emerged in the recent years. A good example is an allergen-free diet devised to remove immunological triggers. Such diets may need to be peanut-free, gluten-free, tree-nut-free, low FODMAP (fermentable carbohydrates), and casein or dairy-free.
Such plans are indicated in the case of known allergies, intolerances, and sensitivities and to identify unknown triggers via elimination. The allergen-free diet is tailored according to individual response, including the type of immune response and other contributing causes such as lack of enzymes or gastrointestinal factors.
At this stage, the bottom line is that personalised nutrition has promise, but more research is needed before we can determine how this can best be put to use. For now, the safest bet is that general established principles of nutrition should apply; eat large amounts of fruit and vegetables, limit added sugar intake and fast foods, ensure adequate but not excessive sodium is consumed, eat meat in moderation and increase vegetable sources of protein, and, most importantly, enjoy eating all of the above!
References
Berry, Sarah, et al. (2020). Human postprandial responses to food and potential for precision nutrition. Nature medicine: 26, 964-973.
Celis-Moralis, Carlos, et al. (2016). Effect of personalized nutrition on health-related behaviour change: evidence from the Food4Me European randomized controlled trial. International Journal of Epidemiology: 46 (2), 578-588.
Dopler Nelson, Mindy, et al. (2010). Genetic phenotypes predict weight loss success: the right diet does matter. 50th Cardiovascular Disease Epidemiology and Prevention and Nutrition, Physical Activity and Metabolism: 79-80.
Ferguson, Lynnette, et al. (2016). Guide and Position of the International Society of Nutrigenetics/Nutrigenomics on Personalised Nutrition: Part 1 – Fields of Precision Nutrition. Journal of Nutrigenetics and Nutrigenomics: 9 (1), 12-27
Institute of Palo Alto. ‘From Nutrigenomic Science to Personalized Nutrition: The Market in 2010’. Available from: https://legacy.iftf.org/our-work/global-landscape/global-food-outlook/from-nutrigenomic-science-to-personalized-nutrition/
