Assistant professor in nutrigenetics at the University of Reading, Dr Vimal Karani believes the sheer number of research articles describing chronic disease outcomes could make the assessment of a study’s conclusions much more difficult.
Speaking at FoodVision in Cannes this month, Karani emphasised that locating a true positive finding amongst the research would be an achievement considering the number of genes that were being analysed.
“For a disease such as obesity that is multifactorial, you need to know what genes are contributing to this condition,” he explained.
“You need to start analysing a panel of genes rather than looking at one or two genes.”
Karani also added that lifestyle factors must be taken into consideration too - whether it was physical activity, dietary intake or smoking -in terms of a nutrigenetics and nutrigenomics approach.
The ‘nutri’ approach
Nutrigenetics and nutrigenomics hold much promise for providing better nutritional advice to genetic subgroups, individuals and the consumer.
As relatively new disciplines, it is difficult to appreciate their relevance and role in personalised nutrition – a concept that the food industry believes can deliver optimal health, delay the onset of disease and diminish its severity.
With food manufacturers such as Nestlé already taking an interest in this nutritional approach, there is opportunity to satisfy public interest that has placed energy levels, sleep quality, mental health and physical fitness as top priority.
Founded in 2011, Nestlé Health Science looks at nutritional therapy as a way to manage health for consumers, patients and its partners in healthcare.
Its Iron Man programme is a coffee-machine style piece of equipment that analyses what is missing in a consumer’s diet and then tailors a product to help make up the difference.
“As part of personalised nutrition, the findings from nutrigenetics and genomics will determine which genes and what dietary factors are interacting and contributing to the disease development,” Karani said.
Nutrigenetics - the area of science that looks into the effect of heredity on diet and nutrition.
Nutrigenomics - The study of an individual's genetic makeup, how it interacts with diet and how this interaction affects a person's health.
Personalised nutrition - The process of translating knowledge garnered from nutrigenetics and nutrigenomics to formulate a tailored dietary regimen that best suits an individual's genetic makeup.
Karani outlined several challenges involved if personalised nutrition was ever going to go mainstream.
A multi-disciplinary approach that required a deep understanding of nutrition, genetics, biochemistry and ever new ‘omic’ technologies, would be needed to integrate the data generated from nutrigenetics and nutrigenomics research.
“There is also a new and upcoming field of research into the gut microbiome, where the diet interacts with the genome, gene expression and the microbiota.”
“Information from all this research has to be integrated and interpreted in terms of implementing personalised nutrition.”
The DNA sequence variants were also mentioned by Karani as a significant challenge. With 3 million genetic variations in human DNA, future research would need to take into account these polymorphisms.
The task is made all the more tricky as it is currently unknown which genes cause obesity. “We have nearly 800 genes that we think play a role in obesity and 800 - 900 genes for type 2 diabetes.”
“Until we know for sure which genes are contributing to these metabolic diseases, we are not in a position to implement personalised nutrition."