Nutrigenomics: It may be possible to design diets that fit a person's genetic profile but is it a good idea to do so? Scientists debated this issue yesterday at the festival of science.
Dr Siân Astley, of the Institute of Food Research, presented the case for nutrigenomics and personalised nutrition.
"What we eat interacts with our body to affect long-term health," she said.
Nutrigenomics aims to optimise health by assessing an individual's genetic risk for diet-related diseases, such as obesity, cancer, heart disease, and diabetes, and then tailoring the diet with foods and supplements that are thought to improve health.
"The 'one size fits all approach' [ to healthy eating] isn't actually working," Dr Astley said. Personalising the health message would be more effective.
However, Dr Helen Wallace, of GeneWatch UK, and Dr Tim MacMillian, from the Food Ethics Council, questioned the ethics and efficacy of this approach.
Nutrigenomics was "a marketing ploy with little actual health benefit", Dr MacMillian cautioned.
Dr Wallace voiced concern about the increase in do-it-yourself genetic testing as seen in the United States and some European countries. For a fee, companies will screen your genes to identify genetic variations linked with disease. All you have to do is send them a swab of cheek cells.
If any risk genes are identified, the company provides dietary advice, which may include taking food supplements or eating more "functional foods". These are foods with added ingredients that are thought to have health benefits.
"Food companies are interested in investing in genetic testing in order to develop and market personalised food products," Dr Wallace said.
She is concerned about the limited regulation of gene-testing companies and the lack of evidence that functional foods actually promote health.
Dr MacMillian warned of the high cost of functional foods, adding that most of these products are sold to healthy, wealthy people and not those with the biggest health concerns.
Dr Astley responded that it was possible to take a personalised approach to nutrition using existing foods.
She said that people with different genetic profiles could benefit from different diets.
Dr Wallace countered by saying "the big problems in [ diet-related health] are how much we eat and how much we exercise, not what genes we have".