Interest in personalised nutrition amongst major food manufacturers has cooled off a little as it has become clear there will be no quick wins, according to an expert in diet-gene interactions.
Speaking at the launch of the new functional food centre at Oxford Brookes University, professor Gerald Rimbach from the Christian Albrechts University in Kiel said there was growing evidence that people with a particular variant (ApoE4) of a gene associated with fat metabolism have a heightened risk of developing Alzheimer's and heart disease.
However, the extent to which this risk can be modified through diet remains unclear, meaning personalised nutrition or 'gene diets' for population sub-groups like the ApoE4s were still some way off, he said.
While some DNA testing companies were already offering personalised dietary advice based on the genetic profile of their customers, many scientists felt this was "very premature", and interest from large food manufacturers had "waned a bit" recently, he said.
"It would be irresponsible to target these groups with tailored foods at this stage. We also know that people with ApoE4 are less responsive to dietary interventions such as vitamin E supplementation."
Another stumbling block for manufacturers was the size of the prize, he said. "If you are developing products just for people with ApoE4, a genotype carried by 20-25% of the population, you are losing an opportunity to market to the other 75-80%. And that's assuming we get to a point in the future when there is widespread DNA screening,"
But new research was throwing up some interesting findings, said Dr Anne-Marie Minihane, who has been exploring diet-gene interactions at the University of Reading. If you gave 100 people a high dose of cholesterol-busting omega-3 fatty acids, up to a quarter could actually see an increase in 'bad' LDL cholesterol because they carried ApoE4, she claimed, highlighting the need for a more tailored approach.
Likewise, it had also emerged that people with a particular genotype of the 0 gene (which codes for a protein controlling the elasticity of blood vessels) had a higher risk of heart disease, making them a potential target for tailored products or advice. "About 99.8% of our DNA is identical to that of the person next to us, but the 0.2% difference seems to be a key factor explaining why two people exposed to the same environmental factors are not equally susceptible to chronic disease."