As we get older, even our DNA shows signs of wear and tear. Dr Michael Fenech, project leader of Genome Health and Nutrigenomics at CSIRO Human Nutrition in Adelaide, Australia explains: "Damage to your individual DNA - your genome - can lead to all sorts of degenerative diseases and cancer."
Some damage is the result of age, and some is inherited. Fenech said, "we are building the database to be able to predict the best diet for each individual to optimise their genetic health."
The work Fenech did after receiving his doctorate related to the effects of ageing and radiation, which led to internationally renowned work in methods for determining the safety of pharmaceuticals, food ingredients and radiation emitting devices.
After some time as a radiation biologist and work in the Cell Mutation Unit at the Medical Research Council in Britain and post-doctoral studies in molecular biology, Dr Fenech returned to Australia to his current post at CSIRO Human Nutrition. Here he began his current work on individual genome health - and the importance of diet.
One of the first studies compared the DNA damage in a group of vegetarians and non-vegetarians. "The vegetarians tend to take in more natural vitamin C than non-vegetarians, and to be a bit higher in their folate [1] intake," he says.
"The bottom line on the data was that B12 and folate were more important in determining DNA damage than vitamins E [2] and C [3], and that there was no great difference between the two groups. The upshot was we needed to know the optimum levels of folate and B12 for prevention of genome damage and not, as they were previously set, for preventing anaemia," Fenech says. Subsequent studies have underlined the importance of the individual genotype in predicting the levels of folate and B12 each of us needs.
Dr Fenech hopes to one day establish Genome Health Clinics [4] where we could have our DNA damage assessed and be given an individualized, optimum diet. In the meantime, he says, "we're living in a low-folate background - 88 per cent of us don't meet the RDA of 400 micrograms a day. And it's hard work getting that RDA from foods that are low in folates."
So what are we looking for? If you have the stomache for it, fried chicken liver delivers 1385 micrograms of folate per 100 grams. Just below that is beef liver at 1057 micrograms, and pig liver at 540.
At 58 micrograms per 100g, you'd have to eat around 700g of lettuce a day to get your RDA. Sardines, whitebait and oysters are also good sources of vitamin B12 because you're eating the whole animal, and folate and B12 are produced by the intestinal flora.
But Dr Fenech suggests you go easy on the wine as you dine. "An excessive amount of alcohol does not help. It destroys folate and damages the DNA."
There is a pressing need to encourage lifestyle changes that can prevent the majority of illness and disease, and a good deal of accidents and injury too. However, there is also a need for the determination of an individualizd diet so people can control and repair their damaged DNA. Let's all wish Dr Fenech the very best in his continuing efforts to develop just such a form of diet therapy.