Many people want to find out whether what we eat in our own lifetime affects the epigenetic marks that control important genes, such as those involved in cancer.

The relationship between epigenetics and cancer is far from clear, but tumour cells generally have comparatively low levels of DNA methylation. Methylation might switch off vital genes and contribute to the development of cancer. Studies in humans and animals suggest a whole list of dietary chemicals from alcohol to zinc that might influence methylation and cancer susceptibility, although sometimes counterintuitive. For example, a diet low in folic acid has actually been linked to excessive methylation at certain genes.

Diet and health are notoriously hard to study in human populations. Not surprisingly, most people are somewhat resistant to being fed the same nutrient-controlled chow day after day, unlike lab animals. A large-scale study of diet and cancer called EPIC encompassing half a million people in ten European countries, may reveal some of the links between methylation modifiers in the diet and cancer risk.

So what’s the evidence that certain compounds in the diet can influence epigenetic marks at certain genes? A quick scan of the scientific literature pulls up a few papers. For example, a study of patients with gastric (stomach) cancer linked methylation of an important gene to a person’s consumption of green tea and cruciferous vegetables. Other researchers have linked folic acid and alcohol intake to methylation at certain key genes involved in bowel cancer. Methylation of a gene involved in head and neck cancer is also associated with low levels of folic acid in the diet.

So if you’re keen to look after your epigenome, then you could try munching on foods that provide the building blocks for methylation in the body (see You are what you eat). For example, leaf vegetables, peas and beans, sunflower seeds and liver are good sources of folic acid, as are fortified bread and breakfast cereals. Choline comes from eggs, lettuce, peanuts and liver (again! My mother was right after all…).

To boost your intake of methionine try spinach, garlic, brazil nuts, kidney beans or tofu. And if you fancy something non-veggie, chicken, beef and fish are all good sources. For zinc, splash out on a plate of oysters. And while you’re on a seafood tip, get some vitamin B12 from fish. Alternatively, try cheese, milk, meat, or our old friend – liver.

Finally, if you’re looking for something to wash down your meal, red wine seems like a good choice, given that its resveratrol might help to prevent cancer and ageing. But, watch out: many wines also contain betaine, especially the cheaper stuff and alcohol can interfere with folic acid in the body, messing up methylation patterns. Maybe it’s best to stick to one glass. And don’t even think about lighting up a post-prandial cigarette. Apart from damaging DNA, some chemicals in tobacco smoke can change epigenetic marks – effectively a double-whammy for causing cancer.

Until we understand more about the links between diet and epigenetics, the best advice seems to be to get lots of green veg, limit your alcohol intake, and eat liver!

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