December 9, 2005

Genes Could Determine Diets

Genes could determine diets
December 9, 2005 - 1:24AM

Doctors will one day be able to tailor disease prevention diets for patients based on their genes, an Australian-based scientist believes.

Michael Fenech, of CSIRO Human Nutrition in Adelaide, will outline his vision of worldwide Genome Health Clinics at a conference in Singapore.

He believes the first one may be only a couple of years, rather than decades, away.

Dr Fenech, a geneticist and nutritionist, said studies had found links between increased DNA damage and adverse health outcomes such as infertility, cancer and neuro-degenerative disease.

But he said DNA damage, which increased as a person aged and reduced the body's ability to fight off diseases, could be minimised by supplementing people with nutrients such as folate and B12.

"How well a person responds depends on their genetic background and other nutrients in their diet," Dr Fenech said in an interview.

"For example, if you have too much riboflavin in a lower folate background, you're actually increasing DNA damage."

Dr Fenech said people with certain genetic defects may actually need higher - or lower - levels of some nutrients than others to offer a protective effect.

For example, he said studies had shown women with a defect in the Manganese superoxide dismutase gene benefitted from an increase in fruit and vegetable intake.

Genome Health Clinics may eventually even give advice on safe levels of alcohol, based on a person's genetic blueprint.

"We know that alcohol is damaging if you cannot detoxify it in the body," Dr Fenech said.

"Alcohol is a risk factor for many conditions, including breast cancer.

"If you knew what genotype you were, in terms of detoxification of alcohol, then of course you would be advised as to the amount of alcohol you should and shouldn't drink."

Visits to Genome Health Clinics may prove vital for women with faults in their BRCA1 and BRCA2 genes, DNA repair genes which are known to be linked with breast cancer.

"If you have those genes, it becomes increasingly important that you do not harm your DNA," Dr Fenech said.

"You could harm your DNA by drinking too much alcohol or by not having enough folate, for example.

"Put those two together, you can see that your odds are getting quite risky.

"It's known that if you're low in folate and high in alcohol your risk for breast cancer goes up, so this all fits. It's very, very plausible."

Ultimately, Dr Fenech wants to build a genome health nutrigenomics database based on the available information on genes and nutrition, which would allow doctors to take a simple blood test from a patient and design a diet to suit the individual.

He will detail his plans to the International Life Sciences Institute's conference on nutrigenomics.

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