Diet Advice Via DNA

Pointers On Personal Nutrition Being Based On Genetics

(AP) 
The company acknowledges that some scientists say it's too soon to offer such a service, but says its testing is based on solid research. Current testing focuses on 19 genes and the company is studying others, said Rosalynn Gill-Garrison, chief scientific officer and a company founder.

Sciona's approach basically starts with standard healthy-eating recommendations and modifies them when genetic analysis indicates a need for something more, Gill-Garrison said.

After a DNA test, Sciona may recommend steps like eating more broccoli or omega-3 fatty acids, she said, or limiting caffeine to protect against bone loss.

Gill-Garrison said studies show that people with a certain version of a gene called MTHFR tend to have high blood levels of a substance called homocysteine, which has been linked to a higher risk of heart disease and stroke. Studies also show that people with this gene version can reduce their homocysteine levels by taking in more folate, she said. So that's the advice Sciona customers with that gene version get.

High levels of homocysteine also can be spotted with a standard blood test at a doctor's office.

Ordovas said the trouble with anybody providing gene-based dietary advice now is that scientists don't yet have the whole picture of what genes should be considered. With current tests, it's like trying to size up a landscape by looking through a keyhole, he said. You can't tell what you're not seeing.

"At least in that very narrow region of our genome that they are looking, they have potential that they may provide some valuable information, and it could benefit some people," he said. But advice based on current tests "can also be misleading because you are ignoring pieces that are very important," he said.

Rodriguez said he doubts anybody will be harmed by the current tests, and that they're beneficial because they get people to think about diet and lifestyle. But he said they remind him of the first VCRs or CD players to hit the market.

"It is an expensive new technology ... and it will probably, in my estimation, become more efficient, more accurate and more affordable with time."

DeBusk, who said she has no financial ties to any of the companies, figures the time for DNA-based diet advice has come.

"The scientist in me says we shouldn't do this now, we need to wait another 20 years until many studies have been done," she said. But her clients want to know what the best science is right now, and "it's difficult to say, 'Come back in 20 years.' You can't do that.

"Do we know everything we'd like to know? No... Do we know enough to start introducing this type of technology and start the long process of educating people? I would say yes."