NEW YORK (AP) – Avoid fast food, eat vegetables and exercise. It sounds like generic health advice, but they are tips that are supposedly tailored to my DNA profile.
The suggestions come from 23andme, one of the companies that offers you to indicate the optimal eating and exercise habits for your genetics. As with most diet regimens, the idea is appealing because it involves an elusive reason why you cannot get fit – in this case your genes.
But Isaac Kohane, a biomedical researcher at Harvard, said research in the field is still limited and that there is little evidence, small effects of genetic variation can be transformed into meaningful dietary advice.
"They don't give much value to the people who buy them," he said, adding that other factors play a much greater role in health, such as how much we eat.
Still, it is tempting to think that your DNA contains traces for your ideal diet. To see what my genes could reveal, I tried two services, 23andMe and DNAFit.
If you pay $ 99 for a 23andMe ancestor report, you can spend $ 1
Among the extra features you get are several wellness reports, including one that predicts your "genetic weight" and offers other dietary content. These results are based on comparisons with data from other 23andMe customers.
After adjusting the default setting from European to East Asian descent, my report said that I am entitled to weigh "on average". For a 40-year-old, 5-foot-6 woman, the company defined an average of 138 pounds. 23andMe notes that most of its customers are of European origin and that its data for other ethnic groups is more limited.
The report then shows 10 habits associated with healthy weights for your DNA profile. For me, it included limiting red meat, avoiding fast food and training at least twice a week. Considering how the formula sounded, I wondered how much the results vary for others.
It turns out that everyone gets the same 10 habits as they are 23 and I decided to investigate people. But the order in which they are listed varies to indicate the magnitude of their supposed effect for you. Alisa Lehman, senior product researcher for 23andMe, said the two top habits of most people limit red meat and avoid fast food as they were to me.
Like many other nutrition studies, the results do not determine cause and effect relationships, but there are links that the company produces between the customers' genes and the study results.
Other wellness reports said I am more likely to be lactose intolerant (check), rinse when drinking alcohol (check) and to consume less caffeine (check). They were more interesting because of their specificity, but did not reveal anything surprising. Another report said that my weight is unlikely to be affected by my intake of saturated fat commonly found in meat.
The only surprise was to learn that I have a genetic variant common to elite practitioners. "When I followed the link, though, about half of the customers have the same variant.
For $ 99.99 you get a saliva collection to produce reports of various fitness and dietary features. have your DNA file from 23andMe, you can upload it to get immediate results for $ 79.
DNAFit says its reports are based on the broader universe of scientific research on genes and diets
Given The general fear of carbs among many dieters, I began with the report "Carbohydrate Sensitivity." It began with an overview explaining the difference between complex carbs like brown rice and refined carbs like sugar digested faster.
After rolled down, the report said I have a "very low" sensitivity, which means I'm less susceptible than others to high sugar and diabetes. Despite this carb tolerance, I suggested limiting refined carbs to 10 percent of daily calories. Again this sounded like quite generic advice and made me think about how much the recommendations vary for others.
Andrew Steele, Product Manager at DNAFit, said that the recommended limit for refined carbs ranges from 6 to 10 depending on people's sensitivity percentage of total calories. For a person who eats 2,500 calories a day, there is a range of 150 calories to 250 calories.
Although it may not seem like a big difference, DNAFit will note a cut from 10 to 6 percent, meaning a 40 percent reduction. Nevertheless, the relatively tight range reinforces the idea that dietary advice would be largely uneven, regardless of your genes.
Another report said that my sensitivity to saturated fat is low and suggested to limit it to 10 percent of calories. DNAFit said that the area for this recommendation is also 6 to 10 percent.
Other reports were more nutritional. One said I have an increased need for omega-3, the cholesterol-lowering fatty acid. Another said I have an increased risk of DNA damage from charged meat and should limit them. (This advice was given over a picture of candles.)
On the fitness side, the reports said that I am more inclined to endurance activities than high intensity activities. I don't know if I take this into account if I start exercising. Others have questioned the accuracy of the fitness reports that rated an Olympic runner's aerobic potential as "medium".
DNAFit and 23andMe say knowing your genetic predisposition can motivate you to stick to diet or exercise routines. You can also have specific reasons to try out the services, especially 23andMe, which most get for ancestral tests and provide many other reports. But for me, the results of both were too broad to affect my habits.
A little note: DNAFit is based in the UK, so if you decide to try it, you may experience a small currency exchange fee on your credit card statement.
Follow Candice Choi at www.twitter.com/candicechoi
The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute's Department of scientific education. AP is solely responsible for all content.