US: Carrots may reduce effects of diabetes genes

The latest research into the human genome suggests that some diabetics - those with a certain genetic mutation - may be able to rely on beta carotene to reduce symptoms.

“Over the past seven to nine years, [researchers] have been finding genetic risk factors. Some of them are pretty potent and have a lot of effects, but a lot is still relative. We are not really finding the smoking guns of the genome that we were expecting, that would really tell us why diseases like Type 2 diabetes have some genetic basis,” says study author Dr. Atul Butte, an associate professor of systems medicine in pediatrics at Stanford.

Using data from the National Health and Nutrition Examination Survey, he and his colleagues found five major environmental factors associated with diabetes; all five, including levels of beta-carotene (a precursor to vitamin A), and a form of vitamin E, could be measured in the blood or urine. They then studied the levels of these five factors in people with different combinations of 18 of the major genetic variants linked to diabetes to see if certain DNA patterns were connected to specific nutrient levels.

In other words, having a genetic mutation isn’t enough; that genetic mutation, in the presence of high or low levels of certain nutrients, might prime the body to process glucose less effectively. That may be the case with people who harbor the gene variant SLC30A4, which codes for a protein that is involved in helping beta cells in the pancreas make insulin, which is critical for breaking down glucose in the diet. Both beta carotene, which is commonly found in carrots, and gamma tocopherol, a form of vitamin D, which is found in vegetable fats like canola oils and margarine, interact with the gene and influence risk for Type 2 diabetes, but in opposite ways. Higher beta carotene levels appears to protect against diabetes, and presumably improve the gene’s efficiency in producing insulin, while elevated gamma tocopherol may increase a person’s risk for the disease.

“What the findings suggest is that if you have a genetic marker now or a predisposition for Type 2 diabetes, all you really need to do is increase the number of carrots you eat to increase your beta carotene, and maybe you can compensate for having that spot in your genome,” says Butte.

Butte’s work is still preliminary, and further studies would be needed to confirm that increases beta carotene levels in the diet would be sufficient to offset the effect of the diabetes-causing genetic variants. But, says Butte, the results are promising.

Source: healthland.time.com

Publication date: Thu 24 Jan 2013