Lower Body Fat May Not Cut Disease Risk

Genetics impacts heart disease type 2 diabetes risk

/ Author:  / Reviewed by: Joseph V. Madia, MD

(RxWiki News) Exercise and a healthy diet are usually enough to promote health and prevent disease. However, it might not be enough to protect from heart disease and type 2 diabetes, a new study has revealed.

A pair of scientists at the Institute for Aging Research of Hebrew SeniorLife, an affiliate of Harvard Medical School, said new research indicates that lower body fat might not reduce the risk of heart disease and diabetes. A lower body fat is generally associated with healthy eating and exercise.

Instead, risk of cardiovascular disease and type 2 diabetes might be linked to genetics.

"Talk to your doctor about your risk for heart disease and diabetes."

Researchers Dr. Douglas P. Kiel, M.D., M.P.H., and Dr. David Karasik, Ph.D., have identified a gene that is associated with having less body fat, but also with an increased risk of type 2 diabetes and heart disease.

Dr. Kiel said the investigators were intrigued by the findings suggesting that those with the specific gene can be predisposed for such metabolic diseases, not just those who are overweight. The gene discovered appears to particularly affect men.

Researchers studied the genomes of more than 75,000 people to look for the genes that determine body fat percentage. They discovered strong evidence for a gene, called IRS1, to be linked with having less body fat. But additional research revealed that this gene also leads to unhealthy levels of cholesterol and blood glucose.

In understanding why a gene that lowers body fat can be harmful, scientists learned  that the gene lowers only the "subcutaneous" fat under the skin, but not the more harmful "visceral" fat that surrounds organs. Researchers believe that those with this gene variant are less able to store fat safely under the skin, prompting their bodies to store fat elsewhere in the body, where it can interfere with normal organ function.

Observations showed the gene was more pronounced in men, demonstrating that many seemingly lean men can still carry too much fat around the middle. Investigators speculate it may be more pronounced in men because of different body fat distributions between the sexes. Since men store less fat than women, they may be more sensitive to distribution changes.

The study was published in journal Nature Genetics.

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Review Date: 
June 27, 2011
Last Updated:
June 30, 2011