FRIDAY, May 17 (HealthDay News) -- After age 50, excess body fat hardens the arteries, potentially increasing the risk of dying from cardiovascular disease, according to a new study.
The blood vessels of young people can adapt to the effects of obesity, but this ability is lost after middle age, British researchers found. As body fat accumulates, arteries become stiffer, they cautioned, suggesting years of being overweight could lead to irreversible damage.
"The effects of having more fat seem to be different depending on your age. It looks like young people may be able to adapt to excess body fat, but by middle age the cumulative exposure to years of obesity may start to cause permanent damage to the arteries," said study leader Dr. Declan O'Regan, of the Medical Research Council Clinical Sciences Center at Imperial College London.
One implication of the study, published in the June print issue of the journal Hypertension, is that the potential benefits of weight loss may depend on your age and how long you have been overweight, he added.
Because blood travels faster in stiff vessels than healthy vessels, the researchers were able to assess artery hardness by using an MRI scanner to measure the speed of blood flow in the aorta of 200 people. Young adults with more body fat had less stiff arteries, they found. In people older than 50, however, excess weight was associated with hardening of the arteries. This was true for both men and women, the researchers noted.
"We don't know for sure how body fat makes arteries stiffer, but we do know that certain metabolic products in the blood may progressively damage the elastic fibers in our blood vessels. Understanding these processes might help us to prevent the harmful effects of obesity," said O'Regan in a college news release.
The study authors pointed out that hardening of the arteries was associated more with body fat percentage, which is estimated by passing a small electric current through the body, than body mass index (BMI), which is a measurement based on height and weight. The investigators added that more research is needed to determine when the harmful effects of obesity result in permanent damage to the heart.
The U.S. National Heart, Lung, and Blood Institute has more about atherosclerosis, or hardening of the arteries.
-- Mary Elizabeth Dallas
SOURCE: Imperial College London, news release, May 15, 2013
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