High-Fat Diets Won't Harden Arteries

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High-Fat Diets Won't Harden Arteries

Low-carbohydrate diets that require patients to fill up on fats

won't lead to harder arteries, researchers say -- at least not in

the short-term. (Getty Images)

By KRISTINA FIORE, MedPage Today Staff Writer

June 1, 2011

Low-carbohydrate diets that require patients to fill up on fats

won't lead to harder arteries, researchers say -- at least not in

the short-term.

Those who lost 10 pounds after curbing their carb intake had no

differences in arterial stiffness than those on a more traditional,

low-fat diet, Dr. Kerry of s Hopkins and colleagues

reported at the American College of Sports Medicine meeting in

Denver.

"Losing weight may be more important to [arterial] health than the

diet you're on," told MedPage Today.

Some researchers have raised concerns that replacing carbs with fats

may have adverse effects on blood vessels, especially since

promoting consumption of fats runs "counter to what the public has

been told [about reducing fat intake] for the last 20 or so years,"

said.

Yet studies have shown that a low-carb diet can have positive

effects on blood pressure, cholesterol, and other parameters that

may reduce the risk of the artery disease atherosclerosis and

subsequent heart disease.

So to assess what the diets are actually doing to patients'

arteries, and colleagues enrolled 55 overweight or obese but

healthy patients ages 30 to 65 in a lifestyle modification program.

None had heart disease or other markers of cardiovascular risk at

enrollment.

In addition to a supervised exercise program -- an hour-long regimen

three days per week -- patients were randomized to either a low-carb

or low-fat diet for six months. The researchers monitored arterial

stiffness and other measures of blood vessel health.

For this analysis, the researchers had data on 23 of 28 patients who

lost 10 pounds on the low-carb diet, and 23 of 27 who did so on the

traditional diet. Those on the low-carb diet lost the 10 pounds

sooner than the low-fat group did -- just 45 days instead of 70

days.

There were no changes in arterial stiffness or endothelial function

in either diet group, and that didn't change after the results were

adjusted for the time it took to shed 10 pounds, said.

"My theory is that if people can achieve weight loss, it will

benefit vasculature in every other system of body," he told MedPage

Today. "Weight loss, in the long run, will count more than the

specific content of the diet."

Nor were there any acute effects on vascular function after a lone

high-fat meal, the researchers found. In a companion study, 66

patients had no changes in endothelial function after eating a

900-calorie, 50-grams-of-fat meal from Mc's. In fact, arterial

stiffness significantly improved by 16 percent after that feast, the

researchers found.

"It really seemed to make the arteries relax more, but we're not

entirely sure how," said. "We'll have to look more deeply

into that."

Some researchers contacted for outside comment said longer-term

follow up may be needed to confirm those benefits. And analyses of

the diet study that include the type of fats eaten would be helpful,

they said.

"It would be nice to know what the fat consisted of, as some may be

safer than others -- i.e. monounsaturated fats and omega-3 fatty

acids and even polyunsaturated fats would be better than saturated

fats," said Dr. Carl Lavie of the University of Queensland in New

Orleans, who was not involved in the study.

said that upcoming analyses will break down the type of fats

consumed, and that the dieticians involved in the study advised

patients to stick to these healthier fats.

He added that the work should help allay physicians' concerns about

recommending a low-carbohydrate diet -- something the medical

community has largely been reluctant to do, he said.

http://abcnews.go.com/Health/low-carb-diets-hurt-arteries/story?id=13728382