Swiss scientists said recently that both low-fat and low-carb diets will help people slash the pounds, but low-carb eating will also raise cholesterol levels. According to a study in the Feb. 13 issue of Archives of Internal Medicine, researchers at University Hospital in Basel, Switzerland, reached their conclusions after analyzing five clinical trials in which they found that an increase in total cholesterol and low-density lipoprotein cholesterol for low-carb dieters offset an increase in HDL "good" cholesterol and a decrease in triglycerides after a year's time.

Their findings, which will anger supporters of low-carb diets, come at a time when 45 percent of the women and 30 percent of the men say they're trying to lose weight. Weight loss does help reduce risk for type 2 diabetes, hypertension and cardiovascular disease.

But many of the people trying to lose weight rely on high-protein, high-fat or low-carb diets, although how they affect cholesterol levels and the cardiovascular system are unknown.

In the Swiss analysis, the trials involved 222 people 42 to 49 on low-carb diets and 225 on low-fat diets. All of them had body-mass indexes of 25 or higher, indicating that they were overweight. Low-carb dieters were restricted to no more than 60 grams of carbs a day without energy restriction. In contrast, low-fat diets were allowed a maximum of 30% of daily energy intake from fat.

For the first six months, low-carb diets proved somewhat advantageous, but by year's end, the differences in increases in the good cholesterol and decreases in triglycerides compared to increases in "bad cholesterol" evened out. Researchers found no difference in blood-pressure levels between the two groups.

Furthermore, they reported that at the halfway point, low-carb dieters were more likely to stick with the diet, and they lost more weight than the low-fat dieters. In addition, beyond six months, triglycerides for the low-carb dieters were lower than triglycerides for the low-fat group.

But for the low-carb diets, which tend to be high in protein and fat, LDL "bad" levels of cholesterol and cholesterol were higher compared with the low-fat diets. What's more, at 12 months, differences in weight loss between the two diets were minor and not clinically relevant, according to the study.

"Because no trials have yet examined the risk of heart attack or death in people on low-carbohydrate diets, it's unclear whether the beneficial effects that low-carbohydrate diets appear to have on HDL and triglyceride levels cancel out their apparent negative effects on overall and LDL cholesterol levels," said Dr. Alain J. Nordmann, the lead researcher, in the study. "We believe there is still insufficient evidence to make recommendations for or against the use of low-carbohydrate diets to induce weight loss, especially for durations longer than six months. Such diets currently cannot be recommended for prevention of cardiovascular disease."

'Clear understanding' needed

Dr. Nordmann and his team wrote that more research is needed to provide "a clear understanding of diets to achieve meaningful weight loss." But Dr. Nordmann wrote that the Mediterranean diet-based on fruits and vegetables, little red meat and a moderate intake of alcohol-is the best for long-term weight maintenance and and reducing deaths from cardiovascular problems.

The findings mirror a similar study in 2004 that showed weight loss from low-carb and low-fat diets were similar after about a year's time. However, low-carb dieters didn't maintain the greater weight losses that they had at the six-month interval, compared with conventional low-fat dieters, according to researchers at the Philadelphia Veterans Affairs Medical Center.

Other studies have confirmed that low-carb diets raise good cholesterol and lowered triglycerides in people who followed the diet for six months, but the studies didn't follow up with them after a year.

But William Yancy, an author of another study and medical professor at Duke University said healthy triglyceride and HDL levels may outweigh the negative effects of LDL "bad" cholesterol, which in the low-carb group represented just minor increases. United Press International noted that part of Yancy's salary comes from the Robert C. Atkins Foundation, which is named after the man who pioneered the low-carb "Atkins Diet."

Yancy told UPI that people need to find what works best for them in the battle of the bulge. He noted that the participants in the analyzed studies didn't have a choice as to what diet they wanted to follow and the results may have differed if they had.

"We don't have to think of one diet pitted against another diet," Yancy told UPI.

Source: Nubella News
Posted by: Steve Smith
Resource: Annals of Internal Medicine
Website: www.nubella.com

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