Low Carb Diets May Pose High Risks

March 08, 2004, HealthNewsDigest.com

by Jennifer Wider, MD, Society for Women's Health Research

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(HealthNewsDigest.com)...Low-carbohydrate products have invaded our supermarkets. From cereal and ice-cream to snack food and drinks, Atkins mania is everywhere. The Atkins diet and other low-carbohydrate, high-protein diets promise a thinner waistline in record time, but the public seems to be ignoring evidence that this type of diet may have long-term health consequences. What's more, a menu rich in protein and fat has particular concerns for women.

Topping the list of women's health concerns are heart disease, cancer and osteoporosis. Studies have suggested that long-term use of high-protein diets can increase the risk of all three.

Cardiovascular disease is the leading killer of women in the United States. Among the many risk factors, dietary habits and weight status have frequently been implicated. High-protein diets are, by and large, loaded with dietary cholesterol and saturated fat.

Ongoing research trials are trying to determine the effects of such diets on blood cholesterol levels, but there is clear evidence that meals high in saturated fat increase the risk of heart attack. The greatest body of evidence supports the claim that limiting saturated fat and cholesterol in the diet will lower the risk of coronary heart disease.

Most people are unaware that colorectal cancer is the third most common cancer in women behind lung and breast cancers. In 1997, the American Institute for Cancer Research definitively stated that diets high in red meat were likely factors in the development of colorectal cancer. In addition, high-protein, low-carbohydrate diets are often low in fiber. Dietary fiber has proven to be protective against colorectal cancers, according to the results of numerous studies.

Diet seems to play a role in the development of breast cancer, as well. Many research studies link diets high in saturated fat to an increased risk for breast cancer. Results from the Nurses' Health Study establish a relationship between increased consumption of animal fat and a higher risk of breast cancer.

Today in the United States, roughly 10 million people have osteoporosis and 80 percent of sufferers are women. Studies have shown that the body loses large amounts of calcium when a person is on a high protein, low carbohydrate diet. There is evidence that high-protein diets promote the loss of calcium in the urine, increasing the risk of kidney stones and osteoporosis.

Even the Atkins diet Web site lists the potential dangers, so why is the public so perplexed? There's so much contradictory information in the media, not all accurate, that consumers are totally confused, Keith-Thomas Ayoob, Ed.D., nutrition clinic director at the Rose F. Kennedy Children's Evaluation and Rehabilitation Center and associate professor at the Albert Einstein College of Medicine in Bronx, N.Y., said.

There is some evidence that the Atkins diet yields positive results. Two studies in the New England Journal of Medicine in May 2003 revealed that patients were able to lose more weight on Atkins than on traditional diets and one study even suggested that the diet could improve certain heart disease risk factors.

The weight loss on Atkins is clear, said Randy Seeley, M.D., an associate director of the Obesity Research Center at the University of Cincinnati and a member of the Society for Women's Health Research's Isis Fund Network on Metabolism, an interdisciplinary research network on metabolic disorders.

But there are no long-term studies to provide information about the advantages or disadvantages of the diet in the long run. In the absence of information, Seeley said, it is dangerous to give people advice.

With the number of obese Americans at record numbers, extreme dieting doesn't seem to be paying off.

Overweight isn't caused by carbs or fat, but by excess, Ayoob said. It's a disease of excess and it's cured with balance. Balance in your diet, your activity and your lifestyle. No one diet will fit everyone, but extreme diets are useless in the long run.

It is clear that many people lose weight on Atkins and similar diets. Because no long-term studies have ever defined the risks, there is a need for more research to fully assess the potential health hazards of these diets.