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Health

Use common sense

A low-carb diet doesn't increase the risk of heart disease, a study finds, but that doesn't mean you can gorge on fat and be healthy.

By Dr. David Lipschitz, Special to the Times
Published December 26, 2006

A study recently published in the New England Journal of Medicine indicates that a low-carbohydrate diet does not increase the risk of heart disease in women. This information goes against the increasing concern about the low-carbohydrate, high-fat Atkins diet, which many Americans use.

But don't throw away your cereal and bring on the bacon just yet.

The study examines the dietary habits of 82,802 women participating in the Nurses' Health Study. About 20 years ago, these women completed a detailed questionnaire that allowed researchers to calculate the percentage of carbohydrate, protein and fat in the women's diets.

The researchers found that nurses who had the lowest percentage of their calories as carbohydrates and a higher percentage as protein and fat did not have an increased risk of heart disease.

However, the women with diets with a higher glycemic load - reflecting a higher proportion of foods that rapidly increase blood glucose - did have an increased risk for heart disease.

But - and most notably - the women who primarily consumed fats derived from plants oils, avocado, nuts had a 30 percent reduction in their risk of a heart attack.

So how should we interpret this information? First, this dietary questionnaire was completed long before Dr. Robert Atkins' diet became common, and the nurses already were aware of the potential dangers of a high-fat diet. None of them was actively pursing an Atkins-style diet. They were merely consuming a diet that contained fewer carbohydrates than the average.

The Atkins diet does, indeed, work. You cut the carbohydrates, increase the fat and the weight can melt off.

This is because a very low carbohydrate diet makes the blood acidic, a process referred to as ketosis. This, in turn, suppresses appetite. Virtually no one can stay on this diet indefinitely, and once carbohydrates are reintroduced, ketosis disappears and weight returns rapidly.

At the height of the Atkins craze, Americans everywhere jumped at the opportunity to order burgers without the buns and cholesterol-filled plates of steak and eggs. All of that excess, and you still lost weight!

But, as the diet became increasingly extreme, many in the medical community began to question its health benefits. Today, we know that any extreme diet is not healthy:

- A diet containing too great a percentage of calories from carbohydrates leads to weight gain, insulin resistance and a higher risk of diabetes, heart attacks, strokes and perhaps high blood pressure.

- A diet containing too much saturated or polyunsaturated fat can also lead to weight gain and an increased risk of heart attacks, strokes and cancer.

The best diet is one in which moderation is key. Only one serving of complex carbohydrates with each meal, and the amount should be no larger than two-thirds the size of your fist.

Make sure that you eat the right kids of fats, including fatty fish, nuts in moderation, avocados and monounsaturated olive or canola oil. Eat all the fruits and vegetables you want, and enough lean meats and fish to meet your protein requirements.

Gerontologist David Lipschitz holds both a medical degree and a Ph.D. and is the author of "Breaking the Rules of Aging." Write to him at askdrdavid@msn.com His Web site is www.drdavidhealth.com

[Last modified December 26, 2006, 12:14:50]