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Dr. Tim Says...
Low Calorie Diets and Atherosclerosis |
March 6, 20006 |
I have written two columns recently on the positive effect that a calorie restricted diet can have on one’s health. In one study people on a reduced calorie diet had dramatically lower cholesterol levels. In another very well designed trial researchers showed that those on low calorie diets had better heart function than those on a standard American diet.
People who are on Caloric Restriction (CR) diets consume a variety of foods that supply 100% or more of the recommended daily allowance (RDA) of all the essential nutrients, while minimizing the number of calories they eat (usually between about 1200 and 2000 calories per day). In general, about 26% of their calories come from protein, 28% from fat and about 46% from complex carbohydrates. They avoid eating processed foods containing trans-fatty acids and stay away from refined carbohydrates, desserts, snacks, and soft drinks.
A traditional American diet averages between 2000-3500 calories per day, with about 18% of calories from protein, 32% from fat and about 50% from carbohydrates. Many of these carbohydrates come from simple sugars like those found in sweets and soft drinks.
In a study published in the Proceedings of the National Academy of Sciences USA (PNAS. 2004; 101: 6659 - 6663), scientists at Washington University evaluated 18 people who had been practicing a calorie restricted diet for between 3 and 18 years. They were compared with 18 participants in a control group who had been eating a traditional American diet. The control group was matched for variables such as age and economic status. The two groups were also similar in that their weights had been stable, they were not on medication for high blood pressure or cholesterol, and were otherwise in good health with no chronic disease.
The researchers evaluated the amount of narrowing of the carotid arteries. These are the two main arteries in the neck that feed blood to the brain. They wanted to see if a calorie restricted diet would lead to less build up of plaques in the arteries that could block blood flow to brain. This is a common cause of stroke and the plaques (called atherosclerosis) are the same type that form in the arteries in that feed freshly oxygenated blood to the heart. Blockage of the coronary arteries leads to heart attack.
What they found is pretty astonishing. There was markedly less plaque build up in the group eating a calorie restricted diet -- by 40%. In fact, none of them had evidence of atherosclerotic plaque (as defined by less than 1 mm of atherosclerotic build up).
Other information was evaluated to determine what health differences there were between the groups. In every case the parameters commonly used to determine risk for illness were better in the CR group. Their blood pressures, cholesterol profile and Body Mass Index (BMI) were all significantly healthier than the control group. Other blood tests that are considered to be an indication of high risk were also improved in those using a calorie restricted diet.
Calorie restriction has been shown in both animal and human tests to be a significantly important strategy at improving long term health. This means that you can eat great food, but being careful to choose the right recipes and ingredients can help you live longer and live better.
Eat well, eat healthy, enjoy life!
Dr. Gourmet
Last updated: 03/06/06
