Resistance Exercise Improves Cholesterol Levels
NEW YORK, May 26 (Reuters Health) -- High-intensity strength training using weight machines and free-weights improves cholesterol levels as much as aerobic exercise in previously sedentary young women, researchers report in the British Journal of Sports Medicine.
The same strength training exercise program also reduced body fat, they add.
Dr. Bharathi Prabhakaran and colleagues from the Old Dominion University, Darden College of Education, Norfolk, Virginia, assigned 12 healthy young women to a high-intensity, progressive strength training program and 12 others to a non-exercising ``control'' group. Women in the exercise group performed a variety of resistance training exercises, including repeated leg curls, leg extensions, presses, press-up and biceps curls. Each training session lasted 45 to 50 minutes and women exercised 3 days a week for 14 weeks.
The control group did not participate in any structured exercise program.
``At the end of training... total cholesterol was significantly lower... in the resistance exercise training group than in the control group,'' the investigators report. Resistance training reduced levels of low-density lipoprotein (LDL) cholesterol -- the so-called ``bad'' cholesterol -- by 14%, and did not affect levels of high-density lipoprotein (HDL) or ``good'' cholesterol.
Body fat also decreased slightly in the group who engaged in resistance training, while measures of muscle strength improved.
In contrast, there were no such changes in the group of women who had not exercised, the investigators note.
Studies link lower levels of both total and ``bad'' cholesterol, as well as higher levels of ``good'' cholesterol to a lower risk of heart disease.
SOURCE: British Journal of Sports Medicine 1999;33:190-195.
Cholesterol Guidelines Too Lenient
CLEVELAND, Sep 09 (Reuters) -- The current cholesterol guidelines are not stringent enough to stop the progression of heart disease, according to a New York researcher. In particular, people need to achieve an even higher level of HDL (''good'') cholesterol, Dr. Antonio Gotto, Jr., dean and medical provost of Cornell University Medical College told cardiologists and nutritionists at a summit meeting on cholesterol and coronary risk sponsored by the Cleveland Clinic Foundation.Currently, the National Cholesterol Education Program suggests that total cholesterol be less than 200 milligrams per deciliter (mg/dL) of blood, HDL should be more than 35 mg/dL, and LDL (''bad'') cholesterol should be less than 160 mg/dL.
However, HDL goals should be ``45 mg/dL for men and 50 mg/dL for women,'' said Gotto in an interview with Reuters Health.
Gotto was an investigator on a recently published study that was the first to find that treatment is beneficial for patients without obvious coronary heart disease, average total and LDL cholesterol, and below average HDL cholesterol.
In the Air Force/Texas Coronary Atherosclerosis Prevention Study, treatment reduced LDL cholesterol by an average of 25%, increased HDL by 6%, and lowered the risk for a first major heart attack by 37%, he said.
In that study, 6,605 men and women were treated with either the cholesterol-lowering drug, lovastatin, or a placebo. The men ranged in age from 45 to 73 years, and women from 55 to 73 years. The average total cholesterol at the beginning of the study was 221 mg/dL and average LDL was 150 mg/dL.
For men, the average baseline HDL was 36 and for women it was 40, and they were treated for an average of 5.4 years.
``Having an HDL of 35 as the cut-off misses a lot of people who would benefit from treatment.... People think that by achieving a safe value, by reducing to the recommended guidelines, they are doing a good job,'' Gotto said. ``But people reduce to the guidelines and develop coronary artery disease anyway,'' he added.
NEW YORK, Oct 12 (Reuters) -- Margarines which are ``trans fatty acid free'' or have moderate amounts of trans unsaturated fat appear to be a healthier choice than butter, according to US researchers.
The researchers tested the effects that butter and two varieties of margarine had on cholesterol levels that affect heart disease risk. One margarine was a standard supermarket variety, the other was a newer, ``trans fatty acid-free'' type.
Compared with butter, both types of margarine had healthier effects on the types of cholesterol linked to increasing the risk of heart disease, with the trans fatty acid-free margarine having the healthiest effect according to the researchers, Dr. Joseph T. Judd of the Beltsville Human Nutrition Research Center in Maryland, and colleagues.
Butter and margarine contain varying proportions of different types of fatty acids. There are a number of types -- including saturated, monounsaturated, polyunsaturated and trans unsaturated fatty acids -- and each type has unique effects on different kinds of cholesterol.
Over the last couple of decades, numerous studies have found that saturated fatty acids raise levels of low density lipoprotein (LDL), or ``bad,'' cholesterol in the blood. And butter is higher in saturated fatty acids than margarine. In light of these studies, margarine seemed a better bet than butter.
But several years ago, researchers discovered that trans unsaturated fatty acids -- found in most margarine, particularly in hard margarine -- also boosted LDL and might lower levels of ``good'' high density lipoprotein HDL cholesterol, as well. While high levels of LDL contribute to a build up of fatty plaque in the arteries leading to the heart -- raising the risk of heart attack -- high levels of HDL appear to have the opposite effect. In the last few years, newer, trans fatty acid-free margarine has become available.
To clarify the effects that the new margarine, margarine containing trans fatty acids, and butter have on cholesterol levels, Judd and colleagues studied 46 volunteers who followed 3 carefully prescribed diets for 5 weeks each. The diets were identical except that one included the trans fatty acid-free-margarine, another included the standard margarine, and the third included butter. The diet approximated the ''typical US diet,'' and the quantities of margarine and butter the volunteers ate were comparable to what the average US adult eats, according to the report. At the end of each 5 week period, the researchers tested the volunteers' blood cholesterol levels.
Total cholesterol levels were 3.5% lower on the margarine diet, and 5.4% lower on the trans fatty acid free margarine diet, than on the butter diet, Judd and colleagues found. And LDL cholesterol levels were 4.9 % lower on the margarine diet, and 6.7 % lower after the trans fatty acid free diet, than on the butter diet.
HDL levels, and levels of other blood fats known to affect heart disease risk, were similar on all three diets, they report in the current issue of the American Journal of Clinical Nutrition.
The findings suggest that trans fatty acid free margarine is a healthier choice than either standard margarine, or butter, the researchers conclude.
``When such a margarine is consumed in place of butter, and presumably in place of other fats high in SFAS (saturated fatty acids), appreciable improvement in blood lipid profiles of the major lipoproteins can be expected for most people,'' Judd and colleagues conclude. ``Because table spreads represent a major portion of the visible fat in the diets of many countries, including the United States, United Kingdom, and Netherlands, selection of products with desirable fatty acid profiles can be an easy means to begin consuming a more healthful diet and reducing the risk of cardiovascular disease.''
SOURCE: American Journal of Clinical Nutrition 1998;68:768-777.