The American Heart Association (AHA) issued an advisory, "Resistance Exercise in Individuals With and Without Heart Disease: Benefits, Rationale, Safety and Prescription," being published in the February 22 issue of Circulation: Journal of the American Heart Association. The exercise program outlined by AHA calls for a single set of eight to 15 repetitions of eight to 10 different exercises, two to three times per week. Although AHA supports weight training, it does not recommend isometric exercise for people with high blood pressure. Isometric exercise involves tensing one set of muscles for a period of seconds, in opposition to another set of muscles or an immovable object.
George A. Kelley, director of the meta-analytic research group, department of kinesiology and physical education at Northern Illinois University in DeKalb, said weight training could help lower resting blood pressure in another study. "Individuals who regularly did progressive resistance exercise experienced about a 2 percent reduction in their resting systolic blood pressure and a 4 percent reduction in their resting diastolic blood pressure," said Kelley. In addition to the decreases in resting blood pressure levels, Kelley said weight training also led to reductions in body fat and increases in lean muscle mass. Participants also increased their muscular strength by 15 percent to 62 percent. About 50 million Americans have high blood pressure. Only about 16 percent of Americans between the ages of 18 and 64 say they participate in progressive resistance exercise.
Zone Diet Craze: In an InteliHealth interview, Lawrence Cheskin, M.D., associate professor of medicine and director of the Johns Hopkins Weight Management Center at Johns Hopkins, debunks the theory behind the latest diet craze, called the Zone diet based on the book "Enter the Zone" that incorrectly theorizes that the low-fat diets, epitomized by the food pyramid, aren't the answer, and in fact may be contributing to the nation's obesity problem. According to Dr. Cheskin, our national obesity problem stems from consuming more food than ever, coupled with an increasingly sedentary lifestyle. The Zone diet focuses on insulin secretion. But insulin secretion is a consequence of your weight. People who are overweight secrete more insulin, and being overweight puts you at risk for diabetes. It's not that the insulin is causing you to gain weight ó the insulin increases when you gain weight. The truth is we're getting heavier and heavier because we're less physically active. We're eating more fat and calories than we ever have.
Insulin resistance syndrome, also known as syndrome X, is a combination of conditions like overweight - especially weight over the belt, such as a pot belly, as opposed to weight around the hips. "It is almost always associated with the central obesity body pattern," says Dr. Barbara V. Howard, president of MedStar Research Institute, a part of the Washington Hospital Center. The other indications show up on blood tests. These include above-normal cholesterol levels, and higher readings on glucose tests commonly used to check for diabetes. People with insulin resistance syndrome also may have elevated blood pressure. The locus of all these signs and symptoms is a growing inability to use insulin. Muscle cells become less able to let the hormone guide nutrients through the cell membrane and into the cells. The pancreas tries to overcome the resistance by pumping out more insulin. "But if the resistance grows, diabetes can result. And cholesterol changes linked to insulin resistance also can lead to clogged arteries and heart disease," says Dr. Robert Sherwin, a professor at Yale School of Medicine and president-elect of the American Diabetes Association.
Here's another way in which exercise may help a person avoid an early death - it fights insulin resistance syndrome, which may affect millions of Americans. Regular, calorie-burning aerobic exercise improves the factors that insulin resistance syndrome worsens. The cells get better in their ability to take up insulin. Cholesterol levels and blood pressure retreats. Even the potbelly shrinks. Exercise combined with diet forms one of the best ways to beat insulin resistance, Sherwin and Howard said. They also conceded it's easier to prescribe diet and exercise than to see their patients follow the regimen. Sherwin stands by vigorous aerobic exercise, at least every other day, at sweat-producing levels found in an aerobic studio or a treadmill run. Anything less hasn't been proved to work, he said. Howard, on the other hand, believes that even brisk walking can accomplish some good.
Dr. Burton Berkson of Las Cruces, N.M. estimated that 65 percent of Americans have some symptom of syndrome X. Berkson calls for fewer refined carbohydrates, such as sugary pastries, and more non-starchy vegetables. Sherwin and Howard both back eating fewer calories but don't think much of diets that recommend certain types of foods, such as more protein and less carbohydrate.
Cancer: Dennis Savaiano, dean of Purdue University's School of Consumer and Family Sciences (www.cfs.purdue.edu ), West Lafayette, Ind., and chairman of FANSA, the Food and Nutrition Science Alliance, said that about one-third of cancer cases are related to diet and lack of exercise. The other two-thirds result from smoking and genetic or other factors. FANSA, a joint committee of the American Dietetic Association (www.eatright.org ), the American Society for Nutritional Sciences (www.faseb.org/ain ) the American Society for Clinical Nutrition (www.faseb.org/asns ) and the Institute of Food Technologists (www.ift.org ), issued a statement outlining steps that can be taken to lower cancer risk: eating plenty of fruits and vegetables, grains and legumes; avoiding empty calories from processed foods high in fat and/or sugar; exercising regularly; and limiting or abstaining from alcohol. Savaiano added that consumers should not let fear of pesticide residues deter them from eating fruits and vegetables because the benefits of eating these foods appear to outweigh any potential risk. "A lot of human suffering can be prevented," said Savaiano, if more of a preventative approach to cancer is taken. Colleen Doyle, director of nutrition and physical activity at the American Cancer Society (www.cancer.org ) agreed that diet plays a "critical" role in cancer prevention. The review is important, she said, because its message is that one-third of all cancer deaths are preventable. The ACS has been trying to get the diet and exercise message out through its nutrition guidelines. Doyle emphasized the need to avoid high fat meats, such as red meat, pork and beef, and to eat a lot of plant-based foods.
Cholesterol: While Robert Atkins suggests a wild low carbohydrate and high meat diet to reduce weight, Dean Ornish on the other hand, in his book "Eat More, Weigh LessĒ suggests virtually vegetarian diet, which is more close to the AHS and ACS recommendations. The American Heart Association recommends that your intake of dietary cholesterol should be restricted. Itís found only in foods from animals. Although itís not the same as a saturated fatty acid, dietary cholesterol can also raise your blood cholesterol level. We need cholesterol for our body to function normally, but our body makes enough so that we donít need to get more from the foods we eat.
Saturated fatty acids are the chief culprit in raising blood cholesterol, which increases our risk of heart disease. But dietary cholesterol also plays a part. The average American man consumes about 360 milligrams of cholesterol a day; the average woman, between 220 and 260 milligrams. Saturated fats and cholesterol are found in meat, poultry, seafood and dairy products. Foods from plants, such as fruits, vegetables, vegetable oils, grains, cereals, nuts and seeds donít contain cholesterol. Egg yolks and organ meats are high in cholesterol. Shrimp and crayfish are somewhat high in cholesterol. Chicken, turkey and fish contain about the same amount of cholesterol as do lean beef, lamb and pork.
Grandma called it Roughage! Fruits, vegetables, whole-grain foods, beans and legumes are all good sources of dietary fiber. The AHA Eating Plan suggests that you eat foods high in both types of fiber. When regularly eaten as part of a low-fat, low-cholesterol diet, soluble fiber has been shown to help lower blood cholesterol. Foods high in soluble fiber include oat bran, oatmeal, beans, peas, rice bran, barley, citrus fruits strawberries and apple pulp.
Nuts and fat: Nuts are packed with nutrients needed to start a new generation of plants and are powerhouses of health-promoting substances. Despite their high fat content and caloric richness, nuts and nut products, which provide satiety often missing from fat-free carbohydrate foods, have been shown to help people adhere to weight-loss diets and to maintain their losses. Depending on the type, 72 percent to 90 percent of the calories in nuts comes from unsaturated fat, which helps to lower low-density-lipoprotein (L.D.L.) cholesterol, which can clog arteries. Except for walnuts, most of the unsaturated fat in nuts is monounsaturated, the kind that predominates in canola and olive oils and in avocados. It is celebrated for its ability to lower harmful cholesterol without affecting the beneficial high-density-lipoprotein (H.D.L.) cholesterol. The walnut is a good source of omega-3 fatty acids, that counters the blood clots that can cause heart attacks and strokes. Nuts are potent sources of antioxidants, including vitamin E, which protects L.D.L.-cholesterol from being oxidized to the form that attaches itself to blood vessel walls. Two other antioxidants in nuts, quercetin and campferol, may suppress the growth of cancers. Most nuts are also fairly good sources of protein, which is why peanut butter and almond butter are often used as protein foods. One ounce of peanuts supplies 7.2 grams of protein, nearly as much as a glass of milk. Protein in nuts is especially rich in an amino acid called arginine. It aids in the body's synthesis of nitric oxide, which causes blood vessels to widen. This, in turn, would lower blood pressure, counteract the stiffness of cholesterol-clogged arteries and perhaps reduce further clogging. Peanuts, almonds, walnuts and hazelnuts are good sources of arginine. The cholesterol found in animal foods clogs blood vessels, while nuts contain plant-based sterols that counter atherosclerosis, the accumulation of fatty deposits in blood vessels. Phytosterols, soluble only in fats, are now being used in some commercial margarines to reduce the risk of heart disease. In animal studies, phytosterols have also been shown to have anti-cancer properties. Pistachio nuts are especially rich in phytosterols. Nuts contain several vitamins and minerals that protect against heart disease, high blood pressure and stroke, including folate, which lowers blood levels of homocysteine. Elevated homocysteine levels can triple the risk of heart attacks. Peanuts are the best nut sources of folate, followed by hazelnuts and walnuts. Beneficial minerals in nuts include calcium, magnesium and potassium, and all protect against high blood pressure. Pistachios followed by almonds are the richest nut sources of potassium, and almonds are the best nut source of calcium. Brazil nuts are rich in selenium, which may prevent prostate cancer. Peanuts contain resveratrol, the compound in red wine that may protect against heart disease and cancer.
At a conference in London convened last month by Oldways Preservation and Exchange Trust, a nonprofit organization that studies and promotes traditional healthful diets, medical researchers described several large studies linking frequent nut consumption to better health. Dr. Frank B. Hu at the Harvard School of Public Health said that among 86,016 participants in the Nurses Health Study, fatal and nonfatal heart attacks were 35 percent less likely to occur among women who consumed nuts five or more times a week than among women who rarely ate nuts. An earlier study of 34,192 Seventh-day Adventist men and women in California, most of whom were vegetarians, revealed a 50 percent reduction in coronary risk among frequent nut eaters.
Dr. Lawrence Kushi, now at Columbia, reported that in the Iowa Womens Health Study, women who ate nuts two to four times a week had less than half the coronary risk of women who almost never ate nuts. Dr. Joan Sabate of Loma Linda University showed that eating a diet in which 20 percent of the calories came from walnuts improved cholesterol levels. Dr. Penny M. Kris-Etherton, a nutritionist at Pennsylvania State University, a diet that provided 36 percent of its calories mostly from peanuts and peanut butter, lowered L.D.L.-cholesterol and triglycerides by more than 10 percent.
Changes in Life Style: Participation in regular physical activity is the one behavioral change that can have the greatest impact on health and longevity. In addition to rejuvenating nearly every organ system, it reduces the risk of heart disease, stroke, hypertension, diabetes, osteoporosis, obesity, stress-induced illness, mental and muscular deterioration, falls and fractures and even cancer of the colon. The surgeon general is calling on employers to help by offering physical activity and fitness programs.
There is probably no other change that could have a greater impact on health than the change in eating habits. Not a week goes by without a new study proclaiming yet another health benefit from eating lots of fruits and vegetables. The risks of developing debilitating conditions like heart disease, stroke, cancers of the breast and prostate and sight-robbing cataracts and macular degeneration are reduced by consuming a plant-rich diet.
Prevention is better than cure! Sreenivasarao Vepachedu, 02/28/2000