Maintaining a healthy lifestyle through diet and exercise may help prevent certain diseases and enhance quality of life.
Antioxidants are the subject of increasing research because of the possible role they play in preventing disease. Antioxidants are molecules that work to prevent damage that occurs in cells and body tissues due to both normal bodily processes and exposure to some chemicals. The potential medical benefit of antioxidants may reside in their ability to prevent or slow the oxidation of molecules. However, there is some debate as to whether antioxidants have health benefits, as clinical trials have produced mixed results.
Research has recently focused on how antioxidant vitamins may reduce cardiovascular disease risk. In addition to being available in a variety of fruits and vegetables, antioxidants are available as supplements. Antioxidant vitamins, including vitamin E and C, and beta-carotene (a form of vitamin A), may have potential health benefits. According to the American Heart Association, approximately 30% of Americans are taking some form of antioxidant supplement.
Exercise is any form of physical activity that helps to promote overall health and decrease the risk of developing illnesses, such as heart disease. Most movement of the body is considered beneficial, as long as it is done in moderation and at the skill level of the person. There are many ways for people to exercise, including gardening, walking, sports activities, and dancing.
Patients beginning an exercise program should choose activities that fit their levels of strength and endurance. Exercise that causes extreme pain or discomfort is considered by many experts as unhealthy, and it may even cause permanent damage to the body. Based on expert opinion, most regular exercise plans adjusted for the abilities and goals of the patient are about equally beneficial.
The American Academy of Family Physicians recommends that patients choose exercise programs they will carry out consistently. They also recommend lower-impact forms of exercise, such as walking or swimming, for pregnant patients and patients unable to handle more intense forms of exercise. The American Heart Association recommends that adults aged 18-65 years participate in moderate-intensity aerobic physical activity for a minimum of 30 minutes at least five days each week. Another option is vigorous-intensity aerobic activity for a minimum of 20 minutes at least three days each week. The U.S. Centers for Disease Control and Prevention (CDC) recommends 30 minutes of moderate activity on all or most days of the week. Finally, the World Health Organization (WHO) suggests 30 minutes of moderate activity every day.
According to the U.S. Department of Health and Human Services and the U.S. Department of Agriculture, poor diet and physical inactivity may be associated with a variety of conditions, including cardiovascular disease, type 2 diabetes, hypertension, osteoporosis, and certain cancers.
Oxidation is a chemical process in which electrons from a substance are transferred to what is known as an oxidizing agent. Oxidation reactions may produce substances referred to as “free radicals.” These molecules may cause chain reactions that can damage many cells in the body. Antioxidants may stop the chain reactions caused by free radicals, and therefore stop the process of this sort of damage occurring in the body. In other cases, antioxidants may stop other kinds of oxidation reactions by becoming oxidized themselves and thus sparing cells and tissues from damage. The potential medical benefit of antioxidants may reside in their ability to prevent or slow the oxidation of molecules in the microscopic parts of the body, such as DNA or proteins.
The most common theory of aging is called the free radical theory. Many researchers believe that free radicals may cause extensive damage to the body’s tissues. Although free radicals are needed for the body to produce energy, maintain immunity, transmit nerve signals, produce hormones, and contract muscles, they may also contribute to the process of aging. Free radical damage begins at birth and continues through adulthood. However, when individuals are young, the effects are minimal because the body has many different ways to repair and replace cells to maintain proper functioning. As individuals age, the damage caused by free radicals increases.
Antioxidants are found in varying amounts in foods such as vegetables, fruits, grain cereals, legumes, and nuts. Some antioxidants such as lycopene and ascorbic acid can be destroyed by long-term storage or prolonged cooking. Other antioxidant compounds are more stable, such as the polyphenolic antioxidants in foods such as whole-wheat cereals and tea. In general, processed foods are thought to contain less antioxidants than fresh and uncooked foods since preparation processes may expose the food to oxygen. In addition to being available in a variety of fruits and vegetables, antioxidants are available as supplements. They are one of the most popular categories of supplements available today. Some of the most popularly used antioxidants are ascorbic acid (vitamin C), glutathione, lipoic acid, carotenes, a-tocopherol (vitamin E), and ubiquinone (Coenzyme Q10).
Experts have suggested that in order for antioxidants to be possibly beneficial, a person must consume them on a regular basis over a period of many years as the proposed benefits of antioxidants may occur by possibly stopping many oxidation reactions over long periods of time. Therefore, consuming a large number of antioxidant supplements over a day, week or month may not reverse the damage that has already been done by free radicals.
Food groups: An appropriate amount of fruits and vegetables should be consumed to stay within one’s energy needs. Two cups of fruit and 2 1/2 cups of vegetables per day are recommended to achieve a 2,000-calorie intake. Food portions may need to be adjusted depending on the calorie level. Vegetables should be selected from all five groups (dark green leafy vegetables, orange vegetables, legumes, starchy vegetables, and other vegetables) several times a week.
At least three-ounce-equivalents of whole-grain products should be consumed each day. Additionally, the remaining grains should come from enriched or whole-grain products. At least half the grains should come from whole grains. Three cups of fat-free or low-fat milk or equivalent milk products should be consumed daily.
Atkins diet™: Despite the common public perception that the Atkins diet™ permits an unlimited consumption of greasy foods, it is actually recommended that dieters consume primarily lean meats, such as seafood and poultry. Like many diet plans, the Atkins diet™ requires regular consumption of nutritional supplements, such as a multivitamin pill, and adherence to a regular exercise plan. The Atkins diet™ does not recommend that individuals adopt the eating plan unless they abide by the nutritional supplements and exercise routine. A qualified healthcare professional should be consulted before beginning any new diet.
Under the Atkins diet™, it is recommended that dieters stop any unnecessary medications. Any changes to medications should be discussed with a qualified healthcare professional. When combined with this diet, diuretics, and, to a lesser extent, other cardiovascular medications and diabetes medications, including insulin, may produce a dangerous overdose. Psychotropic drugs, phenothiazines and antidepressants such as Prozac©, tranquilizers, lithium, and similar drugs, may cause metabolic resistance to the diet. Estrogen, prednisone, and other steroids, and antiarthritic drugs, especially NSAIDS, may cause weight gain or prevent weight loss. For persons metabolically resistant, any medications may aggravate the condition.
During the induction period (the first two weeks), dieters are permitted to eat no more than 20 grams of carbohydrates per day with a diet consisting of nearly unlimited meats, poultry, seafood, eggs, cheeses, oils, butter, margarine, bacon, and sausages. The 20-gram carbohydrate limit is generally derived from trace amounts of carbohydrates in sauces, dressings, cheeses, and a couple cups of lettuce greens or vegetables daily. During these two weeks, participants are not allowed to have any milk, fruits, grains, cereals, breads, or “high glycemic index” vegetables such as potatoes, peas, corn, and carrots.
During the maintenance period, dieters consume no more than 90 grams of carbohydrates daily.
DASH diet: The DASH diet is based on the U.S. Department of Agriculture (USDA) food pyramid. It has been evaluated in medical trials conducted in the late 1990s and early 2000s and has been shown to reduce blood pressure. The National Heart, Lung, and Blood institute updated the diet specifications after the USDA released an updated food pyramid in 2005.
Unlike other diets designed for individuals with high blood pressure, the DASH diet does not make the levels of sodium in the diet the primary focus. However, salt reduction is an important component of the diet. According to the DASH diet, an individual should consume a maximum of 2,400 milligrams of sodium daily. Individuals are encouraged to pay attention to all of the salt in one’s diet, including table salt and salt used in cooking, as well as so-called “hidden salts” in fast foods, processed foods, and foods eaten at restaurants.
Avoiding or reducing consumption of foods such as canned soups, lunchmeats, and junk foods may significantly decrease a person’s sodium intake. As a reference, one teaspoon of salt contains 2,000 milligrams of salt.
Ornish diet: The Ornish diet is a low-fat vegetarian way of eating, with less than 10% of daily calories from fat (an average of 15 to 25 grams of fat per day), 70-75% from carbohydrates, and 15-20% from protein. This diet encourages consumption of beans, fruits, vegetables, and whole grains, and it limits intake of processed foods, high-fat dairy products, simple sugars, and alcohol.
Dr. Dean Ornish, a physician who has directed clinical research for the past 25 years, created this diet as a lifestyle modification to reverse existing heart disease by emphasizing foods that are very low in fat yet filling, such as high-fiber grains and legumes (i.e., beans and peas). In addition to the proposed heart-healthy effects of the Ornish diet, patients may also lose weight. Based on Ornish’s research, patients lost an average of 25 pounds over the course of a year.
The Ornish diet is completely vegetarian. Cholesterol and saturated fat are excluded; no animal products (except egg whites and nonfat dairy products) are allowed. All nuts, seeds, avocados, chocolate, olives, coconuts, and oils are eliminated, except for a small amount of canola oil for cooking and oil that supplies omega-3 essential fatty acids. The Ornish diet also prohibits caffeine but allows a moderate intake of alcohol and salt. There is no restriction on calorie intake. Several small meals a day rather than three large meals is also recommended.
South Beach Diet™: The South Beach Diet™ is a low-carbohydrate diet. Low carbohydrate diets aim to avoid carbohydrates that may spike insulin levels in the body. When a carbohydrate is high in what is considered by some as “bad” carbohydrates, a large burst of insulin is released from the pancreas in response to a drastic elevation in glucose in the blood.
The high insulin levels do not allow glucose to be converted into glucagon, the form of sugar that allows for fat to be used as energy. Instead, these high insulin levels promote the storage of fat in the body. Proponents believe that by avoiding these carbohydrates, individuals could avoid the storage of additional fat, as well as allow for current fat stores to be used as energy.
The South Beach Diet™ consists of three phases: 1. “kick-starting” weight loss, 2. reintroducing the “right” carbohydrates, and 3. “a diet for life.” Phase 1 is intended to be followed for 2 weeks. Phase 2 is intended to last for as long as necessary to lose the desired amount of weight. Phase 3 is focused on maintaining a healthy weight.
Aerobic activity: The American Heart Association states that all healthy adults aged 18-65 years need moderate-intensity aerobic physical activity for a minimum of 30 minutes five days each week. Vigorous-intensity aerobic activity may be substituted instead, for a minimum of 20 minutes three days each week. Additionally, exercise combinations such as walking briskly for 30 minutes twice during the week and then jogging for 20 minutes on two other days is sufficient.
Muscle-strengthening activity: It is recommended that 8-10 exercises be performed on two or more nonconsecutive days each week using the major muscle groups. Muscle-strengthening activities include a progressive weight-training program, stair climbing, and similar resistance exercises that use the major muscle groups.