Nutrients to Build Immunity As if the well-documented health risks associated with overweight, such as heart disease and diabetes, weren't bad enough, some researchers now believe that overweight people have lowered immunity, perhaps because of deficiencies of vitamins and minerals, especially the antioxidants.
Antioxidants such as vitamins C and E are important because they protect our bodies against free radicals, unstable oxygen molecules that damage your body's cells by stealing electrons from healthy molecules. Antioxidants offer their own electrons, neutralizing free radicals and protecting cells.
According to a study done in Poland, overweight people may not be reaping antioxidant benefits. Researchers at the National Institute of Food and Nutrition in Warsaw studied 102 overweight women and found that the women had significantly lower levels of the antioxidant vitamins C and E, as well as of vitamin A, and a higher prevalence of overall vitamin deficiency than those of normal weight.
These deficiencies are at least partially responsible for depressing immunity in overweight individuals, leaving them more susceptible to cancer and infectious illness, say some researchers.
And because of abnormal hormone activity, overweight people may also have greater need for antioxidants than people who are not overweight. Studies show that the excess fat in people who are very overweight drives estrogen production up and testosterone down, a deadly combination that scientists believe could be a major factor in certain female reproductive cancers.
"Overweight people probably need antioxidants more than anybody," says Dr. Robertson, who recommends daily supplements of 1,000 milligrams of vitamin C and 400 international units of vitamin E, along with 25,000 international units of vitamin A. These doses greatly exceed the Daily Values of these nutrients, and vitamin A in particular can be toxic in high doses. Research has found that taking 10,000 international units of vitamin A daily in early pregnancy can cause birth defects. For this reason, this much vitamin A should be taken only under medical supervision, especially if you are a woman of childbearing age. And pregnant women should not use this therapy.
To get more antioxidants through your diet, reach for fruits and vegetables. Those with bright orange coloring, such as sweet potatoes, carrots and cantaloupe, are rich in beta-carotene (a precursor of vitamin A); broccoli, brussels sprouts and citrus fruits will give you a burst of vitamin C; and wheat germ and kale are good sources of vitamin E.
| Food Factors When it comes to weight loss, selecting your foods can be a real balancing act. You have to lose some of what you've grown accustomed to and add some items that may be new to you. Here's what experts recommend to promote weight loss. Reduce fat. With regard to fat, the research is clear: Diets too high in fat promote overweight. You should strive to consume no more than 25 percent of your calories from fat. Don't be so sweet. Numerous studies have linked table sugar to increased calorie consumption. While sugar doesn't do as much dietary damage as fat, you'll find that when you eat sweets, you simply want to eat more . . . of everything. Not only that, but sugar also makes your body excrete chromium, and chromium is a mineral that helps your body build calorie-burning lean tissue. Drink up. "If people want to keep their nutrients in balance, they need to drink plenty of plain, unflavored water every day," says Judy Dodd, R.D., past president of the American Dietetic Association. Water not only acts as a solvent for many vitamins and minerals but also is responsible for carrying nutrients into and wastes out of cells, so the body functions properly. As a rule of thumb, you should drink a half-ounce of water for every pound of body weight daily, unless you're very active, in which case you should increase your water intake to two-thirds of an ounce per pound of body weight daily. Fill up on fiber. You can curb your hunger by increasing your intake of dietary fiber, which is filling, so you feel full but eat less. To do that, experts recommend eating more fruits, vegetables and whole-grain cereals. Get treatment for food allergies. Some researchers believe that overweight is the result of people craving foods that they are allergic to. For these people, weight loss is extremely difficult until they figure out what those trigger foods are and eliminate them from their diets. "There are specific food allergies that trigger uncontrollable craving and bingeing," says Joseph D. Beasley, M.D., director of Comprehensive Medical Care in Amityville, New York, and co-author of Food for Recovery. "It's a common problem in overeaters." If you suspect that food allergies might be part of your problem, ask your doctor to help you identify the offending items. Your doctor may recommend that you see an allergy specialist. |
| Prescriptions for Healing Some nutrition experts find that overweight people have special vitamin and mineral needs, especially if they're trying to lose weight. Here's what these experts recommend. Nutrient Daily Amount
Calcium 1,000 milligrams, 1,500 milligrams for postmenopausal women Chromium 50-200 micrograms (chromium picolinate) Copper 1.5-3 milligrams (1 milligram for every 10 milligrams of zinc) Iron 15 milligrams Magnesium 250-500 milligrams Vitamin A 25,000 international units Vitamin C 1,000 milligrams Vitamin E 400 international units Zinc 15-30 milligrams Plus a multivitamin/mineral supplement containing the Daily Values of all essential vitamins and minerals
MEDICAL ALERT: People with diabetes who take chromium should be under medical supervision, since their insulin dosage may need to be reduced as their blood sugar levels drop. If you have heart or kidney problems, you should talk to your doctor before taking magnesium supplements. Vitamin A in the amount recommended here should be taken only under medical supervision, especially if you are a woman of childbearing age. Women who are pregnant should not use this therapy. If you are taking anticoagulants, you should not take vitamin E supplements. Doses of zinc in excess of 15 milligrams daily should be taken only under medical supervision. |
Chromium Can Help
It might not be the waist-whittling miracle mineral that some advertisements tout it as, but according to the latest research, chromium picolinate (a supplemental form of chromium) may indeed help build lean tissue and reduce fat in adults who exercise.
In one study of 59 college-age students at Louisiana State University in Baton Rouge, researchers found that women taking 200 micrograms of chromium picolinate a day gained almost twice as much lean body mass as those who did not take the supplements, an effect that could result in long-term reductions in body fat, since lean body mass burns more calories than fat.
"What makes the effectiveness of chromium more and more believable is that the results we see in humans are so well-documented in animal studies," says Richard Anderson, Ph.D., lead scientist in the nutrient requirements and functions laboratory at the U.S. Department of Agriculture Beltsville Human Nutrition Research Center in Maryland and a leading chromium researcher. And although chromium will benefit only those who are deficient, Dr. Anderson reports that most people in Westernized countries receive only 25 percent of the Daily Value of 120 micrograms. So a lot of people are deficient.
Chromium also improves the effectiveness of insulin, the hormone that allows cells to pick up glucose (a simple sugar that your body uses for fuel) from the bloodstream. For this reason, chromium may also be helpful in preventing diabetes, which is common in people who are overweight. People with diabetes who take chromium should be under medical supervision, since their insulin dosage may need to be reduced as their blood sugar levels drop.
Doctors who recommend chromium picolinate supplements suggest daily doses ranging from 50 to 200 micrograms. If you'd like to increase chromium through your diet, try whole-grain cereals, black pepper, cheeses and brewer's yeast.
Think Zinc
It's well-documented that zinc, a mineral found in wheat germ, seafood and whole grains, frequently gets left by the wayside when calorie intake dips below 1,200.
Most experts do not recommend such low-calorie regimens. If you're among those who keep a too-tight daily calorie tally anyway, you should know that zinc deficiency not only depresses the immune system but also can be a barber's nightmare, causing brittle, dry hair and hair loss.
"When overweight people show any problems with their hair, nails, gums or skin, I recommend supplementing 20 milligrams of zinc a day," says Dr. Robertson.
Experts usually recommend between 15 and 30 milligrams of zinc daily. Since zinc competes with other metals in the body, however, daily doses of more than the Daily Value of 15 milligrams warrant medical supervision. For the best results, you should take 1 milligram of copper for every 10 milligrams of zinc.
Minerals Make a Difference
Magnesium and iron are the major minerals that doctors find deficient in people who are overweight, particularly in those who are trying to slim down.
Magnesium is essential for every major biological function, including your heartbeat. According to research, even marginal magnesium deficiency is not to be taken lightly, especially when you are dieting and losing weight, as it can lead to potentially fatal heart abnormalities.
"In general, magnesium supplementation helps for a lot of things," says Dr. Steelman. "I use it to treat the muscle cramps that people get when they're trying to lose weight, and it also seems to curb sweet cravings."
Doctors who recommend magnesium supplements call for between 250 and 500 milligrams daily, which is right around the Daily Value of 400 milligrams. (If you have heart or kidney problems, you should check with your doctor before taking magnesium supplements.) Good dietary sources of magnesium include seafood, green vegetables and low-fat dairy products.
Iron is another frequent victim of low-calorie dieting, says Dr. Steelman. "In fact, it's the most common nutrient deficiency I see, especially in premenopausal women."
The most common complication arising from a lack of iron is iron-deficiency anemia, which can cause headaches, shortness of breath, weakness, heart palpitations and fatigue.
Doctors who recommend supplementing iron suggest 15 milligrams a day, particularly for adults who are following a low-calorie diet to lose weight. To pump some iron into your diet, try steamed clams, Cream of Wheat cereal, tofu and soybeans.
Calcium is another mineral that's often in short supply in those who are trying to shed extra pounds. Experts suggest making sure that you're getting the Daily Value of calcium, which is 1,000 milligrams; women who are past menopause should aim for 1,500 milligrams daily.
