A visit to the health food store
can be an overwhelming experience. It's tough to figure out what to choose from
among the dizzying assortment of dietary and nutritional supplements on the
shelf. From vitamins to minerals to weight loss pills, there are thousands of
options to choose from. But do you really need any of them? Do they really
work, and if so, which ones are best?
The Dietary Supplement Health and
Education Act, approved by Congress in 1994, defines dietary supplements as
products that: are intended to supplement the diet; contain one or more
ingredients (like vitamins, herbs, amino acids or their constituents); are
intended to be taken by mouth; and, are labeled as dietary supplements.
It's important to remember that
dietary supplements are designed to supplement your diet, not to replace
nutritious foods. Still, the ADA recognizes that some people may require
supplements because the vitamins and/or minerals they need are hard to get in
adequate amounts in the diet. These groups include: pregnant women, nursing
mothers, strict vegetarians, people with food allergies or intolerance and
senior citizens.
Whether
they really need them or not, sales figures show that plenty of people are
purchasing supplements. Here are some of the most popular supplement categories:
·
Multivitamins
Taking a daily multivitamin with minerals has long been considered
nutritional "insurance" to cover dietary shortfalls.
There is no harm in taking a once-daily multivitamin, as long as you select
one based on your age and sex. Take one daily or just on days when your diet is
inadequate. But better than a multivitamin is to fill in the gaps with food
that offers so much more than supplements.
· Meal Replacements
Powdered and liquid products like Slim Fast and Ensure might not be what
most of us think of as dietary supplements. But they're included in the list
because they are designed to supplement the diet.
For people who can't eat regular food because of illnesses, these
products are good alternatives. Still, eating a wide variety of nutrient-rich
foods is better, if tolerated.
And what about weight management? Using a meal replacement can help
control calories and be beneficial, experts say -- as long as it's part of a
lifestyle that includes exercise and a calorie-controlled diet.
· Sports Nutrition Supplements
This is a broad category that includes both sports performance and weight
loss supplements. It includes pills, powders, formulas and drinks formulated
not just to hydrate but to enhance physical activity. Among them are creatine,
amino acids, protein formulas, and fat burners.
“These products provide a subtle, incremental effect. You can't use a
sports supplement for a week and expect to gain pounds of muscle, but if used
properly, research shows they can provide a slight, not overwhelming,
edge," says Andrew Shoa, PhD, vice president for regulatory affairs for
the Council for Responsible Nutrition, a trade association for the dietary
supplement industry.
· Calcium
Calcium is one of the minerals most often lacking in Americans' diets.
But experts say that whenever you can, you should choose calcium from foods
such as dairy products, fortified foods, dark leafy greens, soybeans, beans,
fish, and raisins.
The U.S. Dietary Guidelines recommends three servings of low-fat or
non-fat dairy each day to help bridge this gap. But there are plenty of people
who shun dairy, the best source of calcium in our diets.
If you do choose a calcium supplement, look for calcium citrate or
lactate. These forms are best absorbed by the body, says Grotto.
·
B
vitamins
B vitamins include thiamin, niacin, riboflavin, pantothenic acid, vitamin
B-6, and vitamin B-12. Many of us don't need these supplements, experts say. In
fact, romance surrounds the B vitamins because people misuse them to reduce
stress and think a supplement will make them a nice person in traffic. But
there is not much research to support this theory. And besides, our diets are
plentiful in B vitamins.
One exception is seniors, who may need additional B-12 because as we get
older, we absorb less of it. Most of us should skip the supplements and get our
Bs from grains, dark green vegetables, orange juice, and enriched foods. People
with certain medical conditions or who take drugs that interfere with vitamin
absorption may also require supplementation.
·
Vitamin C
Vitamin C is often taken in an effort to ward off colds, though there's
little proof this works.
There is scant evidence it may decrease the intensity or duration of
colds, but it won't do any harm up to about 1,000 milligrams a day. Because it
is a water-soluble vitamin, excess amounts are excreted.
Your health-care provider may tell you to take vitamin C if you have a
wound that's healing. But wound otherwise, go for food sources. Rich sources include oranges, peppers,
grapefruits, peaches, papayas, pineapples, broccoli, strawberries, tomatoes,
and melons.
· Glucosamine and Chondroitin
These supplements are often taken by people with joint pain.
In a study published in the New
England Journal of Medicine, these supplements, taken alone or in
combination, were not found to provide significant relief from osteoarthritis
knee pain among all participants. However, results in a subgroup of study
participants with moderate to severe pain showed the combination may be
effective.
While the evidence is not conclusive, some rheumatologists say many of
their patients find relief from the combination.
About 40% of my osteoarthritis patients benefit from taking 1,500 mg of
glucosamine and 1,200 mg chondroitin sulphate a day (for) four to eight
weeks," says Kaiser Permanente rheumatologist Eduardo Baetti. But
"most patients are also taking pain relievers, such as Tylenol."
· Homeopathic Medicines
These are not technically dietary supplements, but are nonetheless a
popular category. Homeopathy, or homeopathic medicine, is a medical philosophy
dating back to the late 1700s. It's based on the idea that our bodies have a
self-healing response. So, the theory goes, if certain a substance causes a
symptom in a healthy person, giving that person a very small amount of the same
substance may cure the symptoms.
The National Institute of Health's National Center for Complementary and
Alternative Medicine web site notes that studies on homeopathy have been contradictory.
Some have suggested the results are similar to a placebo effect, while others
have found positive effects that are not readily explained in scientific terms.
· Vitamins D
Chances are, you are not getting enough vitamin D for good health. "The
current recommendations are not adequate to protect against chronic diseases or
prevent osteoporosis," vitamin D expert Michael Holick, MD, tells WebMD.
"All evidence suggests that infants and adults can tolerate 1,000 IUs a
day as safe, without risk of toxicity.
Holick suggests taking a daily vitamin D supplement or getting safe sun
exposure to maintain proper blood levels of vitamin D.
And be sure to eat a variety of foods rich in vitamin D such as fortified
milk and cereals, salmon, and tuna. Check with your dermatologist about
guidelines for safe sun exposure.
· Fish/animal Oil
Ninety-five percent of the sales in this category come from fish and not
animal oils. Unless a doctor is treating you for heart disease or high
triglyceride levels, you should not take fish oil supplements, says Alice
Lichtenstein, DSc, Tufts University researcher and chairwoman of the American
Heart Association (AHA) nutrition committee.
Studies show that omega-3 fatty acids are cardio-protective and the basis
for the AHA recommendation to consume fatty fish twice weekly. But the studies
do not show that popping a supplement can have the same benefit in healthy
individuals. There is also a misperception that fish oils can lower
cholesterol, but this is not true.
If you don't like fatty fish such as salmon, Lichtenstein recommends
eating other kinds of fish such as canned tuna. (Just be sure to avoid any fish
that is breaded and fried.)
Foods
such as canola oil, soybeans, flax, walnuts and algae are all sources of
omega-3s, but they are not a substitute for fatty fish.
Tips for Choosing
Dietary Supplements
Experts agree there are some rules
of thumb for choosing dietary and nutritional supplements. First, look for
trusted brands that have been around for some time.
Another tip: read the
claims carefully. If they look too good to be true, they probably are. Products
promising to pack on 20 pounds of muscle in a week are not going to deliver
because nothing can yield those kinds of results.
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