Antioxidants - Are they for You?

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Unless you've been holed up underground for the last couple of years, you've probably been hearing about antioxidants -- in the newspapers, on TV talk shows, and in bookstores. But I get asked so many question about antioxidants that it's clear there's a lot of confusion in spite of all the headlines. Here are a few of the questions registered dietitians hear every day:

"What are antioxidants?"
"What do they do?"
"How important are they?"
"Do I need supplements?"
"Is it dangerous to get too many antioxidants?"
"Does my age matter?"

So let's take a closer look at these amazing helpers. We'll start with the metabolic villains that scientists call "free radicals." These are unstable molecules that our bodies form in the normal processes of breathing and digesting food. If they're not stopped, free radicals can damage important parts of our cells -- for instance, our DNA. The damage caused can lead to weakened immune systems, cancer, and heart disease.

But nature has provided antioxidants -- "good guys" -- whose mission is to wipe out free radicals. Different areas of the body use different kinds of antioxidants. The body manufactures some of these antioxidants itself. Others must come to us by way of the food we eat.

And there are many kinds of antioxidants in food. Some are vitamins -- A, C and E. Some are carotenoids, like beta-carotene, which works as an antioxidant by itself, or can split up to form two molecules of vitamin A. Selenium is an antioxidant mineral that helps vitamin E do its work. And then there are phytochemicals -- compounds found in vegetables and fruits. Antioxidant phytochemicals include the many types of flavenoids. Flavenoids are found in apples, onions and garlic, many other vegetables and fruits, plus tea and red wine.

The importance of antioxidants can't be overstated. Although they're not "magic bullets," they do slow down the aging process and protect against many diseases. In one study, for instance, men whose diet was high in flavenoids had two-thirds less heart disease than those whose flavenoid intake was lowest. These men were found to drink tea instead of coffee, and tea is very high in flavenoids.

Vitamin E has been shown to block buildup of plaque in arteries by defeating the oxidation of LDL (the "bad" type of cholesterol). It also seems to help slow the progression of plaque that's already formed. It's being studied for possible protective effects against arthritis. Good sources of E are whole grains, wheat germ, leafy green vegetables, nuts, and seeds.

Glutathione is an antioxidant that the body produces, and it's linked to blood pressure, the immune system, and cholesterol levels. Researchers think that getting enough cruciferous vegetables like Brussels sprouts, kale, cabbage, and broccoli, may raise glutathione levels in the body.

Vitamin C works hard in many ways, but it also scavenges free radicals. It appears to cut risk of cancer, and help raise HDL (our "good" cholesterol). Excellent foods to choose are bell peppers, tomatoes, broccoli, strawberries, kiwi fruits, and citrus fruits.

We hear a lot about beta-carotene, but less often about the family of carotenoids, of which beta-carotene is only one. There are hundreds of carotenoids, and it seems likely that some may be as important as, if not more important than, beta-carotene. In fact, new research shows it's quite likely that health benefits are due to many carotenoids working together to produce antioxidant protection. Lycopene, for instance, is a powerful carotenoid that may protect against heart disease. Tomatoes are rich in lycopene, but have little beta-carotene. Other carotenoids found in green leafy vegetables are being studied for protective effects against eye disease.

What about selenium? It's been seen that people living in areas where the soil is rich in selenium have less cancer. That's not proof that selenium protects against cancer, but it's got researchers working hard to find out. Selenium is found in grains, so if the soil is poor, selenium may be absent. But it's also found in seafood, liver and kidneys, eggs and tuna, so there are other food choices available.

Should we take supplements of antioxidants? Well, there's a lot of scientific arguing about supplement use, and for good reason. Many of the studies that have shown antioxidant benefits used supplements to achieve their effect. Also, medicine has extended our life expectancy, but not necessarily our health -- some researchers believe that we can't get enough antioxidants in our diet to stay healthy to an extended age. Also, as we age, our bodies don't absorb nutrients from food as well; supplements could provide a boost.

On the other hand, nutrients in food are balanced, and those in pills are not. It's entirely possible to load up on beta-carotene and ignore other carotenoids, such as lycopene, that beta-carotene needs to produce its protective effects.

It can even be dangerous to your health. As little as 25,000 IUs of vitamin A daily can damage the liver. There is some evidence that excess vitamin E can lead to stroke, and that large doses of vitamin C can cause gallstones.

The best advice to date is to get DAILY at least:

three servings of vegetables
two servings of fruits
six to eleven servings of whole-grain breads and cereals

Some of the vegetables should be dark-green, yellow or orange, such as spinach, broccoli, pumpkin, squash, sweet potatoes, and tomatoes. And we should all try to get some different fruits and vegetables every day, because they each contain a different set of protective nutrients.

What's a serving? One-half cup of cooked vegetables, or 1/2 cup chopped raw vegetables; six ounces vegetable juice; or one cup raw leafy greens. A serving of fruit would be one medium apple, banana, or orange; 1/2 cup fresh berries; about 15 grapes; 1/2 cup applesauce; 1/4 cup dried fruit; or 6 ounces fruit juice. One serving of breads or cereals would be: a slice of bread; one to one-and-one-half ounces of dry cereal; 1/2 cup cooked cereal, rice, or pasta; 4 small crackers or 2 large crackers; 1/2 bagel, hamburger bun, or English muffin.

Some people have food allergies, medical conditions, or lifestyles that make it difficult to eat a balanced diet. They might benefit from antioxidant supplements. If you think antioxidant supplements might help, first talk to a registered dietitian. This will help you find out whether your diet is balanced, and if it's possible for you to make changes. Your best bet is to get enough nutrient-rich foods.

Your physician can tell you if supplements are likely to be harmful to you. If not, experts generally agree that it's safe to take daily up to 1000 RE (retinol equivalents, the RDA unit of measurement) of vitamin A; 100-500 mg vitamin C; 50-200 IU (international units) of vitamin E as alpha-tocopherol equivalents; and up to 70 mcg selenium. It has generally been acknowledged that 5-15 mg beta carotene per day is safe. However, you may wish to ask your physician to confirm this, in light of recent studies performed on smokers. These studies appear to show a higher death rate among smokers who took 30 mg of beta-carotene daily.

As always, since each of us has a different physiological makeup, it's best to get expert advice before taking supplements of any kind. An important nutrient for one person, may be quite unnecessary for another. A safe level of a nutrient or supplement may be quite different for different people.

Here's to your good health!

About Kathrynne Holden:

Kathrynne Holden is a registered dietitian with a Master's degree in nutrition. She has worked as a hospital dietitian, enjoys writing and public speaking and currently has a private practice in nutrition counseling. She is also editor of the monthly newsletter Spotlight on Food -- nutrition news for people 60-plus. To receive a complimentary sample copy of Spotlight on Food, contact: Kathrynne Holden, MS, RD, Five Star Living, Inc., 604 East Pitkin, Fort Collins, Colorado 80524 USA, Telephone: (970) 493-6532; FAX: (970) 493-6538. e-mail: Fivs...@aol.com

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