Vitamin C, vitamin E and beta carotene have been touted for years by experts as the three most important supplements. They're all antioxidants, which help quench or neutralize free-radical chemicals that cause cell damage and lead to numerous chronic diseases like cancer. This past winter, two announcements in the news quenched some of the praise for beta carotene supplements: 1) the University of Washington reported it halted a study because high doses of beta carotene increased cancer risks for smokers; and 2) early results of a Harvard study of 22,000 doctors found no lower risk of cancer or heart disease in those taking beta carotene supplements.

NEW BOTTOM LINE ON BETA CAROTENE IN FOOD

Keep eating beta carotene-rich foods. Nobody disputes that the beta carotene in food is healthful and safe.

Research from many sources shows that eating lots of fruits and vegetables rich in beta carotene and other antioxidants (five or more servings a day) can help cut the risk of cancer in half, especially lung, esophageal and uterine/cervical cancers. People with high blood levels of beta carotene have lower odds of cancer and heart disease and better immune systems. One reason: beta carotene's antioxidant powers.

Beta carotene-rich foods also possess dozens of other nutrients and antioxidants that contribute to the health benefits.

A few specifics: Men who ate 6mg of beta carotene daily (about one carrot) over 25 years had a 28 percent lower risk of death from all causes compared with men eating the least beta carotene, reported University of Texas researchers in 1995. A Harvard study of 87,000 female nurses found that those eating the most beta carotene (equal to 11/2 carrots a day) had a 22 percent lower risk of heart disease than women eating the least.

Only known downside: Consuming too much beta carotene (for example, glass after glass of carrot juice) can turn your skin - mainly on your soles and palms - yellow. The discoloration is benign and disappears when you cut back.

NEW BOTTOM LINE ON SUPPLEMENTS

Smokers, beware: Smokers should not take megadoses of beta carotene, pending clarification of new findings, experts say. In the University of Washington study halted in February, smokers taking 30mgs of synthetic beta carotene plus 25,000 IU of retinol vitamin A daily had a 42 percent higher risk of lung cancer after six years. A 1994 Finnish study found more lung cancer in smokers who were also heavy drinkers and who took 20mg of beta carotene a day. The Council for Responsible Nutrition advises smokers to take only the amount of beta carotene (3-6mgs) in daily multivitamin supplements.

Researchers suspect extra-high doses of beta carotene might somehow encourage growth of an early- to late-stage cancer already existing in smokers. And beta carotene may interact with alcohol to increase damage in smokers who also are heavy drinkers.

Main message: Longtime smokers who continue to smoke cannot expect beta carotene to save them from lung cancer. Best bet to prevent lung cancer: Stop smoking.

Ex-smokers, rejoice: If you have quit smoking, taking beta carotene supplements could be a good idea. The University of Washington study found that former smokers had a 20 percent lower risk of developing lung cancer. Several ongoing studies of smokers who stop or cut back substantially and also take beta carotene supplements (30mg daily) show a "dramatic" reduction in risk of oral cancer, says researcher Harinder Garewal, University of Arizona. The beta carotene reverses growth of pre-cancers of the mouth in up to 70 percent of patients, he says.

Everyone else, keep an open mind: The Harvard study of physicians found no evidence that taking beta carotene supplements (50mg every other day) reduced the odds of heart disease or cancer after 12 years. The study also revealed no dangers. Study chief Charles Hennekens did not advise people now taking beta carotene supplements to stop.

Jeffrey Blumberg, antioxidant expert at Tufts University, still favors beta carotene supplements (he takes 15mg daily). He argues the studies headlined this winter were faulty, and that much research suggests benefits.

For instance, taking beta carotene supplements (15-60mg daily) has boosted immune functioning, especially in older people, Tufts researchers say. And taking 16mg of beta carotene daily for a year, along with modest doses of 17 other vitamins and minerals, boosted immune functioning and reduced infectious illnesses by half in healthy elderly people in a 1992 landmark study by Ranjit Kumar Chandra of Memorial University of Newfoundland.

Blumberg's advice: If you take beta carotene, also eat a high antioxidant diet and take vitamins E and C; they all work together. "Beta carotene alone," he says, "is not a magic bullet and never was."

Jean Carper's current best-selling book is Stop Aging Now! Comments? Write: Eat Smart, 1000 Wilson Blvd., Arlington, Va. 22229-0012 CLICK HERE TO E-MAIL EAT SMART Please include your age and daytime phone number. Because of the volume of mail, not all will be answered.

2 BETA CAROTENE-RICH RECIPES

Microwave Pumpkin Pudding

1 15-ounce can pumpkin

1 cup skim milk

3/4 cup each of egg substitute and cornmeal

1/2 cup molasses

1/4 cup brown sugar

2 Tbs. white sugar

1/4 cup each of raisins and almonds

1 tsp. cinnamon

1/2 tsp. ginger

1/4 tsp. cloves

Combine all ingredients in a large glass bowl. Microwave on high 5 minutes; stir. Microwave 5 minutes; stir. Microwave 10 minutes till pudding is set (an inserted knife comes out clean). Serve warm alone or with non-fat ice cream. Serves 8.

Per serving: 201 calories, 6.2g protein, 40g carbohydrates, 3g fiber, 3g fat (0.5g saturated, 1.4g monounsaturated, 0.9 polyunsaturated), 78mg sodium, 7.6 mg carotene.

Garlicky Spinach

10 ounces (about 8 cups) fresh spinach, washed, dried and torn in large pieces

2 garlic cloves, crushed or minced

1 Tb. olive oil

Salt and freshly ground pepper, to taste

1 tsp. fresh lime or lemon juice

In a large skillet, saute garlic in olive oil until soft. Add spinach and cook over medium heat until wilted. Add seasonings. Stir and serve. Serves 4.

Per serving: 48 calories, 2g protein, 3g carbohydrates, 2g fiber, 3.6g fat (0.5g saturated, 2.5g monounsaturated, 0.4 polyunsaturated), 56mg sodium, 2.9mg carotene.