Could you eat something that carried a warning label saying "This product may cause digestive upsets, loose stools and blindness"?How about a product that said, "This food may inhibit the absorption of vitamins and other nutrients"?Millions of Americans will, soon. They'll be persuaded, by the pots of dollars that Procter & Gamble will spend, to buy a slew of new products made with P&G's artificial fat, Olean.Olean is P&G's brand name for the synthetic fat olestra. Frito-Lay has licensed the use of olestra and will bring its "Wow" brand of low-fat Lay's and Ruffles potato chips and Doritos corn chips to market this month. Fat-free Pringles are due later this year. Nabisco may jump into the fray soon, too, selling fat-free Wheat Thins and Ritz crackers.For a Nation of NibblersWhat's the big deal here? All these low- and non-fat snack foods made with olestra seem like the perfect solution to a nation of people who love to nibble, but hate the body that comes from the habit. Everybody's watching fat grams, it seems, on the advice of the USDA and other dietary authorities, who urge us to keep our diets at 30 percent fat or even less.Made by combining sugar with the fatty acids from vegetable oils, olestra does seem like a dieter's magic bullet. It provides the taste and "mouth-feel" of fat in snacks and baked goods, but its molecules are too big for our bodies to digest. So the stuff passes through our digestive tract without being used by the body.Well, says the Center for Science in the Public Interest, in its Nutrition Action newsletter for March, the big deal is that olestra may not be safe.Because it isn't digested, olestra shoots through the digestive tract in a hurry. In some people, it causes severe cramping and bowel problems -- some serious enough to require hospitalization. It also seems to flush out of your body the very beneficial substances that may protect you against cancer, heart disease and blindness. These substances, including vitamins A, D, E and K and the carotenoids, have been identified by scientists as healing and protective presences. They help keep you healthy, in short."There are dozens of studies indicating that carotenoids protect against cancer, heart disease and macular degeneration, the most common form of blindness that strikes the elderly," says Walter Willett, head of the nutrition department at the Harvard School of Public Health, in CSPI's recent Nutrition Action newsletter.Yet, says CSPI, "olestra and carotenoids don't mix."The report cites these studies:Two P&G studies showed that 39 people who ate eight grams a day of olestra (the amount contained in 16 chips) with meals for eight weeks had a 50 percent drop in their total blood carotenoids.A 1995 study by a Dutch firm considering its own form of olestra showed that 53 men and women who ate three grams of olestra (the amount found in six chips a day) as margarine had 40 percent less lycopene, a carotenoid that seems to lower the risk of prostate cancer, than normal.A Little Beltway MagicIf all that is true, one might ask, why on earth did the U.S. Food & Drug Administration approve the use of this stuff?Well, it's Beltway Magic again.Seems that nine of the 17 votes to approve olestra for public consumption on the FDA's advisory panel came from P&G-friendly food industry consultants. The advisory panel did not include an expert on carotenoids, nor were any experts on that subject invited to speak on olestra's effect on carotenoids.Moreover, says Henry Blackburn of the University of Minnesota's School of Public Health in CSPI's olestra report, "the FDA staff members had already concluded that olestra was safe and were acting as proponents." Blackburn was one of the five members of the advisory panel to vote against olestra's approval.Look, folks, it's up to you. You can buy and eat this stuff if you want to.I just can't imagine why you would want to. Is vanity everything? If it is, go ahead and dig in. And if olestra-based snack foods contribute to your macular degeneration, you'll have one consolation.You won't be able to see just how fat you've become. Robin Mather is the News Reporter's food columnist.