I remember reading that garlic oil had caused botulism food poisoning. I saw garlic oil recently in the grocery store where I shop. Is it safe to eat?ANSWER - Yes. It's safe. Following two outbreaks of botulism food poisoning traced to garlic packed in oil, the Food and Drug Administration stepped in. The agency now requires that garlic-in-oil mixtures that aren't heat processed and rely for safety on refrigeration must contain other protection: specified levels of either substances that inhibit microbial growth or acidifying agents such as citric or phosphoric acid.

In hindsight, it's easy to see why the food-poisoning cases occurred. To make the mixture, minced garlic is combined with ice water and oil. Unfortunately, the combination of a non-acid mixture, water, lack of oxygen in the jar and a warm temperature created just the right environment for botulinum spores, com-monly found on many tubers and root vegetables, to germinate. The microorganisms then grew, producing the very dangerous toxin.

In both cases, the problem was traced to improper handling. In other words, consumers forgot to keep the product in the refrigerator, despite clear directions on the label. Leaving the mixture out on the counter instead of in the cold proved a critical error. Thanks to the new FDA regulation, the problem is resolved. But this episode underscores the need for consumers to follow directions on the label.

QUESTION - I bought a prickly pear for the first time and really enjoyed it. Can you tell me its nutritional value?

ANSWER - Prickly pear is the fruit of the cactus of the same name. A typical fruit contains about 50 calories and more than one-third of the day's quota for vitamin C. It also provides small amounts of B vitamins and minerals. Whether or not you eat the seeds is a matter of taste. Some like them; others find them too hard.

Until recently, preparing prickly pears was like tangling with a porcupine: The pears often came with spines still attached. One technique used was to singe them before attempting to peel the fruit. Nowadays, though, the spines generally are removed before the fruit appears in the supermarket.

Prickly pears are native to the Americas and were brought back to Spain in the 16th century. They are known by several names, including Indian or Barbary pears, and tuna figs.

QUESTION - My husband is a heart-attack survivor. He has given up smoking, is attempting to follow a cholesterol-lowering diet, and is taking medication to bring down his cholesterol. Despite a doctor's advice to the contrary, he is skeptical about whether this is of any value or whether, as he says, it's "too late" for him. What do you say?

ANSWER - We can assure your husband that his efforts are worthwhile. It's true that the extent of damage to the heart and the severity of coronary-artery disease are moreimportant predictors of risk of a second heart attack, especially in the first few months, than is serum cholesterol. But evidence from a number of studies of individuals who have already sustained one heart attack shows that, over the longer term, reducing serum cholesterol is linked to lowered incidence of both nonfatal and fatal heart attacks.

Dr. Jacques E. Rossouw of the National Heart, Lung and Blood Institute and his colleagues reported in the New England Journal of Medicine that when data from eight such studies were considered together, a 10 percent reduction in serum-cholesterol levels led to a reduction of 19 percent and 12 percent respectively in the number of non-fatal and fatal heart attacks.

These figures aren't much different from those in studies that focus on individuals who are at risk of heart attacks but haven't yet sustained one. In that group, the same cholesterol reduction led to a drop of 25 percent in non-fatal and 12 percent in fatal heart attacks.

As Rossouw points out, these studies have been conducted over relatively short periods. Longer trials and more effective lowering of cholesterol could produce even more positive results. So tell your husband to keep up the good work: He's on the right track with his cholesterol-lowering efforts, and he needn't be discouraged.

We would only hope that his healthier lifestyle also includes regular physical exercise.

1990, Washington Post Writers Group