I've heard that getting a lot of potassium can help protect against high blood pressure. Is that true?ANSWER - Evidence from several studies suggests that it may. Here's the scientific scoop: In some investigations, potassium supplements have lowered blood pressure in individuals with both normal and elevated levels. In comparing populations with markedly different average blood-pressure levels, links have been noted, with differences in both potassium intake and excretion.

Other studies revealed that over a 24-hour period, blood pressure rose as potassium intake fell. In laboratory studies, potassium supplements counteracted the effects of a high sodium intake on blood pressure and prolonged the life span of rats. But data from all investigations haven't provided a completely clear picture.

Several years ago, a large study which followed more than 850 men and women between the ages of 50 and 79 found that strokes were five times more common in women whose potassium intake at the beginning of the study was in the lowest third of the population. The difference in actual food intake, though, was quite small - only about a single serving. The men in the study derived no such benefit, a curious finding that remains unexplained.

Clearly, the potassium-blood pressure connection requires further study. Meanwhile, we urge you to get a steady supply of potassium into your diet by eating plenty of fruits and vegetables. Besides tasting good and generally being low in calories, they are virtually fat-free (except for avocados) and provide generous amounts of vitamins, minerals and fiber.

The same cannot be said of potassium supplements. So unless your doctor tells you otherwise, get your potassium from fruits and vegetables, not from pills, powders and capsules.

QUESTION - What is "freezer burn"?

ANSWER - Freezer burn is damage to the tissues of food you have stored. It can occur due to using an improper wrapping, failing to package food correctly or from holes sustained as the wrapped food sits in the freezer. Contact with the surrounding air at very low temperatures causes food to dry out and turn a whitish color. Eating food that has been damaged in this way isn't harmful, but neither is it terribly appetizing.

Here's how to prevent freezer burn. Choose wrapping specifically designed for the purpose. Make sure to wrap food well, excluding as much air as possible. Once foods have been stored, treat them gently to avoid puncturing the package.

And speaking of damage to frozen food, has your freezer become something of a museum? In many households, freezers are used to hold large food reserves well beyond the time of peak flavor. The way around this problem is obvious, and well worth the extra effort, yet few of us do it.

Begin by cooking from the freezer and emptying it out. As you restock, get into the habit of dating each package. Then store new additions behind older ones and keep an up-to-date inventory of what's put in and what's removed.

QUESTION - Why is guar gum added to foods? Is it harmful?

ANSWER - Guar gum is used as an additive because of its ability to gel and thicken. It's used to prevent "weeping" - leakage of moisture - in cheese; to give body and texture and to help resist heat shock in ice cream; and to improve the shelf life of baked goods. It also helps increase viscosity and improve consistency in salad dressing and sauces.

There's no reason to fear guar gum. It isn't harmful. It's one of the water-soluble fibers shown to contribute to lowering blood cholesterol. However, the amount needed to obtain that effect is far greater than what you get by eating foods in which it's used as an additive.

The gum comes from the starchy portion of a leguminous bean which originated in India and Pakistan.

1991, Washington Post Writers Group