Understanding tuna labels - and why it matters

Q. What's the difference between albacore, white and light tuna?

A. "White" tuna is albacore tuna. It has a milder flavor and whiter flesh than the product labeled "light," which can come from skipjack or yellowfin tuna. Both are good sources of protein and are low in saturated fat, characteristics shared by all seafood.

Each type of tuna offers slightly different benefits to different people. Albacore or white tuna is higher in omega-3 fat, which seems to help protect against heart disease by reducing inflammation and supporting healthy heart rhythms. While some research suggests that omega-3's anti-inflammatory effects could offer anti-cancer benefits as well, more research is needed.

Light tuna provides some omega-3 fat, but white tuna provides about three times as much. But light tuna has its advantages, too: It tends to have less mercury contamination. Mercury consumption can harm young children - even unborn infants.

Current advisories emphasize that albacore tuna is quite safe to eat in moderation, but all women of childbearing age should keep it to no more than six ounces a week (children younger than 6 should limit consumption to perhaps half that amount). Men and older women stand to benefit most from omega-3's heart benefits, so for them, slightly more albacore tuna may be a reasonable choice.

Q. Are broccoli stalks nutritious, or should I just stick to the florets?

A. Broccoli is a nutritional powerhouse, providing vitamin C, folate, beta-carotene and lutein (a compound being studied for its role in eye health). In addition, it is rich in isothiocyanates, phytochemicals that may play a role in fighting cancer.

While researchers cannot pinpoint which areas of the plant supply which phytochemicals, the location of some compounds is known. The florets and leaves, for example, are higher in carotenoids than the pale stalks, although the stalks remain good sources of vitamin C and folate. Broccoli stalks are also great sources of fiber.

Regardless, be confident that the whole broccoli stalk is providing solid nutrition. When the stalks are peeled and sliced thinly on the diagonal, they make a great, less expensive alternative to bamboo shoots in a stir-fry. Their crunchy texture also makes them a welcome substitute in many recipes that call for celery.

Q. What should I look for when purchasing papaya?

A. Great choice! Papayas, which are extremely high in vitamin C, also provide lots of beta-carotene, beta-cryptoxanthin (another carotenoid), folate, magnesium and potassium. These sweet fruits can differ widely in size, shape, and color - the flesh inside may be yellow, pinkish-orange or red.

Because of these color differences, it's difficult to judge ripeness by color. Instead, look for a papaya that gives slightly to palm pressure without being too soft. If needed, ripen the fruit at room temperature. Store ripe papaya in the refrigerator for up to a week.

The cluster of small black seeds in the center cavity is edible, though most people discard them. Serve chunks of papaya in a fruit plate, a green salad, or as a topping for chicken or fish. It's also great chopped with some cilantro and sweet red pepper for a flavorful fruit salsa.

Karen Collins, registered dietitian, writes this column for the American Institute for Cancer Research. To submit a question, please write to Ask the Nutritionist, c/o the Daily Herald, 1759 R St., N. W., Washington, D.C. 20009. Questions will not be responded to personally.