Jewish World Review May 21, 2003 / 19 Iyar, 5763

EATING SMART: The bitter truth about grapefruit

By Sheldon Margen and Dale A. Ogar | The modern grapefruit was developed, probably in Barbados, sometime during the 18th century. It appears to have been a hybrid of some sort, perhaps between a sweet orange -- the Spanish explorer Columbus is said to have taken them with him on his second voyage to the New World -- and a pomelo. By the 19th century, the seeds made their way to Florida, where they became an important crop.

Ancient grapefruit was quite different from what we eat today. It was undoubtedly very bitter and difficult to eat. Hybridization has turned it into delicious fruit, some varieties of which are even seedless.

In recent years, we've seen a lot of promotional hype about grapefruit diets. Unfortunately, this is wishful thinking; grapefruit has no secret enzymes to burn fat -- nor does any other food.

One story about grapefruit, however, is worth paying attention to. This concerns its interaction with certain prescription medications. The substance in grapefruit that gives it such a sour taste (most other citrus fruits do not contain it) affects the way certain drugs are metabolized.

This means that drinking grapefruit juice or eating grapefruit while taking these drugs can raise or lower the concentration of the drug in your bloodstream -- not a good thing. In some cases, it can increase the risk of side effects and serious reactions; or it may mean that you don't get enough of a drug that you need. In the case of statin drugs for lowering cholesterol, a recent study has shown that grapefruit juice can boost the levels of the drug in the blood by up to 12 times, which could be dangerous.

The following drugs most affected by this interaction with grapefruit include:

-- Calcium channel blockers (for high blood pressure and angina), such as felodipine (Plendil) nifedipine (Procardia, Adalat), amlodipine (Norvsac), diltiazem (Cardizem, Dilacor) and verapamil (Calan, Verelan).

-- Lovastatin, simvastatin or other statin drugs for lowering cholesterol.

-- Tranquilizers, such as benzodiazepines (Halcion).

-- Antihistamines, such as Seldane and Hismanal

-- AIDS drugs (the protease inhibitor Crixivan)

-- Toenail fungus drug (Sporanox)

It is hard to make any general recommendations about this since the problem doesn't occur in everybody and not with all varieties of grapefruit juice (for some unknown reason). It is most likely to happen if the medication is always or often taken with juice. If you drink a lot of grapefruit juice and take any of these medications, check with your physician or pharmacist.

For the rest of us, grapefruit is quite a nutritional bargain. It is high in vitamin C -- in fact, half a medium grapefruit will give you almost 70 percent of your daily requirements. An 8-ounce glass of freshly squeezed grapefruit juice will give you more than 150 percent of the RDA for vitamin C. Even canned juice and juice made from concentrate will provide 112 percent and 139 percent, respectively, of the RDA per serving.

Grapefruit also contains a lot of potassium, and the pink and red varieties have some beta carotene. All of this for about 40 calories per half a grapefruit.

You can probably buy grapefruit all year long. Worldwide, most grapefruit comes from Florida, but some of the newer red varieties are also grown in Texas, Arizona and California, as well as a few other places where the weather is consistently warm.

When you buy grapefruit, you should look for those that seem heavy for their size and are round, smooth and glossy, with slightly flattened ends. This is a good guarantee that they will be juicy. Skin discolorations do not usually affect the quality of the fruit inside.

Grapefruit will keep for six to eight weeks in the crisper of your refrigerator, but you can actually leave them out at room temperature for about a week with no problem. In fact, you should serve them at room temperature because they will be juicier.

Grapefruit can be a great portable snack. Simply peel it like an orange, either by using a knife or with your hands. Once you have the skin off, you can pull the segments apart quite easily.

If you want a real treat in the morning, cut the grapefruit in half, run a knife around the edge, and separate the segments by running the knife next to each membrane that divides the individual segments.

Then, put a little maple syrup or brown sugar on top, and stick the fruit under the oven broiler for a few minutes. You can garnish it with a strawberry or a maraschino cherry, and serve it piping hot. You can also try adding cinnamon, ginger or vanilla extract to jazz it up a bit.

No fruit salad is complete without some grapefruit sections. For an attractive and low-calorie dessert, try creating a fruit compote by mixing different colored varieties together and putting them back into an empty grapefruit shell.

Grapefruit is also a nice surprise in a green salad; try it instead of lemon with fish dishes. This is such a healthy fruit, so don't avoid it unless you must because of your medications.

Sheldon Margen, M.D., is a professor of public health at the University of California at Berkeley. Dale A. Ogar is managing editor of the University of California at Berkeley ``Wellness Letter.'' They are the authors of ``The Simply Healthy Lowfat Cookbook,'' ``The Wellness Lowfat Cookbook'' and ``The Wellness Encyclopedia of Food and Nutrition.'' Comment by clicking here.


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