Q: More and more households have microwave ovens, and many new forms of packaging seem to have become available as well. With all this progress, will canned goods become obsolete?
A: So far, the can does not appear to be an endangered species -- at least not in the foreseeable future. It is true there have been many developments in packaging technology. Yet according to figures provided by the Canned Food Information Council, 700 plants still pack no less than 17 billion cans of food a year. In terms of sales, the No. 1 canned food is soup, followed by tuna, pasta and corn. And while we may think we eat a lot of fresh tomatoes, especially when they are in season, as much as 95 percent of those harvested are made into canned products.
Q: My aunt recently let it slip that her doctor says she has something called irritable bowel syndrome. She didn't really want to talk about it, but I would like to know more. Can you explain what it is and what sort of diet is recommended for it?
A: Irritable bowel syndrome is a common condition. Symptoms result from abnormal movement of the colon and can include indigestion, cramping, abdominal pain and diarrhea, which may alternate with constipation.
Restrictive, low-fiber diets were commonly suggested in the past. Nowadays it is recognized that such therapy is not consistently effective. Instead individualized dietary modifications are designed to help provide symptomatic relief.
Increased amounts of fiber are often recommended for either constipation or unformed stools. Avoiding coffee, carbonated beverages and cold drinks may be of benefit if diarrhea is a problem. Cutting down on fat may help to relieve symptoms in some individuals. Legumes, cabbage and other vegetables likely to cause gas production are among the foods associated with symptoms.
Studies have shown that the following foods are linked to symptoms in some, but not all, individuals: tea, coffee, citrus fruits and dairy products. Obviously, people who associate discomfort with the consumption of dairy products are well advised to limit them to amounts they can tolerate easily.
Q: I know that vitamin D is required for the absorption of calcium. But is there any way to get it other than from sunlight or from vitamin D-fortified milk?
A: For the majority of us, those are the only practical ways. Most people do not eat the few other foods that provide vitamin D often enough or in large enough quantities to make significant contributions. Besides, in some foods the amount of vitamin D is related both to the animal's exposure to sunlight and to its diet, which means it can vary greatly.
Compared to milk, fatty fish contribute impressive amounts. A cup of vitamin D-fortified milk provides 100 International Units (IUs) of the vitamin, about half the Recommended Dietary Allowance (RDA). Three and a half ounces of fatty fish, such as salmon or herring, contain 300 IUs of vitamin D. So for those who eat fatty fish on a regular basis, this can become an important source. On the other hand, a piece of liver weighing 3 1/2 ounces before cooking contains anywhere from 15 to 40 IUs, hardly an impressive amount, even at best. A medium egg contains only 25 IUs of vitamin D; a tablespoon of butter, 15 IUs.
So for most of us the only dependable source, especially during the winter months when exposure to the sun is limited, is vitamin D-fortified milk.
Q: What is turkey ham?
A: It is cured turkey thigh meat. Like regular turkey, it is an excellent low-calorie source of high-quality protein and it is low in fat. Because it contains a bit more moisture and a little less protein and fat than regular dark turkey meat, it has slightly fewer calories: 37 per ounce compared to 53 per ounce. It also contains B vitamins, iron and other minerals.
But in the curing process, sodium is added. The result is that while an ounce of dark turkey meat normally provides 25 milligrams (mg.) of sodium, an ounce of cured turkey ham contains more than 10 times that amount, about 280 mg. per serving. By comparison, an ounce of bologna provides about 340 mg. So in terms of sodium, it falls into the league with luncheon meats.
(c) 1988, Washington Post Writers Group