AUSTIN, Texas -- Following are answers from the American Institute for Cancer Research on dietary questions.
Question: How much fiber do bran muffins provide?Answer: The amount varies with the recipe and the size of the muffin. Some may contain quite a bit of bran, others just a trace. Most commercial muffins are made with white flour. For more fiber and nutrients, look for muffins made with whole-wheat flour, or make your own. Muffins are easy to make, and can be frozen for use one at a time.
As muffin size increases, so does fiber content, along with calories. Some small bran muffins without much bran give you only 1 gram of fiber (no different than a slice of white bread); a mega-muffin with more bran may supply 3 to 8 grams of fiber, but may also yield 400 or more calories (equal to two doughnuts!). Check ingredient and Nutrition Fact labels. Health experts recommend 20-35 grams of fiber per day.
Question: Is it true that for best nutrition we should eat all our vegetables raw?
Answer: No. Although cooking does destroy a portion of certain heat-sensitive vitamins such as vitamin C, some sources have misinterpreted this to mean that no nutrients remain in vegetables after they are cooked. This is far from true. If you take care not to cook vegetables until they're limp, you will get plenty of nutrition. Also, cook by steaming, microwaving, roasting or stir-frying to prevent vitamins from leaching out into cooking water.
New research shows that at least one valuable phytochemical (a naturally occurring substance in plant foods) may actually become more available to our bodies when we get it from cooked vegetables. Lycopene, which some studies suggest helps prevent prostate cancer, is better absorbed by the body from processed products such as tomato sauce, soup and juice than from raw tomatoes.
Question: How high in omega-3 fatty acids is farm-raised catfish?
Answer: Catfish, wild or farm-raised, is a very nutritious, low-fat source of protein (as long as you don't deep-fat fry it!). It is not, however, a good source of omega-3 fatty acids. According to USDA data, a 3-ounce cooked portion provides about as much omega-3 as clams and shrimp, only about a tenth as much as you get from fattier fish such as salmon.
Experts note that these components of fat seem to have a variety of health benefits, including reduced risk of heart disease and benefits to the immune system. Some research even suggests that omega-3 fats may help lower risk of breast cancer and, perhaps, other cancers.
These Ask a Dietitian questions were answered by Karen Collins, M.S., R.D. of the American Institute for Cancer Research.