honoluluadvertiser.com

Sponsored by:

Comment, blog & share photos

Log in | Become a member
The Honolulu Advertiser
Posted on: Thursday, May 15, 2008

SHAPE UP
Brush up on a few food facts

By Charles Stuart Platkin

There is a never-ending stream of nutrition questions. So we looked to a few of our expert sources to find answers about whether flaxseeds matter, why red peppers may be better than others, and if frozen yogurt is just plain old dessert.

What are flaxseeds? Why have they received such attention from health-food advocates?

Fact: Flaxseeds (aka linseeds) are about the size of sesame seeds and come from a blue-flowering member of the Linaceae family grown largely in Canada, China and the United States. "The plants have been used for centuries to make fabric and cloth and for other household and industrial purposes (for example, the linseed oil used by painters)," says Marian L. Neuhouser, a nutrition researcher at Fred Hutchinson Cancer Research Center in Seattle.

"The lignans in flaxseeds produce anti-inflammatory prostaglandins that help to reduce the inflammation that may be associated with asthma, arthritis, osteoporosis and migraine headaches. The nutrient benefits have been shown to reduce risk for diabetes, reduce blood cholesterol levels, control blood sugar and insulin levels, and promote gastrointestinal health," Neuhouser adds.

The seeds are brimming with nutrients (including protein, iron, phosphorous, calcium, B vitamins and vitamin E), all packed into a small and quite tasty little seed, says Janet Brill, author of "Cholesterol Down" (Three Rivers, 2006). Specifically, flaxseeds are a good source of fiber, manganese, magnesium and antioxidants. They may be consumed as ground flaxseed meal or as flaxseed oil. Flaxseed meal contains more fiber and phytochemicals, but the oil is higher in omega-3 fatty acids than the meal.

They need to be ground into meal in a coffee grinder (or something similar) to allow the nutrients to become more bio-available, says Anne VanBeber, a professor of nutritional sciences at Texas Christian University.

Fiction: That the omega-3 fats in flaxseeds have the same health benefits as the omega-3s in fish, says Jodi Greebel, a nutritionist in New York City.

Concerns: The primary health benefit is the high content of alpha-linoleic acid — a type of omega-3 fatty acid, which is not the same as the more celebrated EPA and DHA found in cold-water fish, such as salmon. These cold-water fish need to be included in one's diet, adds VanBeber.

Additionally, we need to be wary of over-consumption, because flaxseeds can have a laxative effect.

Bottom line: Including flaxseeds in the diet is a good way to work toward achieving the desired 1:2 ratio of omega-3 fatty acids to omega-6 fatty acids in the body. A lower omega-3:omega-6 ratio is associated with reduced risk of chronic disease, VanBeber says.

Are red bell peppers more nutritious than orange, green or yellow peppers?

Fact: Different-colored peppers are the result of when the pepper is harvested. "Red bell peppers are fully ripened green bell peppers. Green bell peppers are unripe and immature. Other colors, such as orange, yellow and purple, are different cultivars of the bell pepper and reach their appropriate color upon ripeness," says VanBeber, adding that the peppers become sweeter as they ripen. Also, all bell peppers contain a recessive gene that inhibits capsaicin, which is found in chili peppers. As a result, they are not spicy.

Red bell peppers are among the best sources of beta-carotene, the form of vitamin A found in plants. And they contain approximately 11 times the beta-carotene of green bell peppers. Red bell peppers are also an excellent source of the phytochemicals lutein and zeaxanthin, which are known to protect against macular degeneration.

Bell peppers of all colors are also a good source of B6, fiber, folate, potassium and many other vitamins and minerals. In addition, they contain lycopene, shown to reduce the risk for certain cancers. One cup of raw chopped sweet bell pepper is about 25 calories.

While red bell peppers have three to four times the vitamin C of citrus fruits, green, yellow and orange bell peppers are also higher in vitamin C than citrus fruits.

A 2007 study in the Journal of Food Science compared the antioxidant activity in all four colors and found that it was greatest in red bell peppers, followed by orange, yellow and green, VanBeber says.

Fiction: That bell peppers of one color are far more nutritious than other colors.

Concern: Research indicates that all bell peppers are among the top 10 vegetables for containing pesticide residue when grown conventionally — so buy organic.

Bottom line: All sweet bell peppers provide good nutrition in the form of vitamins A, C and B6 and are good sources of fiber, folate, molybdenum and magnesium, says VanBeber. However, red bell peppers pack more vitamin A (beta-carotene) than do the other colors, and they are also sweeter.

Does frozen yogurt offer the same health benefits as regular yogurt?

Fact: "Frozen yogurt is a sweet treat that can provide some bone-strengthening calcium. However, it contains about half as much calcium as regular yogurt. Some frozen yogurts are made with a starter culture (Lactobacillus bulgaricus and Streptococcus thermophilus) that aids digestion and has other health benefits, but if these frozen yogurts have been heat treated, the cultures are destroyed. Look for the 'Live and Active Cultures' seal on the label to obtain a frozen dessert with these cultures. Some frozen yogurts can have added probiotics, but the amounts may not be adequate to confer a benefit," says Joan Salge Blake, a nutrition professor at Boston University.

Fiction: All frozen yogurts contain live and active cultures.

Concern: Many people overindulge in frozen yogurt, thinking that it is low in calories and has live and active cultures, says Salge Blake.

Bottom line: "If you choose one because of its added probiotics, be sure to call the manufacturer to ascertain the type and amount in the product," Salge Blake says. Or look for the National Yogurt Association's Live and Active Culture seal.

Charles Stuart Platkin is a nutrition and public-health advocate, and author of "Breaking the FAT Pattern" (Plume, 2006). Sign up for the free Diet Detective newsletter at www.dietdetective.com.