Q. Do older adults need extra protein to avoid losing muscle? If so, how much is enough?
A. Research suggests that older adults may need somewhat more protein than younger adults to avoid the loss of lean body tissue like muscle and bone that occur as we age.
Most studies involve those over age 65, but some include adults over 55. This does not require huge amounts of meat or protein supplements, however.
The long-time standard protein recommendation for adults has been this formula: your body weight in pounds divided by three (thus, a 160 pound adult needs 53 grams of protein). Quite a few studies in recent years suggest that older adults lose less muscle and may actually gain muscle better if along with strength-training exercise, they consume protein equal to their weight in pounds divided by two. (So a person who weighs 160 pounds may do well to target 80 grams of protein per day.) Studies do not show any further benefit in maintaining or gaining muscle with protein consumption beyond that amount.
U.S. dietary surveys suggest that average protein consumption of adults ages 51-70 generally meets that target. However, about one in four over 70 may be getting less than the minumun and another 25 percent of adults over 50 may be getting less than the proposed higher target.
You can reach this higher level of protein with five to six ounces a day of lean poultry, fish or meat plus three servings of dairy products or dairy alternatives as part of a balanced diet that provides smaller amounts of protein from whole grains, vegetables, beans, nuts and seeds, and perhaps some eggs, too. Those who prefer to omit or minimize meat or dairy products need to include multiple servings of vegetarian sources of protein.
Some research suggests that protein may be more efficiently used when it is spread out through the day. As important as protein seems to be, research also emphasizes the vital role that resistance (strength-training) exercise has in avoiding lean tissue loss.
Q. I'm confused by all the competing claims about different berries. Is there one that offers more health protection than the others?
A. All berries offer health benefits, so enjoy a variety.
Strawberries are highest in vitamin C, yet all are good sources. A cup of most berries -- about two servings -- will supply from a third of the recommended amounts to the complete target.
Actually, much of the health promoting power of fruits and vegetables comes not from the classic antioxidant vitamin C, but from natural protective compounds in plants called phytochemicals. Antioxidants attract and neutralize highly reactive molecules called free radicals that can damage body cells in ways that lead to cancer and heart disease.
Yet focusing only on antioxidant power, and systems that rate that power, misses the big picture. Many phytochemicals in berries may also help protect against cancer and other chronic diseases by decreasing inflammation and stimulating self-destruction of abnormal cells.
Two of these are anthocyanins, which give many berries their red color, and ellagic acid. In animal studies, berries or the compounds they contain have inhibited development of colon, esophageal, cervical, lung and breast cancers. In several experiments all berries were about equally effective.
• Provided by the American Institute for Cancer Research. Learn more about the group and its New American Plate program at aicr.org.