A study published in late January by the Journal of the American Medical Association says foods and supplements containing omega-3 fatty acids do not protect against cancer, dashing some earlier hints that they might.
The analysis, of 38 studies conducted between 1966 and 2005, suggests that omega-3s (which are found in many kinds of fish and some plant sources) have no significant effect on a variety of cancers, including those of the breast, colon, lung and prostate.
Sponsored by the federal government, the report noted that a few studies with a small number of subjects appeared to show that omega-3 fatty acids offer some cancer protection. But most showed no relationship, and a few even showed an increased risk. The studies included more than 700,000 adults tracked for up to 30 years.
Dr. Catherine MacLean, lead author of the study and a researcher at the Rand Corp. in Santa Monica, Calif., says that although omega-3s "are good for your heart and your general health, the benefits don't appear to extend to cancer."
Fish sources rich in omega-3 fatty acids include salmon, mackerel, anchovies, herring and cod liver oil. Plant sources (a slightly different omega-3) include flax seeds, canola oil, soybeans, wheat germ, peanut butter and walnuts.
Walk it off
If a pedometer was among your holiday gifts, clip it on and take a walk. If you need incentive, check out Pedometer Walking: Stepping Your Way to Health, Weight Loss, and Fitness(Lyons Press, 2006, $12.95). Authors Mark Fenton and David R. Bassett Jr. cover topics including how pedometers work (interesting trivia) and walking techniques.
Starting a formal walking program can be a challenge. Fenton (a walking expert, writer and host of the PBS show America's Walking) and Bassett (an exercise science professor at the University of Tennessee) teach readers how to increase steps, suggest ways to incorporate walking into a daily routine, and offer fun ways to take the activity further.
Fenton says it's not always the ambitious hikes that help people become more physically active, but incorporating walking into every day. "Small changes matter," he says.
The book also includes a weekly log, warm-up exercises, and charts for estimating speed and calorie burn. Inspirational mini-bios tell of people who have shaped up and lost weight walking.
"We begin with the simple notion of getting off the couch," says Fenton, "but by the end, it's about trying to be a positive force in the community" by pushing for walkable neighborhoods.
A study in the Journal of the American Medical Association finds that within the first three minutes after awakening, people exhibit impaired mental function and short-term memory.
Pass it on
How might bird flu spread across the country should it arrive on our shores? The journal Nature recently published a paper that drew on a Web-based game, www.wheresgeorge.com, to probe that question. The site traces the path of individual dollar bills across the country, which (like a case of flu) travel by hand, car, truck and plane, passing among many people along the way.