Healthsifter by mary desmond pinkowish, since 2003

Does Sleep Lower Cancer Risk?

Here's a report given this week at the meeting of the American Association for Cancer Research that suggests that getting at least 7 hours of sleep each night reduces cancer risk. The study, conducted in nearly 6,000 women, was conducted under the direction of scientists at the National Cancer Institute. An interesting piece of the puzzle is that while exercise was also shown to reduce cancer risk, that apparently is true only if a person is also getting enough sleep! Here's an excerpt from the press release:

...regular physical activity can lower a woman's overall risk of cancer - but only if she gets a good night's sleep. Otherwise, lack of sleep can undermine exercise's cancer prevention benefits.

"Greater participation in physical activity has consistently been associated with reduced risk of cancer incidence at several sites, including breast and colon cancers," said James McClain, Ph.D., cancer prevention fellow at the National Cancer Institute and lead author of the study. "Short duration sleep appears to have opposing effects of physical activity on several key hormonal and metabolic parameters, which is why we looked at how it affected the exercise/cancer risk relationship."

Even though the exact mechanism of how exercise reduces cancer risk isn't known, researchers believe that physical activity's effects on factors including hormone levels, immune function, and body weight may play an important role. The study examined the link between exercise and cancer risk, paying special attention to whether or not getting adequate sleep further affected a women's cancer risk.

Researchers assessed the association between physical activity energy expenditure (PAEE), sleep duration and incidence of overall, breast, and colon cancer in 5,968 women at least 18 years old with no previous cancer diagnoses. The women completed an initial survey in 1998 and were then tracked through the Washington County Cancer Registry and Maryland State Cancer Registry for nearly 10 years.

The results pointed to a sleep-exercise link. "Current findings suggest that sleep duration modifies the relationship between physical activity and all-site cancer risk among young and middle-aged women," he said.

Yahoo has reported on the story, too.

More on Exercise and Cancer Risk

We have another study this week about the beneficial effect of exercise on cancer risk. This one is notable because it involved a really big group of people--more than 80,000--which tends to increase the validity of the results. The researchers, based in Japan, found that men and women who were physically active had lower risks of stomach, colon, pancreas, and liver cancer than people who were less active. The effects of exercise were most pronounced in people with normal body weight. The story is reported at Reuters, and here's a paragraph from that report:

"Overall, according to the researchers, the risk of developing any cancer dipped slightly as participants' activity levels climbed. On average, the most-active men were 13 percent less likely than the least active men to develop cancer; the most-active women had a 16 percent lower cancer risk than their sedentary counterparts.

The link held true when the researchers accounted for a range of other factors, including participants' age, weight, smoking habits, daily calorie intake."

The original research appears in the August 15th issue of the American Journal of Epidemiology.

Everything You Could Possible Need to Know About Fitness Balls

MayoClinic.com has compiled a group of videos on how to select and use fitness balls. It's so much easier to learn this stuff from a video, or better yet, a live person, than from static photographs.

Runner's World Runners' Tools & Resources

Cool site--everything from how to buy running shoes to training logs to nutrition and weight loss advice.

More on Running and Longevity and Health

Time takes on last week's study showing that joggers/runners live longer and better than other people. But there's more you need to know about these findings, and it's all good news, especially for those of us with Funky Left Knee Syndrome. Here's a snippet from that article (the Eliza Chakravarty they quote here is one of the investigators):

Although the study focused on runners, Chakravarty says, the benefits appear to accrue from any vigorous aerobic exercise. In fact, the data suggested that even a little bit of exercise was better than none. A few of the volunteers from the non-running group did break a sweat sometimes, if not in a prolonged, consistent way — they reported having run for more than one month at a time — and even that short period of regular aerobic exercise appeared to have created positive health benefits, Chakravarty says. For avid runners, more good news: the study found no significant difference between the condition of joints in pavement pounders and their more sedentary peers. Looking at X-rays and arthritis rates, Chakravarty says, "there was clearly no difference."

Run, and Live Longer and Better

Here's how MedPage Today summarized the new study showing that people who run live longer and with less disability than people who don't. The participants, members of a running club and were aged 50 and older when the study started, were compared to a similar-sized group of non-runners. After 21 years of follow-up, the runners were 40% less likely to have died or developed a moderate disability than the non-runners. Compared to the non-runners, runners were significantly less likely to die of cardiovascular disease, cancer, neurologic disorders, infections, and other causes. ScienceDaily also covered this, interviewing one of the authors, who notes that the wellness gap between the runners and non-runners widened the older they got. The original article appeared in the August 11/25 issue of the Archives of Internal Medicine. 

My question: Is there anything magic about running? What about swimmers, walkers (not strollers, walkers), hikers, etc. I'd like to know.

Autism and Vaccines: Autism One Conference, Chicago

AMEDnews reports evenhandedly on the Autism One conference, which was held in Chicago over the Memorial Day weekend.One of the featured speakers was Dr. Andrew Wakefield, the British physician whose 1998 paper in The Lancet claimed an association between autism and the measles, mumps, and rubella (MMR) vaccine and autism in 12 kids. But this is what's happened since then, quoting from AMEDNews:

"Every so often, a small study such as the one conducted by Dr. Wakefield comes along to buttress that belief. In this case, the momentum has held, even though 10 of the 13 authors on the 1998 paper published a statement inThe Lancet in 2004 retracting the original interpretation that their data indicated a causal link between MMR and autism, and Dr. Wakefield faces significant professional scrutiny."

That is, Dr. Wakefield is in danger of losing his license to practice. In June, the UK health authorities declared that measles is now endemic in that country and confirmed a recent measles-related death. In the US, measles rates are at their highest since 2001. It's more than spots: encephalitis and pneumonia are just two possible complications.

Damage done.

The Future of Sports Enhancement and Doping

In the online feature Juicing 3.0, PopSci describes five ways that athletes will try to dodge rules against performance enhancers during the next few years. It's all here, stuff you have and haven't heard about. And most of it is probably undetectable.

Growth Hormone and Athletic Performance

Growth hormone may increase lean muscle mass, but the researchers who looked at collected data that have been published on the effects of growth hormone couldn't find much else to recommend its use. They actually found evidence that the stuff diminishes exercise capacity and causes side effects including edema and fatigue. Quackwatch has covered this issue, and CNN interviewed the scientists who did the current study, which was just published in the current electronic issue of the Annals of Internal Medicine.