Wincing while You Work

After a long day of repetitive work, you may experience pain in your neck and shoulder muscles. This pain can result from muscle and tissue overuse, or from psychological factors, such as low social support, job dissatisfaction, and low individual job control.

In a study published in the journal Spine, researchers evaluated risk factors for neck or shoulder pain and tenderness in over 3,000 workers at 19 production plants. Workers performing nonrepetitive tasks were used as a comparison group.

Almost twice as many workers performing repetitive work (7%) had neck or shoulder pain with muscle tenderness, compared to the comparison group (less than 4%). Pain was strongly linked to a decreased quality of life. Factors associated with neck or shoulder pain were previous injury, high repetitiveness, high force, female gender, and high job demands.

If your job involves repetitive or heavy work, you are especially susceptible to developing work-related neck or shoulder pain. Be sure to follow proper procedures to avoid injury, and talk to your chiropractor about what he or she can do to minimize the pain -- and the risk of developing it.

Reference: Andersen JH, Kaergaard A, Frost P, et al. Physical, psychosocial, and individual risk factors for neck/shoulder pain with pressure tenderness in the muscles among workers performing monotonous, repetitive work. Spine 2002:27(6), pp. 660-667.

To learn more about neck pain click here.

Tea: It Does a Body Good

It's no secret that tea is good for you: Drinking tea is known to help prevent heart disease and cancer. Tea also contains high amounts of caffeine, flavonoids, phytoestrogens, and fluoride -- all compounds suspected of exerting influence on bone mineral density (BMD). Low bone density can increase a person's risk for broken bones.

The authors of a study in the Archives of Internal Medicine wanted to evaluate the effects of tea on bone strength. They questioned over 1,000 Taiwanese individuals about how much tea they drank and how long they had been regular tea drinkers. Bone scans were used to measure BMD in the spine, hip, and total skeleton of the individuals, who were all age 30 or older.

Drinking tea regularly for 6-10 years was associated with higher BMD in the spine, and drinking tea for over 10 years was associated with a higher BMD at all measurement sites. The amount of tea consumed per day or week was not significantly linked to bone density -- only the duration. Half of all the people studied were habitual tea drinkers.

Tea comes in different forms: green (unfermented), oolong (partially fermented), or black (fermented) tea; all three types were similarly related to BMD in this study. Consider drinking any form of tea instead of other less-healthy beverages like soft drinks and coffee.

Reference: Wu CH, Yang YC, Yao WJ, et al. Epidemiological evidence of increased bone mineral density in habitual tea drinkers. Archives of Internal Medicine 2002:162(9), pp. 1001-1006.

For more information on good nutrition click here.

No Argument -- Always Buckle Up

Seat belts are designed to restrain adults safely in car accidents, yet children must use these same belts as soon as they are too old to ride in a car seat. Seat belts may concentrate substantial forces on children's abdomens and spines because of their shorter stature, creating "lap-belt syndrome." Some parents, concerned about this syndrome, don't buckle up their children; others don't out of sheer neglect.

To determine if children are safer wearing or not wearing seat belts, the authors of a study in the British Medical Journal looked at data on 470 children, ages 4-14 years, and nearly three times as many adults involved in car accidents in Canada. Only fatalities and injuries rated at least "moderately severe" were considered.

A frightening 40% of the children involved in car accidents were not wearing seat belts. Even when their parents were belted, 22% of the children were still not buckled up. Children riding in the front seat were almost 10 times more likely to be injured or killed if not wearing seat belts; in the back seat, their odds for injury were more than doubled if not buckled up. Adults also fared better wearing seat belts. They were more than twice as likely to be injured without a belt on, no matter where they were sitting in the vehicle.

There is no debate: Adults and children should always wear seat belts. Despite the possibility of seat belts injuring a vehicle's occupant, the risk for injury and death is always higher if not wearing one. Be sure you and your kids are buckled up before you start to drive, and keep children in car seats until they are old enough to safely ride without them. For more information about child passenger safety, visit www.nhtsa.dot.gov/people/injury/childps.

Reference: Halman SI, Chipman M, Parkin PC, et al. Are seat belt restraints as effective in school age children as in adults? A prospective crash study. British Medical Journal 2002:324, pp. 1123-1126.

For more studies on pediatric health click here.

All for One and One for All

Almost 50 million Americans suffer from high blood pressure (BP), and cardiovascular disease has been the primary cause of death in the U.S. for over 80 years. Studies show that reducing BP reduces risk for heart disease and death, even when lowered by only a small amount. Medications have been shown to lower risk for cardiovascular disease, but because they may have dangerous side effects, aerobic exercise alone can be prescribed to lower BP.

To find out if exercise can reduce BP in all groups of people, the authors of a recent review in the Annals of Internal Medicine examined the results of more than 50 previous studies. They combined the results of these studies (involving a total of about 2,500 individuals) to determine the effectiveness of exercise to reduce BP in various groups, and to determine if specific types of exercise are more effective than others.

Any form of aerobic exercise significantly reduced BP in every type of previously sedentary person, regardless of race, gender, weight, and presence of hypertension (high BP). Frequency and intensity of exercise also did not appear to significantly affect BP.

Even a small decrease in average BP can dramatically lower your risk for cardiovascular disease and death. Whether or not you currently have high blood pressure, maintain a consistent regimen of aerobic exercise to ward off disease, premature death, and obesity.

Reference: Whelton SP, Chin A, Xin X, et al. Effect of aerobic exercise on blood pressure: A meta-analysis of randomized, controlled trials. Annals of Internal Medicine 2002:136(7), pp. 493-503.

To read more about sports and fitness click here.

Catching on to Chiropractic

Chiropractic is the principal and most-regulated form of complementary and alternative health care. There are about 60,000 chiropractors - a number expected to nearly double by 2010. The percentage of Americans who use chiropractic increased from approximately 3.6% in 1980 to 11% in 1997. The profession may be so successful because it exhibits characteristics of both alternative and mainstream health care.

A recent review of chiropractic in the Annals of Internal Medicine highlighted the necessity of research in furthering the profession, and noted that dozens of well-designed studies on spinal manipulation have shown favorable results of chiropractic care. One of the main reasons chiropractic has done so well is because of studies showing its success. The review presented some very positive figures, which are presented below:

Forty-three clinical studies on the effectiveness of spinal manipulation at treating low back pain have been published; 30 of these showed manipulation to be favorable to other treatments, 13 found no major effects, and none showed manipulation to be less effective than the comparison treatment.

Eleven of the back pain studies included a group receiving placebo (or sham) treatment; of these, eight indicated an advantage of chiropractic manipulation over placebo.

Seven of nine studies on the effectiveness of manipulation for treating headache showed positive results.

Serious complications from chiropractic adjustments are rare: only about one per 100 million lumbar adjustments, and one per 400,000-10 million neck manipulations.

As a chiropractic patient, you have probably known for a long time how effective this form of treatment is at resolving multiple health problems. With more research reaffirming chiropractic's effectiveness, perhaps others will start to catch on as well.

Reference: Meeker WC, Haldeman S. Chiropractic: A profession at the crossroads of mainstream and alternative medicine. Annals of Internal Medicine 2002:136(3), pp. 216-227.

To learn more about chiropractic, click here.

In the (O)Zone

Asthma, the most common chronic childhood disease, is on the rise due to factors such as a poor diet, infections, allergens, and air pollution. Competitive athletes sometimes have a higher prevalence of asthma than others, possibly because of breathing in more pollutants. Are children involved in outdoor team sports in highly polluted areas at an increased risk for asthma?

Nine- to 16-year-old children in 12 communities in southern California with varying levels of pollution (six with high ozone levels, six with low ozone levels) were selected for a study in a recent issue of The Lancet. The authors assessed asthma risk in approximately 3,500 children who played zero, one, two, or three or more team sports. The children were followed for up to five years to determine the development of asthma.

Children playing three or more team sports in high-ozone communities were over three times more likely to develop asthma than children playing no sports. Playing three or more sports in low-ozone communities had no significant effect on asthma prevalence, however. More time spent outside (unrelated to playing sports) in high-ozone communities also was linked to a higher incidence of asthma.

This study does not imply that your children should avoid outdoor activities or athletics. If you live in an area with higher-than-normal pollution levels, however, be sure to limit your children's outdoor activities and sports participation on high-pollution days. Most cities with high pollution levels provide daily reports of ozone and air quality, often in the local newspaper.

Reference: McConnell R, Berhane K, Gilliland F, et al. Asthma in exercising children exposed to ozone: A cohort study. The Lancet 2002:359, pp. 386-391.

For more pediatric health information, click here.

Skate at Your Own Risk

Over 500,000 men and 70,000 women in Canada regularly play recreational ice hockey, as do many of their American counterparts. Playing hockey on roller skates is another popular recreational sport. These activities subject participants to intense aerobic activity, though, which in older adults has been linked to a higher risk for heart attacks.

The authors of a recent study in the Canadian Medical Association Journal decided to investigate a link between playing recreational hockey and suffering from heart attacks in middle-aged men, after they had treated multiple patients who had suffered a heart attack following play. The authors monitored the heart rates of 113 recreational ice hockey players over 35 years old, using electrocardiographic monitoring devices before, during, and after hockey games. Data were used to determine heart rates and presence of arrhythmias (irregular heart beats).

For every player, maximum heart rate during play was higher than target exercise heart rate; in three-quarters of players, heart rates were in excess of predicted heart rate. In 70% of cases, heart recovery rate was "poor" following play, and arrhythmias were found in two players.

The elevated exercise level during recreational hockey and other vigorous sports may cause a dangerously high cardiac response in middle-aged or older adults. Excessive aerobic activity in the players in this study led to heart rates higher than target and maximum rates, and poor recovery rates. If you are over 35 years old and not in excellent physical condition, hold off on participating in highly demanding sports like ice hockey until you're in better shape.

Reference: Atwal S, Porter J, MacDonald P. Cardiovascular effects of strenuous exercise in adult recreational hockey: The Hockey Heart Study. Canadian Medical Association Journal 2002:166(3), pp. 303-307.

To read more about sports and fitness, click here.

Can Hormone Therapy Cause Cancer?

For many women going through menopause, the problematic hormonal changes involved can lead them to seek hormone replacement therapy (HRT). HRT involves taking hormones like estrogen and progestin to replenish hormone loss due to aging, for results like improved sleep, hot-flash and night-sweat prevention, and subdued mood swings. A possible association between long-term use of HRT and breast cancer has been shown in numerous studies, however.

The authors of a study in the Journal of the American Medical Association determined the link between HRT use over a five-year period and incidence of breast cancer. Over 700 postmenopausal women 50-74 years old with breast cancer, and nearly as many healthy women, were evaluated for hormone usage.

Overall, breast cancer was 60-85% more likely in women who had used HRT both recently and long-term. HRT use over multiple years and combination therapy of both estrogen and progestin increased risk of one type of breast cancer even more substantially. Continuous long-term and combined-hormone therapy increased lobular breast cancer (a specific type of breast cancer) risk six times.

HRT use also increased risk for nonlobular breast cancer (a more common form). If that isn't enough information to scare you away from hormone therapy, you might be interested to know that other possible side effects include acne; weight gain; increased facial hair; high blood pressure; depression; and heart attacks.

Reference: Chen CL, Weiss NS, Newcomb P, et al. Hormone replacement therapy in relation to breast cancer. Journal of the American Medical Association 2002:287(6), pp. 734-741.

For more women's health studies, click here.