We often look to science to solve life’s difficult questions. But sometimes it hands us more uncertainty. Take three reports in today’s New England Journal of Medicine. One shows that eating less sodium (a main component of salt) could save more than a million lives a year worldwide. A second came to a nearly opposite conclusion — that current average sodium intake is okay for cardiovascular health while getting either too little or too much is a problem. The third study essentially agreed with the second, but found that getting too little potassium may be as bad as getting too much sodium. The findings are certain to fuel the already heated debate on sodium and the international efforts to get people to take in less of it. But until there are good answers to the questions raised by the studies, it’s too soon to throw out recommendations to reduce sodium intake, especially in high-risk groups. Another lesson from the three New England Journal articles worth keeping in mind: getting more potassium from fruits, vegetables, and other foods is a good way to help keep your heart and arteries healthy.
Robert Shmerling, M.D.
Posts by Robert Shmerling, M.D.
Checking seemingly healthy people for cancer—what doctors call screening—seems like a simple process: Perform a test and either find cancer early and cure it or don’t find it and breathe easy. It works for colon, breast, and cervical cancers, but not for others. For colon cancer, there are several effective screening tests: colonoscopy, sigmoidoscopy, and stool testing. Two new studies in yesterday’s New England Journal of Medicine help further quantify their benefits. In the studies, all three types of test reduced the risk of developing or dying from colon cancer. Colonoscopy worked best, followed by sigmoidoscopy and then stool testing. The biggest challenge for colon cancer screening is getting people to have the available tests. About 50,000 Americans die of colon cancer each year—many of these can be prevented with early screening.
A new report suggests that skin cancer can sometimes hide in a tattoo. Writing in JAMA Dermatology, three German clinicians describe the case of a young man who wanted to remove large, multicolored tattoos on his arms and chest. During the removal process, his doctors discovered a suspicious mole inside the tattoo. It turned out to be cancerous—stage II melanoma. Tattoos may make it difficult to evaluate moles. Laser removal therapy is also problematic when moles are present. If you are considering getting a tattoo, either make sure it will be applied to skin that is free or moles or birthmarks, or have your doctor check any moles in the to-be-tattooed area beforehand. If you are planning to have a tattoo removed, check for moles within the tattoo. If you see any, ask your doctor or dermatologist to check them out before starting laser therapy.
How’s this for a mind-bender: Lou Gehrig may not have had Lou Gehrig’s disease. Instead, the disease that ended his life may have been chronic traumatic encephalopathy (CTE). This brain disease is caused by repeated concussions—Gehrig sustained at least four during his baseball career—or other head injuries. It can cause symptoms very similar to those of amyotrophic lateral sclerosis (ALS), now commonly called Lou Gehrig’s disease. More evidence of a connection between CTE and ALS comes from a new study of almost 3,500 retired professional football players, all of whom had played for at least five years in the National Football League. Among the 334 who died during the course of the study, the risk of death from Alzheimer’s disease or ALS was nearly four times higher than expected. Players who manned a “speed” position (such as quarterbacks or receivers) had a risk of dying from Alzheimer’s disease or ALS that was more than three times higher than those playing “non-speed” positions (such as linemen).
There are several good reasons to have cataracts fixed. Restoring clear, colorful vision certainly tops the list. A study published today in the Journal of the American Medical Association (JAMA) adds another benefit—a lower risk of breaking a hip. Researchers analyzed the effect of cataract surgery on the frequency of hip fracture in the following year. Among more than a million adults ages 65 and older who had cataracts, the frequency of hip fracture was 16% lower among those who had cataract surgery compared with those who didn’t have it, and the reduction in risk was even greater (23%) if the cataract was severe. Besides the immediate benefit of improved vision on everyday activities, and the longer-term one of preventing broken hips, cataract surgery may have other, less obvious benefits. These include more independence, better physical fitness, and better mental health.
As Benjamin Franklin once wrote, “nothing is certain but death and taxes.” A new study suggests that death and taxes are more than just unrelated “certainties,” and that one (paying taxes) could lead to the other. Over the last 30 years, an average of 226 Americans died in motor vehicle accidents on the day taxes were due (usually April 15th), compared to 213 on other days. The authors speculated that the increase may be due to distracted driving because of the added stress of tax day, more alcohol drinking, or less sleep. If the JAMA findings are real, staying off the road on tax day could ever so slightly reduce your chances of getting into an accident on the road. But there are other, better ways to keep yourself and others safe while driving every day of the year.
A large study from Europe does little to resolve the controversy over whether men should have a simple blood test to look for hidden prostate cancer. In the study, the number of deaths over the course of the 11-year study were the same in men tested for prostate-specific antigen (PSA) and in men who didn’t have the test. Because prostate cancer usually grows very slowly, detecting it in an older man generally isn’t helpful. Some men live with the side effects of treatment—notably impotence and incontinence—for a cancer that would have had no effect on the length or quality of their lives. This study and others suggest that we rethink the widespread use of PSA testing, especially the yearly screening that is common in the United States.
The bone-thinning condition known as osteoporosis can be a big problem for older people. That’s why older folks are urged to have their bones checked with a test that measures bone density. Exactly how often to have the test hasn’t yet been set. By following 5,000 older women for almost 17 years, researchers found that the timing of the next bone mineral test should depend on the result of the current one. People who get a normal result can wait 15 years, those with moderate osteopenia should have the test every five years, while those with severe osteopenia should have it every year.