Harvard Health Blog
The results of a clinical trial reported in yesterday’s Annals of Internal Medicine showed that low-carb diets helped people lose weight better than low fat diets. A report in today’s Journal of the American Medical Association tells a somewhat different story. A review of 48 head-to-head diet trails showed that average weight loss on either a low-carb or low-fat diet for 12 months was the same, about 16 pounds. And when the researchers compared named diets, which ranged from the low-carb Atkins and South Beach diets to moderates like Weight Watchers and Jenny Craig and low-fat approaches like the Ornish diet, all yielded similar weight loss. The main message from careful comparisons of different diets is that there’s no single diet that’s right for everyone. Any healthy diet can help people lose weight. And there’s more to a diet than weight loss. What’s needed for long-term health is an eating plan that can be followed day in and day out that is good for the heart, bones, brain, and every other part of the body. One eating strategy that can provide all that is the so-called Mediterranean diet.
A heart attack in progress is a medical emergency. The leading way to stop it is with artery-opening angioplasty. But many angioplasties are done for reasons other than heart attack. Some are performed to ease chest pain that appears with physical activity or stress. This is the chest pain known as stable angina. Sometimes the prospective patient has no symptoms at all — just test results that indicate one or more clogged arteries. Cardiologists continuously debate when it’s appropriate to do non-emergency angioplasty. Two studies in JAMA Internal Medicine add some provocative new information: that incomplete or even misleading advice from doctors contributes to unnecessary angioplasties. And that’s a problem because angioplasty can harm as well as help.
Probiotics, the beneficial bacteria found in yogurt and other cultured foods, have long been touted for their ability to ease digestive woes. The strongest evidence for probiotics is in treating diarrhea caused by a viral infection or from taking antibiotics. Do probiotics also work for the opposite problem — constipation? A report from King’s College in London showed that taking probiotics can help soften stools, making them easier to pass, and can increase the number of weekly bowel movements. What we don’t know is which probiotic species and strains are most effective, how much to take, and for how long.
Screening — checking a seemingly healthy person for signs of hidden disease — is an important part of routine medical care. It is done for various types of cancer, heart disease, diabetes, and other chronic conditions. Screening makes sense when finding and treating a hidden condition will prevent premature death or burdensome symptoms. But it doesn’t make sense when it can’t do either. That’s why experts recommend stopping screening in older individuals, especially those who aren’t likely to live another five or 10 years. Yet an article published online in JAMA Internal Medicine shows that many doctors still recommend cancer screening tests for their older patients. Many don’t benefit, and some are even harmed by the practice. Asking people who can’t benefit from a cancer screening test to have one is a waste of their time and money, not to mention a waste of taxpayer money (since these tests are usually covered by Medicare). Screening tests can also cause physical and mental harm. Decisions about cancer screening should be mutually made by an individual and his or her doctor. Equally important, the person should be well informed about the risks of the test and about what will happen if a test suggests there may be cancer that won’t shorten the his or her life.
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.
Obstructive sleep apnea is a common cause of daytime sleepiness. It occurs when the muscles in the back of the throat relax too much during sleep. This lets the tissues around the throat close in and block the airway. People with obstructive sleep apnea can wake up gasping for breath scores of times a night, usually without knowing it. Obstructive sleep apnea can boost blood pressure and increases the risk of stroke. New guidelines from the American College of Physicians recommends an overnight sleep test to diagnose, or rule out, obstructive sleep apnea for individuals with unexplained daytime sleepiness. These are usually done in a sleep center, but home tests can also be done using a portable monitor.
Nearly 40,000 people a year die by suicide in the United States alone. Each of these deaths leaves an estimated six or more “suicide survivors” — people who’ve lost someone they care about deeply and are left grieving and struggling to understand. The grief process is always difficult. But a loss through suicide is like no other, and grieving can be especially complex and traumatic. People coping with this kind of loss often need more support than others, but may get less. Why? Survivors may be reluctant to confide that the death was self-inflicted. And when others know the circumstances of the death, they may feel uncertain about how to offer help.
People who want to follow a healthy diet sometimes need a little help knowing where a meal or snack falls on the healthfulness scale. Several apps let you snap a photo of what you’re about to eat and post it for all to see — and rate. And though many of the “raters” are regular folks without training in nutrition, a new study shows they do a pretty good job gauging whether foods are likely to make you fitter or fatter.
A new report in JAMA Neurology offers yet another reminder why keeping your blood pressure in the healthy range for as long as you can is a good life strategy. Researchers with the long-term Atherosclerosis Risk in Communities (ARIC) Neurocognitive Study found that memory and thinking skills declined significantly more over the course of a 20-year study in middle-aged people with high blood pressure than it did in those with healthy blood pressure. Interestingly, those who had normal blood pressure in midlife but who developed high blood pressure in their late 60s, 70s, and 80s didn’t have similar declines as those who developed high blood pressure earlier. The main take-home lesson from this study? The longer you live with normal blood pressure, the less likely you are to have memory and reasoning problems when you’re older.
The news and images out of West Africa, the center of an outbreak of deadly Ebola virus, are a bit scary. In the three countries affected by the outbreak —Liberia, Sierra Leone, and Guinea — more than 1,300 people have been sickened by the virus and more than 700 have died. Liberia closed its borders in an effort to prevent the infection from spreading. Images of health workers in protective gear ministering to patients and disinfecting the dead flash across screens. The Peace Corps has pulled all of its volunteers out of the three countries, and U.S. health officials have issued a warning not to travel to this area. We live in an interconnected world in which air travel can spread contagious infection thousands of miles away in a few hours. The director-general of the World Health Organization has warned that this outbreak is moving faster than our efforts to control it and it comes with a high risk of spread to other countries. If Ebola does spread, containing the epidemic will take a level of cooperation on the part of the global public that we’ve never before needed.