Harvard Health Blog

Is red meat bad for your heart? A new study suggests it is, but not for the reasons you might expect—like the saturated fat or cholesterol in red meat. A team from a half dozen U.S. medical centers says the offending ingredient is L-carnitine, an amino acid that is abundant in red meat. Their work shows that eating red meat delivers L-carnitine to bacteria that live in the human gut. These bacteria digest L-carnitine and turn it into a compound called trimethylamine-N-oxide (TMAO), which has been shown to cause atherosclerosis, the disease process that leads to cholesterol-clogged arteries, in mice. There’s still a long way to go before we know the full story about L-carnitine and heart disease, but this work suggests that cutting back on L-carnitine (and avoiding L-carnitine supplements) may be good steps for heart health.

Salt is a cheap, easy way to turn on taste buds. That’s one reason why it’s in so many of the foods we eat. It’s so commonly used that most Americans consume more than double the recommended daily limit for it. Three new studies in BMJ (formerly the British Medical Journal) once again confirm the relationship between salt intake and health problems. They show that reducing salt intake can help lower blood pressure and lower the odds of having a heart attack or stroke or developing heart failure. They also show that consuming more potassium is also linked to lower blood pressure and lower risk of stroke. Current dietary guidelines recommend that Americans get no more than 1 teaspoon of salt a day. That’s the equivalent of 2,300 milligrams (mg) of sodium a day. Most Americans get much more than that. It’s possible to cut back by avoiding processed and packaged foods, using herbs and spices to season food instead of salt, and other strategies. It’s best to get potassium from food, especially fruits and vegetables. Green leafy vegetables, beans, and bananas have a lot of potassium.

Chest pain brought on by exercise or stress, a condition known as angina, holds back millions of Americans from living life to the fullest. There’s long been a perception that angina symptoms in women are different than they are in men. Doctors often use the term “typical angina” to describe the angina symptoms that men relate. Symptoms more commonly described by women have been dubbed “atypical angina”—suggesting that women are somehow experiencing an unusual manifestation of heart trouble. A new Harvard study shows that women and men probably experience the same symptoms, but describe them differently. By any name or description, chest discomfort is crucial for women—and their doctors—to pay attention to. And that means acknowledging the possibility of angina no matter how a women describes suspicious chest-related symptoms.

Physical and mental activities are both important for protecting your thinking skills and warding off dementia. But does one trump the other? A study published yesterday in JAMA Internal Medicine tried to tease out if one was better than the other for brain health. Researchers recruited 126 older adults who felt that their memory or thinking skills had recently gotten worse, and divided them into four groups. All were asked to do an hour of mental activity three times a week and an hour of physical activity three times a week. What differed were the intensities of these activities. After 12 weeks, scores on thinking tests improved across the board. The big surprise was that there weren’t any real differences in improvement between the groups. The researchers concluded that the amount of activity is more important for stimulating the brain than the type of activity, because all of the participants both exercised and engaged in mental activities each week.

Chronic pain in the muscles and joints can make life miserable. Standard treatments like ice and heat, anti-inflammatory medications, physical therapy, and appropriate exercises can often ease the pain. But when they don’t, acupuncture is an option with a good track record that’s worth considering. Research from an international team of experts adds to the evidence that it does provide real relief from common forms of pain. The team pooled the results of 29 studies involving nearly 18,000 participants. Overall, acupuncture relieved pain by about 50%. The study isn’t the last word on the issue, but it is one of the best quality studies to date and has made an impression. For new pain, an acupuncturist should not always be the first stop. It’s important to get a clear diagnosis of what is causing the pain to rule out serious medical conditions that should be treated right away—and then seek out acupuncture if appropriate.

If you are worried about your weight, paying more attention to what you eat, not less, could help keep you from overeating. Multitasking—like eating while watching television or working—and distracted or hurried eating can prompt you to eat more. Slowing down and savoring your food can help you control your intake. That’s the bottom line from a report published in the April issue of the American Journal of Clinical Nutrition. It offers two key conclusions: 1) Being distracted or not paying attention to a meal tended to make people eat more at that meal. 2) Paying attention to a meal was linked to eating less later on. Mindful eating is a good solution. It can reduce daily calorie intake, help make healthier food choices, and add to the enjoyment of eating.

Chelation therapy removes metals that have built up in the body. It is an FDA-approved way to treat mercury, lead, and other types of heavy-metal poisoning, as well as for iron overload (hemochromatosis) and some types of anemia. It has also been touted as an alternative therapy that can cure heart disease. Results from the 10-year, $31 million Trial to Assess Chelation Therapy (TACT) show that it slightly reduced the risk of heart problems in heart attack survivors. Proponents of chelation therapy will say this proves what they’ve been preaching. But the editors of JAMA, which published the trial results say that the findings “should serve to dissuade responsible practitioners from providing or recommending chelation therapy for patients with coronary disease and should discourage patients with previous MI [heart attack] from seeking this therapy with the hope of preventing subsequent cardiovascular events.”

Type 2 diabetes doesn’t usually appear all of a sudden. Many people have a long, slow, invisible lead-in to it called prediabetes. During this period, blood sugar levels are higher than normal. However, they’re not high enough to cause symptoms or to be classified as diabetes. It’s still possible at this stage to prevent the slide into full-blown diabetes. Think of prediabetes as a wake-up call. Unfortunately, few people ever hear the alarm. A new report from the Centers for Disease Control and Prevention shows that among Americans age 20 and older, only 10% of those with prediabetes know they have it. Given that as many as 73 million Americans have prediabetes, that’s a lot of missed opportunities to prevent the ravages of diabetes. One reason many people don’t know that they may be headed toward diabetes is they’ve never had their blood sugar tested. This simple test isn’t part of routine preventive care, but perhaps it should be.

All-you-can-eat buffets are a boon for hungry, thrift diners and a nightmare for dieters or those trying to maintain a healthy weight. If you are in the latter camp, here are two tips from Brian Wansink, the master of mindful eating: 1) Take a walk around the entire buffet to scope out your options before serving yourself. 2) Put your food on a small plate instead of a big one. Those come from observations of more than 300 men and women dining in two dozen all-you-can-eat Chinese restaurants. Understanding the many factors that influence what and how you eat can help you take more control of your eating habits. Who you eat with, how you are feeling, and activities like parties or shopping can influence when and how much you eat.

Tiny shock absorbers in the knee (each one is called a meniscus) provide a key cushion between the thighbone and the shinbone. They are prone to tearing, and sometimes just wear out. A torn meniscus can cause pain or other symptoms, like a knee that locks. But sometimes they don’t cause any symptoms. In a youngish person, when a knee-wrenching activity like skiing, ultimate Frisbee, or slipping on the ice tears a meniscus, the damage is often repaired surgically. But a torn meniscus is often seen in the 9 million Americans with knee osteoarthritis, and for them the best course of action hasn’t been crystal clear. Results of the Meniscal Tear in Osteoarthritis Research (MeTeOR) trial published yesterday in the New England Journal of Medicine indicate that physical therapy may be just as good as surgery. Both therapies led to similar improvements in knee function and pain at six and 12 months.

New guidelines for recognizing and managing sports-related concussions could help protect the brains of millions of athletes at all levels of play, from professional football to youth soccer. The guidelines, released today by the American Academy of Neurology (AAN), replace a now-outdated set published in 1997. The guidelines step away from trying to “grade” concussions or diagnose them on the field or sidelines. Instead, they focus on immediately removing from play athletes who are suspected of having a concussion until they can be evaluated. “When in doubt, sit it out.” The AAN estimates that concussions cause between 1.6 million and 3.8 million mild brain injuries each year. Many athletes don’t get medical attention for these injuries, often because they or their coaches don’t recognize the warning signs or take them seriously. The new guidelines should help better identify athletes who have suffered concussions and improve how concussions are managed and treated.

Americans drive while talking on a cellphone or texting more than their counterparts in seven European countries. A report published yesterday showed that 69% of American drivers surveyed said they had talked on a cellphone while driving at least once in the previous month (31% said they did it “regularly or fairly often”), and 31% said they had read or sent text messages while driving. The least distracted drivers were in the United Kingdom. Not surprisingly, younger drivers were more likely to have reported talking on a cellphone or texting while driving. The statistics on distracted driving are chilling: In 2011 (the last year with complete statistics), 3,331 people were killed in motor vehicle crashes involving a distracted driver, and nearly 400,000 were injured. The National Highway Traffic Safety Administration estimates that distracted driving accounts for about one in five crashes in which someone was injured.

If you or a loved one has a latex allergy or sensitivity, think twice before reaching for a product that says “latex free” or “does not contain latex.” That’s the latest advice from the FDA, which says no existing tests can show that a product is completely free from latex. Labeling that suggests a product doesn’t contain the substance could cause trouble for individuals with a latex allergy or sensitivity. Natural latex is used to make a host of stretchy products, including adhesive bandages, condoms, gloves used in health care and dishwashing, balloons, rubber band, elastic used in waistbands and socks, baby bottle nipples, pillows, and more. This kind of latex contains proteins that set off some people’s immune systems, leading to an allergic reaction. The FDA’s warning highlights that products advertised as “latex-free” may not always live up to the claim. That’s because products that are made without latex can be contaminated with latex proteins during the manufacturing or packaging process.

It always takes me a few days to get used to Daylight Saving Time. While I love the extra hour of light at the end of the day, I’m not so wild about the extra hour of darkness in the morning or waking up an hour earlier than I need to. And I sure miss the hour of sleep I lost yesterday. That lost hour seems to be a big deal. A report in this month’s American Journal of Cardiology details the jump in heart attacks seen in a large Michigan hospital the first week after the start of Daylight Saving Time, and the small decline after it ends in the fall. A few years back, researchers showed a similar pattern in Sweden. The number of traffic accidents are similarly affected. In a Canadian study, there were more accidents on the Monday after the start of Daylight Saving Time than there were on the Monday the week before the change. If ever there was a perfect day for a nap, today would be it. A single nap won’t fully reset your body clock or make up for a lost hour of sleep, but it can help. It’s also a good way to stay sharp, especially in the afternoon.

Americans are a diverse lot, so it’s no surprise they give different answers when asked about their well-being. But it seems that well-being differs from state to state, too. In the latest Gallup-Healthways Well-Being Index, which gauges the physical and emotional health of people in all 50 states, residents of Hawaii reported the best sense of overall well-being while West Virginia residents reported the worst. The index calculates overall well-being based on six quality of life categories, each of which is made up of several components. Poll respondents in Hawaii had the highest scores in the emotional health and work environment indexes, and were most likely to say they were thriving. People in West Virginia were most likely to say they were not thriving, and had the worst emotional health, the worst health habits, the most diagnoses of depression, and high rates of obesity. People in the other 50 states fell in between. It’s possible to change both emotional and physical well-being, and improve happiness.

The toll taken by medical mistakes burst into public attention with a 1999 report called To Err Is Human from the U.S. Institute of Medicine. The report estimated that between 44,000 and 98,000 people die each year as a result of preventable medical errors. Such errors can be headline grabbers, like the death of Boston Globe columnist Betsy Lehman from an overdose during chemotherapy. The safety of hospital stays and encounters with health-care providers got a boost today with the publication of 22 evidence-based “patient safety strategies.” Although most focus on care that takes place in hospitals, they extend to almost all interactions between individuals and their doctors, nurses, and other care providers. Very few of the safety practices are expensive, high-tech interventions. Instead, they are almost old-fashioned efforts that aim to improve communication between health-care providers and their patients, and to improve the practice of medicine rather than the art of medicine. The theme of all of these interventions is to create systems that help caregivers follow every step that is known to improve patient care, and to avoid relying on fallible human memory. To err may be human, but it is also often preventable.

Five seemingly different mental health disorders—major depression, bipolar disorder, schizophrenia, autism, and attention-deficit hyperactivity disorder—may be more alike than we think. A ground-breaking new study has identified four regions of the genetic code that carry same variations in people with these disorders. Two of the affected genes help control the movement of calcium in and out of brain cells. That might not sound like much, but this movement provides a key way that brain cells communicate. Subtle differences in calcium flow could cause problems that, depending on other genes or environmental factors, could eventually lead to a full-blown mental illness. But this work offers tantalizing hints that bipolar disorder, major depression, and schizophrenia—and possibly autism and attention-deficit hyperactivity disorder—may not be so distinct after all, but could be different manifestations of the same underlying disorder. This could change the way we view mental illness and open the door to more effective therapies.

People tend to think that the telltale sign of depression is sadness—a pervasive down, dragging feeling that won’t let up, day after day. But depression often manifests itself as something else entirely—like aches and pains or memory lapses. These “unusual” symptoms are actually quite common. They can mask depression—and delay an important diagnosis—especially in older people, who often display their depression in ways other than sadness. These include trouble sleeping, lack of energy, fatigue, trouble concentrating or remembering, loss of appetite, and aches and pains that don’t go away. If you have one or more of these symptoms that can’t be traced to an illness or ailment, a frank talk with a trusted doctor about the possibility of depression might be a good step forward.

The results of a new trial being made public today should get everyone interested in following a Mediterranean-style diet. What makes these new results so important is that they come from a randomized controlled trial, what many consider to be the gold standard of medical research. In the five-year trial, there were fewer heart attacks, strokes, and deaths from cardiovascular disease among participants who followed a Mediterranean-type diet than among those following a low-fat diet. A Mediterranean-style approach to food represents a diet of abundance, not restriction. Add not smoking and daily physical activity to this flexible eating strategy and you have a blueprint for protecting, and perhaps even improving, health.

Memory slips are aggravating, frustrating, and sometimes worrisome. When they happen more than they should, they can trigger fears of looming dementia or Alzheimer’s disease. But there are some treatable causes of forgetfulness.

The message that drinking a little alcohol is good for the heart has gotten plenty of attention. A new study linking alcohol with increased risk of dying from various cancers may temper that message a bit. About 4% of cancer deaths worldwide are related to alcohol use. A new study shows the in the United States, alcohol causes 3.5% of cancer deaths, or about 20,000 cancer-related deaths each year. The most common alcohol-related cancers were mouth, throat, and esophageal cancer in men, and breast cancer in women. At the same time, drinking alcohol in moderation (no more than two alcoholic drinks a day for men and no more than one a day for women) has been linked to lower rates of heart disease and deaths related to it. Advances in genetics may one day let us predict more accurately who can use alcohol in moderation and who should avoid it completely. Until then, it’s best to personally weigh the benefits and risks, ideally with a trusted health care provider.

The term “chocoholic,” usually said with a smile, actually nods to a potentially serious question: can a person become addicted to food? There are three essential components of addiction: intense craving, loss of control over the object of that craving, and continued use or engagement despite bad consequences. People can exhibit all three of these in their relationships with food. It’s most common with foods that deliver a lot of sugar and fat — like chocolate — because they trigger reward pathways in the brain. In some animal studies, restricting these foods induced a stress-like response consistent with the “withdrawal” response seen in addiction. Much of the scientific discussion about food addiction has been sparked by the epidemic of obesity sweeping the U.S. and many other countries. Many people who are overweight crave food, lose control over eating, and experience negative health effects that should, but don’t, serve as a deterrent. The influence of stress on eating provides another link between food and addictive behavior.