Harvard Health Blog
Some years the flu vaccine works quite well. Other years it doesn’t. It has done a particularly poor job this year against the main flu virus. The CDC reported yesterday that this year’s flu vaccine has been just 18% effective. The estimate for children is even lower. And it looks like the nasal spray vaccine may not have worked at all among children. One reason for this year’s mismatch between virus and vaccine is that experts must decide months in advance which of the hundreds of flu viruses to include in the vaccine. What became the dominant flu virus this year, a new strain of H3N2 influenza A, wasn’t around last year when experts were determining this year’s vaccine.
Sitting in a sauna is one way to chase away the cold. A new report in JAMA Internal Medicine makes this pastime even more appealing: regularly spending time in a sauna may help keep the heart healthy and extend life. Among 2,300 middle-aged Finnish men, those who took a sauna bath four or more times a week were less likely to have died over a 20-year period than those who took a sauna once a week or less. Frequent visits to a sauna were also associated with lower death rates from cardiovascular disease and stroke. Sauna baths are generally safe and likely beneficial for people with well-controlled coronary artery disease or mild heart failure, but may not be so hot for those with unstable angina or a recent heart attack. The high temperature in a sauna can boost the heart rate to a level often achieved by moderate-intensity physical exercise. Is sitting in a sauna the equivalent of exercising? No. But exercising and then taking a sauna seems like a very healthy routine.
Peanut allergies can cause severe and sometimes deadly allergic reactions. A new study holds out the possibility that peanuts themselves may prevent peanut allergies. An international team asked parents of infants who were prone to a peanut allergy to give their children a peanut-based snack called Bamba or peanut butter three times a week until age five. The parents of another group of peanut allergy-prone infants were asked to make sure their children didn’t eat any peanuts, peanut butter, or other peanut-based products until age five. The results were surprising and dramatic. A peanut allergy developed in 1.9% of children who ate Bamba or peanut butter, compared with 13.7% of those who didn’t eat peanuts. This new work suggests that preventing peanut allergies may be a possibility in the near future.
According to conventional medical wisdom, menopause-related hot flashes fade away after six to 24 months. Not so, says a new study of women going through menopause. Hot flashes and related night sweats last, on average, for about seven years and may go on for 11 years or more. The new estimates of the duration of these symptoms come from the Study of Women’s Health Across the Nation (SWAN), a long-term study of women of different races and ethnicities who are in the menopausal transition. The “reality check” the SWAN study provides on hot flashes should encourage women to talk with a doctor about treatment options. These range from estrogen-based hormone therapy to other medications and self-help measures.
If you knew that a vaccine could prevent your daughter or son from developing a relatively common and potentially deadly cancer later in life, would you have her or him get it? Such a vaccine is available, and it’s about to get even better than it is now — but fewer than half of all teens have gotten it. The vaccine helps prevent infection with the human papilloma virus (HPV). It is responsible for cervical cancer, which strikes 12,000 women each year in the United States and kills 4,000. HPV also causes cancer of the vulva, vagina, penis, anus, mouth, and throat. The vaccine, approved in 2006, attacks four types of HPV. The new one attacks nine types, and can help prevent most types of cervical cancer. Some parents worry that having their pre-teen daughters and sons vaccinated against HPV will nudge them into becoming sexually active or becoming sexually promiscuous. Studies, including a new one from Harvard, show that doesn’t happen.
Worrying about a problem or a long to-do list at bedtime can be a recipe for insomnia. Mindfulness meditation — a mind-calming practice that focuses on breathing and awareness of the present moment — can help, according to a report in JAMA Internal Medicine. Mindfulness meditation involves focusing on your breathing and then bringing your mind’s attention to the present without drifting into concerns about the past or future. It helps you break the train of your everyday thoughts and relax. In addition to calling on mindfulness meditation at night to fight insomnia, it’s a good idea to practice it during the day, too, so it’s easier to evoke the relaxation response at night when you can’t sleep.
Getting to a healthy weight and staying there isn’t always easy. Many complicated diets offer solutions. A study published in today’s Annals of Internal Medicine suggests that something as simple as aiming to eat more fiber each day can be just as good as a more complicated diet. In a head-to-head study of a simple diet (eat more fiber) and a complex one (eat more fruits, vegetables, high-fiber foods, fish, and lean protein but also cut back on salt, sugar, fat, and alcohol), participants lost almost the same amounts of weight on either diet. Both diets led to similar improvements in blood pressure the body’s response to insulin. The results of the study don’t prove that a high-fiber diet is necessarily as good (or better) for health than the AHA diet or the highly in-vogue Mediterranean diet. But it does suggest that one simple step can make a difference and that encouraging healthy behaviors may be more effective than discouraging unhealthy ones.
Warnings against eating foods high in cholesterol, like eggs or shrimp, have been a mainstay of dietary recommendations for decades. That could change if the scientific advisory panel for the 2015 iteration of the Dietary Guidelines for Americans has its say. A summary of the committee’s December 2014 meeting says “Cholesterol is not considered a nutrient of concern for overconsumption.” Translation: You don’t need to worry about cholesterol in your food. Why not? There’s a growing consensus among nutrition scientists that cholesterol in food has little effect on the amount of cholesterol in the bloodstream. And that’s the cholesterol that matters. Doing away with the beware-cholesterol-in-food warning would simplify the art of choosing healthy foods. And it would let people enjoy foods that contain higher amounts of cholesterol, such as eggs, shrimp, and lobster, without worrying about it. A better focus is on reducing saturated fat and trans fat in the diet, which play greater roles in damaging blood vessels than dietary cholesterol.
Nearly 2 billion people around the world are anemic, meaning they don’t get enough iron to produce the red blood cells and oxygen-carrying hemoglobin needed to nourish their myriad cells. In developed nations like the United States, though, iron-poor blood is uncommon. The body stores most of its iron in hemoglobin inside red blood cells and in ferritin, a protein that latches onto iron and sequesters it in the liver, spleen, and bone marrow. Most Americans get all the iron they need from food. The body absorbs iron from meat more easily than it absorbs it from plants. Getting enough vitamin C helps the body absorb iron from food. Because the body does not excrete iron rapidly, it can build up over time and possibly cause problems. That’s why it’s a good idea to ask your doctor if you need to take an iron supplement.
Jogging is one of those activities that seems to embody the concept of healthy physical activity. A new study from Denmark may prompt a rethinking of the benefits of strenuous jogging. Researchers with the ongoing Copenhagen City Heart Study found that, compared to healthy but inactive non-joggers, the death rate of light joggers was 90% lower. No surprise there. But the death rate for strenuous joggers was no different than that of sedentary non-joggers. In this study, the most beneficial exercise was jogging at a slow or moderate pace two to three times a week for a total of 60 to 145 minutes. This one study certainly shouldn’t change the current recommendations for physical activity. But it helps debunk the “no pain, no gain” myth of exercise and supports the idea that any activity is better than none—but there may be an upper limit.