Harvard Health Blog

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.

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.

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.

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.

There are many reasons why you might want to give someone chocolate on Valentine’s Day. There’s the tradition of it, and the idea of sweets for your sweetheart. Here’s another tempting reason: certain compounds in chocolate, called cocoa flavanols, have recently been linked with improved thinking skills. Italian researchers found people who drank a daily cocoa brew with a lot of flavanols (more than 500 milligrams) significantly improved their scores on tests that measured attention, executive function, and memory. How might cocoa flavanols boost thinking skills? They may help brain cells connect with each other. Dark chocolate is a good source of flavonols. It’s also a good source of calories. Adding it to your diet without taking out other foods can lead to weight gain, which may wipe out any health gain.

Medications can do wonderful things, from fighting infection to preventing stroke and warding off depression. But medications don’t work if they aren’t taken. Some people don’t take their medications as prescribed because they forget, or are bothered by side effects. A new report from the National Center for Health Statistics shines the light on another reason: nearly 1 in 10 people skip medications because they can’t pay for them. Other strategies for saving money on drug costs included asking doctors for lower-cost medications, buying prescription drugs from other countries, and using alternative therapies. Not taking medications as prescribed can cause serious problems. It can lead to unnecessary complications related to a medical condition. It can lead to a bad outcome, like a heart attack or stroke. It can also increase medical costs if hospitalization or other medical interventions are needed. Safe money-saving options include using generic drugs when possible, pill splitting, shopping around, and making lifestyle changes such as exercising more and following a healthier diet, which can sometimes decrease the number and dose of drugs needed.

Men are at greater risk for developing prostate cancer if their fathers or brothers also developed the disease. A new study shows that having second- or third-degree relatives with the disease also increases a man’s risk.

If you are a sociable soul, here’s some interesting news about exercising with others: A study published online in the British Journal of Sports Medicine shows that being part of an outdoor walking group can improve health in many ways, including improvements in blood pressure, resting heart rate, total cholesterol, body weight, body fat, physical functioning, and risk of depression. In addition, people who were part of a walking group tended to keep exercising and not slack off. The findings are interesting because walking group participants reaped health benefits even though many of the groups did not meet international guidelines for moderate activity. This supports the idea that any activity is better than none.

The standard recommendation for exercise is at least 150 minutes of moderate-intensity activity each week. But that may not be the best recommendation for everyone, especially those who are older and have trouble exercising, or those who don’t exercise at all. If we think of exercise as a spectrum, with no activity on one end and 150 minutes or more a week on the other end, there’s a continuum in between. Getting individuals to move along that continuum, from no exercise to a little, a little to more, and so on, is an important goal. New research on the hazards of sitting for prolonged periods should get all of us to sit less and stand or move more.

More than half of the average person’s waking hours are spent sitting: watching television, working at a computer, commuting, or doing other physically inactive pursuits. But all that sitting could be sending some to an early grave. That’s the conclusion of a Canadian study published in this week’s Annals of Internal Medicine. People in the study who sat for prolonged periods of time had a higher risk of dying from all causes — even those who exercised regularly. The negative effects were even more pronounced in people who did little or no exercise. In addition to premature death, the study documented higher rates of type 2 diabetes, cancer, and cancer-related deaths in very sedentary people. If you sit for work, try standing or moving around for one to three minutes every half hour. Better yet, think about working at a standing desk. At home, stand when watching TV or talking on the phone.

Ninety years ago, type 1 diabetes was a death sentence: half of people who developed it died within two years; more than 90% were dead within five years. Thanks to the introduction of insulin therapy in 1922, and numerous advances since then, many people with type 1 diabetes now live into their 50s and beyond. But survival in this group still falls short of that among people without diabetes. A Scottish study published this week in JAMA shows that at the age of 20, individuals with type 1 diabetes on average lived 12 fewer years than 20-year-olds without it. A second study in the same issue of JAMA showed that people with type 1 diabetes with better blood sugar control lived longer than those with poorer blood sugar control.

Although a long-term study has shown that men who had a vasectomy have a slightly increased risk of developed high-grade prostate cancer, not all experts believe that the link is real.

Feeling young may be one way to keep getting older. In a new study, a pair of researchers from University College London found that older people who felt three or more years younger than their actual age were more likely to be alive eight years later than those who felt more than one year older than their actual age. Does a youthful feeling keep people alive? Possibly: feeling younger may lead to better health habits, like exercising and eating healthfully. Feeling younger may also inspire a sense of resilience that keeps people young.

A growing number of aging men are trying to hold on to their youthful vigor by taking testosterone. Unsettling study results suggest that men with low but “normal” testosterone levels who take a testosterone supplement may be increasing their risk of having a heart attack, stroke, or developing heart disease.

If your fingers turn ghostly white and numb when they get cold, you may have Raynaud’s syndrome (or disease or phenomenon). This common condition Raynaud’s is an exaggeration of the body’s normal response to cold. It usually affects fingers and toes, but may also affect the nose, lips, ears, and nipples. Named after the French physician who first described it in 1862, Raynaud’s is a problem in the body’s arteries. They spasm and collapse in response to cold or stress. Without a steady supply of warm blood circulating through them, the affected body part becomes pale. When the spasm ends and the arteries reopen, allowing blood to flow again, the finger, toe, or other body part turns pink or red. It may throb or tingle. Prevention—staying warm—is the best medicine. It’s possible to cut an attack short by running your hands under warm water, putting them in your arm pits, or waving your arms in circles to get the blood flowing. Other options include thermal feedback and relaxation techniques. More experimental options include Botox injections and sildenafil (Viagra).