Preventive care Archive

Sodium doesn't affect everyone equally, but there's good reason to stick to moderate amounts in your diet.

On average, Americans eat too much salt — more than a teaspoon and a half a day. Most often it doesn't come out of a shaker, but is hidden in the foods you eat. But is it really bad for your heart to eat too much, or is that just a concern for people with certain risk factors? There's been some debate on this topic, even among members of the scientific community. We asked Nancy Cook, a professor of medicine at Harvard Medical School, for her thoughts on salt — or more precisely, sodium, a mineral that makes up 40% of salt — and how it affects your health and your heart.

Is salt really bad for your heart?

"There is a fairly undisputed effect of sodium on blood pressure," says Cook. The effect is stronger in people with high blood pressure (hypertension), a sustained blood pressure reading of 120/80 or higher. The data for an effect on cardiovascular disease are somewhat more controversial, she says, but in general, the bulk of research does seem to link lower sodium intake with both lower blood pressure and a lower risk of cardiovascular disease.

Whole grains contain fiber and nutrients that can help your health.

It's a low-carb world, and many people are pushing grains off their plate in an effort to control their waistline. But they may be doing their body a disservice. Whole grains have some unique properties that make them a valuable addition to the diet. Not only do they contain a host of nutrients, such as iron, B vitamins, copper, zinc, and magnesium, but studies have linked diets rich in whole grains to a lower risk of colon cancer, which is a growing health threat for many younger Americans.

"The main benefit of whole cereal grains, such as wheat, oats, and barley, is in the fiber," says Teresa Fung, adjunct professor in the Department of Nutrition at the Harvard T.H. Chan School of Public Health. "Cereal fiber is different from vegetable fiber or bean fiber."

Research we're watching

Do you know someone who is taking supplements in hopes of boosting their energy levels, gaining muscle, or losing weight? You may want to warn them about potential dangers. A study published online June 5, 2019, by the Journal of Adolescent Health found that products sold to boost energy, promote weight loss, or build muscle were linked to three times the number of severe medical events compared with vitamins. Researchers came to this conclusion after looking for supplement-related adverse events reported between January 2004 and April 2015 to the FDA. In total, they identified 977 cases of harm linked to supplements. Of those, 40% were severe medical events that resulted in death or hospitalization. While energy, weight loss, and muscle-building supplements appeared to be the riskiest, products sold to promote sexual function or to cleanse the colon were problematic as well. The FDA has found that some of these supplements contain dangerous substances or contaminants, such as pesticides, harmful chemicals, or heavy metals. Past studies have connected weight-loss and muscle-building supplements with serious, sometimes fatal, health problems, including liver damage, stroke, and testicular cancer.

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Research we're watching

If the contents of your lunch bag are looking less than wholesome, you're not alone. A survey sponsored by the American Heart Association found that more than half of Americans who eat lunch at work reported that their midday meal often falls short when it comes to good nutrition. In addition, 91% of those surveyed said they would be interested in making healthier lunch choices. So, what's making people choose less healthful lunch options? Top reasons included the convenience of unhealthy foods (cited by 60% of respondents), taste (54%), and a lack of healthy food options (cited by 43%). If you're looking to improve your own lunch quality, the American Heart Association offers some tips on its website at www.heart.org/healthyforlife.

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Ask the doctor

Q. My smartphone tells me how many steps I take each day, but I don't know how many I should shoot for. What should my goal be?

A. You've read in these pages and elsewhere that regular physical activity reduces the risk of heart disease, type 2 diabetes, obesity, and possibly several types of cancer. Regular exercise also reduces the risk of premature death. No medicine yet invented can claim such benefits. Probably the advice you've heard most often is that moderate exercise — like a brisk walk (at about 3 mph) for 30 minutes at least five times a week — will bring all of the above health benefits.

Bacteria and mold can accumulate in various parts of the device. But regular equipment cleaning reduces risks.

Continuous positive airway pressure (CPAP) can be hard to get used to. The mask may feel bulky, or it may feel strange to have air blowing in as you try to breathe. That keeps many people from using a treatment that may, in fact, be a lifesaver (see "What is CPAP?").

People also can be put off because they've heard that a dirty CPAP machine can make you sick. Is that true? "Yes, if you don't clean the machine regularly," says Dr. Lawrence Epstein, a sleep expert at Harvard-affiliated Brigham and Women's Hospital.

The proper warm-up, equipment, and health considerations are key to maintaining an outdoor routine.

You've grabbed a hooded jacket, and you're ready for a brisk walk in the great outdoors. But is that enough to keep you safe in cooler temperatures? An outdoor exercise routine at this time of year brings unique risks and benefits. You need a little planning and preparation to keep exercising outside in the weeks or months to come.

Know the risks

Being exposed to long periods of cold weather poses numerous health risks.

Simple swaps like whole grains instead of white rice maintain flavor while boosting health benefits.

There's nothing quite like coming in from the cold and sitting down to a hot, hearty meal. The icy temperatures seem to make us yearn for foods that will warm us up inside, stick to our bones, and soothe the soul. "We are warm-bodied creatures, and as the weather cools we actually crave more calories so we can stay warm," explains Sandra Allonen, a registered dietitian with Harvard-affiliated Beth Israel Deaconess Hospital.

But digging into comfort foods all winter — like a savory beef stew, spicy spaghetti and meatballs, macaroni and cheese, fluffy pancakes, gooey pizza, or buttery mashed potatoes — comes with health risks.

News briefs

Sugary drinks are becoming more plentiful at large restaurant chains, and some drinks are getting sweeter. That's according to a study published in the August issue of the American Journal of Preventive Medicine. Harvard researchers analyzed the beverage offerings of 63 fast-food, fast-casual, or full-service restaurant chains from 2012 to 2017. Over that period, the number of sugary beverages available at the restaurants increased by 82%. Among newly introduced sugary beverages such as sodas, fruit drinks, and sports drinks, from 2012 to 2016 the number of calories per drink increased by about 50, and the average amount of sugar per drink reached a whopping 63 grams. Newly introduced sweetened teas roughly doubled in sugar and calories from 2012 to 2016, jumping from an average of about 140 calories per drink to about 300, and from 25 grams of sugar to 56. But remember: the American Heart Association recommends limiting added sugar to 25 grams per day for women and 36 grams per day for men. If you want to splurge on a sugary drink, try not to consume all of it, or chose a lower-sugar option.

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