Nutrition Archive

News briefs

The amount of sodium we're bringing home from the grocery store has dropped significantly in the past two decades, according to a study published online June 5, 2017, by JAMA Internal Medicine. Excess sodium intake is associated with a higher risk of heart disease. Researchers analyzed the sodium in about 1.5 million products purchased by more than 172,000 households in the United States from 2000 to 2014. Sodium in packaged foods brought into these homes declined from about 2,300 milligrams (mg) per person per day to about 1,900 mg per person per day. The declines were seen in all kinds of products — especially those notoriously high in sodium like condiments, sauces, dips, and salty snacks. The study can't tell us if the amount of sodium people consume is also declining. But it's a good reminder to keep an eye on your intake, since a salty diet can lead to high blood pressure, a major risk factor for heart disease and stroke. The American Heart Association says an ideal limit is 1,500 mg of sodium per day for most adults. That's hard to achieve, but being a savvy shopper for lower-sodium foods can help.

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Limiting animal-derived foods is only part of the story.

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If you're not totally sure what constitutes a plant-based diet, you're not alone. Many people believe a plant-based diet means a vegetarian diet — a family of eating patterns that omits some or all foods that come from animals (see "Vegetarian variations").

But plant-based diets don't necessarily exclude animal-derived foods. While the main focus is on plants — grains, vegetables, fruits, legumes (dried beans and peanuts), and nuts — these diets may include limited amounts of fish, meat, poultry, and dairy products.

Research we're watching

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Want to maintain your muscle strength as you age? A study in the July issue of The American Journal of Clinical Nutrition suggests that eating protein at breakfast, lunch, and dinner may help.

While it has been long thought that when you got your protein during the day didn't make a difference as long as your intake was sufficient, emerging research shows that this may not be the case. Researchers in this study looked at a group of 1,741 healthy older men and women in Canada and followed them for three years. They assessed the participants' strength and mobility at the outset of the study, and then tracked their diets and reassessed their strength at the end of the study period. People who ate protein at all three meals throughout the day were stronger at the beginning and the end of the study than those who mostly ate their protein only at dinner — even if they ate roughly the same amount of protein over all.

Find out a Harvard Medical School doctor’s secret to a quick, budget friendly, and simple healthy breakfast.

Beans, lentils, chickpeas, and other "pulses" are loaded with protein, fiber, and other nutrients.

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Legumes are great sources of protein for those on a meat-free diet. Lately one branch of the legume family has been in the international spotlight. "Pulses" are legumes that are harvested for their dried seeds, such as chickpeas (garbanzo beans), lentils, and dried peas and beans. They're such an important protein source that the United Nations declared 2016 the International Year of the Pulses.

"When we as nutritionists talk about beans, most of them are pulses — kidney beans, navy beans, black beans, broad beans, lima beans, butter beans — there are quite a few," says registered dietitian Kathy ­McManus, director of the Department of Nutrition at Harvard-affiliated Brigham and Women's Hospital. By contrast, legumes such as soybeans, peanuts, peapods, and green beans don't count as pulses.

News briefs

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If you haven't been good about eating a healthy diet, take heart: A Harvard study published July 13, 2017, in The New England Journal of Medicine found that changing to one of three scientifically developed healthy eating programs was associated with longer life. The healthy diets included the Alternate Healthy Eating Index, the Alternate Mediterranean Diet, and the Dietary Approaches to Stop Hypertension (DASH) diet. Scientists looked at self-reported diet and health data from nearly 74,000 healthy men and women who significantly improved their diets and maintained them for 12 years. Scientists then looked at participants' risk of death for another 12 years. The results: people who improved their diet the most were up to 17% less likely to die, whereas those whose diets worsened the most were up to 14% more likely to die. This study strongly indicates that improving your diet, even if you start in middle age, can add years to your life — and vice versa. If you're re-evaluating your diet, check out the Harvard Special Health Report Healthy Eating for a Healthy Heart (www.health.harvard.edu/HEHH).

News briefs

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As we reported in May 2016, regularly drinking coffee is associated with lower blood pressure, less weight gain with aging, and less chance of developing type 2 diabetes or dying from cardiovascular or neurological diseases. Now a pair of 16-year studies published July 10, 2017, in Annals of Internal Medicine link coffee drinking with longevity. One study analyzed the coffee consumption of more than 520,000 men and women. People who drank three or more cups of coffee per day — either caffeinated or decaffeinated — were up to 12% less likely to die during the study, compared with people who didn't drink coffee. The other study involved more than 185,000 middle-age or older coffee drinkers who were African American, Native Hawaiian, Japanese American, Latino, or white. Those who drank four or more cups per day were 18% less likely to die for any reason during the study period compared with nondrinkers. This was the first large study of coffee drinking and longevity that included a racially and ethnically diverse group of people. The findings from these studies suggest, but don't prove, that regular coffee drinking helps you live longer. The beneficial effect of coffee seemed to plateau at more than four cups per day.

Research we're watching

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Want to help improve your cholesterol profile? Swap your midmorning muffin for a handful of almonds, suggests a study in the Aug. 1, 2017, Journal of Nutrition.

Nutritionists have long known that eating almonds and other nuts tends to lower harmful LDL cholesterol and raise desirable HDL cholesterol. But recent evidence suggests that the heart-protecting effects of HDL depend on a person's particular complement of the various forms of HDL, some of which are more beneficial than others.

On call

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Q. I keep hearing about how great coffee is for your health. Is this just hype, or are there real benefits?

A. Multiple studies have associated drinking coffee with reduced rates of diseases, such as diabetes, kidney stones, and dementia. However, just because people who drink coffee appear to get certain health benefits, these types of studies don't prove that the coffee itself is the reason.

Ask the doctors

Q. I recently decided to give up soda and switched to flavored seltzer water. Is this a better choice for my health?

A. First, congratulations on giving up soda. Sugary drinks like soda have been linked to an increased risk of type 2 diabetes, heart problems, and other chronic health conditions, so that is definitely a win for your health. Switching to seltzer is a much better choice, provided you choose a brand that is sugar- and calorie-free.