So far, the evidence that foods and drinks rich in good bacteria can improve cardiovascular health is promising but limited.
A number of foods — yogurt, sauerkraut, as well as some less-familiar ones such as kimchi and tempeh — are made by fermentation, an age-old tradition for preserving food. These foods, as well as the fermented drinks kombucha and kefir, have been getting buzz in recent years, mostly focused on their potential to enhance gut health. Fermented products contain naturally occurring beneficial bacteria known as probiotics, which are thought to improve digestion.
Probiotics found in fermented foods may also provide modest heart-related benefits, according to a review article published in the Journal of the American College of Cardiology last year. One study found that eating kimchi (see “What are fermented foods?”) daily helped people lose weight and lowered their blood pressure. Another noted improvement in blood sugar and cholesterol levels.
What are fermented foods?Fermented foods are made by allowing microbes to feed on sugar and starch naturally found in the food. This preserves the food and fosters various species of good bacteria (probiotics) and other healthful food metabolites. The following fermented foods are available in most large supermarkets.
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Yes to yogurt
Several small trials suggest that eating yogurt may lower harmful LDL cholesterol and blood markers of inflammation, both of which signal cardiovascular risk. What’s more, population-based studies from different countries suggest that people who eat fermented dairy products such as yogurt and some cheeses have a lower risk of cardiovascular disease compared with people who don’t eat those foods.
“People have been eating yogurt for centuries, and it’s the main source of fermented food in the American diet,” says Dr. Eric Rimm, professor of epidemiology and nutrition at the Harvard T.H. Chan School of Public Health. But we don’t really know if yogurt is healthy because it’s fermented or for some other reason, he says. Also, people who eat healthier diets over all may be more likely to eat yogurt. “If you have a bowl of plain, low-fat yogurt and berries for breakfast, that’s a lot better than having Froot Loops,” says Dr. Rimm.
Now that other fermented products, including beverages such as kefir and kombucha, are becoming more popular, we’ll have a unique opportunity to study their potential health effects, Dr. Rimm says. Although the evidence seems to favor adding fermented products to your diet, pay attention to what else the foods contain that might be less desirable for your heart health.
Mind the salt and sugar
For example, sauerkraut, kimchi, and pickles tend to be quite high in sodium, which can raise blood pressure. In fact, in the kimchi study noted above, people ate three servings (100 grams) a day. That amount (a total of about 3/4 cup) contains close to 1,000 milligrams (mg) of sodium. The American Heart Association (AHA) recommends no more than 2,300 mg of sodium daily and ideally less than 1,500 mg.
Some yogurts also contain three or more teaspoons of added sugar per serving. That’s half the daily limit of added sugar the AHA suggests for women and a third of the suggested limit for men. High-sugar diets have been linked to a higher risk of heart disease.
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