Wednesday, May 4, 2016
Cranberry Juice Can Boost Heart Health
Drinking two glasses of cranberry juice a day can lead to significant heart health benefits, according to a study led by Janet Novotny, an Agricultural Research Service (ARS) physiologist at the Beltsville Human Nutrition Research Center in Beltsville, Maryland.
Novotny gave 56 people either low-calorie cranberry juice or a similar-tasting placebo twice a day for 8 weeks and found that the juice lowered several risk factors for cardiovascular disease (CVD), diabetes and stroke. The 30 women and 26 men were given 8-ounce servings at breakfast and dinner in a double-blind study in which they ate only foods provided as part of the study.
The cranberry juice was sweetened with sucralose and had the same juice content (27 percent) and nutrients as most sugar-sweetened cranberry juice available in stores. The placebo was a flavor-matched, calorie-matched, artificially colored beverage. The research was funded by Ocean Spray Cranberries Inc. Ocean Spray provided the juice, but was not involved in conducting the study or analyzing the results.
After 8 weeks, volunteers given the juice had lower levels of 5 of 22 indicators of cardiometabolic risk in their blood, compared with volunteers given the placebo. The differences could be considered “a notable result,” Novotny says. Cardiometabolic risk is the combined risk of cardiovascular disease (CVD), diabetes and stroke, which together causes more deaths in the developed world than anything else. CVD alone causes 930,000 deaths in the United States each year. Risks of developing CVD, diabetes and stroke can be modified with diet and exercise.
The results showed that volunteers given the juice had lower levels of 5 of 22 risk factors compared to volunteers on the placebo. “Finding differences in 5 of 22 factors is a notable result,” Novotny says.
The effects included lower levels of triglycerides (8 percent), C-reactive protein (44 percent), diastolic blood pressure (3 percent), glucose (2 percent), and a health indicator known as “homeostasis model assessment of insulin resistance,” or HOMA-IR (3 percent). Triglycerides are type of fat in the blood, and high levels increase the risk of heart disease. Higher levels of C-reactive protein may be associated with increased risk of CVD. High blood pressure can lead to stroke and high glucose. HOMA-IR levels increase the risk of diabetes.
Previous studies have shown that cranberries are rich in the types of polyphenols associated with a reduced risk of heart disease, diabetes and stroke. But Novotny’s study is the first to show that cranberries confer such health benefits in a controlled-diet, double-blind clinical trial, which is considered the gold standard in health and medical research.