Another study finds beneficial health effects from eating real foods - this time eating Montmorency tart cherries reduces blood pressure and insulin levels up to 5 hours after ingestion. Of course. It was a small study done in the United Kingdom, with only 11 middle-aged participants, all with metabolic syndrome (increased blood pressure, high blood sugar, excess body fat around the waist, and abnormal cholesterol or triglyceride levels). It is estimated that about a third of U.S. adults have metabolic syndrome, which significantly increases the risk of cardiovascular disease and type 2 diabetes.
It was a nicely designed study, and the Montmorency tart cherries were taken in either juice form or capsules which contained freeze-dried Montmorency tart cherry powder. Drinking the juice had slightly better health effects than the freeze dried capsules. It would have been nice if they had also looked at a group of people eating fresh Montmorency tart cherries, rather than just juice or freeze dried cherries.
Keep in mind that this study found positive health effects from real food. However, in contrast, studies find that taking supplements and vitamins generally don't result in health benefits (e.g. calcium, omega-3, niacin, antioxidants), and can even cause harm - unless one has a nutritional deficiency. Studies also don't find that there are "superfoods" - instead, what is beneficial or not is the overall dietary pattern. Studies show that a diet rich in fruits, vegetables, whole grains, nuts, seeds, and legumes has many health benefits (something along the line of the Mediterranean dietary pattern). Try to eat a variety of fruits and vegetables - each has different micronutrients, and even different microbes (good!). Eating that way also results in a high fiber intake, which has many health benefits.
Montmorency tart cherries reduced systolic blood pressure, insulin levels and insulin concentrations in adults with metabolic syndrome participating in a small pilot study published in the Journal of Functional Foods.
While previous studies on Montmorency tart cherries have explored individual aspects of metabolic syndrome - such as blood pressure and triglycerides - this is the first study to examine the full cluster of conditions that comprise metabolic syndrome, including insulin resistance, hypertension and central obesity, or belly fat. Nearly 35% of U.S. adults are estimated to have metabolic syndrome, which significantly increases the risk of cardiovascular disease and type 2 diabetes.
"Our most noteworthy cardiovascular response observed in the study was the significant reduction in systolic blood pressure for the first two hours after consumption," said lead author Terun Desai, from the School of Life and Medical Sciences at the University of Hertfordshire in Hatfield, UK. "The unique composition of tart cherries, including the synergistic influence of anthocyanins, other polyphenols, and fiber may be a factor."
A group of 11 men and women, ages 37-61, participated in this randomized, placebo-controlled crossover trial. All participants met at least three of the five criteria for metabolic syndrome (waist circumference > 35 inches for women or 40 inches for men, high or borderline high triglyceride levels, low levels of HDL, high blood pressure, and high fasting blood sugar).
During the 6-week study, on three different occasions, each separated by a 14-day washout period, participants consumed either Montmorency tart cherry juice (30 ml of juice concentrate mixed with 100 ml of water), Montmorency tart cherry capsules (10 capsules to match the anthocyanin content of the juice with 130 ml water) or a placebo drink (30 ml of a fruit-flavored syrup mixed with 100 ml of water). The juice contained the equivalent of about 90-110 whole tart cherries and the capsules were made from about 100 whole tart cherries. The placebo drink was matched to the tart cherry juice for calories, taste and visual appearance using maltodextrin (a flavorless carbohydrate), citric acid and red and black food coloring.
The U.K. researchers found Montmorency tart cherry juice led to a significant, clinically-relevant reduction in systolic blood pressure when compared to the placebo 2 hours after consumption, and Montmorency tart cherry juice and Montmorency tart cherry capsules both lowered insulin levels significantly more than the placebo at 1 hour and 3 hours, respectively. Arterial stiffness was also improved 2 hours after consumption of Montmorency tart cherry juice compared to the placebo, however the significance of this finding is unclear as other indicators of vascular stiffness were not improved. No significant differences were found for the other outcomes examined. The results are preliminary and more research is needed with a larger sample size.