Tart cherries, a relatively new entrant to the superfruit category, have been shown to benefit heart health as well as body weight, in a study on obese rats.
The University of Michigan researchers found that after 12 weeks, rats fed cherries had 54 per cent body fat compared with 63 per cent for those rats fed a “Western diet”.
This was particularly so in fat deposited around the waist area, which contributed most to heart disease risk, according to the American Heart Association.
The researchers said the high levels of antioxidants found in tart cherries were responsible for the heart health benefits. They also noted cherry consumption may effect important fat genes and genetic expression.
Tart cherries had the potential to lower cholesterol and reduce inflammation which had heart benefit links, the Cherry Marketing Institute-funded study found. It will be presented at the annual meeting of the America Dietetic Association next week.
The conditions the study references are often grouped together as Metabolic Syndrome.
The rats were fed either a HFMC (high fat and moderate carbohydrate diet – 45 per cent kcal from fat, 40 per cent from carbohydrate). Others were on a LFHC (low fat, high carbohydrate – 10 per cent kcal from fat, 75 per cent from carbohydrate) diet.
These diets either came with or without added whole tart cherry powder, totalling one per cent of the diet.
Those rats being fed cherry-enriched diets reduced total cholesterol levels by about 11 per cent.
Inflammation marker TNF-alpha was reduced by 40 per cent and interleukin 6 (IL-6) was lowered by 31 per cent. In their genetic analysis, the researchers found the cherry-enriched diets reduced the genes for these two inflammation compounds, suggesting a direct anti-inflammation effect.
“The findings suggest that physiologically tart cherry-enriched diets reduce plasma triglycerides, central adiposity, and systemic inflammation, known risk factors for Type II diabetes and cardiovascular disease,” the researchers wrote.
While inflammation is a normal bodily recuperation process, chronic inflammation can increase the risk for diseases and is thought to be more prevalent in the overweight or obese.
The researchers said the study should prompt further clinical studies in humans to explore the link between diet, weight, inflammation and lowering heart disease risk.
“This research gives us one more support point suggesting that diet changes, such as including cherries, could potentially lower heart disease risk,” said Dr Steven F. Bolling, a cardiac surgeon at the University of Michigan Cardiovascular Center, and head of the U-M Cardioprotection Research Laboratory, where the study was performed.
The LFHC diet significantly increased plasma triglycerides, an effect that was significantly reduced in cherry-fed rats.
Nearly two out of three Americans are overweight, a figure that is replicated in most Western countries.
While the Cherry Marketing Institute funded the study it was not involved in its design, conduct or analysis. Other tart cherry studies conducted at the University of Michigan have highlighted osteoporosis benefits.
Tart cherries are frequently sold in dried, frozen or juice form.
Source: Journal of the American Dietetic Association
Volume 108 , Issue 9 , Pages A14 - A14 E
“The Effect of Tart Cherry-Enriched Diets on Abdominal Fat Gene Expression in Rats”
Authors: EM Seymour, A Lewis, A Kirakosyan, S Bolling.