The cherries were Montmorency tart cherries grown in northern Michigan, frozen, and powdered. Michigan is the nation's largest producer of tart cherries, which are used in pies and jams as well as juice. They are different from the sweet Bing cherries that are often eaten raw, and have higher concentrations of antioxidant anthocyanins than sweet cherries.
By the end of the study, the rats that received the 1-percent cherry diet had total cholesterol, triglyceride, glucose and insulin levels that were significantly lower than those of the rats that did not receive cherries. The same was true for those on the 10-percent cherry diet, compared with rats that received a diet with an equivalently high level of carbohydrates not from cherries.
The researchers also measured plasma TEAC, a measure of antioxidant capacity in the blood on which a higher reading means better ability to neutralize damaging free radical molecules produced in the body during metabolism. The rats that received cherries had higher antioxidant capacity, indicating lower oxidative stress in their bodies, than those that did not.
In addition to blood measures, the researchers measured the level of fat in the livers of the rats, and the genetic expression of PPAR (peroxisome proliferator-activating receptor) in the liver.
The "fatty liver" measure is important because the storage of excess energy as fat in the liver is a common effect in metabolic syndrome ?and because it feeds the vicious cycle of increased cholesterol and decreased response to insulin that can lead to cardiovascular disease and Type 2 diabetes.
Meanwhile, the measure of PPAR messenger RNA in the liver reflects the readiness of the liver tissue to express functional PPAR. PPAR is important to the process by which the body burns fat instead of storing it, and it is important in the formation of blood lipids like LDL, typi
Source:University of Michigan Health System