The new research, presented at the April 19 Experimental Biology convention in New Orleans highlights the potential of blueberries in reducing risk factors associated with cardiovascular disease and metabolic syndrome. The effect is thought to be due to the high level of phytochemicals - naturally occurring antioxidants - that this superfood contains, and researchers believe that blueberries may change the way we processes fat and sugar in our diet.
The study was performed on rats. Scientists studied the effect of a blueberry-enriched powder that was mixed into the rat diet, as part of either a low- or high-fat diet. They performed comparisons between the rats consuming the test diets and the control rats receiving no blueberries.
In all, after 90 days, the rats that received the blueberry-diet, measured as 2 percent of their diet, had less abdominal fat, lower triglycerides, lower cholesterol, and improved fasting glucose and insulin sensitivity, which are measures of how well the body processes glucose for energy. They also had lower body weight, lower total fat mass and reduced liver mass. An enlarged liver is linked to obesity and insulin resistance, a characteristic of diabetes.
Although the study was carried out on rats, the researchers hope that they also have implications for human health. Many people suffer fatty liver disease and metabolic syndrome as a result of high-polyunsaturated and oxidized fat diets and obesity. Metabolic syndrome is a group of health problems that include too much fat around the waist, elevated blood pressure, elevated blood sugar, high triglycerides, and together these conditions increase the risk of heart attacks, strokes and diabetes.
Blueberries contain beneficial flavonoids such as anthocyanins, which protect and strengthen blood vessels and help transport nutrients around the body, and resveratrol, a flavonoid that protects against inflammation. One serving of blueberries provides as many antioxidants as five servings of broccoli, apples or carrots, and many studies have ranked them above all other fruit and vegetables for antioxidant activity.
To enjoy the full range of health benefits of blueberries, they are best eaten raw as part of a healthy, well-balanced diet. When cooked or dried, much of their Vitamin C content is destroyed, although they retain some flavonoid activity.