Food and diet patterns are difficult to study.
Much of our knowledge comes from epidemiological studies that can show associations, but not cause and effect. An example would be a study that reviews the food intake of a population and finds that people who ate more vegetables had a lower incidence of heart disease than anticipated.
This is important information, but not proof of cause and effect. A randomized clinical trial (RCT) provides stronger evidence of cause and effect. This is what was published in January in Clinical Nutrition.
The purpose of the study was to determine whether blueberries, when eaten with a high fat/high sugar meal, could decrease the cardiometabolic dysfunction that follows this type of meal. The 46 subjects were obese with metabolic syndrome.
People with high blood pressure, high blood sugar, excess body fat around the waist and elevated cholesterol or triglycerides have metabolic syndrome. This diagnosis increases the risk of heart disease, stroke and diabetes.
Study subjects were given a high calorie, fat and sugar drink. The experimental group’s drink had powdered blueberries added and the control group had placebo. The anthocyanins in blueberries are protective against most every disease you don’t want. After the drink, blood was drawn at timed intervals for 24 hours.
Results showed that for people with metabolic syndrome, adding the equivalent of one cup of blueberries significantly reduced post meal blood levels of glucose, insulin and cholesterol. Reducing glucose and insulin spikes is beneficial.
Anthocyanins are disease-fighting flavonoids that give pigment to blue, purple, and red foods. Other anthocyanin-rich foods are blackberries, grapes, cranberry, red cabbage, red onion, tart cherries, and the skin of eggplant and plums.
Blueberries are terrific and so are most other colorful vegetables and fruits. Adding colorful vegetables and fruits to your intake throughout the day keeps bad blood spikes away.
Sheah Rarback MS, RDN is a registered dietitian nutrition in private practice in Miami.
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