Researchers fed a special cultivar of broccoli, a combination of wild and commercially available broccoli that contains high levels of glucoraphanin, to nineteen volunteers each week for three months. They compared the first group to two other groups eating the same diet, except one consumed commercially available broccoli and the third ate none of the crucifer. The team observed that those eating the glucoraphanin-rich vegetable showed signs of an improved metabolism.
The scientists determined that a compound commonly found in crucifers, known as sulforaphane, improved the chemical reactions inside mitochondria, the power source for our cellular machinery. The study found that glucoraphanin helped 'retune' metabolic processes in the cells that get disrupted as we age. Lead author, Dr. Richard Mithen commented, "We think this provides some evidence as to why people who eat diets rich in broccoli may keep in good health... mitochondria are really, really important, and when they start to go wrong it leads to many of the diseases of aging."
The nutritionists performing the study recommend eating broccoli two to three times a week. Other health-promoting members of the cruciferous vegetable family include Brussels sprouts, kale and cauliflower. Dr. Mithen concluded "We think it is significant because it shows in humans a measurable effect on our metabolism, which is central to our overall health and could explain the diverse range of beneficial effects many observational dietary studies have shown previously." It is important to note that while this study used a specially concentrated type of broccoli to produce the stated results, consumption of commercially available broccoli and crucifers have been shown to exhibit similar anti-cancer properties when eaten over a longer period of time.