A superfood broccoli developed by British scientists retunes metabolism to combat the effects of ageing, research has shown.
The vegetable, sold under the brand name Beneforte, contains boosted levels of a plant compound believed to protect against heart disease and cancer.
Scientists who tested it on volunteers saw metabolic changes that were the biological equivalent of a car's 12,000-mile service.
Tiny energy generators in cells called mitochondria, which become less efficient with age, were given a new lease of life and had their performance improved. Eating the broccoli helped reverse mitochondrial malfunctions that contribute to problems such as obesity, diabetes, heart disease and some forms of cancer.
Beneforte was created using conventional breeding techniques by crossing conventional broccoli with a wild Italian variety that has naturally high levels of glucoraphanin.
It contains two to three times more of the compound than ordinary broccoli and much higher levels than other "cruciferous" vegetables such as Brussels sprouts, kale and cauliflower.
The findings underlined the health benefits of eating cruciferous vegetables in general, although Beneforte showed the most striking effect, said the team led by Professor Richard Mithen from the Institute of Food Research.
Writing in the American Journal of Clinical Nutrition, the researchers concluded: "A diet rich in cruciferous vegetables effectively retunes our metabolism.. In this manner, cruciferous vegetables may be able to reduce the risk of many chronic diseases associated with ageing."
The scientists recruited 48 volunteers who were split into three groups and ate 400 grams a week of either Beneforte, standard broccoli, or peas for three months. Blood tests showed clear signs of improved metabolism in the high-glucoraphanin Beneforte group. In particular, two biochemical processes vital to mitochondrial function were "rebalanced".
People in the Beneforte group also had reduced levels of compounds linked to inflammation in their blood. A compound called sulphoraphane, which is derived from glucoraphanin, is known to promote antioxidant activity in cells. This has the effect of clearing away destructive oxygen molecules that can disrupt mitochondrial machinery, experts believe.