Two recent studies have found that grapefruit helps with weight loss and may also cut the cancer risk associated with smoking.
Subjects lost up to 3.5 pounds without trying
In the weight loss study, researchers assigned 100 men and women who were obese to one of four groups. One group received grapefruit extract, another drank grapefruit juice with each meal, another group ate a half grapefruit with each meal, while the fourth group received a placebo. All subjects participated in 30 minutes of exercise a day.
At the end of 12 weeks the placebo group lost on average just under half a pound, the extract group 2.4 pounds, the grapefruit juice group 3.3 pounds, and the fresh grapefruit group 3.5 pounds.
More research is needed as to the exact cause of the weight loss, although researchers found that grapefruit helps fight insulin resistance, which tends to develop as people become obese.
Reduces carcinogenic enzyme
In the smoking study, grapefruit juice helped decrease the activity of an enzyme that makes cigarette smoke more carcinogenic.
Scientists gave 49 smokers grapefruit juice or another test food, onions. They evaluated the subjects¡¯ urine to evaluate the activity of a liver enzyme called CYPIA2, thought to activate the cancer-causing chemicals found in tobacco smoke. Those who drank three six-ounce glasses of grapefruit juice a day reduced the activity of the enzyme.
Other studies have also found that foods rich in flavonoids, like grapefruit, can inhibit the activation of carcinogens.