长期以来,经由医界、媒体报道,乳制品是钙质无可取代的标准来源这一观念已经深入人心。然而,牛奶真有那么大的功效吗?根据科学家们最新的研究,乳制品的钙质可能比绿叶蔬菜还要少,而补钙的最佳食品则可能是易于吸收的豆制品。
Children who drink more milk do not necessarily develop healthier bones, researchers said in a report that stresses exercise and modest consumption of calcium-rich foods such as tofu and broccoli.
Appearing in the journal Pediatrics, the report drew its conclusions from previously published studies and was written by researchers from the Physicians Committee for Responsible Medicine, which advocates a strict vegetarian diet.
"Under scientific scrutiny, the support for the milk myth crumbles. This analysis of 58 published studies shows that the evidence on which U.S. dairy intake recommendations are based is scant," said study author Dr. Amy Lanou in a statement.
Some earlier studies that extol dairy products as a calcium source have been funded at least in part by the dairy industry.
The U.S. government has gradually increased recommendations for daily calcium intake, largely from dairy products, to between 800 and 1,300 milligrams to promote healthy bones and prevent osteoporosis.
But the Physicians Committee's report said boosting consumption of milk or other dairy products was not necessarily the best way to provide the minimal calcium intake of at least 400 milligrams per day. Other ways to get the absorbable calcium found in one cup of cow's milk include a cup of fortified orange juice, a cup of cooked kale orturnip greens, two packages of instant oats, two-thirds cup of tofu, or 1-2/3 cups ofbroccoli, the report said.
Several of the studies, which examined such factors as bone density and rate of fractures, concluded that exercise may be more important than increased calcium consumption in developing strong bones.
Data was scarce on the effect of calcium intake for children younger than 7 years, the report said. Dairy products provide 18 percent of the total energy and 25 percent of the total fat intake in the diets of American children, who are developing increasing rates of obesity, it said.
In an editorial in the journal commenting on the report, Frank Greer, a pediatrician at the University of Wisconsin in Madison, said the ideal way to achieve the goal of healthy bones is to make sure children exercise and consume up to 1,300 milligrams a day of calcium.
turnip greens: 萝卜汤
broccoli: 青花菜,甘蓝汤
(实习生江巍 英语点津 Annabel 编辑)