MedWire News: Recent findings from the Shanghai Women’s Health study show an apparent protective effect of calcium and magnesium against Type 2 diabetes risk.
In Western populations, balanced diets that include good sources of calcium and magnesium such as low-fat dairy and whole-grain foods are associated with a lower risk for Type 2 diabetes. Little is known, however, about the contributions of specific nutrients in populations with different dietary patterns.
Raquel Villegas (Vanderbilt University Medical Center, Nashville, Tennessee, USA) and colleagues evaluated data from 64,191 participants in the Shanghai Women's Health Study, which included women aged 40 to 70 years who were free of Type 2 diabetes at study recruitment and living in Shanghai, China.
Interviews conducted at the beginning of the study and at the first biennial follow-up collected information on dietary intake, physical activity, lifestyle factors and anthropometric data. Over the 6.9-year follow-up period, 2270 cases of Type 2 diabetes were confirmed.
“Calcium and magnesium intakes were both associated with a decrease in risk of Type 2 diabetes,” write the authors in the American Journal of Clinical Nutrition.
Women with a calcium intake among the highest fifth, at a median of 649.6 mg/day, had a 27% lower risk for diabetes compared with those whose intake was among the lowest fifth at 277.5 mg/day.
Magnesium was also associated with a protective effect. Subjects whose intake of magnesium was highest at a median of 318.1 mg/day experienced a 20% lower risk for diabetes compared with those in the lowest category with a median intake of 213.8 mg/day.
In this Chinese population, the authors found that calcium and magnesium from milk sources appeared to be more protective than plant sources.
Although they did not have information on the vitamin D intake of the participants, the authors noted that the protective effect associated with dairy products could be due to their vitamin D as well as calcium content. Vitamin D combined with calcium has been shown to be associated with a reduction in the risk for Type 2 diabetes in previous research.
The implications of these results are important for a country in which consumption of dairy products is generally low and sources of calcium and magnesium differ from those in Western populations.
"Our findings support the hypothesis that calcium and magnesium play a protective role in the development of Type 2 diabetes," the authors conclude.
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