Archief Roodbont

Tuesday, June 1, 2010

Air pollution, sunlight, vitamin D and type-two diabetes

Does air pollution cause diabetes, or does pollution cause vitamin D deficiency, which then leads to diabetes?

New research from Germany showed that women who lived in heavily air-polluted areas were at greater risk for type-two diabetes than those who lived in less-polluted areas. Those who lived within 100 meters of busy roadways doubled the diabetes risk. http://www.newswise.com/articles/study-suggests-link-between-air-pollution-and-type-2-diabetes-in-women

The authors assumed that the inhalation of pollutants was responsible for the increased risk of diabetes among those living in heavily-polluted areas, but I suggest another possibility: It is well-known that air pollution filters out sunlight and correlates to profoundly lower vitamin D levels. [1] [2] [3]

But do vitamin D levels have an influence on type-two diabetes? Research shows that Vitamin D levels correlate closely to insulin sensitivity; the higher the vitamin D levels, the more receptive the body is to the action of insulin, which makes carbohydrates easier to metabolize.[4] This same study shows that the higher the vitamin D levels are, the lower are the blood sugar levels. Other research shows that men with the highest vitamin D levels had a 30% reduced risk of type-2 diabetes compared to those with low levels,[5] probably because the beta cells of the pancreas (the insulin producing cells) have vitamin D receptors[6] and function more efficiently when vitamin D levels are higher.[7]

It is highly likely that the reason for the increased risk for diabetes was not the inhalation of air pollutants, but rather the lack of sunlight and subsequent vitamin D deficiency. It is time to leave the pollution and return to the sun.