A new study shows that girls who don't drink milk frequently are at higher risk of asthma than other girls, especially if they are overweight, Reuters Health reports.
In a study that included more than 700 girls between the ages of 8 and 10, Canadian researchers identified a link between rare milk consumption - twice a week or less - and asthma risk, but only to celebrate.
Compared to the other girls, in girls with asthma there is a 2 times higher probability to drink milk less. Some older studies have suggested that those children who drink little or no milk have a higher chance than other children of becoming overweight and being overweight was also associated with an increased risk of asthma in children.
However, the current study found that low levels of milk and excess weight increase the risk of asthma in girls. In addition, the combination of the two is extremely problematic.
The study found that asthmatic girls are overweight and drink milk 4 times less often than other girls. This association was also observed after analyzing some potential factors, including the entire diet of children, physical effort and family income.
All this suggests that low milk consumption can directly affect the risk of asthma without its weight being a favorable factor.
Children who do not drink much milk have a low level of vitamin D, especially if they live in colder areas where sun exposure is limited. It seems that vitamin D affects how the body's cells respond to estrogen.
Some studies suggest that estrogen is involved in inflammation of the airways and that estrogen influences asthma symptoms in women.
Such an effect may be exaggerated in overweight girls because their estrogen levels are much higher than those of normal weight girls.
For the moment, this information remains a speculation. The researchers believe that more studies are needed to clarify the relationship between milk consumption, weight and risk of asthma in children.
November 19, 2007