In the News: Magnesium, Flavonoids and Vitamin D

Magnesium May Improve Lung Function

Observational studies have reported beneficial effects of magnesium on the occurrence and management of asthma. To test whether this mineral could bolster lung function in asthmatics, researchers at Bastyr University in Washington recruited 55 people with mild to moderate asthma who received either 340 mg of magnesium or a placebo pill daily for 6 ½ months (1).

The supplemented group showed a greater improvement in lung function compared to those receiving placebo pills. In order to determine the ability of the airways to stay open, both groups were given a drug that causes the airways to constrict and narrow, as they do during an asthma attack. The magnesium group needed 20% more of the drug to constrict the airways to the same degree as seen in the placebo group. Finally, quality of life, assessed by questionnaire, improved only in the magnesium takers.

Americans Face Dietary Magnesium Gap

Magnesium has anti-inflammatory actions that could improve asthma control, and it may enhance the capacity of the lungs to expand by favorably affecting cell membranes. While not all trials have reported a beneficial response to magnesium, these findings support its use for those with mild to moderate asthma. That’s important because less than half of US adults consume recommended levels of this mineral, according to the last National Health and Nutrition Examination Survey.

Flavonoids May Lower Stroke Risk in Women

Increased intakes of flavonol-rich foods may reduce a woman’s risk of stroke by 20%, according to a new review of studies involving over 110,000 people (2). Flavonols (also known as flavonoids) make up a sub-group of the bioflavonoid family, and are found in a variety of fruits and vegetables such as onions, apples and broccoli – as well as tea.

Dutch researchers conducted a meta-analysis (a review of studies) using data from people who were free of cardiovascular disease or stroke when the studies started. People in these studies were followed from 6 to 28 years, during which time the incidence of stroke was documented. Strokes occur when blood clots or an artery bursts in the brain and interrupts the blood supply to part of the brain. It is the leading cause of disability and the 3rd leading cause of death in the US.

While the researchers caution that more clinical research is needed, they conclude that accumulating evidence supports a role for flavonol-rich foods in maintaining vascular health.

Vitamin D Helps Fend Off Heart Disease and Diabetes in Older People

British researchers conducted the first ever review of studies looking at the relationship between blood levels of vitamin D and cardiovascular disease (CVD), type-2 diabetes and metabolic syndrome. Twenty eight studies were included providing data on nearly 100,000 people (3).

The analysis found that the highest blood levels of vitamin D were associated with a 33% risk reduction in CVD, a 55% reduction in type-2 diabetes, and a 51% drop in the risk of metabolic syndrome, compared with the lowest blood levels.

These findings add to a rapidly expanding body of science supporting the benefits of adequate vitamin D levels. A review that may lead to the establishment of higher recommended intakes is being conducted by the Institute of Medicine.

References

1. Kazaks AG, et al. Effect of oral magnesium supplementation on measures of airway resistance and subjective assessment of asthma control and quality of life in men and women with mild to moderate asthma: a randomized placebo controlled trial. J of Asthma 47:83-92, 2010.
2. Hollman PCH, et al. Dietary Flavonol Intake May Lower Stroke Risk in Men and Women. J of Nutrition, Epub Jan, 2010.
3. Parker J, et al. Levels of vitamin D and cardiometabolic disorders: Systematic review and meta-analysis. Maturitas 65:225-36, 2010.