Nutrition News Bites: Magnesium & the Mediterranean Diet
Magnesium Fights Metabolic Syndrome
Eating a magnesium-rich diet could be important in fighting against the Metabolic Syndrome according to a new study funded by the National Heat, Lung and Blood Institute.
The Metabolic Syndrome is a cluster of risk factors including excess weight around the waist, high blood pressure, low levels of HDL cholesterol, elevated triglycerides and high fasting blood sugar levels. Having 3 or more of these components raises the risk of heart disease and diabetes. Previous studies have linked magnesium intake to individual components of the syndrome, mostly in older people. The new findings suggest that it may target the whole package of risk factors in younger adults as well.
Researchers tracked over 4600 participants in the Coronary Artery Risk Development in Young Adults Study for 15 years. They found that the more magnesium a person consumed, the less likely he or she was to develop metabolic syndrome. Those who had the most magnesium in their diet were about 31% less likely to have metabolic syndrome than the participants who ate the least. A higher intake of this mineral also reduced the risk of developing individual elements of the Metabolic Syndrome and was linked to lower fasting blood levels of insulin.
Choose Greens and Grains for Magnesium
The findings of this study are in sync with the role magnesium is believed to play in releasing insulin from the pancreas, as well as with other reports that magnesium improves insulin sensitivity. To get more of this mineral, include green leafy vegetables, whole grains and beans. Bananas, avocados and fish are also good sources.
The authors of this study wisely caution against relying on magnesium alone to ward off Metabolic Syndrome, pointing out that magnesium is just one component of a healthy diet. Magnesium-rich foods are some of the most nutritious around, and the great news is that they're found abundantly in the Mediter-ranean style diet ("Med" diet).
For Heart Health & Memory: Go Mediterranean
Regular readers of Staying Healthy know that the "Med" diet has emerged as one of the healthiest ways to eat (September, 2005, Embracing the Mediterranean Style Diet). Two new reports bolster the evidence supporting this dietary pattern.
The first study followed more than 2,250 older Americans for 4 years. Their eating patterns were analyzed, and their cognitive function was evaluated every 18 months with a battery of neuropsychological tests. Since there's no one exact "Med" diet - people in Greece eat differently than those in Italy for example - the researchers used common components of this diet to evaluate the participants' eating habits. They looked for high intake of fruits, vegetables, beans, nuts, fish and cereals; relatively low intake of saturated fats, meat, poultry and dairy; and mild to moderate alcohol use.
They found that adhering to this dietary pattern was the best predictor of Alzheimer's risk, even when other known risk factors were taken into account. Those who followed the diet most closely were almost 40% less likely to have developed Alzheimer's than subjects with the poorest adherence.
The second clinical trial confirms that eating a "Med" diet enriched with walnuts or olive oil is better than a low-fat diet for the heart. Over 770 adults at high risk for cardiovascular disease were assigned to one of 3 diets: 1) low-fat, 2) a "Med" style with about 4 cups of additional olive oil weekly, or 3) "Med" style with an extra ounce or so of nuts daily.
Compared to the low-fat diet, both "Med" style diets resulted in significant benefits to blood sugar levels, systolic blood pressures, and ratios of total to HDL cholesterol. Significant reductions were also seen in C-reactive protein - a biomarker for inflammation that is one predictor of heart disease.
- Ka He, et al. Magnesium intake and incidence of Metabolic Syndrome among young adults. Circulation 113:1675-82, 2006.
- Scarmeas N, et al. Mediterranean diet and risk for Alzheimer's disease. Annals of Neurology 59:912-21, 2006.
- Estruch R, et al. Effects of a Mediterranean-style diet on cardiovascular risk factors: a randomized trial. Annals of Internal Medicine 145:1-11, 2006.