In the news: Zeroing in on Magnesium: Recent Research

Multiple Roles of Magnesium

Magnesium is required by more than 300 enzyme systems that regulate many biochemical reactions in the body. So it’s no wonder that magnesium plays a role in many diverse processes: It helps regulate muscle and nerve function, as well as blood pressure and blood sugar levels. It is also needed to make protein, DNA, and is involved in the formation of bone.

While surveys show that most of us recognize the importance of magnesium, many - about 50% of Americans-- aren’t consuming an adequate amount of this mineral. The recommended daily magnesium intake for adults is 420 mg (men) and 320 mg (women). Good food sources include green leafy vegetables, beans, nuts, seeds, and whole grains.

Several observational studies published in the last few months, underscore the potential benefit of getting more magnesium-containing foods in our daily diet.

More Magnesium, Stronger Muscles & Bones

British researchers set out to investigate the relationship between dietary magnesium and skeletal muscle and bone health by analyzing data from over 156,500 men and women participating in the UK Biobank Study (1).

The investigators found that those consuming the most magnesium had better grip strength (1.1% men, 2.4% women) and higher bone mineral density (2.9% men, 0.9% women) compared to those consuming the least. Compared to the lowest intake group, the higher magnesium intake group also had greater fat free mass as percent of body weight (3% men, 3.6% women; fat free mass refers mainly to lean muscle mass and bone).

While these differences may sound modest, they are clinically important considering the annual losses of bone mineral density and skeletal muscle that occur with aging. The participants in this study ranged from 39 to 72 years old. Among men over the age of 60 with high magnesium intake, grip strength was about twice that of younger men. This study strongly suggests, though doesn’t prove, that eating adequate amounts of magnesium may be protective of muscle and bone in middle age and as we grow older.

In a related study (2), UK researchers explored the relationship between magnesium intake (from food and supplements) and bone fracture risk in a large group of older men and women participating in the Osteo-arthritis Initiative over a follow-up period of 8 years.

Compared with the lowest magnesium intake, the highest intake was associated with a 62% (women) and 53% (men) reduced risk of fracture. The findings are promising since stemming loss of bone mineral density doesn’t always translate to lower fracture risk. Clinical trials testing magnesium’s ability to reduce fractures are warranted, according to the authors.

Magnesium is required for insulin secretion by the pancreas, and for tissues to respond to insulin by taking up glucose (sugar) from the blood stream.

Magnesium, Glycemic Index & Diabetes

Magnesium is required for insulin secretion by the pancreas, and for tissues to respond to insulin by taking up glucose (sugar) from the blood stream. Researchers from Tufts and Harvard Universities analyzed data from three large studies, which included more than 200,000 people followed for 28 years. They found higher magnesium intake to be associated with a 15% lower risk of type 2 diabetes (3).

That association was even stronger in those who ate high glycemic index (GI) diets- diets low in fiber and high in processed carbohydrates such as white flour and sugary foods and beverages.

Taken together, these studies offer a compelling reason to make magnesium-rich foods a priority in our diets.

References

1. Welch AA, et al. Dietary magnesium may be protective for aging of bone and skeletal muscle in middle and younger older age men and women: Cross-sectional findings from the UK Biobank Cohort. Nutrients; 9:1189, 2017.
2. Veronese N, et al. Dietary magnesium intake and fracture risk: data from a large prospective study. Br J Nutr; 117:1570-76, 2017.
3. Hruby A, et al. Magnesium Intake, Quality of Carbo-hydrates and Risk of Type 2 Diabetes: Results From Three U.S. Cohorts. Diabetes Care 40:1695-1702, 2017.