In the News: Magnesium & Heart Disease; Omega-3 & Skin Health; B-vitamins & AMD

Magnesium Reduces Risk of Heart Disease

Magnesium helps maintain muscle and nerve function, keeps heart rhythm steady, supports the immune system, and helps keep bones strong. It also helps regulate blood sugar levels, promotes normal blood pressure, and is involved in energy metabolism.

Researchers have long been interested in the role of magnesium in preventing and managing disorders such as diabetes, hypertension and cardiovascular disease (CVD). A new review of studies from Harvard’s School of Public Health bolsters the support for magnesium’s role in reducing the risk of CVD. 

The review (1), which included data for over 313,000 people from 16 studies, found that the risk of CVD fell by 30% (for every 0.2 mmol/L increase in circulating magnesium levels). Dietary intake of magnesium (per 200 mg/day increment) was associated with a 22% lower risk of ischemic heart disease.

The recommended daily intake for magnesium is 320 mg for women and 420 mg for men – amounts that many adult Americans fail to meet according to government surveys. To get more of this important mineral, eat a wide variety of leafy green veggies, beans, nuts, whole grains, and fish.

Can Omega-3 Fats Help Protect the Skin?

A preliminary, but promising study suggests that omega-3 fatty acids may have a role in helping to keep skin healthy.

Exposure to UV radiation in sunlight suppresses the skin’s immune system, specifically cell-mediated immunity. This suppression of immune activity can affect the body’s ability to fight skin cancer and possibly infections. 

The omega-3s have been shown to protect against UV-caused immune suppression in mice, but their impact in humans isn’t known.  This led Investigators at the University of Manchester in England to clinically test whether a regular dose of fish oil can boost skin immunity to sunlight (2). 

After 3 months of taking 4 grams of EPA/DHA or placebo supplements, the 79 study participants were exposed to the equivalent of 8, 15 or 30 minutes of summer midday sun using a special light machine. Immune suppression was 50% lower in people receiving EPA/DHA compared to those in the placebo group for the 8 and 15 minutes sun exposure. The authors caution that their results need to be verified in larger trials, and that taking omega-3s should add to the protection against sun damage afforded by sunscreen and protective clothing, but would not replace these measures. They also emphasize that the beneficial changes, though small, suggest that a continuous low level of protection from the omega-3s could provide meaningful skin protection over a lifetime. Additionally, lower doses of omega-3 may be needed when they’re taken for longer periods of time (since checking with your doctor is advised for doses over 3 grams).

B-vitamin Intake Linked to Lower AMD

A clinical trial published in 2009 reported that daily supplementation over time with high dose vitamin B6 and B12, and folic acid could reduce the risk of age-related macular degeneration (AMD) in women.

Results of a new study (3) lend credence to these clinical findings, and suggest that more moderate intakes of folic acid and supplemental B12 may lower AMD risk.

Participants in the Blue Mountains Eye Study were followed for 10 years. Those with elevated blood levels of damaging homocysteine, low levels of folic acid, or vitamin B12 deficiency, were at significantly greater risk of developing early or late stage AMD.

Participants who reported taking B12 supplements were 47% less likely to develop AMD. That’s important because B12 deficiency is fairly common in older people, and supplemental B12 is more bioavailable than dietary sources of this vitamin.

References

1. Del Gobbo LC, et al. Circulating and dietary magnesium and risk of cardiovascular disease: a systematic review and meta-analysis of prospective studies. Am J Clin Nutr 98:160-173, 2013.    
2. Pilkington SM, et al. Randomized controlled trial of oral omega-3 PUFA in solar-simulated radiation-induced suppression of human cutaneous immune responses. Am J Clin Nutr 97:646-52, 2013. 
3. Gopinath B, et al. Homocysteine, folate, vitamin B-12, and 10-y incidence of age-related macular degeneration. Am J Clin Nutr 98:129-135, 2013.