In the e-Alert “Waiting to Exhale” (9/13/04), I told you about a study that showed how the use of an inhaler – also known as inhaled corticosteroids (ICS) – to treat asthma or chronic obstructive pulmonary disease may contribute to fracture risk due to weakened bones.
That study was conducted at a Veterans Administration hospital, so nearly all the subjects were men. Now I’ve come across a study that shows how an adequate intake of dietary zinc may help men maintain a healthy bone mass density (BMD).
Researchers at the University of California, San Diego, recruited nearly 400 men between the ages of 45 and 92. The BMD was measured for each subject at the outset of the study, and again four years later. Dietary habits were assessed with food-frequency questionnaires, and zinc levels were measured with blood tests. Analysis of the data showed that both dietary zinc intake and plasma zinc both had a positive association with BMD in men. (Previous studies have already associated low zinc intake with osteoporosis in women.)
In this study, the average dietary zinc intake was just over 11 mg per day, which is the recommended daily allowance (RDA) for males over the age of 19. The best source of zinc is animal protein. Oysters deliver the highest amounts of zinc, followed by red meat and chicken. Other sources include fish, whole grains, nuts and beans.
In addition, zinc has been shown to enhance the immune system, help repair damaged tissues, inhibit the abnormal clotting that contributes to cardiovascular disease, and is one of the key nutrients needed for DNA reproduction and repair. Zinc also helps keep your vision healthy.
And for those of you who already include zinc in your daily supplement intake, it’s a good idea to add a little copper as well.
In the e-Alert “Aim High” (5/7/03), Dr. Spreen noted that zinc can create a copper deficiency, and vice versa. And Jonathan V. Wright, M.D., agrees, stating that, “Zinc supplements should usually be offset by a small amount of copper, 1-2 mg daily.” Fortunately, many multivitamins already take care of the dual zinc/copper need with a low dose of copper.
“Bottled Water: Pure Drink or Pure Hype?” National Resources Defense Council, nrdc.org “Zinc Intakes and Plasma Concentrations in Men with Osteoporosis: The Rancho Bernardo Study” American Journal of Clinical
Nutrition” Vol. 80, No. 3, September 2004, ncbi.nlm.nih.gov