Over 2,000 black and white men and women ages 70-79 years old were asked to complete a questionnaire to determine how much magnesium they were receiving from food and various supplements. Additionally, researchers performed bone mineral density tests on the participants.

The study revealed that those who ingested more magnesium had significantly higher bone density than those who got the least amount of magnesium. For every 100 milligram per day increase in magnesium intake, data showed a 1% increase in bone density.

However, this link was only true for the older white men and women. Previous research has demonstrated that black men and women may process vitamin D and other calcium regulating hormones differently than whites, thus possibly explaining the lack of association between magnesium and bone density among them in this study.

"Although this [1% increase] seems small, increases across a population may have large public health impact," states lead researcher Kathryn M. Ryder.

The recommended daily allowance of magnesium is 320 mg/day for women and 420/mg day for men in this age group. Most people in this age group get far less than this daily amount.

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It was revealed during this period that 560 persons (13.4 percent) were diagnosed as having new AMD, the majority of whom had early-stage AMD, but that risk was modified by diet, in particular, where vitamin E and zinc was achieved by consumption of whole grains, vegetable oil, eggs, and nuts, meat, poultry, fish and dairy products.

On the basis of this study, foods high in these nutrients appear to be more important than nutritional supplements.

Good sources of beta carotene are carrots, kale, and spinach, while vitamin C is found in citrus fruits and juices, green peppers, broccoli, and potatoes.

The researchers say that until more research is available, the information may be useful to persons with signs of early AMD or to those with a strong family history of AMD.

They say that although their findings need confirmation, their observational data suggests that a high intake of specific antioxidants from a regular diet may delay the development of AMD.

The study is published in the December 28 issue of JAMA.