Studies published in a recent issue of JAMA reveal a decreased risk of Alzheimer’s disease and cognitive decline among individuals who report greater adherence to a Mediterranean diet.

In one study, Nikolaos Scarmeas, MD and his associates found that greater physical activity was associated with a lower risk of developing Alzheimer’s disease among 1,880 elderly men and women. When adherence to a Mediterranean diet was analyzed, those in the top third had experienced a 40% reduction compared to the lowest third.*

In a second study, greater adherence to a Mediterranean diet was associated with a reduction in cognitive decline.*

“The findings of Scarmeas, et al and Féart, et al fit into a larger and potentially optimistic view of prevention of late-life cognitive impairment through application, at least by midlife, of as many healthy behaviors as possible, including diet,” David S. Knopman, MD, concluded in an accompanying editorial.*

—Dayna Dye

Research conducted by Catherine Peterson and Mary Heffernan at the University of Missouri’s Department of Nutritional Sciences has correlated low vitamin D levels with an increase in a marker of inflammation.*

The study included 69 healthy women classified as being high or low in vitamin D based on ultraviolet-B exposure. Not surprisingly, mean serum 25-hydroxyvitamin D levels were significantly greater in those with increased sun exposure compared with those in the low D group. Dr. Peterson found that the inflammatory marker tumor necrosis factor-alpha averaged 0.79 picograms per milliliter (pg/mL) in the high vitamin D group and 1.22 pg/mL among those categorized as low in the vitamin. Higher serum 25-hydroxyvitamin D levels were also correlated with lower TNF-alpha levels.

The discovery could help explain the protective association found for vitamin D against inflammatory diseases such as heart disease and rheumatoid arthritis.

—Dayna Dye

A new study published online in Human Brain Mapping reports that elderly individuals who were obese or overweight had significantly less brain tissue than individuals of normal weight.1

The study, led by Paul Thompson, a University of California Los Angeles neuroscientist, reviewed the brain images of 94 people in their 70s who had participated in an earlier study looking at cardiovascular health and cognition. They were followed for five years, and it was discovered that clinically obese people had 8% less brain tissue, while simply overweight people had 4% less brain tissue compared to normal-weight humans.

“The brains of obese people looked 16 years older than their healthy counterparts, while those of overweight people looked 8 years older,” Thompson said. “This is the first study to show physical evidence in the brain that connects overweight and obesity and cognitive decline.”2

—Jon Finkel

A study funded by the British Heart Foundation charity and conducted by researchers at Imperial College London on mice has found evidence that a chemical in broccoli could protect arteries from clogging.*

In the report published in the journal Arteriosclerosis, Thrombosis and Vascular Biology, the research team found that a compound called sulforaphane, which occurs naturally in broccoli, had the ability to switch on a protective protein, called Nrf2, that is inactive in parts of the arteries that are vulnerable to clogging.

“What our study showed was that sulforaphane can protect those regions by switching on the Nrf2,” Paul Evans of the National Heart and Lung Institute at Imperial College said about the report.

While the research was conducted using purified sulforaphane, not actual broccoli, Evans said the next step is to test the effect of the chemical as it is found naturally in vegetables.

—Jon Finkel

An article published online in the American Journal of Clinical Nutrition revealed that vitamin C status has improved in the United States over the past decade, yet a significant incidence of deficiency still exists among smokers and individuals of low socioeconomic status.*

For their report, researchers at the Centers for Disease Control and Prevention in Atlanta compared data from the National Health and Nutrition Examination Survey (NHANES) III, conducted from 1988 to 1994, to data from NHANES 2003-2004. Overall, the presence of vitamin C deficiency among NHANES 2003-2004 participants was 7%, down from 12.4% among NHANES III participants. Smokers had levels that were one-third lower than nonsmokers, and had over three times as great a risk of deficiency. Vitamin C concentrations rose and deficiency declined with increased socioeconomic status.

“The vitamin C status of the US population appears to have substantially improved from 1988-1994 to 2003-2004,” the authors conclude.

—Dayna Dye