LOMA LINDA, Calif.Eating just one serving of tree nuts a day may help lower the risk of metabolic syndrome and obesity, according to a new study published in the journal PLoS ONE. The findings come on the heels of a landmark study released in December that found eating 1.5 ounces of nuts a day lowered total mortality in both men and women, and had significant inverse associations for deaths due to cancer, heart disease and respiratory disease.

For this study, researchers at Loma Linda University looked at the association between tree nuts (almonds, Brazil nuts, cashews, hazelnuts, macadamias, pecans, pine nuts, pistachios and walnuts), metabolic syndrome and obesity in a population with a wide range of nut intake ranging from never to daily.

They studied 803 Seventh-day Adventist adults using a validated food-frequency questionnaire and assessed both tree nut and peanut intake together and separately. Mean tree nut intake was 16 grams/day among the high tree nut consumers and 5 grams/day among low tree nut consumers.

"Our results showed that one serving (28g or 1 ounce) of tree nuts per week was significantly associated with 7% less metabolic syndrome," said lead researcher Karen Jaceldo-Siegl, PhD. "Doubling this consumption could potentially reduce metabolic syndrome risk by 14%. Interestingly, while overall nut consumption was associated with lower prevalence of metabolic syndrome, tree nuts specifically appear to provide beneficial effects on metabolic syndrome, independent of demographic, lifestyle and other dietary factors."

Metabolic syndrome is a cluster of risk factors shown to be associated with death, a twofold increased risk for cardiovascular disease, and a fivefold increased risk for type 2 diabetes. While the diagnostic criteria can vary, presence of any three of the five following conditions results in a diagnosis of metabolic syndrome : abdominal obesity, elevated triglycerides, low HDL cholesterol, high blood pressure, and hyperglycemia.

In addition to the effect of nuts on metabolic syndrome, the researchers also looked at the effect on obesity.

"We found that high tree nut consumers had significantly lower prevalence of obesity compared to the low tree nut consumers," Jaceldo-Siegl said. "And, high consumers of tree nuts had the lowest prevalence of obesity when compared to the low peanut/tree nut groups."

Commenting on the results of the study, Maureen Ternus, M.S., R.D., Executive Director of the International Tree Nut Council Nutrition Research & Education Foundation (INC NREF), said: "All of this new research supports the growing body of evidence showing that consuming nuts can improve your health. In 2003, FDA (in its qualified health claim for nuts and heart disease) recommended that people eat 1.5 ounces of nuts per daywell above current consumption levelsso we need to encourage people to get their handful of nuts every day."