Vinson's study evaluated nine types of raw and roasted nuts and two types of peanut butter to assess the total amount of polyphenols found in each, as well as the polyphenols' expected ability to inhibit oxidation of lower density lipoproteins, often referred to as "bad cholesterol." His study found that walnuts had the highest levels of antioxidants and that the quality, or potency, of antioxidants present in walnuts was highest among the nuts.
"Walnuts rank above Brazil nuts, pistachios, pecans, peanuts, almonds, macadamias, cashews and hazelnuts," said Vinson. His study also found that total polyphenols in peanut butter were considerably lower than roasted peanuts, but the difference was not statistically significant.
Vinson's study also analyzed the daily consumption of nuts in both the U.S. and European diets. His research shows that nuts account for barely 8% of the daily antioxidants in the average person's diet.
"The total nut consumption (tree nuts and peanuts) in the U.S. was estimated at 12.9g per day, which is similar to the 2007 European Union consumption of 11.1g per day," Dr. Vinson reported in the study. "Peanuts comprised 65% of the nut consumption in the U.S. and 45% in the European Union."
Vinson surmises that the relative low consumption of nuts in the daily diet might stem from many people being unaware that nuts are such a healthful food. Others may be concerned about gaining weight from a food so high in fat and calories. However, he points out that nuts contain healthful polyunsaturated and monosaturated fats rather than artery-clogging saturated fat.
Vinson's research concluded, "Nuts are high in fiber, low in saturated fats, high in beneficial unsaturated fats, and very high in antioxidants. Nuts are a nutritious snack and food additive providing both nutrients and bioactive antioxidants which provide significant health benefits to the consumer."
Vinson notes that consumers should keep the portion size small. He said it takes only about seven walnuts a day, for instance, to get the potential health benefits uncovered in previous studies.
From the January 10, 2011, Prepared Foods' Daily News.