Research Study Ranks Antioxidant Value of Nuts: Walnuts Top List
A new study by University of Scranton Chemistry Professor Joe Vinson, Ph.D., published in The Royal Society of Chemistry’s journal Food and Function online on Dec. 21, 2011, shows nuts pack a healthy punch and ranks walnuts at the top for having both more healthful antioxidants, called polyphenols, and a higher antioxidant potency than the other nuts analyzed.
Dr. 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 Dr. Vinson. His study also found that total polyphenols in peanut butter were considerably lower than roasted peanuts, but the difference was not statistically signiﬁcant.
Dr. Vinson’s study also analyzed the daily consumption of nuts in both the United States and European diets. His research shows that nuts account for barely eight percent of the daily antioxidants in the average person’s diet.
“The total nut consumption (tree nuts and peanuts) in the United States was estimated at 12.9 grams per day, which is similar to the 2007 European Union consumption of 11.1 grams per day,” Dr. Vinson reported in the study. “Peanuts comprised 65 percent of the nut consumption in the United States and 45 percent in the European Union.”
Dr. 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. But he points out that nuts contain healthful polyunsaturated and monosaturated fats rather than artery-clogging saturated fat.
Dr. 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.”
Dr. 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.
Dr. Vinson also presented this research at the 241st National Meeting and Exposition of the American Chemical Society in March 2011.
The Royal Society of Chemistry is the United Kingdom’s professional organization for chemical scientists and an international society for advancing chemical scientists with more than 47,000 members, according to its website. The society publishes several academic journals including Food and Function.