Walnuts

“Walnuts rank above peanuts, almonds, pecans, pistachios and other nuts,” said Joe Vinson, PhD, who did the analysis. “A handful of walnuts contains almost twice as much antioxidants as an equivalent amount of any other commonly consumed nut. But, unfortunately, people don’t eat a lot of them. This study suggests that consumers should eat more walnuts as part of a healthy diet.”

Vinson noted that nuts in general have an unusual combination of nutritional benefits - in addition to those antioxidants - wrapped into a convenient and inexpensive package. Nuts, for instance, contain plenty of high-quality protein that can substitute for meat; vitamins and minerals; dietary fibre; and are dairy and gluten free. Years of research by scientists around the world link regular consumption of small amounts of nuts or peanut butter with decreased risk of heart disease, certain kinds of cancer, gallstones, Type 2 diabetes, and other health problems.

Despite all the previous research, scientists until now had not compared both the amount and quality of antioxidants found in different nuts, Vinson said. He filled that knowledge gap by analysing antioxidants in nine different types of nuts: walnuts, almonds, peanuts, pistachios, hazelnuts, Brazil nuts, cashews, macadamias and pecans. Walnuts had the highest levels of antioxidants.

Vinson also found that the quality, or potency, of antioxidants present in walnuts was highest among the nuts. Antioxidants in walnuts were 2-15 times as potent as vitamin E, renowned for its powerful antioxidant effects that protect the body against damaging natural chemicals involved in causing disease.

“There’s another advantage in choosing walnuts as a source of antioxidants,” said Vinson, who is with the University of Scranton in Pennsylvania. “The heat from roasting nuts generally reduces the quality of the antioxidants. People usually eat walnuts raw or unroasted, and get the full effectiveness of those antioxidants.”