Nature`s perfectly packaged nuts -- walnuts -- have the highest levels of antioxidants in the nut family and should be consumed as part of a healthy diet.
"Walnuts rank above peanuts, almonds, pecans, pistachios and other nuts," said Joe Vinson, from the University of Scranton in Pennsylvania, who conducted the analysis.
Vinson said it takes only around seven walnuts a day, for instance, to get the potential health benefits uncovered in previous studies.
"A handful of walnuts contains almost twice as much antioxidants as an equivalent amount of any other commonly consumed nut. This study suggests consumers should eat more walnuts as part of a healthy diet," said Vinson.
Antioxidants in walnuts are two to 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, according to a Scranton statement.
Vinson noted that nuts in general 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 worldwide 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.
Vinson said his work is the first to compare both the amount and quality of antioxidants found in different nuts.
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.
These findings were presented at the 241st National Meeting and Exposition of the American Chemical Society.