LOS ANGELES,US -- Walnuts have a combination of more healthful antioxidants and higher quality antioxidants than any other nut, US researchers have found.

Study findings were presented on Sunday at the 241st National Meeting & Exposition of the American Chemical Society (ACS) in Anaheim, Southern California.

Nuts contain plenty of high-quality protein that can substitute for meat, vitamins and minerals, dietary fiber, and are dairy- and gluten-free, ACS researchers said in the study.

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Moreover, nuts contain healthful polyunsaturated and monosaturated fats rather than artery-clogging saturated fat, according to the study.

The researchers based their conclusion on analysis of antioxidants in nine different types of nuts: walnuts, almonds, peanuts, pistachios, hazelnuts, Brazil nuts, cashews, macadamias and pecans.

They found that walnuts have the highest levels of antioxidants, with plenty of high-quality protein that can substitute for meat, vitamins and minerals, dietary fiber, and are dairy- and gluten-free.

The latest study adds more evidence that walnuts are top nuts for heart-healthy antioxidants, the researchers said.

Previous studies showed that regular consumption of small amounts of nuts or peanut butter can decrease the risk of heart disease, certain kinds of cancer, gallstones, Type 2 diabetes, and other health problems.

But the latest study is the first to compare both the amount and quality of antioxidants found in different nuts.

"Walnuts rank above peanuts, almonds, pecans, pistachios and other nuts," said Joe Vinson, Ph.D., who led the latest study.

"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."