Walnuts Are Top Nut for Heart-Healthy Antioxidants

A new scientific study positions walnuts in the No. 1 slot among a family of foods that lay claim to being among Mother Nature’s most nearly perfect packaged foods: Tree and ground nuts. In a report at the 241st National Meeting & Exposition of the American Chemical Society in Anaheim (27 March 2011), scientists presented an analysis showing that walnuts have a combination of more healthful antioxidants and higher quality antioxidants than any other nut.

“Walnuts rank above peanuts, almonds, pecans, pistachios and other nuts,” said Joe Vinson, Ph.D., 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 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 fiber; 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 analyzing 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.”

If nuts are so healthful and nutritious, why don’t people eat more? Vinson’s research shows, for instance, that nuts account for barely 8 percent of the daily antioxidants in the average person’s diet. Many people, he said, may not be aware 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. As for the calories, eating nuts does not appear to cause weight gain and even makes people feel full and less likely to overeat. In a 2009 U. S. study, nut consumption was associated with a significantly lower risk of weight gain and obesity. Still, consumers should keep the portion size small. Vinson said it takes only about 7 walnuts a day, for instance, to get the potential health benefits uncovered in previous studies.

Nutrition Information about the health benefits of walnuts with dietitian Cara Rosenbloom.

 

A ‘Nutty’ Solution To Type 2 Diabetes Management

Eating nuts daily could help control type 2 diabetes and prevent complications.

TORONTO, Ont., July 12, 2001–Eating nuts every day could help control Type 2 diabetes and prevent its complications, according to new research from St. Michael’s Hospital and the University of Toronto.

In the research, published online by the journal Diabetes Care, a team of researchers led by Dr. David Jenkins (University of Toronto Department of Nutritional Sciences; St. Michael’s Hospital Risk Factor Modification Centre) reports that consuming two ounces of nuts daily as a replacement for carbohydrates proved effective at glycemic and serum lipid control for people with Type 2 diabetes. The article, entitled “Nuts as a Replacement for Carbohydrates in the Diabetic Diet,” is available here:http://care.diabetesjournals.org/content/early/2011/06/02/dc11-0338.abstract

“Mixed, unsalted, raw, or dry-roasted nuts have benefits for both blood glucose control and blood lipids and may be used as part of a strategy to improve diabetes control without weight gain,” said Dr. Jenkins, who also has appointments with St. Michael’s Division of Endocrinology and Metabolism and the U of T’s Department of Medicine. He also serves as Canada Research Chair in Nutrition and Metabolism.

Jenkins and his colleagues provided three different diet supplements to subjects with Type 2 diabetes. One group was given muffins, one was provided with a mixture of nuts including raw almonds, pistachios, walnuts, pecans, hazelnuts, peanuts, cashews, and macadamias, and one group was given a mixture of muffins and nuts.

Subjects receiving the nut-only supplement reported the greatest improvement in blood glucose control using the glycosylated hemoglobin (HbA1c) test. The nut diet subjects also experienced a reduction in low-density lipoprotein cholesterol (known as LDL, or “bad cholesterol”). The subjects provided the muffin supplement or mixed muffin-and-nut supplement experienced no significant improvement in gylcemic control but those receiving the muffin-nut mixture also significantly lowered their serum LDL levels.

“Those receiving the full dose of nuts reduced their HbA1c [the long-term marker of glycemic control] by two-thirds of what the U.S. Food and Drug Administration recognizes as being clinically meaningful for therapeutic agents. Furthermore, neither in the current study nor in previous reports has nut consumption been associated with weight gain. If anything, nuts appear to be well suited as part of weight-reducing diets,” Dr. Jenkins said.

“The study indicates that nuts can provide a specific food option for people with Type 2 diabetes wishing to reduce their carbohydrate intake.”