Walnuts Have More, Better Antioxidants Than Peanuts, Pistachios, Other Nuts, Researcher Says
By Kathleen Doheny
WebMD Health News
Latest Diet & Weight Management News
Reviewed by Louise Chang, MD
March 28, 2011 (Anaheim, Calif.) -- Walnuts are the No. 1 nut for heart health, says a researcher who presented his findings Sunday at the American Chemical Society annual meeting.
That's because walnuts were found to have more antioxidants -- and better-quality antioxidants -- than other popular nuts tested, says Joe Vinson, PhD, a researcher at the University of Scranton in Pennsylvania.
Antioxidants protect cells against damage caused by harmful molecules known as free radicals. The damage can play a role in heart disease and other health conditions.
When Vinson analyzed the amount of antioxidants found in walnuts and a variety of other nuts, walnuts came out on top.
"Twenty-eight grams of walnuts (an ounce) have more antioxidants than the sum of what the average person gets from fruits and vegetables," he says. "That is not to say they are a replacement for fruits and vegetables, but they are very antioxidant dense."
The research was internally funded by the university.
Nuts & Health: Back Story
"Nuts have had a negative connotation,'' Vinson says. Many people shy away from eating them, he finds, worried the fat content and calories will lead to weight gain.
An ounce of English walnuts has 185 calories, according to the U.S. Department of Agriculture. That ounce also has 4 grams of protein, nearly 2 grams of fiber, and more than 18 grams of fat -- but lots of ''heart-healthy'' fat.
Studies have shown that people who incorporate a handful or so of nuts in their diet daily either maintain weight or lose weight, Vinson says.
Now, evidence is emerging that nuts can also help brain health, he says.
Vinson encourages nuts as snacks. "One of the reasons nuts are such a good snack is, it's not empty calories for certain, and you feel full," he says. That makes it likely you won't overeat at the next meal.
A Closer Look at Nuts
Besides walnuts, Vinson analyzed the antioxidant content of other popular nuts, including:
- Brazil nuts
- Macadamia nuts
Brazil nuts were the runner-up for antioxidant content. Peanuts also fell short of walnuts.
Walnuts and Health Benefits: Second Perspective
"This study tells us something important about the composition of walnuts," says David Katz, MD, MPH, director of the Yale University Prevention Research Center. He reviewed the findings for WebMD.
The walnut industry has funded two studies Katz has done, he says. But it had no say in the study design, analysis, interpretation, or publication.
''Antioxidants are important nutrients, and in principle, a food rich in antioxidants is apt to confer health benefits," Katz says. "In the case of walnuts, that principle is not in doubt." Studies, including some by Katz, show that walnuts improve cardiac risk factors and enhance blood flow, he says.
This study was presented at a medical conference. The findings should be considered preliminary as they have not yet undergone the "peer review" process, in which outside experts scrutinize the data prior to publication in a medical journal.
SOURCES: Joe Vinson, PhD, researcher, University of Scranton, Scranton, Pa.241st National Meeting & Exposition of the American Chemical Society, Anaheim, Calif., March 27-31, 2011.David Katz, MD, MPH, director, Yale University Prevention Research Center, Derby, Conn.
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