Over two crop seasons, the National Pecan Shellers Association collected fresh pecans from several states for the study.
"It was a really good, national, geographically viable sampling," said Ron Eitenmiller, a food scientist with the UGA College of Agricultural and Environmental Sciences. "Significant pecan cultivars were selected from Arizona, Texas, Alabama, Mississippi, Georgia and other pecan-growing states."
Eitenmiller analyzed the samples in his Athens, Ga., lab. He found the pecans' nutritional profiles to be constant among cultivars and across regions.
"The vitamin E content looks to be pretty stable from year to year as well," he said. "This work shows that pecans are not only a really good source of vitamin E. They are also a constant source."
Pecans contain the alpha tocopherol form of Vitamin E that humans best absorb, Eitenmiller said.
"Vitamin E is the primary antioxidant we use," he said. "It protects our bodies when chemical reactions produce oxidative stress, which can be dangerous."
Vitamin E comes from plants. "We have to get vitamin E from our diet because our bodies don't produce it," Eitenmiller said. "The major sources are edible oils from soybeans, peanuts, tree nuts, peanut butter, shortening and those kinds of foods."
Connie Crawley, an Extension nutritionist with UGA's College of Family and Consumer Sciences, offers suggestions on getting the best of pecans' vitamin E into your diet.
Use a small kitchen scale to weigh 1-ounce portions of nuts. Then chop and store them in single-serving containers.
"Then you can sprinkle them on your cereal at breakfast or on your salad at lunch," she said. "They're a very concentrated source of calories. This way you're not tempted to eat too many."
Nuts and natural vegetable oils are the preferred sources of vitamin E. Sunflower seeds are the highest source, Crawley said. The UGA study found pecans have vitamin E levels similar to those in almonds, pistachios and walnuts and higher than those in cashews, macadamia nuts and dry-roasted peanuts.
But getting all your vitamin E from pecans isn't a good idea.
"There's really almost no way to get the recommended vitamin E in your diet from pecans," Crawley said. "You'd have to eat a whole lot of nuts. The recommended dietary intake for vitamin E is relatively low, and some nutrition groups recommend taking a supplement containing 200 to 400 milligrams each day."
Deciding whether to take supplements is a choice you should be make with your physician's advice, she said.
Vitamin E isn't pecans' only good quality.
"There's good information coming out about peanuts and tree nuts being really good sources of monounsaturated fat," Eitenmiller said.
"They also have other components that help with cholesterol," he said. "The pecan industry has studied the impact of pecans on serum cholesterol and found that they lower it if you routinely ingest them."
When eaten before meals, pecans can actually suppress your appetite, he said. Crawley agrees.
"Eating any fat before your meal will make you feel full," she said. "So, eating a small amount, like an ounce or 10 nuts, as an appetizer or snack before meals may take the edge off your hunger."
But when it comes to eating pecans and other high-fat nuts, you have to develop a delicate balance.
"Studies show pecans and other nuts can help reduce hypertension when eaten several times a week," Crawley said. "They contain beneficial fiber, and they're a source of protein that's low in saturated fats."
Compared to other high-fat foods, nuts are a good choice as long as you can control your portion size. "But that's the hard part," Crawley said.
(Sharon Omahen is a news editor with the University of Georgia College of Agricultural and Environmental Sciences.)