Why can't you buy cashews in the shell, like you can with walnuts, peanuts and other types of nuts?
Frankly, not too many people would want cashews in the shell.
Cashew shells have an inner and outer wall, with honeycomb-like substance in between. That tissue contains a caustic oil, similar to what you might find in the cashew tree's distant relatives, poison ivy and poison sumac.
Without pretreatment, cracking the cashew shell would contaminate the nut -- and your hands -- with the irritant. By roasting the nut in the shell beforehand, processors draw off the oil and make the shell more brittle and easier to crack, so it can be carefully extracted. (The oil, a resin, is used in varnishes and insecticides, and for other manufacturing purposes.)
The cashew is also a relative of the mango, and looks rather funky on the tree. The seed pod, where the nut resides, looks like a curved handle on the bottom of a larger, pear-shaped "cashew apple," also called the pseudofruit of the cashew tree. The apple is highly perishable: Once it has ripened and fallen from the tree, it rots within a day. But before that happens it can be eaten raw or processed into jelly, juice, wine or other products.
Nutrition-wise, an ounce of cashews (about three tablespoons or 13 cashews) has 160 calories, 120 of which are from fat -- mostly the heart-healthy monounsaturated fat. They're also an excellent source of copper, and a good source of magnesium.
In the U.S. Department of Agriculture's MyPyramid food guidance system, an ounce of cashews counts as two ounces in the meat group and two teaspoons of oil. That might not sound like much, but overall, adults should consume just five to 6.5 ounces from the meat and beans group per day and five to seven teaspoons from the fats and oils group, depending on age, sex and activity levels. See http://mypyramid.gov for more information. Input your information in "My Pyramid Plan" to check recommended amounts for you. To see how nuts fit into the diet, go to "Inside the Pyramid" and click on the purple triangle (representing the Meat and Beans group) for details.
Keep that in mind the next time you grab a handful of your favorite nut. Don't think of it as a snack. Think of it as a substitute for some of the other protein and fat you would otherwise eat over the course of the day.
Chow Line is a service of Ohio State University Extension and the Ohio Agricultural Research and Development Center. Send questions to Chow Line, c/o Martha Filipic, 2021 Coffey Road, Columbus, OH, 43210-1044, or firstname.lastname@example.org.
This column was reviewed by Gail Kaye, registered dietitian and state specialist for Ohio State University Extension, and Michelle Tansy, dietetic intern, both in the Department of Human Nutrition, College of Education and Human Ecology.
To receive a PDF file of Chow Line via e-mail, contact Martha Filipic at email@example.com.