Have you noticed that when you buy a can of fancy mixed nuts, the label invariably proclaims "less than 10% peanuts"? This is not because there's something wrong with peanuts. Quite the opposite, in fact. What you're seeing is truth in labeling, because in the social hierarchy of nuts, peanuts are the poor relations.
Because peanuts are both plentiful and inexpensive, it is tempting for food packagers to dilute an expensive can of mixed nuts--cashews, walnuts, pecans and hazelnuts--with peanuts in order to increase profits.
Nonetheless, even in the most expensive selection of mixed nuts, you will rarely see macadamia nuts, which are as rare and costly as peanuts are plentiful and inexpensive. And if you've ever seen a "raw" macadamia, you know why. Harvesting them and bringing them to market is a labor-intensive process.
It can take up to five or six years after planting just to harvest a crop. The trees bear annually after that, but these extremely delicate nuts are covered by such a hard shell that they require 300 pounds per square inch to crack. And, of course, they are most valuable when they are in one perfect piece.
Macadamias have a reputation for being unusually high in fat. This is true, but over 80% of the fatty acids in macadamia nuts are of the monounsaturated type, more than even olive oil. Monounsaturated fat (often called "the good fat") has been shown to lower blood cholesterol and may even have some cleansing effect on the arteries. Because of the potential benefits of highly monounsaturated oils, they are the subject of much research. Like all vegetable products, macadamia nuts have no cholesterol and, unless roasted and salted, little sodium.
If the researchers are correct and the highly monounsaturated fats have as big an effect on cardiovascular health as they seem to, then macadamia nuts and macadamia nut oil are going to become important additions to your pantry.
One word of caution, however: Just because certain forms of fats are shown to be beneficial, you shouldn't dramatically increase the overall amount of fat you consume. Fat is still fat. However, when choosing which fats to include in your diet, remember that the monounsaturated fats, like the ones found in nuts, are likely to have the greatest positive effect on your health. So if you are going to include nuts in your diet in any way, give macadamia nuts a try. Just be careful. They're highly addictive and can become an expensive habit.
Dr. Sheldon Margen is a professor of public health at UC Berkeley; Dale A. Ogar is managing editor of the UC Berkeley Wellness Letter. Send questions to Dale Ogar, School of Public Health, UC Berkeley, Berkeley, CA 94720-7360, or e-mail firstname.lastname@example.org.