Monday, March 22, 2010
The Avocado Advantage
High in the Good Fat
The avocado's image first took on some polish with a 1996 study by researchers at the Instituto Mexicano del Seguro Social in Mexico (Archives of Medical Research, Winter 1996) that looked at the health benefits of daily avocado consumption. The 45 volunteers who ate avocados every day for a week experienced an average 17% drop in total blood cholesterol. Their cholesterol ratio also changed in a healthy way: Their levels of LDL (low-density lipoprotein, or "bad fat") and triglycerides, both associated with heart disease, went down. Their HDL (high-density lipoprotein, or "good fat") levels, which tend to lower the risk of heart disease, climbed.
Researchers have also discovered that avocados are rich in beta-sitosterol, a natural substance shown to significantly lower blood cholesterol levels. In a review article published in the December 1999 issue of the American Journal of Medicine, researchers pointed out that beta-sitosterol was shown to reduce cholesterol in 16 human studies.
Everything in Moderation
Sneaking monounsaturated fats into your own daily diet may allow you to enjoy similar health benefits, says Melanie Polk, a registered dietitian and director of nutrition education at the American Institute for Cancer Research in Washington, D.C. Used creatively, she says, avocados can add variety -- and good nutrition -- to your diet. Instead of spreading butter or cream cheese on your bread or bagel, use some mashed avocado instead. Replace that mayo you'd usually put on a sandwich with avocado slices. You'll not only save calories, you'll be cutting out saturated fat and increasing your daily intake of monounsaturated fat as well.
But before you pile avocados onto every dish, remember that when it comes to calories, avocados have lots of them -- because of all that fat. Fat of any type has double the calories of the same amount of carbohydrates, says Polk. "Avocados add great variety to a well balanced, low-fat diet, but you have to eat them in moderation."
A recommended serving size is 2 tablespoons, or roughly one-sixth of a medium-sized avocado. Each serving provides 5 grams of fat and 55 calories. Still, compared with butter or mayonnaise -- which each pack 22 fat grams and 200 calories in a 2-tablespoon serving -- they don't seem so bad.
Giving Avocados a Try
If you decide to incorporate more avocados into your diet, look for them at your local farmer's market or grocery store. If they are hard, place them in a paper sack for a day or two until they ripen and dent when gently squeezed, then use them right away. The green flesh will quickly turn an unappealing shade of brown when exposed to air. To prevent this, place plastic wrap as tightly against the avocado flesh as possible, or sprinkle the cut fruit with a little lemon juice and refrigerate.
Despite their popularity and health benefits, there are still plenty of people who haven't tried avocados, especially those living outside California and Texas. Those two states alone consume as many avocados as the rest of the country combined, says Bliss. But he and his wife are doing their best to spread the avocado gospel: "As we travel east in our motor home, we give out avocados to anyone we meet who hasn't tried them," he says. "We know that as soon as they get a taste for avocados, they'll enjoy them and want them again."