American author Paula Danziger is quoted as saying, "Pistachio nuts cure any problem."
Although I doubt pistachios cure any problem, they might protect us from heart disease and stroke because they reduce serum low density lipoprotein (LDL), or "bad" cholesterol. A recent study demonstrated that, in those with high cholesterol, one or two servings of pistachios per day significantly reduced LDL in only four weeks.
Low density lipoprotein (LDL) is one of a family of proteins that transport cholesterol throughout the body. LDL is clinically important because it is able to carry cholesterol into the walls of the arteries. Once there, if oxidized by free radicals, the cholesterol is firmly deposited into the arterial wall, resulting in atherosclerosis and increasing the risk of heart attack and stroke.
Many studies have suggested that antioxidants can prevent or slow the oxidization of LDL and ultimately reduce the risk of heart disease and stroke. Interestingly, more than a decade of pistachio research indicates that they prevent the oxidization of LDL, lower cholesterol and can reduce the risk of heart attack and stroke.
The pistachio nut comes from the tree, Pistachio vera. Earliest records of the pistachio indicate that it was originally cultivated in the Middle East and Western Asia. Pistachio nuts are rich in vitamins, minerals and antioxidants as well as an excellent source of monounsaturated fat (like olive oil). A diet rich in monounsaturated fat is associated with a reduced risk of heart disease.
Earlier this year, a medical study published in the Journal of Nutrition demonstrated some of the health benefits of the pistachio. This 12-week study compared the benefits of a low-fat diet alone to a low-fat diet that also contained either one or two daily servings of pistachios. Twenty-eight participants with high cholesterol followed these three specific diets, each lasting four weeks.
Serum levels of specific antioxidants, LDL and oxidized LDL were measured after completion of each four-week diet regimen. While eating the pistachio-enriched diets, participants found that serum levels of several important antioxidants - lutein, vitamin E and beta carotene - were significantly higher than for those on the low-fat diet alone. More importantly, LDL and oxidized LDL levels were significantly lower when on the pistachio-enriched diets.
This study did not last long enough to directly determine if pistachios actually reduce heart disease or cardiac-related death. However, based on other research, higher antioxidants in the blood and lower oxidized LDL correlate strongly with a lower risk of heart disease and cardiac-related death.
Other studies have shown that daily consumption of pistachios can reduce LDL levels by as much as 23 percent. That reduction is comparable to that seen with statin medications, without the potential side effects.
Contrary to some claims, adding nuts to the diet will not increase cholesterol levels (overwhelming research demonstrates the opposite). They are safe, healthy and nutritious - bon appétit.
• Patrick B. Massey, M.D., Ph.D is medical director for complementary and alternative medicine for the Alexian Brothers Hospital Network.