Written by Greg Arnold, DC, CSCS. Studies show that high-walnut-enriched diets significantly decreased total and LDL cholesterol for the duration of the short-term trials but did not significantly change values of HDL cholesterol, triglyceride levels or body mass index (BMI).

Walnuts were introduced to the Americas by Spanish explorers in the 1700s (1) and are currently the second largest nut crop produced in the U.S. (second only to almonds). Now a new study (2) has confirmed the heart-health benefits of walnuts in regards to cardiovascular disease, which costs our healthcare system $448 billion per year (3).

In the study, researchers conducted a review of 13 studies lasting between 4 and 24 weeks and including 365 patients. They examined the role of walnuts (making up 10-24% of total daily calories) in cardiovascular disease risk factors. The researchers found “significantly greater decreases” in patients taking walnuts on both total and LDL cholesterol with decreases of 10.3 mg/dL and 9.2 mg/dL, respectively. There were no significant changes in HDL cholesterol, triglyceride levels or  body mass index (BMI) in the walnut group.

For the researchers, “high-walnut-enriched diets significantly decreased total and LDL cholesterol for the duration of the short-term trials” but that “larger and longer-term trials are needed to address the effects of walnut consumption on cardiovascular risk and body weight.”

Source: Banel, Deirdre K., and Frank B. Hu. “Effects of walnut consumption on blood lipids and other cardiovascular risk factors: a meta-analysis and systematic review.” The American journal of clinical nutrition 90.1 (2009): 56-63.

© 2009 American Society for Nutrition

References:

  1. “Commodity Highlights: Walnuts” posted on the USDA Website.
  2. Deirdre K.  Effects of walnut consumption on blood lipids and other cardiovascular risk factors: a meta-analysis and systematic review.  American Journal of Clinical Nutrition, Vol. 90, No. 1, 56-63, July 2009.
  3. “Cardiovascular Disease at a Glance” posted on the Centers for Disease Control and Prevention website.
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