Nuts and Cholesterol

In a Coaching Article about snacking we talk about how important snacking is as well as the best snack choices. Some people are savory or salty snackers (pretzels or chips), while other are sweet snackers (cookies or chocolate). We suggest some healthier options for each snacker type: fruit for sweet snackers, for example, and nuts for savory snackers. (Personally, I like bananas and pecans or pistachios.)

We've known for a while that nuts are great for you, and not just because eating nuts in place of other snacks won't result in weight gain. There are many studies on the effects of eating many different nuts on cholesterol levels. Recently a team of researchers in Barcelona, Spain and in Loma Linda, California pooled the results of 25 different studies on nuts and cholesterol to see if the type of nut made a difference in the cholesterol-lowering effects of eating nuts (Arch Intern Med 2010;170(9):821-827).

The studies the researchers reviewed came from 7 countries and included over 580 men and women. Each study included information on Body Mass Index, cholesterol scores both before and at the close of the study, and excluded people who were taking cholesterol medication. Some studies included people with poor cholesterol scores while other studies only included people with normal cholesterol scores. The types of nuts studies also varied, including walnuts, pecans, macadamia nuts, almonds, pistachios and hazelnuts.

After analyzing the correlation between the amount of nuts each participant ate on a daily basis over the course of each study and their cholesterol scores, the researchers found that those diets that included nuts helped reduce total cholesterol, LDL cholesterol (bad cholesterol), the ratio of LDL to HDL (good) cholesterol, and the ratio of total cholesterol to HDL cholesterol (all improved scores). The HDL score, however, was not affected, while eating nuts only helped reduce triglyceride scores in those who actually had high triglycerides.

Intrigued, the researchers decided to control for the type of nut and found that the cholesterol improvements were the same regardless of what type of nut the participant ate. Even further, they discovered that those with a lower Body Mass Index tended to improve their cholesterol scores more than those with higher BMI, and that scores also improved more for those who ate a more Western-style diet as opposed to those who followed a more Mediterranean or simply low fat diet.

What this means for you

The beauty of these studies that pool results from several studies is that several small, not-very-strong studies can be grouped together to yield stronger results. In this case, the take-home message is that eating nuts is good for you. It doesn't appear to matter what kind of nut it is, but adding nuts to your diet, whether they're in your food or if you eat them by themselves as a snack, can help improve your cholesterol scores, won't make you fat, and are very satisfying. Eat nuts!

First posted: May 12, 2010