Eating whole walnuts can help to lower blood pressure, new research finds.
Walnuts contain a type of omega-3 called alpha-linolenic acid, which is heart healthy.
People in the study swapped out 5 percent of their saturated fat intake for walnuts to achieve the benefit.
After eating the walnuts for six weeks, their blood pressure was lower.
Reducing saturated fat intake helps, but there is something special about walnuts, explained Professor Penny Kris-Etherton, study co-author:
“When participants ate whole walnuts, they saw greater benefits than when they consumed a diet with a similar fatty acid profile as walnuts without eating the nut itself.
So it seems like there’s a little something extra in walnuts that are beneficial — maybe their bioactive compounds, maybe the fiber, maybe something else — that you don’t get in the fatty acids alone.”
The study included 45 overweight or obese people.
They were split into three groups and for six weeks each was fed a slightly different diet to test the effects of walnuts.
Dr Alyssa Tindall, the study’s first author, explained:
“Walnuts contain alpha-linolenic acid — ALA — a plant-based omega-3 that may positively affect blood pressure.
We wanted to see if ALA was the major contributor to these heart-healthy benefits, or if it was other bioactive component of walnuts, like polyphenols.
We designed the study to test if these components had additive benefits.”
The results of the study showed that reducing saturated fats helped reduce blood pressure.
However, walnuts produced the greatest drop in blood pressure.
Dr Tindall said:
“An average American diet has about 12 percent calories from saturated fat, and all our treatment diets all had about seven percent, using walnuts or vegetable oils as a replacement.
So, seeing the positive benefits from all three diets sends a message that regardless of whether you replace saturated fats with unsaturated fats from walnuts or vegetable oils, you should see cardiovascular benefits.”
Professor Kris-Etherton has this advice:
“Instead of reaching for fatty red meat or full-fat dairy products for a snack, consider having some skim milk and walnuts.
I think it boils down to how we can get the most out of the food we’re eating, specifically, ‘how to get a little more bang out of your food buck.’
In that respect, walnuts are a good substitute for saturated fat.”
About the author
Psychologist, Jeremy Dean, PhD is the founder and author of PsyBlog. He holds a doctorate in psychology from University College London and two other advanced degrees in psychology.
He has been writing about scientific research on PsyBlog since 2004. He is also the author of the book “Making Habits, Breaking Habits” (Da Capo, 2003) and several ebooks:
- Accept Yourself: How to feel a profound sense of warmth and self-compassion
- The Anxiety Plan: 42 Strategies For Worry, Phobias, OCD and Panic
- Spark: 17 Steps That Will Boost Your Motivation For Anything
- Activate: How To Find Joy Again By Changing What You Do
The study was published in the Journal of the American Heart Association (Tindall et al., 2019).