The link between walnuts and heart health has been established before, but now researchers believe they have identified why walnuts are so beneficial.
Nuts, particularly walnuts, have long been known to promote healthy heart function. Walnuts are rich in omega-3 fatty acids, which help to reduce the risk of heart attack and stroke.
But what wasn’t clear was exactly how the mechanism between walnuts and your heart worked, just that it does.
Now, scientists from Texas Tech University believe the benefits of walnuts to your heart begins in the gut.
In a study presented to the annual meeting of the American Society of Biochemistry and Molecular Biology, the researchers state it is the action of a particular omega-3 fatty acid, alpha-linolenic acid (ALA), that is responsible for the positive heart effects of walnuts.
The study examined 42 patients, all identified as being at an “elevated risk for cardiovascular disease”. The patients were given a “traditional Western diet” for two weeks, with a nutritional breakdown of 50 per cent carbohydrates, 16 per cent protein and 34 per cent fats.
After the two weeks, participants’ gut microbiomes were studied, and the participants were split into three groups for the next six-week phase of the experiment.
The first group was given roughly one cup of walnuts (57-99 grams) daily, along with their normal diet.
The second group was given ALA supplements equivalent to that in a cup of walnuts, but without actually eating walnuts.
The third group also did not consume walnuts, and took oleic acid supplements instead of ALA supplements.
At the end of the six-week period, the researchers collected stool samples and examined the gut microbiome present in each.
They found the group that consumed walnuts had higher levels of Gordonibacter bacteria than either of the other two groups, a bacteria with anti-inflammatory, anti-cancer and lipid-lowering properties.
The walnut-eating group also had higher levels of genes involved in increasing levels of the amino acid L-homoarginine. A deficiency in this amino acid has been previously identified as a risk factor for cardiovascular disease (CVD).
Mansi Chandra, co-author of the study, says the findings may open new treatment and management possibilities for CVD management and prevention – even in those who don’t eat, or may be allergic to, walnuts.
“Research has shown that walnuts may have heart-healthy benefits like lowering cholesterol levels and blood pressure,” Ms Chandra says.
“Since a lot of people are allergic to nuts, these findings also suggest that other food supplements that boost the endogenous production of homoarginine may also be helpful.”
Do you regularly eat walnuts? Would you consider adding some to your diet now? Let us know in the comments section below.
Also read: Nuts that help you lower bad cholesterol
I’ve been eating walnuts for years, 3 to 4 times a week, about a small handful. I have also heard they are good for your brain.