Walnuts Health Benefits
1. Super Plant Source of Omega-3s
Walnuts are significantly higher in omega-3 fat than any other nut, providing 2.5 grams per 1-ounce (28-gram) serving.
Omega-3 fat from plants, including walnuts, is called alpha-linolenic acid (ALA). It’s an essential fat, meaning you have to get it from your diet.
According to the Institute of Medicine, adequate intake of ALA is 1.6 and 1.1. grams per day for men and women respectively. A single serving of walnuts meets that guideline.
Observational studies have shown that each gram of ALA you eat per day lowers your risk of dying from heart disease by 10%.
2. Supports Weight Control
Walnuts are calorie dense, but studies suggest that the energy absorbed from them is 21% lower than would be expected based on their nutrients.
What’s more, eating walnuts may even help control your appetite.
In a well-controlled study in 10 obese people, drinking a smoothie made with about 1.75 ounces (48 grams) of walnuts once a day for five days decreased appetite and hunger, compared to a placebo drink equal in calories and nutrients.
Additionally, after five days of consuming the walnut smoothies, brain scans showed that the participants had increased activation in a region of the brain that helped them resist highly tempting food cues, such as cake and French fries.
3. Rich in Antioxidants
Walnuts have higher antioxidant activity than any other common nut.
This activity comes from vitamin E, melatonin and plant compounds called polyphenols, which are particularly high in the papery skin of walnuts.
A preliminary, small study in healthy adults showed that eating a walnut-rich meal prevented oxidative damage of “bad” LDL cholesterol after eating, whereas a refined-fat meal didn’t.
That’s beneficial because oxidized LDL is prone to build up in your arteries, causing atherosclerosis.
4. May Decrease Inflammation
Inflammation is at the root of many diseases, including heart disease, type 2 diabetes, Alzheimer’s disease and cancer, and can be caused by oxidative stress.
The polyphenols in walnuts can help fight this oxidative stress and inflammation. A subgroup of polyphenols called ellagitannins may be especially involved.
Beneficial bacteria in your gut convert ellagitannins to compounds called urolithins, which have been found to protect against inflammation.
ALA omega-3 fat, magnesium and the amino acid arginine in walnuts may also decrease inflammation.
5. Help Lower Blood Pressure
High blood pressure is a major risk factor for heart disease and stroke.
Some studies suggest that eating walnuts may help lower blood pressure, including in people with high blood pressure and in healthy people when under stress. Other studies did not observe this effect.
Among other diets, the four-year PREDIMED study in about 7,500 adults at high risk of heart disease tested a Mediterranean diet supplemented with 1 ounce (28 grams) of mixed nuts daily, of which half were walnuts.
At the end of the study, people on the nut-enriched Mediterranean diet had a 0.65 mmHg greater decrease in diastolic blood pressure (bottom number) than people on a similar heart-healthy control diet who weren’t given nuts.