New Research: This Powerhouse Nut Can Lower Cholesterol, Blood Pressure and Diabetes Risk

It's a long-regarded superfood. Now an international review finds it wields powerful effect against the conditions that comprise "metabolic syndrome"—reducing risk of one disease by almost 70%.

One in three American adults has metabolic syndrome, according to the National Institutes of Health (the NIH). Metabolic syndrome is defined as having at least three co-occurring conditions having to do with how the body processes and converts energy—such as excess fat around the midsection, abnormal glucose levels, high blood pressure, concerning cholesterol numbers, and high triglycerides. A significant amount of past research has shown that metabolic syndrome increases an individual’s risk for heart attack, stroke, other cardiological events, and diabetes.

Lifestyle changes and adopting a healthy diet are usually among physicians’ top recommendations for preventing or treating metabolic syndrome. Two often-promoted diets to this end are the DASH diet, which limits saturated fat, added sugar, and sodium; and the Mediterranean diet, which promotes vegetables, fruits, fish, beans, and nuts. A new analysis landed on one type of nut that researchers say could be one of the most powerful weapons in the fight against metabolic syndrome. 

A study led by Iranian medical researchers and published January 28, 2024 in the journal Food Science and Nutrition compiled multiple studies on the benefits of walnuts to see if they could be used to combat this cluster of conditions.

What they found were several strong associations with markers of metabolic health in people who regularly consumed the nut. The unique properties of this little soldier from a shell, which include polyphenols and beneficial polyunsaturated fats like omega-3s, acted on many of these separate associated conditions to lower the overall risk of developing metabolic syndrome.

Walnuts can protect against cardiovascular disease

In the meta-analysis, walnuts were associated with improved blood profiles, including a reduction in triglycerides, lower overall cholesterol, a decrease in “bad” HDL cholesterol levels and even improved blood flow. “Overall, research suggests that consuming walnuts may have promising effects in reducing the risk of cardiovascular disease,” the researchers commented.

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Walnuts can prevent and improve symptoms of diabetes

Walnuts also appeared to combat some complications of diabetes, including lowering fasting glucose levels, reducing HbA1C, and improving insulin sensitivity.

One study the researchers noted even found that walnut eaters had a 68% lower risk of diabetes compared to non-walnut eaters. This may be thanks to more conscious eating habits in general, but a near-70% differential is noteworthy.

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Walnuts might be useful for weight loss and weight maintenance

Weight is another important factor in the development of metabolic syndrome and its complications. Several studies the researchers reviewed showed the benefit of eating walnuts on body weight and its association with higher satiety levels.

However, other studies led to inconclusive results, making it unclear whether walnuts were themselves a factor in weight gain or loss. “Due to the promising effects of walnut consumption on other complications of MetS (metabolic syndrome), walnuts can be added to a diet without concern about the negative effects on BMI or body weight,” the researchers concluded.

Just be sure to note the amount of fat—even though it’s “healthy fat,” the fat in walnuts still carries the same amount of energy, nine calories per gram, as less-healthy types of fat. 

Meaghan Cameron, MS
Meaghan has more than 15 years of experience in writing and editing food, travel, fitness, sports, and lifestyle material. Her professional journey began at Reader's Digest, where she honed her skills and developed a passion for creating engaging content. Throughout her career, she has contributed her expertise to renowned platforms such as Food Network, Martha Stewart, Outside Television, and Eat This, Not That! Additionally, Meaghan has valuable experience in radio and video production. Before entering the world of content creation, Meaghan spent more than a decade working in the restaurant industry. This hands-on experience has provided her with insider knowledge and secrets about the workings of the industry. Meaghan holds a bachelor's degree in English from the State University of New York (SUNY) Purchase and a master's degree in publishing from Pace University.