Walnuts are superfoods that lower blood pressure

Since ancient times, walnuts have been eaten as a source of intelligence.

Tree nuts were native to the Mediterranean region and a precious commodity traded on the Silk Road. There exist at least 30 varieties of walnuts, but the three most popular varieties are the English or Persian walnut, the black walnut, and the white or butternut walnut. After planting, the tree takes approximately four years to produce its first major crop.

Now, we know from research what the ancients knew from experience — those walnuts are good for you. They are packed with nutrients, especially omega-3 fatty acids, which are essential for optimum health.

A study conducted at the University of Scranton in Pennsylvania in 2012 and published in the journal Food and Function compared the amount of polyphenols in nine types of raw and roasted walnuts and two types of peanut butter.

Polyphenols are powerful antioxidants that can protect and possibly repair cells damaged by free radicals, the molecules produced when the body breaks down certain foods or is exposed to environmental hazards such as tobacco smoke and solar radiation. Free radicals have been implicated in some cancers, cardiovascular illness and other diseases.

The researchers also tested just how effective the antioxidants in the nuts are in maintaining a healthy heart. Raw and roasted walnuts beat the peanuts by a considerable margin. Walnuts had the highest amount of polyphenols which researchers found to reduce heart disease by lowering levels of “bad” cholesterol, improving blood flow, and reducing the vascular inflammation that leads to heart disease.

“Nuts are a nutritious snack and food additive, providing both nutrients and antioxidants, which provide significant health benefits,” that study concluded.

While most nuts are good nutrition, walnuts are at the top for brain health. Plant compounds in walnuts reduce inflammation in the brain and improve cognitive performance. They have a much higher concentration of DHA, a type of omega-3 fatty acid.

DHA has been shown to protect brain health in newborns, improve cognitive performance in adults and possible slow or prevent cognitive decline as we age. Research has also shown that walnuts and walnut oil help lower resting blood pressure and lower blood pressure responses to stress.

There have been numerous other studies showing health benefits of walnuts. They are a rich source of energy and provide several B vitamins including niacin, thiamine, folic acid, riboflavin, B-6, and pantothenic acid. Walnuts are also an excellent source of vitamin E.

Minerals such as iron, potassium, copper, magnesium, manganese, zinc and selenium are found in walnuts. Their anti-inflammatory properties lower the risk of high blood pressure, coronary artery disease, strokes and various cancers. New research into omega-3s is showing a possible benefit as an adjunct in the treatment of depression and other mood disorders.

The February 2019 issue of the journal, Nutrients, published a National Health and Nutrition Examination Survey report showing that a study of 26,656 people who regularly ate nuts, especially walnuts, had consistently lower depression scores.

The journa,l Diabetes, Obesity and Metabolism, published an interesting study from Harvard Clinical and Translational Science Center in 2017 that showed walnuts were of benefit in weight control diets because it seemed to control appetite and impact glycemic control. Further study on this is underway.

One-quarter cup, or 30 grams, of walnuts contains 4 grams of protein, 19.5 grams of “good” fat, 2.8 grams of carbohydrates, 1 gram of sugar, 1.45 grams of fiber, and 190 calories. There is less than 1 gram of sodium. Walnuts, like all tree nuts, are high in calories so moderation in consumption is prudent. And of course, people with an allergy to tree nuts must avoid walnuts as well as other nuts.

Walnuts are available in grocery stores year-round. They can be bought packaged and shelled or in bulk still in their shells. The shelled nuts should be stored in the refrigerator or freezer to preserve freshness and avoid rancidity, but the unshelled nuts may be stored for several months in a cool and dry location.

The nuts can be eaten as a healthy snack, plain, salted or sweetened. They can be a flavorful addition to a variety of foods, such as salads, stir fries, yogurt, desserts and breads. Walnut butter is an alternative to peanut butter for people looking for that better nutritional boost. Walnut oil can be used for cooking and also has non-edible uses such as base oil in traditional medicine preparations in massage and aromatherapy. It also can be used cosmetically to keep skin supple and prevent dry skin.

Think twice when reaching for a cookie or similar snack when a handful of walnuts will give you a nutritional boost along with a good taste.

Mia Smitt is a longtime nurse practitioner. She writes a column for Tucson Local Media.