May 20, 2019

Celebrate the Health Benefits of Walnuts

According to A.J. Schenkman:

“… if Washington did cut down a cherry tree it was most likely to make room for planting a walnut tree, and if he did have wooden teeth his real teeth likely were ruined breaking walnuts. One thing is true, confirmed by sources both foreign and domestic: General Washington, whether at home in Mount Vernon or at his headquarters in Newburgh, always had plenty of walnuts on hand."

Washington's personal papers are littered with references regarding purchases of [nuts] he was, in fact, fond of nuts of all kind. Walnuts, however, were his favorite. He "planted several varieties," including black and English walnuts, on his Virginia plantation, Mount Vernon. ….. English walnuts seemed to be a particular favorite of Washington—he planted some 30 trees at Mount Vernon in just 1763 alone; between 1790 and 1799 he planted at least eight more that we know of from his writings.”1 This being the case, one would think that National Walnut Day would somehow be connected to some important Washington commemorative date but instead it is celebrated on May 17th and apparently has been since 1949. It wasn’t until 1958 that Eisenhower, then President, made it official.

In recent years there seems to have been an upsurge of scientific research on the health benefits of eating nuts and in particular on walnuts. Thus it feels appropriate to take a few minutes and to remind ourselves about some of these newer papers.

Walnuts contain a number of nutritive compounds including:

“… vitamin E and polyphenols. Among common foods and beverages, walnuts represent one of the most important sources of polyphenols, hence their effect over human health warrants attention. The main polyphenol in walnuts is pedunculagin, an ellagitannin. After consumption, ellagitannins are hydrolyzed to release ellagic acid, which is converted by gut microflora to urolithin A and other derivatives such as urolithins B, C, and D. Ellagitannins possess well known antioxidant and anti-inflammatory bioactivity, and several studies have assessed the potential role of ellagitannins against disease initiation and progression, including cancer, cardiovascular, and neurodegenerative diseases.”2

There are some very intriguing walnut studies. In December 2018, Freitas-Simoes et al reported a trend that eating walnuts may preserve telomere length in elderly people. Preserving telomere length is the Holy Grail of longevity research.3

People have this thing about eating nuts - they worry that nuts will make them fat. Over the years we’ve lost count of all the studies that suggest this is nonsense. A September 2018 reaffirmed this, that supplementing the diet with nuts, in this case walnuts, doesn’t add either pounds or inches.4

Eating walnuts (45 grams or about 1.5 ounces/day for 16 weeks) improved metabolic syndrome, increasing HDL cholesterol and lowering fasting blood sugar, A1c and adiponectin.5 Adding in a similar amount of walnuts into daily smoothies over 5 days reduced the bad LDL cholesterol fractions and increased the good HDL fractions in a placebo-controlled trial that was published May 14, just in time for Walnut Day.6

In a paper published last December, eating walnuts was associated with lower risk of depression, especially among women.7 Eating nuts improves the gut microbiome, an admirable goal that more and more people who come to see us seem to be fixated on of late.8 A number of studies are suggesting that eating walnuts might lower risk of specific cancers9 including breast,10,11 colon,12 prostate,13 and lung.14

There are some great walnut recipes on Walnuts.org, the website of The California Walnut Board and Commission.

Categorized Under