Go nuts with nuts: New studies demonstrate improved cognition and gut health

11 Nov 2022 --- Researchers are revealing that just four weeks of eating mixed tree nuts could have positive effects on mood, memory and overall thinking capability. This same study and others also found that eating nuts can help to modulate metabolites, bacteria and microbes in the gut.

We look at two recent studies – one on mixed nuts and one on almonds – to see how the tree-born treats can best benefit the body, especially hazelnuts, walnuts and almonds. Though all of the nuts on their own have previously been found to have their correlated benefits, the new studies suggest that a mix of many may provide the most noticeable health boosts.

One study, published in The Journal of Nutrition, focused on mixed nuts and their effects on cognition and the microbiome. Dr. Crystal Haskell-Ramsay, professor of biological psychology at Northumbria University, Newcastle upon Tyne, UK, and lead author of the study states, “This study provides exciting evidence for improvements to cognition following only 4-weeks consumption of tree nuts.” 

“Since the study participants were healthy, non-elderly adults, it’s possible that more profound effects may be shown in those at increased risk for cognitive decline or in those with poor gut health,” she adds.

Eating 30 g of mixed tree nuts a day can increase brain power, add fiber to the diet and help maintain a healthy gut.

Getting highbrow with hazelnuts
The mixed nut study, funded by the organization INC International Nut and Dried Fruit, is a randomized, placebo-controlled, double-blind and counterbalanced trial including 76 healthy volunteers from 18 to 49 years of age.

The participants were given 30 g of mix of nuts – 15 g walnuts, 7.5 g hazelnuts and 7.5 g almonds – each day for four weeks, along with one microcrystalline cellulose placebo capsule. Following that, they performed a four-week washout and then switched to two placebo capsules a day for four more weeks.

The cognitive test included word, number, picture and location recall, measuring choice reaction times and accuracy and logical reasoning along with other factors.

The results show “significant increases” in reaction and recall times across all factors, as well as an increased aversion to false selections when recalling the pictures, numbers and words.

An almond a day?
The study further measured the nuts’ effects on the makeup of the microbiome. Researchers took stool and urine samples twice (before and after) during the trial. 

It found that the bacteria Lachnospiraceae was significantly increased through supplementation, which has been found to produce short-chain fatty acids. It also found a 25% increase in the short-chain fatty acid butyrate. 

A separate study, published in The American Journal of Clinical Nutrition, found that eating roughly 46 almonds a day (about 56 g) can improve butyrate levels in the microbiome, improve overall gut health and act as a source of fiber.Eating 46 almonds a day may greatly improve gut health

“Butyrate is involved in several health-promoting processes such as providing energy to the cells lining the gut, regulation of the immune system and signaling to the cells of the gut to absorb certain nutrients,” Dr. Alice Creedon, lead author of the almond study, recently told NutritionInsight.

Moreover, Dr. Creedon further stated that “due to the effect of almonds on increasing butyrate production, they could be promoted as a snack food that can be consumed to benefit gut health by targeting bacterial metabolism.”

Additionally, higher levels of butyrate in the gut have been linked to decreased bloating, a decreased severity in irritable bowel syndrome symptoms and reduced inflammation in the gut and body.

By William Bradford Nichols