Sushi for Brain Health?

While I grew up on the East Coast, I moved to Hawaii right after school and lived there many years.  My wife was born there and graduated from the University of Hawaii.  (Go Rainbows!).  All of our children were born there.  Like about a third of the population of Hawaii, Amy's ancestry is Japanese, and she and many others share their Japanese cultural artifacts in the Hawaii cultural smorgasbord.  One of these is a love for sushi, although more than a century of separation from its islands of origin have led to a form of sushi quite different from either modern Tokyo or, for that matter, Seattle.  

While I like the sushi I've had in Japan and Seattle, I've never really cared for the sushi people make in Hawaii.  But one thing they all share is wasabi as an ingredient, and I do love that.  I had been told, and always believed, that wasabi was just the Japanese name for horseradish.  And I like to put horseradish on various foods.  But I recently learned that they are not the same thing, although horseradish (a product cheaper to produce) is often portrayed as wasabi.  (Just add green food coloring.)  They do share similar taste and the ability to clean out your nose.

So why are we talking about this?  Some recently published research from Japan found that consumption of an extract from wasabi (something that's apparently not in horseradish) can significantly improve cognition in older adults -- age 60 to 80.  Note that this is among cognitively healthy adults.  No research has been conducted with Alzheimer's patients.

The research was published in the journal Nutrients.  It studied a cohort of 72 subjects, about half of whom were given an extract from wasabi called  6-MSITC.  (The rest received a placebo.)  The study's lead researcher, Rui Nouchi, told reporters, "We knew from earlier animal studies that wasabi conferred health benefits.  But what really surprised us was the dramatic change. The improvement was really substantial."

According to the research, participants who received 100mg of wasabi extract at bed time improved episodic memory scores an average of 18%.  They scored on average 14% higher than the placebo group overall. 

Why should this happen?  The researchers believe that the wasabi reduces oxidation and inflammation in the hippocampus.  What a coincidence.  Those are the main modes of action of the dementia toolkit we describe in Beating the Dementia Monster.

Reading this research prompted my wife and me to immediately start scouring the refrigerator and pantry to see if we had any on hand.  We, of course, were looking for genuine wasabi, and not horseradish disguised as wasabi (dyed green).  The tube of paste we thought we had was gone, but we did find a small unopened can.  It had expired in February 2020.

Here's a news article about this.

Apparently, to be effective, the wasabi needs to be fresh.  In paste form, it's usually refrigerated.  Since I do like wasabi, and the researchers say it doesn't take much to see a result, I went ahead and ordered some on Amazon.  We'll see if anything amazing happens.