Why it's hard to forget sushi

Photo by Cath Smith on Unsplash

A recent study conducted by Japanese scientists at Tohuko University has claimed eating wasabi, a key ingredient of sushi, can improve memory.

Rui Nouchi, the study's lead researcher and an associate professor at the Institute of Development, Aging, and Cancer, told CBS News that despite the study's limited sample of healthy subjects without existing health issues, the results surpassed their expectations.

Nouchi highlighted the significant improvement observed, even though earlier animal studies had already hinted at the health benefits of wasabi.

Wasabi is a traditional Japanese spice from Eutrema japonicum and is popular worldwide for its use in sushi.

The research, published in the journal Nutrients, revealed that its primary bioactive compound, Hexaraphane (6-MSITC), belonging to the isothiocyanate family, possesses antioxidant and anti-inflammatory properties.

Previous studies suggested that these properties play a crucial role in the cognitive health of older adults, indicating the potential positive effects of 6-MSITC on their cognitive performance.

Subjects receiving the wasabi treatment experienced an average 18 per cent increase in their episodic memory scores compared to those who didn't, with an overall 14 cent higher score than the placebo group.

The researchers theorised that 6-MSITC reduces inflammation and oxidant levels in the hippocampus, the brain's memory center, and enhances neural plasticity.

The study noted that the wasabi-treated group exhibited improved verbal episodic memory and better face-name associations, often a major memory-related issue in older adults.

However, there's a catch: most wasabi served at sushi restaurants is typically made from ordinary white horseradish dyed green. Authentic wasabi needs to be freshly consumed with the plant's stem grated just before eating.

The report highlights that a small amount of genuine wasabi offers similar benefits as the capsule supplements used in the study, providing about 0.8 milligrams of 6-MSITC.