What exactly is Spermidine?
A drop in brain function is a normal process of aging, but the steps on how this occurs and what we can do to affect this process remain an active area of research. A recent study using humans, rodents, and fruit flies added to our understanding of the brain's aging process and how we can delay a decline in brain function using spermidine (Cell, 35, April 13, 2021).
Spermidine is a natural dietary food supplement that has been studied and identified as a compound that can protect us from aging. Many studies have determined that spermidine works primarily by increasing a process called autophagy. Autophagy (as many of you may know) is a procedure by which how our cells recycle old proteins and organelles within our cells and earned the scientist who first described it a Nobel Prize in Medicine in 2016. By removing these ancient proteins and organelles, cells can make new structures and remain more youthful. Given their many essential life roles, the best organelle to regenerate by this mechanism would be the mitochondria.
So what discoveries were made on spermidine?
First, the researchers showed that spermidine could pass through the brain barrier. It is a significant discovery given that few compounds, be they natural or manufactured, can pass through this brain barrier. This means that spermidine cans have a direct positive effect on our brain cells. Second, spermidine increases mitochondria function. Mitochondria are cell organelles that produce energy (ATP) through cellular respiration. In addition, mitochondria have been closely linked to many processes determining our lifespan. In this study, the researchers showed that spermidine increased the brain's cellular respiration, which means more energy for our brain cells. Interestingly, the researchers noted that spermidine could only have these positive effects on our neurons if autophagy were upregulated.
In other words, they found that if they were to block autophagy, all of the benefits would also be blocked, which adds more support that spermidine functions through autophagy. Finally, and more practically, the researchers also showed that spermidine improved cognitive learning, such as spatial learning (our brain senses the environment). Those who forget where we left our car keys or parked our car may benefit from some spermidine improved spatial learning!