*The following article is a summary of the findings from a recent study titled "Dietary Spermidine Improves Cognitive Function." Further information and details on this study are located in the links below.*
One of the key biological and physiological markers of aging is neurological decline. Despite it being one of the most universal indicators of aging, we still don’t fully understand the mechanisms involved. Despite this, recent research has identified spermidine as a supplement that extends lifespan and works to protect brain health, mainly through its role in autophagy. In human analogs, spermidine is able to travel across the blood-brain barrier to increase mitochondrial function. In mice, spermidine supplementation improves spatial learning, hippocampal respiration and mitochondrial respiratory capacity. These findings suggest that spermidine supplementation can help maintain key mitochondrial function and autophagy pathways that improve cognition and slow the neurological decline often associated with aging.
While aging is a multifactoral process, one of the hallmarks of poor aging is neurological decline. Mitochondrial dysfunction is strongly associated with cognitive impairments and alterations in memory formation due to the mitochondria’s role in neurotransmission and CNS plasticity. The loss of quality control in mitochondria can be traced back to a drop in autophagy, our body’s natural cellular clean up process, which also happens as we age. Autophagy works to clean out dying or damaged organelles to make room for new ones and keep our body systems functioning at full capacity. As we age, however, this process begins to slow and the damaged organelles, like mitochondria, begin to pile up faster than our body can clean them out.
Spermidine, a naturally-occuring polyamine, plays a direct role in autophagy and promotes the autophagy process. Dietary supplementation of spermidine increases mitophagy, a mitochondrial-specific form of autophagy, which in turn also increases our mitochondria’s respiration and abundance. It has also been shown to improve synaptic plasticity and prevent memory damage caused by age in flies. Researchers have shown that supplementing spermidine later in life can improve overall cognitive function and autophagy in mice and flies. In humans, it has been shown that spermidine supplementation can lower the risk of neurological impairment as well.
There are several different pathways in which spermidine works to improve cognitive function, including passing the blood-brain barrier to improve spatial and temporal memory, enhancing hippocampal mitochondrial respiration capacity, increasing the quality-controlling mitochondrial capacity and enhancing overall cognition.
These findings present a broad potential for the use of spermidine as an extremely useful tool in treating cognitive disorders and preventing neurological decline that happens as we age. Other findings also point to the use of spermidine to improve cortical thickness and hippocampal volume in an aged population, which also helps to fight against age-related cognitive decline. The research behind the benefits of spermidine supplementation is extremely promising and continues to point to the conclusion that it is the future of human longevity.