Why Would a Hormone that Makes You Hungry Also Improve Your Brain Function?

While commonly known as the 'hunger hormone,' ghrelin, a hormone produced primarily by the stomach with minor contributions from the small intestine, pancreas, and brain, is involved in more than just appetite regulation. The interaction between this hormone and brain function is particularly intriguing. Recent research has highlighted the potential of ghrelin to promote neurogenesis, the growth of new brain cells, which could have significant implications for brain health and cognitive function.

Understanding Ghrelin: The Hunger Hormone

Ghrelin is produced mainly in the stomach, increasing just before mealtime, which explains why it is often referred to as the 'hunger hormone.' This hormone stimulates appetite, increases food intake, and promotes fat storage. When introduced to humans, it can increase food consumption by up to 30%, acting on the hypothalamus, a critical area of the brain involved in the control of appetite, and regions like the amygdala, involved in reward processing.

Neurogenesis: The Birth of New Brain Cells

Jeffrey Davies, a researcher at Swansea University in the UK, and his team have made groundbreaking discoveries about ghrelin's role in brain health. They found that ghrelin can stimulate brain cells to divide and multiply, a process known as neurogenesis. When the hormone is applied to mouse brain cells grown in a dish, it activates a gene called fibroblast growth factor (FGF), which is known to trigger neurogenesis. This discovery suggests that ghrelin might have the potential to enhance brain function and neuroplasticity.

Evolutionary Insights: The Multiple Roles of Hormones

Throughout evolution, useful products from one process are often repurposed for another, and this appears to be the case with ghrelin. Some plant hormones, for example, have precursors that are similar to those found in humans, indicating that multiple functions of hormones have roots in evolutionary adaptations.

The reason for ghrelin's role in brain function is not definitively known. While the exact mechanism remains a mystery, it is believed to arise from evolutionary causes. Throughout the course of evolution, hormones and organs have developed to serve multiple functions. The exact reasons for specific functions, however, remain a mystery, often unanswerable due to the lack of fossil evidence for hormones and organs. Studies on simple life forms such as insects offer some insights, but the full role of chemistry and function in organisms is still largely unknown.

Memory and Appetite: The Connection?

Despite its well-documented role in appetite regulation, some studies suggest that ghrelin may also have a positive effect on memory. However, the nature of this effect is not entirely clear. It is unclear whether ghrelin improves memory in general or specifically memory related to food. Further research is needed to understand the full scope of ghrelin's impact on brain function and memory.

Conclusion: The Future of Ghrelin Research

The discovery that ghrelin can stimulate neurogenesis opens new avenues for research into brain health and cognitive function. While more studies are needed to fully understand the mechanisms involved, this finding could have significant implications for treatments targeting neurodegenerative conditions and cognitive decline. The multifaceted nature of hormones, and ghrelin in particular, underscores the complex relationship between our bodies and our brains, further fueling the intrigue of endocrinological research.