As we age, our bodies go through a lot of changes, and one of the most significant changes is cognitive ageing. Cognitive ageing is the process of the brain's gradual decline in function, which can lead to memory loss, decreased attention span, and slower reaction times. While cognitive ageing is a natural part of the ageing process, there are several factors that contribute to it. 

One of the primary causes of cognitive ageing is the deterioration of the mitochondria. Mitochondria are tiny organelles found in every cell of our bodies, and they are responsible for producing energy that allows the cell to function properly. As we age, the mitochondria become less efficient at producing energy, which can lead to a decline in cognitive function. This is known as Mitochondria Dysfunction, and it affects 48% of people under 40 [1] Dave Asprey: Super Human 2019). 

Without properly functioning mitochondria, there isn't enough energy for the brain cells to work normally. This contributes to the many symptoms of declining brain function, including memory loss, decreased attention span, and slower reaction times. While there is no cure for cognitive ageing, there are several things that we can do to slow down the process. 

One of the most effective ways to slow down cognitive ageing is to exercise regularly. Exercise has been shown to increase blood flow to the brain, which can help to improve cognitive function. Additionally, exercise can help to reduce inflammation in the body, which has been linked to cognitive decline [2] (Harvard Health Publishing, 2018). 

Another way to slow down cognitive ageing is to eat a healthy diet. A diet that is rich in fruits, vegetables, whole grains, and lean protein can help to provide the nutrients that the brain needs to function properly. Additionally, a diet that is low in saturated and trans fats can help to reduce the risk of cognitive decline [3] (Mayo Clinic, 2021). 

Finally, it is essential to stay mentally active as we age. Engageing in activities that challenge the brain, such as reading, playing games, or learning a new skill, can help to keep the brain sharp and improve cognitive function [4] (National Institute on Ageing, 2021). 

In conclusion, cognitive ageing is a natural part of the ageing process, but there are several things that we can do to slow down the process. By exercising regularly, eating a healthy diet, and staying mentally active, we can help to keep our brains functioning at their best. While there is no cure for cognitive ageing, taking care of our bodies and minds can help us to age gracefully and maintain our cognitive function for as long as possible. 

References: 

1. Super Human: The Bulletproof Plan to Age Backward and Maybe Even Live Forever (Bulletproof, 5): 9780062882820: Asprey, Dave: Books https://www.amazon.com/Super-Human-Bulletproof-Backward-Forever/dp/0062882821  
2. Harvard Health Publishing. (2018). Regular exercise changes the brain to improve memory, thinking skills. https://www.health.harvard.edu/blog/regular-exercise-changes-brain-improve-memory-thinking-skills-201404097110  
3. Mayo Clinic. (2021). Alzheimer's prevention: What can you do? https://www.mayoclinic.org/diseases-conditions/alzheimers-disease/in-depth/alzheimers-prevention/art-20047880  
4. National Institute on Ageing. (2021). Staying sharp https://www.nia.nih.gov/health/staying-sharp