If only our brains could stay as young as we feel when we finally discover the joys of napping, drinking tea, and wearing socks with sandals. But alas, the brain ages just like the rest of us. And while we may be getting wiser, our neurons aren't always in the mood to celebrate. They slow down, connections start to fizzle, and some cells take early retirement, leading to a slew of degenerative brain diseases.
Taken from: https://altoida.com/blog/paying-attention-to-brain-health-as-you-age-can-help-maintain-healthy-aging/
So, What Actually Ages Our Brain?
Aging might be inevitable, but the mechanisms behind it are complex, involving everything from genetic mutations to the cellular garbage we accumulate over the years.
Protein misfolding
Picture your closet filled with clean clothes, but instead of being neatly folded, they’re in a jumbled, wrinkly mess. That’s essentially what happens to proteins in the brain as we age. Misfolded proteins like beta-amyloid and tau clump together, especially in Alzheimer's, gumming up cell-to-cell communication.
Mitochondrial dysfunction
As we are all taught in school, the mitochondria are the powerhouses of cells. As we age, they’re not exactly working overtime. In fact, their function declines, leaving cells energy-starved and vulnerable to damage. This “brain power outage” contributes to neurodegeneration, particularly in diseases like Parkinson’s where dopaminergic neurons (cells that produce dopamine) are particularly susceptible to mitochondrial failings. But wait, there’s more—this decline in energy kicks off a chain reaction! Reduced mitochondrial efficiency leads to oxidative stress, where rogue reactive oxygen species (ROS) wreak havoc on proteins, DNA, and membranes. Think of it as your neurons being under constant biochemical attack, triggering protein misfolding, DNA damage, and inflammation. Diseases like Parkinson’s love to crash this party, with their hallmark dopaminergic neurons being prime victims of this energy crisis.
DNA damage
Cell division comes with a tiny chance of DNA errors, and as these accumulate, they mess with neurons’ ability to function. Some cells even give up and enter a state of senescence, where they simply stop dividing but refuse to die—a process that’s as unhelpful as it sounds. This DNA damage is especially prominent in conditions like Alzheimer’s, where specific genetic factors can accelerate the whole problem.
Neuroinflammation
The brain’s immune sentinels, the microglia, are like overzealous bodyguards. In youth, they’re sharp and efficient. But as time goes on, they can’t tell friend from foe, launching an all-out inflammatory assault. They flood the brain with cytokines like TNF-α and IL-1β, and while this might be okay for a quick fix, chronic inflammation spells doom. Overactive immune responses don’t just stay in the brain either—there’s a striking similarity to autoimmune diseases like rheumatoid arthritis, where the immune system constantly attacks the body’s own tissues. In the brain, this leads to neurodegenerative disorders like Alzheimer’s, with amyloid plaques acting like flares to call in more immune reinforcements.
In the image above, the green and yellow sections indicate higher activity or healthier brain regions, while the purple and blue regions entail reduced activity or degeneration in certain areas. This just shows how, as we age, our brain also ages, causing neurodegeneration and other issues.
Can We Slow or Reverse the Process?
While we might not have access to a full-blown “Benjamin Button” scenario for the brain (yet!), modern science has produced several strategies to fight brain ageing.
For one, CRISPR technology and other gene-editing methods are being used in clinical trials to correct mutations that lead to neurodegeneration. For example, researchers are exploring ways to stop the production of tau and amyloid-beta proteins, which could halt or even prevent Alzheimer's.
On top of that, stem cell therapy is a promising frontier. Imagine if you could replace dying neurons with new ones, like swapping out old batteries for fresh ones. That’s the aim of stem cell therapy, where scientists can either stimulate the brain to produce its own new cells or transplant fresh cells into affected areas. While not yet perfected, this therapy could be key in regenerating lost neurons in conditions like Parkinson’s.
Lastly, senolytic drugs could be helpful too. Senescent cells—those “zombie” cells that hang around doing nothing helpful—are a huge problem in ageing. As such, scientists have developed senolytic drugs to target these cells and encourage them to clear out, giving healthy cells room to work efficiently. Early studies suggest these drugs may slow ageing-related brain degeneration.
The Future of Brain Ageing
Today, there are several strategies currently in development to improve brain ageing. These include strategies such as caloric restriction, ketogenic diet, promotion of cellular nicotinamide adenine dinucleotide (NAD+) levels, removal of senescent cells, enhancement of adult neurogenesis, stem cell therapy, vascular risk reduction, and non-pharmacological lifestyle strategies. This may seem like a mouthful, but their effects on preventing, or even reversing neurodegeneration will be remarkable, giving us a solution to the age-old issue of brain ageing.
However, as these methods are highly complicated, clinical evidence is limited and many of these strategies are awaiting findings from large-scale clinical trials which are nascent in the current literature. We are still in the midst of finding out ways to reverse brain ageing. At the very least, the future seems promising, and with continued efforts and resources invested to develop the aforementioned strategies, we will not only not only be able to reduce the degenerative effects of brain ageing, but will also enhance our current understanding of the human brain and improve future neuroscience knowledge.
Conclusion
Science hasn’t delivered a miracle cure for brain ageing yet, but the strides being made are genuinely encouraging. We’re learning how to target everything from genetic issues to inflammation, and promising therapies are emerging on the horizon. While we may not be able to stop brain ageing entirely, we’re getting closer to delaying its more severe consequences, meaning a future where we can keep our wits about us, possibly well into our nineties and beyond. In the meantime, we might as well enjoy the brain we’ve got: play a little chess, learn a new language, try some Sudoku, and, of course, nap responsibly. After all, the best thing we can do for our brains right now is to keep them engaged, challenged, and, most importantly, appreciated.
References
Gupta, Sanjay. Keep Sharp : How to Build a Better Brain at Any Age - as Seen in the Daily Mail. London, Headline, 2022.
Heinrichs, Jan-Hendrik. “Brain Age Prediction and the Challenge of Biological Concepts of Aging.” Neuroethics, vol. 16, no. 3, 23 Sept. 2023, https://doi.org/10.1007/s12152-023-09531-4. Accessed 25 Oct. 2024.
so informative!! 😍🔥