Maybe old dogs can’t learn new tricks, but what about elderly people? There’s no denying that as humans get older, we seem to slowly lose our brain capacity. For decades, we’ve been told that aging naturally leads to the death of brain cells, but new research is challenging this myth. The big question is can the human brain continue to regenerate even as we age?
One 2018 study published in the Journal of Cell Stem Cell (1) says that new neurons can still be found in the hippocampi of adults. This region of the brain enables us to learn and remember while regulating our mood. The researchers of this paper explain that the amount of intermediate neural and young neurons in the hippocampal dentate gyrus (DG) of the brain is the same regardless of age.
However, another paper published soon after by the Nature Journal (2) disagrees with the results of the previous study. This paper suggests that even though adults still have undeveloped neurons in their brains, the number of cells is less than that of younger people.
The Innovative Stereology Breakthrough
Even though the evidence contradicts each other, the first study published by the Cell Stem Cell Journal is fascinating because of its methodology. The researchers used stereology to count the number of grown and young neurons in the hippocampi of healthy people. Stereology is an industry-standard technique used by animal scientists; it is very effective for determining the amount and types of cells in a particular tissue.
One neurobiologist known as Xinyu Zhao, from the University of Wisconsin-Madison, says that the ability of the researchers to use stereology on human hippocampi is outstanding (3). This is because normally there would not be enough brain tissue to perform this test.
Using Staining to Understand Neurogenesis
The second study from the Journal of Nature had a different approach. The researchers from Columbia University analyzed the brain tissue of 28 corpses between the ages of 14 to 79 of people who died within 26 hours. Their tests focused on the regeneration of new cells in the brain, a phenomenon called neurogenesis (4). For this, they used antibody staining to count the cells. Their findings claim that the older a person is, the less new neurons they have.
The brain is the most researched organ in the body, yet we still do not fully understand how it works. However, thanks to the advent of neuroplasticity, we now know that healthy brain cells can regenerate even after physical or emotionally traumatic events.
But the evidence cannot clearly say if this process of regeneration continues into old age. And if the brain can revive itself, what about the other organs in the body?
We need more research to support or dismiss the claims of these few studies. Still, one thing is for sure, eating a healthy diet and exercising daily will improve and help you maintain a properly functioning brain and body even as you age.