Aging: The Race Against Time

From the moment we’re born, we have already begun the process of aging. As we grow and mature, so do our cognitive abilities. Our cognitive abilities are the ways that our brain works to remember, reason, think, and pay attention. In fact, many of these skills peak within the first few decades of life. However, some of these abilities gradually decline over time. You may find yourself having a harder time remembering a fact or learning a new skill as you get older. This is a natural part of life, but it is not always the case. We see a phenomenon in some individuals called “super-agers”¹. These super-agers are people who are in their 70’s or 80’s and have a remarkably good memory. So good that their memory rivals that of people in their 50’s or 60’s! But just what is the secret to living a long life without any diminishing cognitive abilities? 

As it turns out, it takes two to tango! Long life and retaining good cognitive abilities can both be attributed to both environmental factors and genetics. Environmental factors can include hygiene, access to healthcare, diet, nutrition, exercise, and lifestyle to name a few. Researchers at Northwestern University² have studied this phenomenon of super-agers that hail from a wide variety of backgrounds (e.g., varying levels of education, activity, and life experiences). 

But what is the common trait among this group? 

Specifically, these researchers observed that the brains of super-agers were physically different compared to other elders. Super-agers had brains with thicker cortices. Cortices are the outer layer of the brain associated with intelligence and high-level functions. This layer generally thins with age, so thicker cortices may make brains more resistant to cognitive decline. In addition, super-agers do not appear to accumulate aging-associated proteins³ in their brains. The build-up of protein (e.g., beta-amyloid plaques and tau tangles) in the brain is associated with aging-related illnesses such as Alzheimer’s and dementia. Being born with a thicker cortex may provide some resistance to wear and tear of this layer that comes with aging. 

Aside from physical differences, general lifestyle is another facet of long life and cognitive abilities. Studies have shown that exercise⁴ can help keep your cortex from thinning. Not only does staying active work to keep your brain fit but staying social can help too! Studies suggest that social bonds⁵ can contribute to healthy cognitive aging. Friends and familial connections can improve brain health and keep these super-agers cognitively sharp.

Maybe it’s environmental, or maybe it’s in their genes, too. Aside from the environment people live in, other potential factors that lead to a longer life are genetic. Researchers have observed a variant of the MAP2K3 gene⁶, which is a part of a biological pathway linked to memory, in the blood of super-agers. However, genetics are only part of the age-old debate regarding nature versus nurture. 

Living longer is one of the greatest achievements of the modern era, but how do we make sure that we are living better as well? Hopefully, continuing research on super-agers can help us find commonalities and develop tools that everyone can use throughout their lives to keep their minds sharp as tacks. It is definitely food for thought!

References

1. https://www.c2st.org/brains-of-superagers-hold-secrets-to-long-mentally-agile-lives/

2. Rogalski, E. J., Gefen, T., Shi, J., Samimi, M., Bigio, E., Weintraub, S., Geula, C., & Mesulam, M. M. (2013). Youthful memory capacity in old brains: anatomic and genetic clues from the Northwestern SuperAging Project. Journal of cognitive neuroscience, 25(1), 29–36. https://doi.org/10.1162/jocn_a_00300

3. Hoenig MC, Willscheid N, Bischof GN, van Eimeren T, Drzezga A, Alzheimer’s Disease Neuroimaging Initiative. Assessment of Tau Tangles and Amyloid-β Plaques Among Super Agers Using PET Imaging. JAMA Netw Open. 2020;3(12):e2028337. doi:10.1001/jamanetworkopen.2020.28337

4. Falck, R. S., Hsu, C. L., Best, J. R., Li, L. C., Egbert, A. R., & Liu-Ambrose, T. (2020). Not Just for Joints: The Associations of Moderate-to-Vigorous Physical Activity and Sedentary Behavior with Brain Cortical Thickness. Medicine and science in sports and exercise, 52(10), 2217–2223. https://doi.org/10.1249/MSS.0000000000002374

5. Cook Maher, A., Kielb, S., Loyer, E., Connelley, M., Rademaker, A., Mesulam, M. M., Weintraub, S., McAdams, D., Logan, R., & Rogalski, E. (2017). Psychological well-being in elderly adults with extraordinary episodic memory. PloS one, 12(10), e0186413. https://doi.org/10.1371/journal.pone.0186413

6. Huentelman MJ, Piras IS, Siniard AL, De Both MD, Richholt RF, Balak CD, Jamshidi P, Bigio EH, Weintraub S, Loyer ET, Mesulam M-M, Geula C and Rogalski EJ for The Alzheimer’s Disease Neuroimaging Initiative (2018) Associations of MAP2K3 Gene Variants With Superior Memory in SuperAgers. Front. Aging Neurosci. 10:155. doi: 10.3389/fnagi.2018.00155