What do you fear most about growing older? If you’re like most people, losing your memory and cognitive function is near the top of the list. And for good reason? No one enjoys depending on other people to care for their daily needs or relishes the bewilderment of not being able to remember once-familiar words or recognize people.
While exercise and plastic surgery have allowed seniors to age more gracefully, there’s been less success in finding a supplement combination that can consistently enhance memory in the elderly. But could a simple lifestyle habit and dietary change be the missing link?
An exciting trial recently published by the National Academy of Science showed that a calorie-restricted diet can improve cognitive function and memory, at least in the short term. It’s not surprising that scientists are exploring the potential of a calorie-restricted diet on brain health.
Calorie restriction improves both duration and quality of life in every animal group studied. For rodents, one study found that those who ate a calorie-restricted diet enjoyed a 50% improvement in lifespan. But what impact could calorie restriction have on the brains of animals and humans?
Testing the Idea of Calorie Restriction for Brain Health in Humans
Researchers conducted an experiment on a group of healthy older women. The only difference between the test groups was one group had a substantial 30 percent reduction in calorie intake. The result? After only three months, the women in the calorie-restricted group showed a startling 30 percent improvement in memory while none of the other groups showed no change. The only chemical markers to change in the calorie-restricted group were insulin levels and measures of whole-body inflammation which both decreased. These reductions bode well for brain health too.
While this study sounds promising, it needs further study in human populations. One problem was the research was brief, only three months. Plus, only women were enrolled in the study, raising questions as to whether men would have the same benefits. Most importantly, few people can sustain a 30 percent reduction in calorie consumption for an extended period.
A study published in Nutrition Reviews is also encouraging. When researchers reviewed thirty-three studies, they found that twenty-three of the thirty-three showed improvements in cognition in response to calorie restriction. Based on this research, restricting calories improved how quickly people processed information and boosted their short-term memory. There were drawbacks though. Calorie restriction made participants less mentally flexible. So, there may be upsides and downsides to following a calorie-restricted diet for cognition.
Why Would Calorie Restrict Boost Brain Health?
You might wonder how calorie restriction boosts cognitive function and slows brain aging? One theory is that calorie restriction reduces the amount of cellular damage that cells sustain throughout life. Consuming fewer calories slows down resting metabolism. This decreases free radical formation, insulin levels and inflammation.
In addition, blood pressure, blood sugar, blood cholesterol, and metabolic rates are also lower in those who restrict calories. In the final analysis, aging, including brain aging, is the lifelong accumulation of cellular damage, and restricting calories may slow the onslaught of oxidative damage and inflammation that fuels it.
But scientists have discovered another intriguing mechanism by which calorie restriction slows brain aging. There’s a gene called the OXR1 gene that influences brain aging. When it’s working well, your brain ages more slowly. If it isn’t, it can accelerate how fast your brain ages. Scientists discovered that this gene helps recycle proteins inside brain cells. This recycling action benefits brain health. When you don’t eat as much, your body produces more OXR1, slowing brain aging. So, in simple terms: what you eat affects your body and your brain, and eating less might help protect both as you get older.
Still, dropping calories by 30% is challenging and if you aren’t careful with the foods you choose, it could lead to nutrient deficiencies. Plus, such an approach wouldn’t be appropriate for people who have eating disorders and might even worsen them. So, the best approach may be to eat sensibly, choose nutrient-dense foods that your brain can benefit from, choose more antioxidant-rich and anti-inflammatory foods, and eat mindfully, so you’ll be satisfied with less.
Conclusion
There’s still more to learn about calorie restriction and the way it affects aging, so don’t jump on the calorie restriction train without careful consideration and talk to your doctor first. And make sure you’re living a holistic, brain-healthy lifestyle.
References:
- Pifferi, F., Terrien, J., Marchal, J. et al. Caloric restriction increases lifespan but affects brain integrity in grey mouse lemur primates. Commun Biol 1, 30 (2018). https://doi.org/10.1038/s42003-018-0024-8.
- Yu Q, Zou L, Kong Z, Yang L. Cognitive Impact of Calorie Restriction: A Narrative Review. Journal of the American Medical Directors Association. 2020;21(10):1394-1401. doi:https://doi.org/10.1016/j.jamda.2020.05.047.
- de Carvalho TS. Calorie restriction or dietary restriction: how far they can protect the brain against neurodegenerative diseases? Neural Regen Res. 2022 Aug;17(8):1640-1644. doi: 10.4103/1673-5374.332126. PMID: 35017409; PMCID: PMC8820686.
- News N. Eat Less, Live Longer: Dietary Restrictions Increase Lifespan and Improve Brain Health – Neuroscience News. Neuroscience News. Published January 12, 2024. Accessed October 12, 2024. https://neurosciencenews.com/diet-longevity-brain-health-25449/
- John O’Leary, Chloé Georgeaux-Healy, Lucy Serpell, The impact of continuous calorie restriction and fasting on cognition in adults without eating disorders, Nutrition Reviews, 2024;, nuad170, https://doi.org/10.1093/nutrit/nuad170.
- Kenneth A. Wilson, Sudipta Bar, Eric B. Dammer, Enrique M. Carrera, Brian A. Hodge, Tyler A. U. Hilsabeck, Joanna Bons, George W. Brownridge, Jennifer N. Beck, Jacob Rose, Melia Granath-Panelo, Christopher S. Nelson, Grace Qi, Akos A. Gerencser, Jianfeng Lan, Alexandra Afenjar, Geetanjali Chawla, Rachel B. Brem, Philippe M. Campeau, Hugo J. Bellen, Birgit Schilling, Nicholas T. Seyfried, Lisa M. Ellerby, Pankaj Kapahi. OXR1 maintains the retromer to delay brain aging under dietary restriction. Nature Communications, 2024; 15 (1) DOI: 10.1038/s41467-023-44343-3.
- Asif S, Morrow NM, Mulvihill EE, Kim KH. Understanding Dietary Intervention-Mediated Epigenetic Modifications in Metabolic Diseases. Front Genet. 2020 Oct 15;11:590369. doi: 10.3389/fgene.2020.590369. PMID: 33193730; PMCID: PMC7593700.
- Mattison, J. A., et al. (2017). Impact of caloric restriction on health and survival in rhesus monkeys from the NIA study. Nature, 489(7415), 318-321. doi:10.1038/nature12080.
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