How does insulin impact the brain?

An important branch of study that has gained traction over the last several years is the interaction between metabolism and the immune response in the brain. Along these lines, a study was recently published that further highlights  the role of insulin resistance in causing chronic diseases[1].

In the study, a control group of mice was fed a standard diet while another group was fed a diet that caused them to become insulin resistant. Both sets of mice were then put in the same maze multiple times a day over the course of several days to determine both learning ability and memory. By the end of the maze trials, the insulin resistant mice took significantly longer to escape the maze than the control group, showing that their learning ability and memory were both profoundly impacted. Researchers also checked the insulin resistant mice for neuroinflammation and found that it was significant.

But how does insulin impact the brain?

Part of the problem with insulin resistance is that it leads to chronically elevated insulin levels, or hyperinsulinemia. This rodent study found that hyperinsulinemia in neurons alters mitochondria–the powerhouse of the cell–in such a way that it drives inflammation, what we call neuroinflammation.

Neuroinflammation isn’t always bad; it’s meant to be a protective response. When neuroinflammation functions as intended, it protects the central nervous system from things like infection or pathogens and it aids the body in tissue repair. The problem comes when inflammation becomes chronic. Chronic neuroinflammation leads to neurodegeneration, like that found in Alzheimer’s and Parkinson’s diseases[2].

How, then, can one address chronic neuroinflammation in the brain? 

By controlling insulin.

How to control insulin for brain health

There are a few simple ways to control insulin, or become more insulin sensitive, including controlling stress, getting more sleep, and even exercising [3]. However, by far the most effective way to increase insulin sensitivity is diet.

A diet built around three pillars has been shown to make the body more insulin sensitive [4]:

Prioritize protein: Regularly consume high-quality protein foods, like eggs, meat, and dairy, as well as other animal proteins or fermented plant proteins.

Fill with fat: Protein and fat virtually always come together in nature, and they should in our diet, as well. Don’t fear other fat sources, like coconut oil, butter, olive oil, and similar.

Control carbohydrates: Stay away from simple, refined starches and sugars; focus instead on fiber-rich vegetables and fruits. 

Scientific evidence continues to mount showing the influence of insulin resistance in chronic disease. If you want to keep your body and mind in their best shape, control your insulin.

References

1. https://www.frontiersin.org/articles/10.3389/fnins.2022.1036872/full
2. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5260818/
3. https://www.medicalnewstoday.com/articles/type-2-diabetes-how-exercise-helps-restore-brain-insulin-sensitivity
4.  Walton, C. M., Perry, K., Hart, R. H., Berry, S. L. and Bikman, B. T. (2019) Improvement in Glycemic and Lipid Profiles in Type 2 Diabetics with a 90-Day Ketogenic Diet. J Diabetes Res. 2019, 8681959