The Brain-Health Factor 90% of Adults Aren't Optimizing
- Austin Perlmutter MD
- 2 days ago
- 4 min read
Why metabolic health is key to brain health
By Austin Perlmutter, MD
Most people see the brain as a separate part of the body, largely unaffected by the happenings in seemingly distant regions like our fat cells, our muscle tissue and immune organs. But one of the most important contributors to brain health and dementia risk runs completely counter to this belief. In this article, I’ll share exactly why your metabolic health is fundamental to your brain health, and some of the most important and cost effective ways to gauge your metabolic health today.
Like it or not, our brains are incredibly dependent on the rest of our bodies, but this is especially the case for energy and oxygen. Without blood flow to the brain, our cognition almost immediately collapses. This is because our brains are almost exclusively dependent on the bloodstream for delivery of energy (primarily glucose) and oxygen to function. With a daily use of roughly 20% of our body’s circulating glucose and oxygen, the brain is perhaps the single most energy-hungry organ in the body relative to its weight.
The idea that your brain needs constant fuel is important, but far more significant for most people’s health is the concept of stable metabolic function. Metabolism describes how our bodies use energy, and metabolic health is the study of how this translates into actual health outcomes and disease risk. At a very superficial level, markers of poor metabolic health include high blood pressure, high blood sugar, obesity, and cholesterol issues, but the reality is that there are several deeper ways to analyze metabolic health (like getting a DEXA scan, or getting more advanced lab testing). Regardless, the key statistic here is as follows: in the United States, roughly 90% of adults have suboptimal metabolic health. This is a massive issue, because metabolic health directly relates to brain health.
Across all aspects of metabolic health measurements, be they blood sugar (prediabetes and type two diabetes are correlated with more rapid brain aging and dementia risk), unhealthy cholesterol levels like elevated LDL, the location of our fat cells (e.g., if they are clustered around our organs vs more superficial) or simply excess weight, the risk to our brains when things are out of alignment are anything but trivial. Yet this story, unlike others, has a very positive correlate.
Our metabolic health is unique in that it is directly modifiable through lifestyle changes. While there are some (for example, type 1 diabetics or those with inborn errors of metabolism) for whom lifestyle will not reverse the underlying issue, most people can dramatically improve their metabolic health through application of diet, exercise and other practical daily changes. Metabolic health is also directly testable using a range of readily available (and often quite cheap) measurements.
Some of my favorite tests for metabolic health (grouped by cost)
Waist circumference or waist-to-hip ratio: measures your belly fat, which more strongly correlates with metabolic health than overall weight.
Resting heart rate: You can easily test this with a clock. A lower heart rate generally speaks to better metabolic health, with higher rates correlating with higher risk for metabolic dysfunction. Some people (e.g. those with heart pacers, etc) will need to be more cautious in interpretation.
Grip strength: A simple measure of muscular function that has been associated with cardiometabolic health as well as important aging outcomes, including cognitive health
Blood pressure: Often free if you can go to a drugstore or supermarket with an automated machine. Blood pressure is one of the key factors in diagnosing metabolic syndrome, and is a great number to track over time. Also, high blood pressure is an independent risk factor for Alzheimer’s in part through an increased risk for stroke.
Cholesterol panel (lipid panel): While cholesterol itself isn’t a villain when it comes to your brain, the cholesterol panel or lipid panel is a low cost and important way to gauge metabolic health. Despite the advocacy of carnivore and other high saturated fat diets, elevations in levels of molecules like LDL and triglycerides (not the whole story, I know!) are associated with higher dementia risk.
Hemoglobin A1c and fasting glucose: Both numbers give you a sense as to your blood sugar regulation, which is itself predictive of brain health and dementia risk. These are very cheap labs and can provide several months’ worth of data (in the case of the HbA1c)
Other considerations
Fasting insulin: While not as commonly performed, fasting insulin may give early information about metabolic dysfunction and risk for progression to conditions like prediabetes and diabetes.
Uric acid: This test was once used primarily for conditions like gout, as well as rarer conditions related to medications or malignancy, but it is now understood to give important data regarding metabolic state
DEXA (Dual-Energy X-ray Absorptiometry) Scan: Once used mainly for bone density, this low dose x-ray test is the standard for examining lean muscle mass and fat mass. A cheaper version is using bioimpedance testing (some scales do this) but DEXA is more reliable and accurate.
Advanced lipid panels and adjunct testing: There are several ways to get more information about your cholesterol related numbers than a basic lipid panel. ApoB (Apolipoprotein B) and Lipoprotein(a) are now considered by many experts to be invaluable add on tests. Beyond this, some practitioners use advanced lipid panels that can tell you the detailed size and particle makeup of your cholesterol-carrying molecules, but the value here is still disputed, especially for the public.
A couple notes here. First, this is just for educational purposes, and you should discuss this with your doctor or health practitioner. Second, while getting testing and further data is a great plan for many, there’s no reason to wait before starting to take steps to care for your metabolic health. Eating a more balanced, minimally-processed diet, engaging in regular exercise, prioritizing sleep and participating in stress mitigation processes can all help.
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This content is for informational and educational purposes only and does not constitute medical advice. Please consult with a qualified healthcare provider before making significant changes to your diet or lifestyle.
So basically, if your metabolism is sluggish, your brain is starving. It makes total sense why diet shifts change your mental clarity so fast. One small habit that completely changed my afternoon focus was taking a quick 10-20 minute walk right after lunch to help my body process the glucose. This isn't pseudoscience by the way. There are plenty of legit studies proving that a short walk clears glucose out of your system incredibly fast. Besides the walking, like many others I also added Phytomem One to my routine for brain health support. It is really surprising how stacking a few little daily habits together can make such a massive difference for your focus.