It has become clear that insulin resistance is a major driving factor in many, if not most, cases of cognitive impairment and dementia.

Recall that insulin resistance means that the body’s organs, especially liver and muscle, do not respond normally to insulin, thereby reducing the entry of glucose into cells for energy. The pancreas therefore compensates by producing greater quantities of insulin. Fasting blood insulin levels in someone who is insulin sensitive: 1-4 mIU/L. Fasting insulin levels in someone who is insulin resistant: 30, 70, 130 mIU/L—not just a little higher, but 10-fold or even 100-fold higher. Insulin is the hormone that drives accumulation of fat, especially abdominal visceral fat and prevents fat mobilization.

For unclear reasons, however, insulin resistance leads over time to reduced entry of insulin into the brain. In other words, high insulin levels in the body somehow lead to low insulin levels in the brain. How this paradoxical response develops is unclear. However, this observation has been strengthened by the recent observation that insulin administered intranasally (a way to access the brain) improves cognition for several weeks in people with established dementia. The lack of insulin in the brain also leads to the brain’s inability to access glucose for energy that can be visualized using a method called FDG PET in which impaired consumption of glucose can be seen in someone with cognitive decline and dementia.

The key is to therefore address insulin resistance in the periphery before the brain insulin deprivation effect develops. Accomplishing this is actually quite easy, though don’t expect your doctor to understand anything beyond prescribing a GLP-1 agonist for weight loss (a disastrous class of drugs in my view) and prescribe something like metformin. You can do a lot better than that.

Factors that you can address that have significant effects on reducing/minimizing insulin resistance:

  • Avoid foods that raise blood glucose and insulin—Because repeated cycles of high blood glucose-high blood insulin cause insulin resistance. Stop initiating these cycles and insulin resistance recedes. To accelerate the process, consider following my blood glucose “No Change Rule.” By not allowing blood glucose to rise above 100 mg/dl, you have slowed many of the phenomena of aging, also, that would have occurred through the process of protein glycation.
  • Address common nutrient deficiencies that influence insulin resistance—This should be a familiar list by now: vitamin D, omega-3 fatty acids, iodine, magnesium. When restored to ideal levels, a synergy develops that further minimizes insulin resistance.
  • Address colonic dysbiosis, small intestinal bacterial overgrowth—And you thereby address endotoxemia, a major driver of insulin resistance. My preferred starting method is to make my SIBO Yogurt, a combination of strains of L. reuteri, L. gasseri, and B. coagulans that 1) colonize or germinate in the small intestine, and 2) produce bacteriocins, natural antibiotics effective against the species of SIBO. In addition to reducing the burden of unhealthy fecal microbes, you also enjoy shrinking abdominal fat, reduced blood glucose and insulin, restoration of youthful musculature, and many other benefits.
  • Restore factors from animal organs lacking in the modern diet-–Modern dietary advice to cut saturated fat and cholesterol (for which there never was good evidence) caused most Americans to abandon consumption of organ meats and thereby collagen and hyaluronic acid that you should have obtained by including tongue, heart, stomach and other organ meats in your diet. Restoring these two lost dietary factors reduce abdominal fat, restore muscle, while also rebuilding dermal collagen for smoother skin, rebuilding joint cartilage and lubricating synovial fluid, and benefiting arterial health (via the glycocalyx). Hyaluronic acid also nourishes microbes in the GI tract, causing a bloom in butyrate-producing species, adding further to reduction in insulin resistance.
  • Restore carotenoids lacking in the modern diet—Carotenoids play an important role in many health phenomena, including controlling abdominal fat. You can obtain carotenoids by including organic spinach, kale, dandelion greens, peppers and other vegetables. You can also get carotenoids by consuming the astaxanthin of salmon and lobster, the most potent carotenoid of all.
  • Obtain sufficient quality sleep—Which becomes easier with restoration of L. reuteri that exerts major influence over sleep.
  • Minimize cortisol surges—That develop with stress. This also becomes easier with the cortisol-suppressing properties of restored L. reuteri and L. gasseri.
  • Physical activity—Becomes a more pleasant, less onerous process with the heightened physical performance provided by astaxanthin, L. reuteri, B. coagulans, and reduced endotoxemia obtained by doing the above.

Put it all together and, not only do you have magnificent control in minimizing or eliminating insulin resistance and thereby preserving cognitive health, you also obtain slenderness, youthful musculature, restored hormonal youthfulness, healthier joints and skin, and you enjoy the social and emotional benefits of a boost in oxytocin. If you’d like support in engaging in all the elements of this return-to-the-wild approach, i.e, restoring factors lost in modern lifestyles, then I invite you to join our conversations, including two-way Zoom discussions, in my DrDavisInfiniteHealth.com Inner Circle. We have just launched what will become a multi-part series on Preserving Cognitive Health discussing additional topics like this.