Many of us are concerned about the prospect of developing cognitive impairment and, eventually, dementia, that leaves us helpless, unable to perform basic functions of life, even losing the ability to recognize loved ones. Although fictional, anyone who has seen or read Nicholas Sparks’ The Notebook movie or book knows how painful and tragic the process can be.

The science behind cognitive decline and dementia has advanced considerably over the past decade. But you’d never know this if you relied on your primary care doctor or neurologist, as they will tell you silly things that have little to no effect on the condition They may advise you, for example, to learn a new language or do crossword puzzles. Or they may say that, when the time comes, they will prescribe drugs like memantine or rivastigmine. The truth is that such strategies have no impact on risk for cognitive decline and dementia. Why would they? Will learning Spanish reduce the accumulation of β-amyloid plaque or phosphorylated tau protein, increase the level of brain trophic hormones like brain-derived neurotrophic factor, or prevent hippocampal atrophy (i.e., all the physiological and anatomical hallmarks of dementia)? Of course they will not.

It is also clear that there is no single explanation for the deterioration of brain health that leads to dementia. Contributing causes therefore include history of head trauma, small vessel disease, heavy metal exposure, deficiency of DHA, endotoxemia, polymicrobial bacterial and fungal infestation, and others. But there is one cause that is nearly universal in all forms of dementia, Alzheimer’s and otherwise: insulin resistance, i.e., the inability of the body’s organs to respond to insulin that, in turn, causes the pancreas to produce 10- to 100-fold greater quantities of insulin. High levels of insulin drive a vicious circle of high insulin that expands abdominal fat and inflammation that increases insulin that expands abdominal fat and inflammation, an amplification effect that makes the situation worse over time.

The curious thing about insulin resistance in the brain, however, is that, despite high levels of insulin in the bloodstream, the level of insulin in the brain eventually drops, i.e., brain hypoinsulinemia. The brain is therefore deprived of glucose and is unable to conduct normal metabolic activities. This process is neurotoxic, i.e., destructive to brain cells, leading to reduced levels of trophic growth hormones and atrophy. The idea that the paradoxical lack of brain insulin and glucose has been bolstered by observations that medium-chain triglycerides and exogenous ketones transiently improve mentation (but do not necessarily exert beneficial effects on brain anatomy–remember: a nootropic effect does not necessarily mean that there is a neurotrophic effect). Also,  administration of intranasal insulin likewise transiently improves mentation.

Because two-thirds of the American population has insulin resistance, it means that, as a population, we are sitting ducks heading towards a future of impaired cognition and dementia, not to mention more obesity, type 2 diabetes, heart disease, breast cancer, and other health conditions that we see all around us. In addition to the useless advice dispensed by most doctors on dementia, they also dispense useless advice on how to reduce or minimize insulin resistance. At best, they will prescribe pharmaceuticals such as metformin or a GLP-1 agonist like semaglutide, or say something useless like “Just lose weight.” So it is therefore important for you to know that insulin resistance is easily, readily, inexpensively, and safely reversible and it requires no pharmaceuticals to do so.

So what can you do to reduce or minimize insulin resistance? It’s easy, just:

  • Eliminate foods that raise blood glucose and insulin—Because repeated cycles of high blood sugar and high blood insulin generate insulin resistance. It means eliminate wheat, grains, and sugars, the worst culprits of all.
  • Address nutrient deficiencies common in modern people that contribute to insulin resistance—We therefore address lack of magnesium, omega-3 fatty acids, vitamin D, and iodine. Combined, they constitute a synergistic combination that reduces insulin resistance.
  • Address endotoxemia—The entry of bacterial endotoxin that develops from colonic dysbiosis or small intestinal bacterial overgrowth, SIBO, is a major driver of insulin resistance. Endotoxemia is also a direct neurotoxin that yields all the hallmarks of dementia such as ß-amyloid plaque. We therefore engage in a comprehensive program to reduce overgrowth of fecal microbial species and cultivate a return of beneficial species. We do so by consuming plenty of fermented foods, re-implanting keystone species such as L. reuteri and L. gasseri, and include plentiful microbiota-accessible carbohydrates in our diet.
  • We optimize body composition—i.e., we specifically minimize inflammatory abdominal visceral fat and restore muscle mass lost with aging (and worsened by any attempts at weight loss that involve loss of muscle). We therefore enjoy the boost in oxytocin—the hormone of body composition—from restoration of L. reuteri. The effect can be amplified by restoring lost nutrients such as collagen peptides, hyaluronic acid, and carotenoids, obtainable by a return to organ meat and whole food consumption or through supplementation.

Reducing or minimizing insulin resistance pays off in dividends. Not only do you hugely reduce risk for cognitive impairment, but you also accelerate loss of abdominal visceral fat and slash potential for type 2 diabetes, coronary disease, hypertension, and breast cancer. You also enjoy the benefits of improved body composition: smaller waist, restored muscle and vigor, protection from frailty, fractures, and loss of independence, improved reproductive and sexual health, smoother skin with less wrinkles. And, of course, you reduce potential for cognitive decline and dementia.

In my DrDavisInfiniteHealth.com Inner Circle, we posted an eight-segment series called “Preserving Cognitive Health” that covers all the major issues relevant to this topic, including practical solutions that you can follow without the interference of the doctor.