The Relationship Between the Modern Western Diet and Alzheimer's Disease
The following excerpt is adapted from Amy Berger's new book The Alzheimer's Antidote: Using a Low-Carb, High-Fat Diet to Fight Alzheimer’s Disease, Memory Loss, and Cognitive Decline (2017, Chelsea Green Publishing).
Alzheimer’s disease is frightening. It instills fear because other than generally striking older individuals, there seems to be little rhyme or reason to it. Families face economic strain due to the expenses of assisted living, long-term care, or abandoning careers to provide fulltime caregiving for affected loved ones, but these financial burdens pale in comparison to the emotional, psychological, and physical tolls Alzheimer’s exacts from afflicted individuals and their caregivers. There are currently no effective treatment strategies for this most dreaded condition. Every pharmaceutical drug developed to date for it has failed to have an appreciable impact on disease progression. It’s time to stop waiting for a silver bullet discovery or “magic pill” in the fight against this formidable disease. It’s time for a new approach.
The research is unambiguous. Alzheimer’s disease results primarily from a failure of parts of the brain to harness sufficient energy from glucose. As a consequence of this insufficient fueling, neurons in the affected brain regions degrade and degenerate, leading to a loss of communication among them. This breakdown in neuronal communication results in the confusion, memory loss, and behavioral changes characteristic of Alzheimer’s disease (AD). The connection between glucose handling, insulin signaling, and AD is so strong that many researchers now refer to AD as “diabetes of the brain,” or “type 3 diabetes.” Although type 2 diabetes and AD are closely associated, we must not be fooled into believing that type 2 diabetes causes AD. Many people with type 2 diabetes will never go on to develop AD, and many Alzheimer’s patients are not diagnosed diabetics. The relationship between the two is more like that of physiological cousins; that is, they result from the same underlying metabolic disturbances, but they manifest differently depending on which parts of the body are affected. In type 2 diabetes, for example, insulin resistance and disturbed carbohydrate metabolism affect the muscles, organs, and periphery (the rest of the body aside from the brain and central nervous system); in AD, damage is mostly localized to the brain.
Using a Low-Carb, High-Fat Diet to Fight Alzheimer’s
If Alzheimer’s is ultimately the result of metabolic disturbances similar to those seen in type 2 diabetes—namely, insulin resistance and hyperinsulinemia (elevated levels of insulin in the bloodstream for extended periods of time)—then the same causes as are seen in type 2 diabetes are likely to be behind AD. While there are many factors that contribute to dysregulated insulin signaling, one of the most powerful is a diet that is mismatched to basic human physiology.
The pattern of eating that has become the “standard American diet” and that has morphed and spread into the “modern Western diet” in many other parts of the world, is very different from the one on which our human ancestors are theorized to have evolved. Although the current commonly accepted dietary recommendations from government health agencies and medical organizations are slowly shifting, over a half-century of fear-mongering regarding saturated fats and dietary cholesterol in the modern industrialized world has led to recommendations to consume a diet low in total fat and cholesterol, with an emphasis on carbohydrates—specifically, grains, such as wheat, corn, and rice—as the primary source of calories. The few fats that are recommended are vegetable oils (such as soybean and corn oil), which are high in fragile, easily oxidized polyunsaturated fatty acids; we have been cautioned away from the saturated fats found predominantly in animal foods and tropical plants (such as butter, coconut, and palm oils), which are more chemically stable and better suited for cooking.
The modern industrial diet is also generally lower in phytonutrients and antioxidant-rich dark green and brightly colored vegetables and fruits than the diet our robust, healthy ancestors likely consumed. The majority of the plant foods we now consume are starchy carbohydrate sources, such as wheat, potatoes, and corn. This evolutionarily discordant diet has been linked to conditions as diverse as heart disease, acne, obesity, poor eyesight, polycystic ovarian syndrome (PCOS), and cancer. When the physiological and biochemical effects of these foods, coupled with a lack of micronutrient-rich vegetables and whole, unprocessed, naturally occurring fats start affecting cognitive function later in life, we can add Alzheimer’s disease to the list of conditions likely caused by this dietary derailment.
There are ways to address the dietary and lifestyle factors that affect the aberrant insulin and glucose dynamics believed to underlie Alzheimer’s without pharmaceutical drugs or other expensive and ineffective interventions. Certainly, many unanswered questions remain and there are many decades of research ahead of us, but that doesn’t mean we are completely without actionable information right now. The Alzheimer’s Antidote is a layperson-friendly translation of the scientific literature intended to arm individuals with this condition and their loved ones and caregivers with information so that they can take control of their health destiny.