Could fructose cause Alzheimer's Disease? A Macroeconomic perfect storm

In nature, the simple sugar fructose appears in fruits which ripen in autumn. Consumption of fructose does not result in satiety and causes an increase in thirst and hunger. The consumption of fructose stimulates foraging in animals. Specifically, the fructose survival pathway involves reducing energy expenditure for bodily processes at rest and devoting energy to only necessary activities, such as foraging.

The decrease in energy expenditure is achieved by reducing the sensitivity of tissues, such as muscles, to insulin, resulting in a lower intake and consumption of glucose. At the same time, excess energy is stored in the liver in the form of fat and glycogen.

These physical responses evolved to maximize the animal’s food consumption before the lean winter season.

Individual fruits only contain a relatively low quantity of fructose, and only 1–2% of ingested fructose reaches the brain. The fiber in whole fruits slows down absorption of fructose. Eating whole fruits is healthful since they contain a lot of water, fiber and a relatively low amount of fructose.

Fast forward from our hunter-gatherer evolutionary years to today.

The average American eats massive amounts of fructose, both synthesized from corn (high-fructose corn syrup) and in sucrose (table sugar, which is a dimer of fructose and glucose). Far more and for a longer period of time than humans evolved to process.

Studies have shown that a higher intake of high-fructose corn syrup or table sugar, high glycemic index foods, and salty foods are associated with an increased risk of Alzheimer’s disease.

Consistent with this, metabolic disorders such as obesity, insulin resistance, and diabetes that are associated with increased intake of these foods are also risk factors for Alzheimer’s disease.

Previous studies have shown higher levels of fructose in the brains of patients with Alzheimer’s disease, especially before the loss of neurons during the early stages of the disease.

The linked article presents a hypothesis that the activation of this fructose survival pathway over a prolonged duration leads to the disruption of metabolism, replicating several features of metabolic syndromeTrusted Source.

These include insulin resistance, elevated blood pressure, body weight gain, and persistent low-level inflammation. In addition, the fructose survival pathway can also impair brain metabolism.

Brain metabolism is impaired in critical regions, such as the hippocampus, before the later characteristics of Alzheimer’s Disease, such as beta amyloid clumps, can be seen. The authors hypothesize that fructose in the brain can explain AD from beginning to end.

This is producing a perfect Macroeconomic storm.

The Standard American Diet (SAD) is loaded with sugar and high-fructose corn syrup. The average American adult, teenager, and child consumes about 17 teaspoons of added sugar a day, or about 270 calories. The average 20-ounce bottle of sugar-sweetened soda, lemonade, or iced tea contains about 65 grams of added sugar, often from high-fructose corn syrup. That’s the equivalent of 16 teaspoons of table sugar.

Yesterday, @Goofyhoofy posted an article that had maps showing medical debt and Medicaid coverage by state. It’s no surprise that medical debts are highest where states do not provide Medicaid coverage to many people. Many of these states also coincide with the highest obesity rates in the U.S. and therefore the worst health outcomes.

Put these factors together.

Obesity is caused by a high-sugar obesogenic diet that has been linked with a higher incidence of Alzheimer’s Disease. This is most prevalent in the same states that have lower Medicaid coverage which is needed to care for the poor people who are most likely to be obese and to be lacking personal savings to pay for nursing home care.

This will be a perfect storm of rising burdens and unmet needs. This involves millions of people so the scale is Macroeconomic.

As individuals, we should avoid processed foods that contain sugar and high-fructose corn syrup. Our minds depend on our diets.



This has been theorized for at least a decade if not two.

It is more than casual but the scope of how it works is broad. Whether it is gaining weight or bad sleeping habits sugar plays a role. It is not just the sugar by itself which weakens the theory but not really. We are all in this pool of life with all of its make up. Added sugar hurts us.

Per the mention of metabolic syndrome, here are the parameters for a self check

Thing is, these features are all late stage phenomena in the drift away from healthy homeostasis and the arbitrary values aren’t a cut off point with “health” on one side and “disease” on the other.

I suspect that there’s likely to be significant pathology going on long before someone manages to eat and sit their way to a girth of 40" (male) /35" (female), fasting glucose of 100 or triglycerides of 150 etc. etc.


Thank you for posting this article.

It has long been theorized that carbs can have an impact on Alzheimer’s, along with so many other health issues, which is one reason why I went low carb over 20 years ago. I have not yet had the time to closely examine the article, but some points stand out after a skimming.

There seems to be a synergy between this article and a book that you recommended, The Angel and the Assassin. IIRC, this book talked about microglia’s potential role in Alzheimer’s and other brain related conditions, theorizing their role as indiscriminate scavenging of brain material, taking away the healthy as well as that which should be removed. One of the suggestions was to lower your carbs. I do however need to take the time to reread that book as well.

The foraging induced behavior from excess carbs was also very interesting. There seems to be a predisposition towards Alzheimer’s in my family, as well as a drug like craving for more carbs triggered by the consumption of carbs. Sugar is worse for me than an opiod addiction ever could be, and the only way I have been able to end those cravings was to “eliminate” the simple carb trigger from my diet, largely through the elimination of sugars and grains. (While that sounds dramatic and somewhat insensitive to those with opiod addiction, opiods simply don’t work for me and many members of my family. Had to fight with the hospital staff to give our son IV Ibuprofen instead of the delaudid they insisted on which did nothing for his pain. The oxy they sent his home with went unused and has landed in a drug take back bin. Without an ounce of extra fat on him, Youngest also intentionally limits refined carbs to improve his ADHD and depression issues. There is no one size fits all when it comes to the best diets for an individual.) My eating style could best be described as low glycemic Mediterranean.

So again, these were the quick observations that registered from the quick reading of article. Appreciate the hope that I am taking the right approach with my eating style in an effort to avoid the family curse.