Skip to main content

Recently, a patient was discussing some concerns with her father. Lately, he’s started forgetting things, occasionally driving to the other side of town and getting lost on his way home. What used to be a short trip to a familiar location – like the grocery store or gas station – could take 2 hours instead of 5-10 minutes. When asked to describe her father’s favorite food, she immediately responded with two of the most dreaded words in health: “Anything sweet.” That’s the answer we never want to hear from a patient when they have concerns about dementia and memory loss because excess sugar can damage the brain and even shrink it.

Overeating sugar is damaging to the entire body, but it’s especially detrimental to the brain.  The connection between sugar and brain shrinkage has been more seriously studied by the scientific community as the rate of Alzheimer’s Disease keeps growing. After dozens of theories on contributing factors of Alzheimer’s disease – from toxic metals to genetics – could Alzheimer’s be labeled as “Type 3” Diabetes?

Alzheimer’s Disease and a Sweet Tooth: A Tale of Woe

Alzheimer’s disease, like many other illnesses, is on the rise:

  • 5.1 million Americans are living with Alzheimer’s disease, and by 2050, The Alzheimer’s Association estimates that number could almost triple to 13.8 million. [1]

This concern extends far beyond fleeting moments of forgetfulness that we all experience from time to time. More doctors want to know if sugar could be one of the contributing factors to the rise in Alzheimer’s disease. While people are starting to pay attention to sugar’s effect on the waistline, we should also consider the potential effects that excess sugar could have on the brain.

In fact, diabetes has long been a known risk factor for dementia. But you don’t need to be diagnosed with diabetes for high glucose levels to impact dementia risks. It’s shown to increase your risk even if you don’t meet the threshold for diabetes. [2]

The Trauma of Alzheimer’s for Patients and Their Loved Ones

Anyone who’s ever witnessed the slow and painful fade of a loved one with Alzheimer’s disease understands the desperate need for answers from the medical community. They’re the ones typically credited with having the answers, yet they don’t seem to have any solid solutions. Meanwhile, we race against the clock as we age, hoping this disease isn’t inevitable because of our genes.

The trauma of watching someone you love mentally slip away – forgetting their identity, their family, their life, their experiences, and forgetting you – is very painful. At the same time, you most likely feel the need to protect yourself and your family from going through it as well. The mind holds the best of life – and the best of ourselves – in its center.  The destruction that comes through Alzheimer’s disease makes it one of the cruelest diseases in existence.

Two Risk Major Factors

There are two things to look at closely to reduce your risk:

  1. Heavy metals – Metals are harmful because the brain is made of fat, which absorbs toxins like heavy metals. Be sure to avoid toxic personal products, high-mercury fish, and cooking food in aluminum containers.
  2. Massive shrinkage of the brain – What causes that massive shrinkage? There may not be one factor to blame, but nutritional habits are being studied more closely to determine the potential effects of food on brain atrophy.

Glucose Stats and Alzheimer’s

One study found that diets high in carbohydrates increased the risk of developing Alzheimer’s by 89%, while a high-fat diet reduced it by 44%. [3] Why is that? Your brain is 96% fats and proteins and only 4% sugars and carbohydrates.

Many people might say, “But my blood sugar is fine, so I can eat as much sugar as I want.” That’s not necessarily the case. Blood glucose is a snapshot in time because it fluctuates throughout the day and with every meal.

  • For example, your glucose level might be 82.
  • Someone you know also tested 82.
  • You both also compared hemoglobin A1c scores – an A1c score is the average blood glucose over the course of 2-3 months.
  • Your friend tested at a 4.8, and you tested at a 5.6 because of some unhealthy habits in the past, which causes the body to not manage sugar as well.
  • Why is this important? The higher score is associated with higher brain shrinkage. [4]

Scores below 5.3 are correlated with a friendly environment for brain growth.

Once the score hits 5.3, there’s often a linear acceleration of brain memory centers shrinking, which is a significant factor in the progression of Alzheimer’s disease. How do we know? That average blood glucose score is directly related to your body’s intake and management of sugar. Therefore, two people with the same blood sugar can have significantly different A1c numbers with different health outcomes. Science has been telling us more and more recently that Alzheimer’s disease is more closely related to a form of “Type 3” Diabetes, and it’s worth considering.

Sugar Shrinks Your Brain: Alzheimer's Disease is type 3 diabetes

Sugar and Its Possible Connection to Alzheimer’s

When your body stops processing the sugar properly, your glucose tends to stay high. That’s how you can develop an elevated hemoglobin A1c. Not only is that an overall health and wellness issue, but the excess sugar could contribute to the oxidation of brain tissue. That’s not good. Think about a bike left out in the rain. If it’s exposed to the elements for long enough, it can get rusty. When metal oxidizes, it rusts and starts to break down.

Your brain can do something similar, and for some people, excess sugar consumption contributes to this process. When the brain isn’t functioning as it should, it starts to break down. Then, when you try to remember something you should recall easily, it can be difficult because your brain isn’t functioning optimally.

Alzheimer’s disease is the 6th leading cause of death, and sadly, the numbers keep growing. Why are we seeing this? Sadly, the research points to several contributing factors, with excess sugar among them. Eating high amounts of sugar, day after day, over a long period of time can contribute to brain atrophy. But is that the only factor at play here? New theories emerge every day, but they’re all worth a second glance for the sake of the body’s most important organ.

Sugar Developed a Bad Reputation in the 1950s

Obviously, the sugar industry didn’t like this negative reputation. The average family in the 1900s ate 5 pounds of sugar a year, and today, the average American person eats around 150 pounds. Only 29% is table sugar, with most of the sugar hidden in processed foods. In the 1960s, the Sugar Research Foundation funded a study for Harvard researchers to look into this correlation, and they concluded that fats and cholesterol were the real culprits of coronary disease.

This sugar-funded study vilified the foods we should be eating and informed the creation of the highly flawed food pyramid. This shift in dietary recommendations could be a reason behind the increasing disease rates we’ve seen over the past 50+ years, including Alzheimer’s disease.

Feed Your Body for a Healthy Brain

Cutting fats and protein added unnecessary sugars to the diet, which is not the best nutritional choice to support the body. Depending on the type of fats and protein consumed, fats and protein tend to be more beneficial to the body than detrimental. When we eat these foods, we’re feeding the brain what it is made of, which is more in line with the composition of the body.

  • How do you poison an environment? Put something in it that doesn’t belong.
  • How do you poison a plant? Feed it motor oil.
  • How do you poison a dog? Feed it chocolate.
  • How do we poison a human? Feed the body foods that don’t support its needs.

When we chronically give the body what it doesn’t need, it may not bounce back easily from illness. That’s when we start having a problem processing sugars, which can lead to liver problems, insulin resistance, adrenal issues, and thyroid issues. Many people fed their families based on this nutritional advice, and the children carried these same habits into adulthood. Since sugar can be addictive, consumption continues to increase by as much as 20% each year! Be careful of those habits over time, because they can take a toll on your body and overall health.

How Can We Reverse the Trend of Modern Food Habits?

  1. Start by reducing sugary and processed foods: Sugar is always hiding under different names.
  2. Get properly tested for your sugar levels and notice how your unique body chemistry is processing that sugar.
  3. This step might be difficult, but you may want to consider increasing your fats. Talk with your doctor or health restoration coach about how much fat is appropriate for your needs. Unfortunately, many people can’t easily absorb fat from foods. If your doctor advises it, start with little bits of healthy fats at a time by taking shots of coconut oil or avocado oil daily! Your brain needs these fats to a certain extent.

The Standard American Diet Needs to Change

Take steps to start decreasing your risk of nutritional habits shrinking your brain over time. Improving your food choices may not necessarily prevent Alzheimer’s disease (because there are many factors considered, remember), but it could benefit your body in other ways as well. If you feed your brain better, it’s going to function better for you in the long run.

Written by Dr. Jason Nobles | May 7, 2019
Republished January 19, 2024

Videos and Webinars to Expand Your Sugar and Health Knowledge:

Sugar Part 1: Is Sugar Bad for You? | A Different Perspective
Sugar Part 2: What to Stay Away From | A Different Perspective
Less Sugar, More Health: The Science and Benefits Explained | A Different Perspective

Articles and Comprehensive Guides to Keep You Informed and Motivated:

The No-Sugar Challenge Guide 
5 Common Benefits of Giving Up Sugar (and how to be successful at it!) 
5 Ways Cutting Sugar Intake Benefits the Gut
Sweet Sugar Swaps: 5 Healthier Options


Subscribe to our newsletter for health tips & updates.

Join the community

Disclaimer: This content is for educational purposes only. It’s not intended as a substitute for the advice provided by your Wellness Way clinic or personal physician, especially if currently taking prescription or over-the-counter medications. Pregnant women, in particular, should seek the advice of a physician before trying any herb or supplement listed on this website. Always speak with your individual clinic before adding any medication, herb, or nutritional supplement to your health protocol. Information and statements regarding dietary supplements have not been evaluated by the FDA and are not intended to diagnose, treat, cure, or prevent any disease.


  • Jonathan N says:

    Wow. My grandmother has recently developed memory issues, and my family has not yet realized the gravity of the situation. Part of it is due to aging, of course, but my family often says that she has a “sweet tooth” (which she does). I am going to share this article with her. Thank you, Dr. Nobles.

Leave a Reply