Is Your Diet Giving You Alzheimer's Disease?

For the past 20 years, scientists have wondered whether Alzheimer’s Disease might be a neuro-endocrine disorder, like diabetes. In 2005, Dr. Suzanne de la Monte had a breakthrough.

During her research, she made two discoveries:

  1. the brain makes its own insulin, and
  2. Alzheimer’s disease depletes insulin

Based on these discoveries, Dr. de la Monte went beyond theorizing that there is a connection between Diabetes and Alzheimer’s.

She actually identified the Alzheimer’s Disease process as Type 3 Diabetes.

What Is Type 3 Diabetes?

To understand Type 3 diabetes, you have to understand Types 1 and 2. So, bear with me for a minute while I give you a refresher course on Diabetes.

Type 1 Diabetes.

Type 1 diabetes is an autoimmune disease. An autoimmune disease results when the body’s system for fighting infection (the immune system) turns against a part of the body. In diabetes, the immune system attacks and destroys the insulin-producing beta cells in the pancreas. The pancreas then produces little or no insulin. A person who has type 1 diabetes must take insulin daily to live.

Type 2 Diabetes

.Type 2 diabetes is the most common form of diabetes. About 90 to 95 percent of people with diabetes have type 2. This form of diabetes is most often associated with older age, obesity, family history of diabetes, previous history of gestational diabetes, physical inactivity, and certain ethnicities. About 80 percent of people with type 2 diabetes are overweight.

Type 3 Diabetes

  • Insulin has numerous functions within your body.
  • The most well known function is that it helps convert food into energy.
  • What you may not know is that insulin is also active in your brain.

It helps us to learn and to make new memories.

Here’s how it works:

  • In the spaces across which brain cells communicate (called Synapses) and where memories are conceived, neurons reserve special parking spots just for insulin.
  • When the hormone pulls in, a connection is made that enables new memories to form.
  • Since new memory formation is one of the first things to go awry in people with early stages of Alzheimer’s Disease, this insulin-initiated process has been a popular research topic for neuro-scientists for the past 20 years.

In August, a team of scientists at Northwestern University were the first to show why the brain’s “memory function” fails in the face of an insulin shortage.

Earlier research had already identified the culprit: toxic proteins called amyloid beta-derived diffusible ligands (ADDL), which are known to pile up in the brains of people with Alzheimer’s.

Scientists also knew that Alzheimer’s patients’ brains have lower levels of insulin and are insulin resistant.

But what the Northwestern team discovered is the molecular mechanism behind that resistance: when ADDLs bind to neurons at synapses, they obliterate the receptors that are normally reserved for insulin.

Without those parking spaces on the brain cells’ surface, insulin has no place to connect, and memory fails.

Q:  So Where Do The ADDLs Come From?

A:  The ADDLs are a side effect of inflammation in the brain.

Q:  So Where Does The Brain Inflammation Come From?

A:  The brain inflammation is a result of high insulin levels.

Q:  So Where Do The High Insulin Levels Come From?

A:  High Insulin levels are produced when we eat a diet high in carbohydrates.

More specifically, a diet that consists of meal after meal of high glycemic load foods results in:

  • high blood sugar,
  • high insulin levels,
  • Metabolic Syndrome,
  • Type 2 Diabetes, and now, thanks to the wonders of science,
  • Type 3 Diabetes / Alzheimer’s Disease.

And if you don’t believe that high insulin levels are the culprit behind those nasty little ADDLs

The Research

University of Washington researcher Dr. Suzanne Craft and her research team signed up 16 very brave volunteers to test this hypothesis. These men and women, ranging in age from 55 to 81, let research doctors give them two-hour infusions of both insulin and sugar. This kept their blood sugar at normal levels while creating the same kind of high insulin levels seen in people with insulin resistance.

Insulin resistance is a common symptom of people who eat the typical American diet. Though to be fair, it is not just Americans who eat this way. Like many other cultural contributions, the Golden Arches et al have spread across the globe. Even the French are buying into the American diet.

Back to the study…..The volunteers then let the researchers give them a spinal tap so they could analyze their spinal fluid.


Just this brief rise in insulin levels had what Craft calls “striking” effects:

  • It set off inflammation in the brain.
  • The spinal fluid had increased levels of a compound called F2-isoprostane. Alzheimer’s patients have unusually high brain levels of F2-isoprostane.
  • Brain levels of beta-amyloid increased.

Except for the spinal tap, many Americans already are undergoing the same experiment as the study volunteers did. And they are doing it for a lot longer than two hours.


According to Samuel Gandy, MD, PhD. Gandy, chairman of the Alzheimer’s Association’s medical and scientific advisory committee, director of the Farber neuroscience institute at Thomas Jefferson University, Philadelphia and all around good guy:

“I think this reinforces the idea that it’s wise to maintain your brain. Controlling blood sugar and body weight…all those things we know are good for your heart health are also really good at preventing Alzheimer’s disease. So there are more and more reasons not to be slouchy about getting these things under control.”

Craft and colleagues reported their findings in the October issue of Archives of Neurology.

My Two Cents

For all of you people that don’t think that eating a diet based on processed foods is a big deal, listen up:

This is your BRAIN
This is your BRAIN
This is your BRAIN on Big Macs, pizza, Coke, Twinkies, Slurpees, Chalupas, Crispy Cremes and all you can eat chinese buffets
This is your BRAIN on Big Macs, pizza, Coke, Twinkies, Slurpees, Chalupas, Crispy Cremes and all you can eat chinese buffets
Your choice...Alzheimer's BRAIN or Healthy BRAIN
Your choice…Alzheimer’s BRAIN or Healthy BRAIN


  1. Yet another example of “you are what you eat”. A little inflammatory perhaps, but I think the more we examine the effects of diet and environment on health, the more we will find evidence like this.
    I wish there were more research on the effects of car exhaust and air pollution.

  2. A recent meta-analysis associated obesity (but not overweight) with dementia. Obesity seems to cause hyperinulinemia/insulin resistance, which apparently increases inflammation, which might lead to dementia.

    Sorry to sound so wishy-washy, but we are in the infancy of understanding this. I’m sure there are other factors involved. For example, underweight is also associated with dementia in the same study. [Not to mention the apoE4 allele.]

    Here’s the link to the abstract:

    The traditional Mediterranean diet is felt to be anti-inflammatory, which may help explain why it prevents dementia.


  3. Interesting ideas. I’d be interested to see where/if aluminum fits in this, as many say that aluminum in our bodies is a common cause of Alzheimer’s. Does this cause the buildup of ADDLs too?

  4. Great post! However, as steve noted, there are too many confounding factors in AD. Time will tell, or it will remain an enigma. Red wine, cigarettes, playing chess, etc. have all been linked to prevention (and the cause, in case of smoking), but none conclusively.

  5. Obviously not a simple subject.

    There are so many aspects of our health that are out of our control.

    When I see that a diet of Big Gulps and Doritos can lead to something as terrifying as Alzheimers, I hope that people would come to their senses and choose their meals based on health rather than convenience.

  6. Hi Susan,

    I remember hearing about the link to aluminum when I was a kid. My mom threw out all of our aluminum pots and pans.

    I am going to do some hunting through the journals. I will report back if and when I fin something of interest.

    Thanks for dropping by.

  7. Doc Parker,
    I read that study as well. It certainly is interesting stuff.

    You probably know better than I would, but I keep seeing inflammation being linking to a lot of chronic diseases.

    I wonder how many of these conditions would lay dormant or disappear altogether if they didn’t have the fire of inflammation to aid their growth.

    Thanks for the comment. It’s good to have an M.D.s perspective on these topics.

  8. Not so sure of this. My great grandmother is in stage six of seven of the disease, and does not have a history of diabetes. She also ate very well for a woman of southern culture, and remains very thin and healthy aside from her Alzheimer’s.

  9. “High Insulin levels are produced when we eat a diet high in carbohydrates”

    Doesn’t this also mean that a vegetarian diet causes high insuline. Since a vegetarian diet is high in carbohydrates. Or is this just the bad carbs like refined carbs…or all carbs?

  10. All carbs raise insulin levels. There is nothing inherently wrong with that. It’s how our bodies work.

    The problem begins when we eat a diet high in overall carb load and/or eat foods with very high glycemic loads that cause big spikes of insulin to be released over and over and over.

    We want small, discrete secretions of insulin, not a never-ending flood of insulin

  11. How can we find out if we have got the balance right between the the intake of Omega 6 and omega 3. I understand to prevent the return of breast cancer we need more Omega 6 but need the correct balance otherwise its dangerous?

  12. Susan,

    All the research I can find says that Omega 6 encourages the growth of breast cancer tumors. (here is a 2008 study)

    In the standard western diet, the ration of Omega 6 to Omega 3 fatty acids is highly skewed in the favor of Omega 6. Unless you eat super healthy and eat a lot of fatty fish, you are likely to be getting waaaayyyy more omega 6 than omega 3

    If you want, send me a food log for a week. i will look at it and you can discuss with your doc (re cancer issues)

  13. I eat a load of steamed vegetables every single day. Partly because it’s a hang-over of a long standing eating disorder (there are few variations to the foods I eat because I gain weight especially easy and yes, I am currently a very healthy weight/BMI21) and also because I like eating them.

    I also have a great grandmother who had anorexia, lived with it but it wasn’t really picked up on, she maintained a very skinny weight and ate a far more balanced diet then me, just a lot less of it. She exercised by walking the huge dog she had, 4 times a day. She has had Alzhiemers for the past 10+ years and at the moment cannot communicate, walk or feed herself. It’s very shocking and sad.

    Is there anything I can do to help myself more here? Do you think the volumes of green veg I am eating every day (no sauce, and yes I eat protein) will push me closer to the disease then it would for say my sister, who does it it in small portions but hates her veg and just eats more or less the average full fat diet (eg full fat dairy, beef/red meat, chocolate, chips, potatos, smoothies/juice…etc all the foods I avoid) with the occasional pizza and Mc D’s (and is slimmer then I am: no eating disorder to screw up her body!) Who do you think is more at risk?

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