Wil Dubois

Need help navigating life with diabetes? Ask D'Mine! That would be our weekly advice column, hosted by veteran type1 and diabetes author Wil Dubois. This week he's offering some wisdom on the connection between mental capacity and diabetes.

Yes, they can be related. Read on for more...

{Got your own questions? Email us at [email protected]}



Dan, type 3 from New Jersey, writes: I have a question that relates to older folks with Type 1. Specifically, how likely or common is it that Type 1 would cause or contribute to dementia? I have noticed changes in an older parent and wonder whether or how much diabetes is contributing. Thanks as always for your informative columns!

[email protected] D’Mine answers: Let’s see… I used to know the answer to that question… But now I can’t seem to remember it… :)

Sorry. I couldn’t resist. But before any of you itchy-fingered flamers cut loose, rest assured that I do know that dementia is no laughing matter. I’ve experienced it first hand. Under my own roof.

It’s tragic and scary for all involved.

But to answer your question, Dan, yes, diabetes—as always it seems—has a role to play.

First and foremost, it’s been known for a long, long time that there’s a link between T2 diabetes and dementia, especially dementia of the Alzheimer’s variety. Quoting the Alzheimer’s Association, “numerous studies” have found T2s suffer “a lower level of cognitive function and are at higher risk for dementia than individuals without diabetes” as they age. Most research suggests a two-fold risk of developing dementia for type 2s over sugar-normals.

But what about us T1s? The sad truth is that until recently, we simply didn’t live long enough for anyone to worry about it. Then, enter Rachel Whitmer, PhD, a senior scientist for Kaiser Permanente’s Division of Research. She wondered if, given the fact that T1s now routinely live into our senior years, we too would forget our glory days in higher numbers like type 2s do, and she set about finding out.

Whitmer and her gang combed through the data of Kaiser’s Northern California members and found close to half a million members over 60 who were dementia-free in 2002. Of that group 334 had type 1 diabetes. With a good sample size, Whitmer et al then looked downstream to 2014 to see how their members had fared over the intervening dozen years.

What did they find?

Once again, I find myself in the role of the bearer of evil tidings.

According to a WedMD write up of the study, 16% of the T1s went on to develop dementia. While those numbers don’t sound all that scary, it actually works out to an 83% increased risk for dementia for type 1s, compared to persons without diabetes.

Well, that’s fickin’ depressing.

But what does it really mean?

Whitmer, literally, was the first person—at her presentation of her study at the Alzheimer’s Association International Conference in 2015—to point out that her observational study doesn’t prove that type 1 causes dementia, but only that the two diseases were linked. Apparently Whitmer said she couldn’t prove diabetes caused the dementia, because, “We don’t have tissue from these people’s brains.”

Yipes! She sure looks like a nice lady, but that quote gave me chills. I need to remember to decline dinner invitations from Dr. Whitmer.

Anyway, with a link established, does the cause really matter? Hell yeah. More on that in a minute. But to muddy the waters, while I was reading up on Dr. Whitmer’s work, I found some commentators where correctly pointing out that type 1 diabetes treatment has evolved at a stunning pace over the last few decades, and they wondered if that meant we younger type 1s aren’t necessarily fated to develop the higher levels of dementia type 1s from the days of more primitive treatment do. It doesn’t change the facts on the ground for anyone with an aging parent with type 1, but I wanted to throw that out as a possible piece of good news for us pre-seniors with diabetes.

Still, thanks to Dr. W, we now know there is a relationship between type 1 and dementia. For the sake of argument, what if the relationship between diabetes and dementia is more than casual? How might diabetes fuel dementia? One perennial favorite is, of course, high blood sugar, the bringer of most bad shit in the diabetes universe. However, there are some frightening cases of early onset dementia in type 1s that are fueling a controversial theory that it could be frequent brain-cell killing hypos that lead to dementia. If this theory proves true, the smoking gun in dementia in type 1 would be hypoglycemia, not technically the diabetes.

Does the distinction matter in the trenches? Yes. Absolutely. Hypoglycemia is caused by diabetes treatment, not by diabetes. If it turns out that dementia is caused by hypos, not by diabetes in and of itself, not by high blood sugar, we have a way to change the diabetes and dementia statistics in our favor—by focusing on preventing hypos. If on the other hand, high sugars turn out to be the cause, then we need to continue striving for tighter control. 

Lastly, what if it turns out that dementia is simply part of diabetes, uncontrolled or not? Well, then there’s not much we can do but get drunk. And the first round is on me.

Now where did I put my wallet?


This is not a medical advice column. We are PWDs freely and openly sharing the wisdom of our collected experiences — our been-there-done-that knowledge from the trenches. But we are not MDs, RNs, NPs, PAs, CDEs, or partridges in pear trees. Bottom line: we are only a small part of your total prescription. You still need the professional advice, treatment, and care of a licensed medical professional.


Disclaimer: Content created by the Diabetes Mine team. For more details click here.


This content is created for Diabetes Mine, a consumer health blog focused on the diabetes community. The content is not medically reviewed and doesn't adhere to Healthline's editorial guidelines. For more information about Healthline's partnership with Diabetes Mine, please click here.