Is Alzheimer’s a Blood Sugar Problem? What We Discovered

Eight years into Alzheimer’s, our mom still walks miles, cracks jokes, and lives at home with our dad. But if we could go back to Day 1 of her diagnosis, we’d change one thing—check her blood sugar first.

What if we told you Alzheimer’s is sometimes called Type 3 Diabetes? That’s because blood sugar problems may fuel cognitive decline long before memory loss begins.

We hadn’t heard of Type 3 Diabetes when our mom was diagnosed with Alzheimer’s in 2019. But once we discovered the connection, everything changed.


When Sugar Becomes Poison for the Brain

At first, we had no idea her blood sugar was an issue. She ate home-cooked meals and wasn’t overweight, but she also had a serious sweet tooth—and we never thought much of it.

Her lab tests showed normal A1C and fasting glucose levels, so doctors never flagged a problem. We assumed everything was fine.

However, the brain relies on glucose as its primary energy source. And when insulin resistance prevents glucose from reaching brain cells, something dangerous happens. Instead of fueling neurons, excess sugar:

  • Damages blood vessels
  • Triggers inflammation

These effects can lead to memory loss, brain fog, and cognitive decline.

We now understand that glucose is essential fuel for every cell in the body—when it’s at normal levels. But when blood sugar runs too high, it can act like a slow-acting poison, damaging small blood vessels, shrinking the brain, and disrupting neuron communication. The very symptoms we associate with Alzheimer’s—confusion, trouble processing information, and forgetfulness—can be signs that the brain is starving for fuel. (Harvard Medical School).

That realization was a turning point. It meant we had some control over something that directly impacted our mom’s brain health.


Insulin Resistance: The Missing Piece

The more we learned, the more we realized our mom showed clear signs of insulin resistance (also known as Type 3 Diabetes):

  • Frequent urination
  • Fatigue after eating simple carbs (like pizza)
  • Waking up multiple times a night

However, insulin resistance flew under the radar because her lab results were within the normal range. We needed proof that food affected her symptoms, so we tracked her blood sugar in real-time instead of guessing.

Why Continuous Glucose Monitor (CGM) Is a Game Changer?

We started cutting refined sugar from her diet the year before, but we weren’t sure if we had done enough. A CGM gave us the answer.

  • Standard lab tests can miss insulin resistance. Our mom’s bloodwork looked fine, but real-time tracking told a different story.
  • We could see exactly how her body reacted to food. Blood sugar spikes after meals? Confirmation.
  • Until March 2024, CGMs required a prescription. However, you can now get one over the counter and track your blood sugar.

My brother Kevin started using Signos in May 2024 because we suspected he was insulin-resistant like our mom. Unlike traditional CGMs, Signos provides real-time data and personalized insights, helping us connect food, movement, and blood sugar in a whole new way.

The results? We discovered we hadn’t eliminated enough refined sugar, so we needed to do more to stabilize our mom’s blood sugar levels.

The More Stable Her Blood Sugar, the Sharper She Thinks

The biggest surprise? The more stable our mom’s blood sugar is, the more she is herself.

  • On days when her blood sugar was steady, she was sharper, more engaged, and could follow conversations more easily.
  • On days when her blood sugar spiked or crashed, she struggled more with confusion, word-finding, and memory lapses.

It wasn’t just about long-term brain health. We could see the difference in real-time.

That’s when it became clear: Alzheimer’s isn’t just a memory problem for our mom. It’s also a metabolic problem.

Could Insulin Resistance Be Affecting Your Loved One?

Looking back, we wish we had known how insulin resistance silently impacts brain health.

Signs to look for:

  • Normal A1C and fasting glucose, but unexplained fatigue after eating.
  • Frequent urination, even when well-hydrated.
  • Brain fog, forgetfulness, and disrupted sleep patterns.

If these sound familiar, tracking blood sugar could give you answers.

What You Can Do Today?

  • Try a CGM for one week – See how your body processes sugar in real time.
  • Start paying attention to symptoms. Fatigue after eating, sugar cravings, and brain fog could be warning signs.
  • Start your day with a savory breakfast—something high in protein, like eggs or Greek yogurt. It’ll help keep your blood sugar steady from the get-go. Then, pay attention to how you feel.

Kevin and our mom started using Signos in 2024 when Continuous Glucose Monitors (CGMs) became available without a prescription in the U.S. We chose Signos because it offers real-time data and personalized insights, helping us better understand how food and movement affect blood sugar.

We opted for the 3-month subscription because the price difference wasn’t huge, and we wanted enough time to learn something new. But now that we’ve gone through it, you could start with the one-month plan and still get great value.

Scroll to Top