Type 3 Diabetes and Brain Health

When we think of diabetes, we usually picture its effects on blood sugar, heart health, or kidneys—but did you know your brain is also at risk?

In recent years, scientists have started referring to Alzheimer’s disease as "Type 3 Diabetes"—a term highlighting the connection between insulin resistance and cognitive decline. While it’s not an official medical diagnosis, this concept sheds light on how metabolic health and brain health are deeply connected.

What Is Type 3 Diabetes?

Type 3 diabetes refers to a form of insulin resistance that specifically affects the brain. Just like your body needs insulin to use glucose for energy, your brain does too. But when insulin signaling in the brain breaks down—often due to the same factors that lead to type 2 diabetes—it can contribute to the development of Alzheimer’s and other forms of dementia.

Key signs of this link include:

• Insulin resistance found in the brains of people with Alzheimer’s disease

• Impaired glucose metabolism in key brain regions (seen on imaging)

• Overlapping risk factors: obesity, type 2 diabetes, high blood pressure, and high cholesterol

How Nutrition Impacts Cognitive Health

The good news? Lifestyle—and especially nutrition—can play a powerful role in protecting your brain.

Here’s how a brain-healthy diet helps:

1. Supports Insulin Sensitivity

Eating fewer refined carbs and sugars helps reduce insulin resistance—not just in your muscles and liver, but potentially in your brain. Think:

• Whole grains (like oats, quinoa, brown rice)

• Legumes and beans

• Vegetables and fruits with fiber

2. Reduces Inflammation

Chronic inflammation is a major driver of both type 2 diabetes and neurodegeneration. Anti-inflammatory foods include:

• Fatty fish (rich in omega-3s like DHA)

• Extra virgin olive oil

• Leafy greens and colorful vegetables

• Berries (especially blueberries)

3. Fuels Brain Cells

Your brain loves glucose, but it also thrives on ketones—an alternative fuel your body produces during fasting or low-carb states. Emerging research suggests intermittent fasting or a Mediterranean ketogenic diet may benefit cognitive function.

4. Prevents Oxidative Stress

Antioxidants protect brain cells from damage. Some brain-boosting options:

• Green tea

• Nuts and seeds (especially walnuts and flaxseed)

• Dark chocolate (at least 70% cacao)

• Spices like turmeric

5. Feeds Your Gut-Brain Axis

Your gut and brain are in constant communication. A diverse, fiber-rich diet supports a healthy microbiome, which in turn may reduce brain inflammation.

What Does a Brain-Friendly Plate Look Like?

Here’s a snapshot of what a daily brain-protective menu could include:

• Breakfast: Steel-cut oats topped with walnuts and blueberries

• Lunch: Grilled salmon salad with mixed greens, olive oil vinaigrette, and quinoa

• Snack: Green tea and a handful of almonds

• Dinner: Lentil stew with turmeric, garlic, spinach, and a side of roasted broccoli

Final Thoughts: Protecting Your Brain Starts

Early

Dementia doesn’t start overnight. The processes that lead to Alzheimer’s can begin decades before symptoms appear—often in our 40s or 50s. That’s why preventive nutrition matters now, even if your memory feels sharp today.

By managing blood sugar, reducing inflammation, and fueling your brain with the right foods, you’re not just preventing diabetes—you’re giving your future brain the best chance at staying clear and sharp.

Interested in learning more about how food impacts your brain?Let’s talk. I offer personalized nutrition plans to help you prevent chronic disease—and protect the health of your most important organ: your brain.