As I dive into the research on the aging brain and metabolic health, I'm becoming more and more fascinated with the topic. Last week I briefly described how insulin resistance in the brain and decreased glucose metabolism play a central role in developing Alzheimer's disease (AD).

Today, let's discuss nutrition and lifestyle measures to improve our chances of mental acuity in our golden years. To support healthy brain function, we should aim to:

• Reduce peripheral insulin levels to restore sensitivity at the blood-brain barrier
• Restore sufficient energy production in neurons
• Provide an abundant supply of protective substances.

Let's start with peripheral insulin resistance.

How do we get insulin-resistant (IR)? Our modern Western diet of high-carb, high-sugar combined with a lack of physical activity requires the body to produce high amounts of insulin to process loads of glucose after we eat. When our cells are exposed to high insulin levels over a long period (years), they become less sensitive to it, "tuned out." Then the body produces even more insulin to get cells' "attention." This is the vicious cycle of a gradual increase of insulin needed to get cells' response and a corresponding decrease in cells' sensitivity to it.

One of the signs of insulin resistance in the body is increasing weight, as well as age, waist size, and C-reactive protein. To assess your level of insulin resistance, calculate your IR index. You need to know your fasting glucose and fasting insulin levels to plug them into a formula. The healthy range is between 0.5 and 1.4. Above 1.9 indicates early insulin resistance, and above 2.9 - significant insulin resistance.

To reverse insulin resistance, we need to reduce our insulin levels. Here is how:

• Reduce carbohydrate intake. Eat less or avoid sugar, grains, and starches.
• Go on a walk or do another physical activity after you eat.
• Eat three times a day or less.
• Try intermittent or more prolonged fasting (1-3 days).

It might sound drastic, but you can do some of these measures. Begin with one change, and when ready, add another. You can reduce insulin resistance at any age and as quickly as within three weeks.

Next week I'll talk about protective substances for the brain.

Stay tuned,

Olga