Why insulin spikes matter for long-term health and longevity

Insulin and brain health, including Alzheimer’s disease

The brain relies heavily on glucose for energy, but it also depends on insulin signalling to function properly. Research has shown that impaired insulin signalling in the brain is associated with reduced glucose uptake, inflammation, and changes in brain structure.

Some scientists now refer to Alzheimer’s disease as “type 3 diabetes”, not because it is caused by sugar intake alone, but because insulin resistance appears to play a role in its development. Studies have found that people with insulin resistance or type 2 diabetes have a significantly higher risk of developing Alzheimer’s disease and other forms of dementia.

Importantly, these changes can begin years before symptoms appear. Insulin resistance may contribute to amyloid plaque accumulation, oxidative stress, and chronic low-grade inflammation in the brain, all of which are associated with cognitive decline.

This does not mean insulin spikes cause Alzheimer’s disease. It means long-term metabolic health appears to influence brain resilience over time.

Insulin, inflammation, and visible ageing

Chronically raised insulin levels are also linked to increased systemic inflammation and oxidative stress. These processes affect collagen, elastin, and cellular repair mechanisms in the skin.

Higher insulin and glucose exposure can accelerate glycation, a process where sugars bind to proteins such as collagen, making skin stiffer and less elastic. Over time, this contributes to wrinkles, loss of firmness, and slower tissue repair.

Insulin resistance is also associated with hormonal changes that affect muscle mass, fat distribution, and skin quality, all key components of how we age physically.

What this means in practical terms

The research does not suggest eliminating carbohydrates or obsessing over numbers. It points towards the importance of metabolic flexibility, allowing insulin levels to rise when needed and fall when they are not.

Long periods of persistently elevated insulin may reduce the body’s ability to repair, adapt, and age well. Supporting balanced insulin responses is therefore about preserving healthspan, not chasing youth.

At Bespoke Health Clinic, we use this evidence to guide thoughtful, individualised care, focusing on patterns over time rather than single test results.

If this raises questions about your own health, a free Clarity Call can help you decide whether further support or investigation would be useful.

The information shared here is for general educational purposes only and is not intended to replace personalised medical advice, diagnosis, or treatment. Health decisions should always be made in discussion with a qualified healthcare professional who understands your individual medical history and circumstances.