Type 3 diabetes is a title that has been proposed for Alzheimer’s disease which results from resistance to insulin in the brain. It is not yet a medical term or a recognised condition, but is a term now used in research looking into the causes of Alzheimer’s disease.

What is insulin?

Insulin acts like a key. It’s job is to open the doors that allow glucose to enter the body’s cells from the bloodstream. Muscle cells can use glucose and fats to fuel movement; however brain cells rely fully on glucose to fuel it’s activities. These activities include concentration, alertness, attention, decision-making, organisation, memory, awareness, personality, speaking, motor skills, self-monitoring and inhibition of behaviour.

A staggering 20% or more of the body’s glucose supply is used to fuel these brain activities.

‘Diabetes of the brain’

In type 2 and type 3 diabetes the body becomes less sensitive to insulin; it is like the locks and keys for the doors to the cells are rusty and don’t fit in as easily anymore. The result is that less glucose is able to enter into the cells. In type 2 diabetes, this leads to high blood glucose levels in the bloodstream and feelings of weakness and fatigue.

In type 3 diabetes the brain cells, called neurons, become starved of glucose, which in turn can lead to a progressive reduction in memory, reasoning, judgement and insight that characterises Alzheimer’s disease.

Am I at risk?

People that have insulin resistance, in particular those with type 2 diabetes, have a 50% to 65% increased risk of suffering from Alzheimer’s disease. Furthermore, research has found deposits of amyloid beta protein in the pancreas of people with type 2 diabetes; a similar protein has been found to deposit in the brain tissue of people with Alzheimer’s disease.

While Alzheimer’s disease does also develop without having high blood glucose levels, having type 2 diabetes appears to accelerate the progression of Alzheimer’s.

How can exercise help?

According to the Alzheimer’s Research & Prevention Foundation, regular physical exercise can reduce your risk of developing Alzheimer’s disease by up to 50%. What’s more, exercise can also slow further deterioration in those who have already started to develop cognitive problems. Exercise protects against Alzheimer’s and other types of dementia by stimulating the brain’s ability to maintain old connections as well as make new ones.

Exercise makes every cell in the body more sensitive to insulin – it is like WD40 for the rusty locks and keys in the doors to the cells. Exercise lubricates these locks, allowing insulin (the key) to bind to a receptor (the lock) so the door can open and glucose can enter the cell.

The effect of exercise on insulin sensitivity peaks at 24 hours after exercising and lasts for up to 72 hours. For this reason, it is suggested not to let more than 48-72 hours pass between exercise sessions for maximum benefit.

Which type of exercise is best?

Aim for at least 150 minutes of moderate intensity exercise each week. The ideal exercise plan involves a combination of cardio exercise and strength training. Good activities for beginners include walking, swimming, and resistance band or body weight exercises.

Build muscle to pump up your brain, and moderate levels of weight is all it takes. Strength training not only increase muscle mass, it helps you maintain your brain health. For those over 65, adding two to three strength sessions to your weekly routine may cut your risk of Alzheimer’s in half.

Include balance and coordination exercises. Head injuries from falls are an increasing risk as you age, which in turn increase your risk for Alzheimer’s disease and dementia. Balance and coordination exercises can help you stay agile and avoid trips or falls. Try yoga, Tai Chi, or exercises that involve balance like standing on one leg, or on an uneven surface like a cushion.

What else can I do?

Regular exercise, combined with a healthy diet, social engagement, mental stimulation such as puzzles and memory games, quality sleep, and stress management are the six pillars of Alzheimer’s prevention.