Back when I was a kid, “muscle head” was a term of derision applied to weight-lifters, and maybe the occasional football player, a class of people thought to be a bit dimwitted.

Weight-lifters may get the last laugh, because it turns out strong muscles are a key to protecting your brain and memory. Fortunately, you don’t need to be Popeye-strong to reduce your dementia risk by a huge amount.

But if you want a strong mind, you do need to keep your muscles active as you get older so you don’t lose muscle mass. Size does matter.

When muscle loss occurs, it can also cause the brain’s cortex to thin and shrink. You want to avoid this at all costs, because the cortex is essential for memory and cognition.

It’s also where language is stored. So, when the cortex starts to shrivel, our mastery of language can fail us, too.

Muscle Loss Leads to Brain Shrinkage

Groundbreaking research from the Australia National University links a lowering of body mass index (a measurement of muscle, fat and bone weight) in late life to the risk of brain shrinkage.1

Marnie Shaw, lead author, states, “In older people (60s and 70s) who are losing weight, we saw more cortical thinning than those with stable weight. That’s because at that age, it [weight loss] is generally related to muscle loss.”2

Their results suggest losing muscle mass later in life is associated with brain changes that can increase the risk of dementia and have other consequences for brain health.

Dementia Symptoms Can Hide for Over 20 Years

In a 2017 report published in Alzheimer’s and Dementia, Ms. Shaw and her team analyzed the association between body mass and dementia, using data from more than 1.3 million adults from Europe, the US and Asia. This report indicates those who have unexplained weight loss in their later years are often losing muscle, not fat.3

The study also reveals that losing body mass (muscle), a common problem in older people, can be an early sign of dementia 20 years or more before cognitive decline is noticeable.

This period of time is called preclinical dementia. It can last for years, or even decades.

According to these researchers, “. . .muscle loss close to the onset of dementia (less than 10 years before diagnosis) might be a consequence of the preclinical disease rather than a cause of dementia.”

A study published in The Journal of the American Medical Association was conducted on 1,890 men over a 32-year period. The results showed that dementia-associated weight loss begins before the onset of the clinical symptoms as an early non-cognitive sign, and accelerates by the time the disease is actually diagnosed.4

In another investigation, researchers in Seattle performed a study involving 2,288 people who were 65 years and older with no dementia. The participants were followed up nine years after the initial study. The scientists observed that low levels of physical activity were associated with an increased risk of dementia and Alzheimer’s disease.5

Lack of physical activity may precede the onset of dementia, and higher levels of physical activity may be associated with a delayed onset.

How You Can Protect Yourself

You want to stay strong and hold onto your muscle mass as long as possible. This can be as simple as walking every day. Not only does walking keep you strong, but it also uses complex systems in your brain, keeping it active.

Other good activities (no gym required) are. . .

  • Take the stairs instead of the elevator
  • Walk to a nearby store or coffee shop
  • Walk on a treadmill
  • Go for a bike ride or ride a stationary bike

If you’re feeling spry, begin an exercise routine that includes lunges, squats, push-ups, leg raises and step-ups, using your own body weight or light weights. Videos showing how to do these exercises are readily available on the Internet. Doing them will ensure your body muscles, along with your brain “muscles,” stay strong and healthy for years to come.

  1. Body mass index is associated with cortical thinning with different patterns in mid- and late-life.
  2. Low BMI, aging and brain shrinkage.
  3. Body mass index and risk of dementia: Analysis of individual-level data from 1.3 million individuals.
  4. A 32-year prospective study of change in body weight and incident dementia: the Honolulu?Asia Aging study.
  5. Performance-based physical function and future dementia in older people.