ALS, also known as Lou Gehrig’s disease and formally known as amyotrophic lateral sclerosis, is a specific disease that causes the death of neurons that control voluntary muscles. Symptoms of ALS frequently include stiff muscles, muscle twitching, and gradually worsening weakness due to muscles decreasing in size. Stephen Hawking is perhaps the most famous example of an ALS patient – and someone who has had remarkable success beating the odds by outliving all expectations.
It is generally thought that ALS patients have a higher level of physical fitness and lower body mass index (BMI) than average, but there has been little examination of any relationship
between cognitive fitness and ALS risk. In a new study1, however, researchers took a look at both physical and cognitive fitness in relation to future risk of ALS.
Researchers used data on 1,838,376 Swedish men aged 17–20 years at conscription during 1968–2010. This data included physical fitness, BMI, intelligence quotient (IQ) and stress resilience, and their subsequent ALS diagnoses were identified through the Swedish Patient Register.
The connection beween one’s physcial and cognitive state at 17-20 years of age and the risk of ALS later in life became clearer. Of the 439 ALS cases found during follow-up, the mean age at diagnosis was 48 years old, and the generally accepted view of physical fitness seemed to hold true: individuals who were fitter in youth were more likely to get ALS. Those who scored above the highest tertile in physical fitness had a higher risk of ALS before the age of 45 years compared with others. Conversely, individuals with BMI ≥ 25 tended to have a lower risk of ALS at all ages compared with those with BMI < 25.
On the cognitive side, those who scored above the highest tertile for IQ also had a statistically significantly increased risk of ALS, but at an age of 56 years and above, whereas individuals with stress resilience above the highest tertile had a lower risk of ALS at an age of 55 years and below.
Although more research is needed, the bottom line from this study is that physical fitness, BMI, IQ and stress resilience in young adulthood might be associated with the development of ALS at an early age.
1. Longinetti, E., D. Mariosa, H. Larsson, C. Almqvist, P. Lichtenstein, W. Ye, and F. Fang. “Physical and cognitive fitness in young adulthood and risk of amyotrophic lateral sclerosis at an early age.” European Journal of Neurology(2016).