It has been known that regular exercise can reduce the risk of dementia by 30% and Alzheimer’s disease by 45%. Regular exercise increases the heart rate and more oxygen flows through our brains. Most of us do not have a regular exercise regimen.
Lifestyle has a major impact on our health and longevity. A study done in the United Kingdom followed over 2,000 men for 35 years. Five lifestyle choices were examined – regular exercise, not smoking, moderate alcohol intake, healthy body weight, and healthy diet. The risk of developing dementia was reduced the most by exercise.
Additional studies show that aerobic exercise improves thinking, memory, attention, and processing speed compared to non-aerobic exercise. The aerobic activity tracked in these studies averaged 20-30 minutes several times weekly and was maintained for at least a year. Aerobic exercise increases the size of the hippocampus, the area of the brain controlling memory.
No studies prove that exercise, aerobic or non-aerobic, prevents dementia. However, some new studies are promising. Of particular interest to me is the comparison of fasting and exercise and the resulting impact on developing dementia.
BDNF (Brain-Derived Neurotrophic Factor)
https://medlineplus.gov/genetics/gene/bdnf/. BDNF is a protein in the brain that promotes the survival of nerve cells. Cell-to-cell communications occur at the synapse of two nerve cells. BDNF supports this communication through synaptic plasticity, improving our ability to learn and extract memories.
If BDNF can be used for new neuropathic connections, it is logical to assume that the brain can be protected from age-related diseases such as dementia. Animal models have shown remarkable success in brain capacity preservation and cognitive performance. However, human research has been lagging.
BDNF is increased with exercise. Most of us do not like to exercise or want to invest time and effort into exercising. However, fasting might offer a practical compromise. Fasting is becoming a lifestyle choice for some. Intermittent fasting is relatively easy to achieve daily.
Exercise vs. Fasting
The January 11, 2023, Journal of Physiology’s article, Fasting for 20 hours does not affect exercise-induced increases in circulating BDNF (brain-derived neurotrophic factor) in humans. https://physoc.onlinelibrary.wiley.com/doi/full/10.1113/JP283582. Preliminary results indicate that fasting does not increase BDNF more than high-intensity exercise alone. What does this mean to most of us?
HIIT (High-Intensity Interval Training)
https://www.hsph.harvard.edu/nutritionsource/high-intensity-interval-training/, HIIT incorporates high-intensity exercise to increase heart rate for a brief time, followed by a low-intensity activity. It has been called sprint interval training, Tabata, and circuit training.
HIIT decreases body fat, increases strength and endurance, and raises the levels of BDNF. What duration of HIIT is required to obtain higher BDNF levels? Studies indicate that six minutes of HIIT is needed to raise BNDF levels.
BDNF and Alzheimer’s Risk
https://www.newsmax.com/health/health-news/exercise-high-intensity-brain/2023/01/12/id/1104128/. Research has shown that HIIT improves BDNF levels. Fasting improves neurobiological health in animals. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8470960/. Additional clinical studies show substantial benefits of fasting for epilepsy, Alzheimer’s disease, and multiple sclerosis. The biological mechanisms of fasting show promise for Parkinson’s disease, ischemic strokes, autism spectrum disorder, and mood and anxiety disorders. Fasting improves brain health but does not increase BDNF levels compared to HIIT exercise.
BNDF improves and protects our brains. Fasting improves brain health. Could the two work together and provide even better results? The answer is NO.
HIIT exercise works exceptionally well to increase BDNF levels. While fasting (intermittent and prolonged) enhances cognitive function and overall brain health, it does not increase BDNF levels over that of HIIT exercise alone.
Six minutes of HIIT is enough to demonstrate increased BDNF in the brain. Incorporating HIIT with a healthy aging lifestyle should provide another layer of insurance to prevent or reduce the risk of dementia and brain-related diseases associated with aging.
This is the first study I have seen that incorporated HIIT and fasting to determine if one is better or if the combination of the two might show synergistic effects. HIIT exercise improves BDNF levels about four to five times higher than fasting alone.
This is a small study of a dozen men and women using cycling as an HIIT exercise and low-intensity follow-up. The study used ninety minutes of low-intensity cycling followed by six minutes of HIIT, where the heart rate approaches 80% of the maximum heart rate. That is a substantial exercise protocol, especially for an older adult. One advantage older adults have is that their maximum heart rate decreases with age.
The standard age-related maximum heart rate is determined by subtracting your age from 220. https://www.cdc.gov/physicalactivity/basics/measuring/heartrate.htm#:~:text=You%20can%20estimate%20your%20maximum,beats%20per%20minute%20(bpm).
When I was 50 years old, my age-related heart rate would be 220 minus 50, which is 170. Eighty percent of 170 is 136. This means that my theoretical maximum heart rate at the 80% level would be 136 beats per minute. However, I routinely trained with a heart rate of 155-160 beats per minute in my 50s.
Today, at 76 years old, my maximum theoretical age-related heart rate is calculated to be 220-76, equating to a heart rate of 144. Eighty percent of 144 beats per minute equals 115 beats per minute. For many old guys, 115 beats per minute are not hard to achieve and maintain for at least six minutes.
In summary, HIIT exercise increases BDNF levels four to five times greater than fasting alone.
Live Longer & Enjoy Life! – Red O’Laughlin – RedOLaughlin.com