Researchers at the University of Otago, New Zealand, report that six minutes of regular high-intensity exercise can slow brain aging and delay the onset of neurodegenerative diseases such as Alzheimer’s and Parkinson’s. High-intensity exercise increases the production of BDNF, a protein involved in memory, learning and brain plasticity, which might protect the brain from age-related cognitive decline.
This information regarding exercise is part of the drive to develop accessible, equitable, and affordable non-drug approaches that anyone can take to promote healthy aging.
Six minutes of high-intensity exercise might extend the lifespan of a healthy brain and delay the onset of neurodegenerative disorders, such as Alzheimer’s disease and Parkinson’s disease.
A specialized protein called brain-derived neurotrophic factor (BDNF) promotes neuroplasticity (the brain’s ability to form new connections and pathways) and the survival of neurons. Animal studies have shown that increasing the availability of BDNF encourages the formation and storage of memories, enhances learning, and generally increases cognitive performance. These key functions and its apparent neuroprotective qualities have led to interest in BDNF for aging research.
Lead author Travis Gibbons, from the University of Otago, New Zealand, stated: “BDNF has shown great promise in animal models, but pharmaceutical interventions have so far failed to safely harness the protective power of BDNF in humans. We saw a need to explore non-drug approaches that can preserve the brain’s ability that humans can use to naturally increase BDNF to help with healthy aging.”
To separate the influence of fasting and exercise on BDNF production, researchers at the University of Otago, New Zealand, compared the following factors to study isolated and interactive effects:
- 20 hour fast.
- Light exercise (90 minute low intensity cycling).
- High intensity exercise (six minutes of vigorous cycling).
- Fasting and exercise combined.
They found that brief but vigorous exercise was the most efficient way to raise BDNF compared to a fasting day with or without a prolonged bout of light exercise. BDNF increased four to five times (396 pg L-1 to 1170 pg L-1) more compared to fasting (no change in BDNF concentration) or prolonged activity (slight increase in BDNF concentration, 336 hp L-1 to 390 hp L-1).
The cause of these differences is not yet known and more research is needed to understand the mechanisms involved. One hypothesis is related to the change in brain substrate and the metabolism of glucose, the main source of fuel for the brain.
Brain substrate switching is when the brain switches from its preferred fuel source to another to ensure that the body’s energy demands are met, for example, metabolizing lactate instead of glucose during exercise. The transition of the brain from consuming glucose to lactate initiates pathways that result in elevated levels of BDNF in the blood.
They found that brief but vigorous exercise was the most efficient way to raise BDNF compared to a fasting day with or without a prolonged bout of light exercise.
The increase in BDNF observed during exercise might be due to the increased number of platelets (the smallest blood cells), which store large amounts of BDNF. The concentration of platelets circulating in the blood is more influenced by exercise than by fasting and increases by 20%.
Twelve physically active participants (six men, six women aged 18-56) participated in the study. The balanced ratio of male and female participants was to provide a better representation of the population rather than indicate gender differences.
Further research is ongoing to delve deeper into the effects of caloric restriction and exercise to distinguish the influence on BDNF and cognitive benefits.
Travis Gibbons noted: “We are now studying how fasting for longer periods of time, for example up to three days, influences BDNF. We are curious if vigorous exercise at the beginning of a fast accelerates the beneficial effects of the fast. Fasting and exercise are rarely studied together. We believe that fasting and exercise can be used together to optimize BDNF production in the human brain.”
