Why Brains Age; Why Mental Exercise Helps
What is brain aging?
Age-related changes in the human brain fall into three categories, all thought to begin gradually while we’re in our thirties.
- Progressive damage to brain cells due to natural wear and tear.
- Reduction in brain plasticity.
- Reduction in the availability of signaling chemicals called neurotransmitters.
Damage can result from head trauma, environmental toxins, and everyday substances in food and drink.
Many scientists believe that free radicals also produce significant damage.
“You might say that we’re actually rusting on the inside,” says Wic Wildering, (University of Calgary). “These free radicals actually cause damage inside nerve cells, and … the accumulation of this damage eventually leads to learning and memory dysfunction and other kinds of neurological impairments.”
Oxidative stress: Energy-making units, called mitochondria, convert glucose (from food) and oxygen into energy. About 2% of the time the process inadvertently creates superoxide molecules, free radicals that damage neighboring molecules. The affected cells can sometimes repair themselves, but damage to a DNA molecule leads to a growing number of errors as the DNA replicates. And damage to mitochondria increases free radical production, accelerating the oxidative stress.
Reduction in the brain plasticity
MRI scans show that brain volume reduces by about two per cent per decade after we reach adulthood. The reduction results from the winnowing of branches or dendrites, sprouting from our neurons: As neurons age, their plasticity decreases and they can no longer maintain the dendrite connections. Since the formation of new memories involves synapse formation the loss of synaptic plasticity means that the brain has more difficulty forming new memories and integrating new skills in later life.
Not only memory, but all of general cognition suffers from this process, including attention, perception, computation, analysis, language and memory. Deficits in one cognitive area can negatively affect others accelerating overall decline.
Changes in neurotransmitters
A decrease in the neurotransmitter substance acetylcholine affects learning, memory, and muscle control. This is accompanied by decreases in the neurotransmitters serotonin and dopamine. Serotonin helps controls mood, aggression and sleep. Dopamine helps regulate mood, reward and motivation, attention and learning.
What role does genetics play?
Dr. Roland Auer, a physician and neuroscientist at the University of Calgary, believes that although these changes happen in many people, we shouldn’t think of them as inevitable.
“We’ve all come across people in our lives that are as sharp as a razor until the end, so obviously, these changes don’t necessarily affect us all,” he says. Genetics plays a part. For instance, we inherit the efficiency of our mitochondria and therefore, our susceptibility to oxidative stress, from our mother.
“The evidence that genetics plays a role in aging is all around us,” says Wildering.” Just look at a fruit fly that lives for 30 days and compare that to a human that lives for 80 years.”
Eating for your brain
“One of the best ways currently available to slow the aging process is to eat your vegetables,” says Dr Wildering.
Vegetables, especially the colorful ones rich in antioxidants, go after free radicals, including superoxides.
Research also indicates that reducing our intake of saturated and trans fats while boosting omega-3s, helps prevent plaque deposits in blood vessels and the brain, reducing the risk of stroke, dementia, and Alzheimer’s disease. Reducing our salt intake can help lower our blood pressure, which also prevents plaque deposits.
Flexing your mental muscles
Keeping our minds challenged and engaged can help slow the loss of synaptic connections associated with natural aging.
Crossword puzzles, Sudoku, reading and board games can all help. Continually challenging the brain across a range of cognitive tasks is key.
The Brain Fitness Pro Training software functions as an excellent way to stimulate the brain, increasing plasticity while improving memory and focus.
Exercise produces endorphins raising levels of dopamine and serotonin, boosting mood and attention. Exercise also increases blood flow and oxygen uptake in the brain, increasing fitness. Improved cardiovascular health is an added benefit of exercise, helping to lower blood pressure and counter blood vessel hardening.