An article from the European Journal of Pharmacology (15) details the effects of stress on one’s brain health. Long-term stress caused by environmental factors, or allostatic overload, can result in depression, Alzheimer’s disease, and other health effects.
According to the American Institute of Stress (AIS) (16), stress is the major cause of minor cognitive impairment and a significant factor in Alzheimer's disease. Stress can cause an increase in tau protein tangles, which affect the hippocampus's ability to form, organize, and store memories.
This area of the brain is often the first region of the brain to suffer the most cell death, and thus stress makes one vulnerable to the symptoms of Alzheimer's disease. Stressful life events and chronic stress have a higher effect on one's risk of Alzheimer's disease than everyday, motivating stressors.
RESEARCH
We’ve looked at multiple resources and research studies concerning the effects of six practices on brain health. In our own research, we’ve found that many students may improve their brain health through mind-stimulating games, exercise, sleep, limiting use of alcohol and other drugs, lowering stress, and employing a healthy diet. By understanding the underlying factors of these behaviors that affect brain health, students may have a larger understanding of how crucial it is to create healthy habits.
Games
According to the Medical Directors Association (7), frequently playing “brain games” has been proven to stimulate the brain and thus slow the decay of neural connections. Over time, these neural connections can degrade when they are unused and cause hippocampal atrophy, also known as cognitive decline. Mental activity, however, may allow a person to use the cells that are affected and thus slow or even stop such decline. When paired with physical activity, mental activity through games reaps more powerful effects in slowing cognitive decline than mental activity alone.
A prospective study from the Journal of Physiology (8) showed that playing board games, puzzles, and other strategy games can inhibit the symptoms associated with Alzheimer’s disease and other forms of dementia. Because these games create new synapses in the brain, “people who engage in more cognitively-stimulating leisure, social, and job activities are at a reduced risk for cognitive decline.”
Further, a journal article from Frontiers in Psychology (9) states that one’s brain is able to create neuroplastic changes, or neural changes in response to one’s environment, to compensate for difficult mental tasks. The more one engages in challenging mental activities, therefore, the more beneficial it will be for one’s brain. Playing games will increase the brain’s grey matter and/or cortical thickness, which leads to positive neuroplastic changes. Grey matter is the cell bodies that process information, and there is a positive correlation between cortical thickness and this cognitive ability. This model, or the supply-demand mismatch model of cognitive plasticity, concludes that keeping one’s brain active with challenging games will keep it in shape and combat future health concerns.
Exercise
The study from the Medical Directors Association (7) also concluded that exercise has an effect on one’s brain health. Exercise can maintain one’s cognitive capacity and decrease age-related brain atrophy, or the loss of cells that are not used over time. Further, there is a positive correlation between exercise and brain improvement and its effects are as beneficial to those suffering from depression as are antidepressants (10).
Aerobic activities such as walking, running, swimming, and biking are the most beneficial types of exercise for the brain (7). Synaptic plasticity, or the strength of communication between two neurons, is directly improved by such exercise. Further, exercise is beneficial for neurogenesis, or the process of forming new neurons and thus increasing brain capacity. Due to the combination of these two effects, exercise increases the ability to form and retain information over a lifetime.
Sleep
According to the National Institute of Health (NIH), sleep allows for the removal of toxins from the brain that build up during one’s waking hours (11). Sleep also helps to store and consolidate memories formed throughout the day, as rest of the body and mind allows for the increase of neural connections in the hippocampus. A lack of sleep will impair reasoning and problem-solving during the day, which not only inhibits one’s life but also makes it more difficult to retain further information.
During the day, toxic protein beta-amyloid builds up in one’s brain. The glymphatic system, or the series of channels that carry fluid surrounding the brain and blood vessels, removes these toxic proteins while one is asleep. Thus, when the system cannot remove them due to a lack of sleep, the buildup of beta-amyloid inhibits cognitive function and the creation of new synapses. Such effects have been proven in studies of mice, which showed that beta-amyloid buildup disappeared twice as quickly when mice were asleep.
Alcohol and other drugs
Alcohol, being a poison, has many toxic effects on the brain. Firstly, the chemicals in alcohol react unfavorably with important compounds in the brain to create acetaldehyde, or a highly-toxic substance known to be in carcinogens. In a study from the Journal of the Korean Medical Association (12), alcohol was shown to induce glutamate excitotoxicity, which over-excites neurotransmitter glutamate. Glutamate excitotoxicity may damage or even kill the molecule, thus preventing the brain from carrying out normal processing, memory, and retention functions.
Alcohol is more damaging in women due to their lower tolerances and in children during periods of brain development. Hangover and blackouts that are caused by alcohol are early signs of the brain damage that alcohol causes. The NIH (13) details the medical problems that may be caused by alcohol, such as fetal alcohol syndrome, encephalopathy (inflammation of the brain), head injury, depression, and anxiety. Further, the NIH also cites studies involving animals that show the disruption of brain cell growth when given large doses of alcohol.
Marijuana, another drug, has a strong effect on children and adolescents. According to the NIH (14), adults who smoked marijuana in their childhood have impaired neural connective fibers in their brain, which are important for learning and memory. Later on in life, a high use of marijuana is correlated with an increase in depression and anxiety. Many other types of drugs such as opioids, heroin, oxycodone, and other morphine-derived drugs can lead to a strong dependence or addiction. This causes the brain to function normally when the drugs are used, but abnormally when they are not taken. After taking these drugs for a long period of time, and thus developing tolerance, it becomes extremely difficult to stop; withdrawal symptoms can physically hurt the person by inducing the brain to release large amounts of noradrenaline triggering jitters, anxiety, muscle cramps, and diarrhea.
Ted-Ed and Shai Marcu show how sleep restructures your brain in a way that’s crucial for our memory and well-being.
DNews explains how exercise can re-wire your brain to better cope with stress.
Stress
Ted-Ed and Madhumita Murgia show how chronic stress can affect brain size, structure, and functions, right down to your genes.
A study from the Journal of Physiology (8) found that people who adhere to the Mediterranean Diet have shown a decreased risk of stroke by 46% compared to other diets. The Mediterranean Diet (MeDi) is “characterized by high intake of fruits, vegetables, cereals, fish, nuts and olive oil” and is associated with a decrease in dementia, stroke, and other health problems. Omega-3, often found in fish, plays a large role in this diet as it reduces white matter damage and grey matter atrophy in the brain. Polyphenols, which are found in vegetables and fruits (especially berries), also reduce inflammation in the brain, combat oxidative stress, and enhance neuroprotection. Oxidative stress is caused by free radicals in the body, a byproduct of metabolism, and interfere with the function of essential proteins, lipids, and nucleic acids. Neuroprotection is an important process in the brain that helps regenerate neurons. Due to the effect of polyphenols on combating these negative processes, including high amounts of berries in one’s diet has been shown to slow cognitive aging by 2.5 years.
Ted-Ed and Mia Nacamulli explain why you are what you eat.