The brain is perhaps the most vital organ in the human body. The brain controls and coordinates actions and reactions, permits sensations and thinking, and warrants feelings and memories- all the things that essentially make us human. Even though the brain is a super highly functional and important organ, there are many cognitive impairments it may face. One common problem that limits brain capabilities is known as dementia. Dementia is an illness, usually of chronic and accelerating nature. It is provoked by a variety of brain ailments that affect memory, thinking, behavior, attention span, executive function, and the capacity to perform everyday activities. Executive functions (EFs) consist of higher-level cognitive functions that include planning and taking initiative. Dementia is caused by the demolition of brain cells. Damage to the brain cells inhibits the ability of brain cells to communicate with one another and perform various tasks. Along with a decline in cognition, dementia also usually leads to behavioral problems.
Alzheimer’s disease is the most common form of dementia, accounting for sixty to eighty percent of dementia patients. Dementia is known for being the sixth leading cause of mortality in the United States. Patients everywhere suffer from dementia. The disease not only creates problems with the sufferer but also takes a toll on caretakers of dementia patients. As dementia progresses, individuals necessitate more assistance with activities of daily living (ADLs), such as balancing, showering, writing, and using the bathroom. The biggest issue with dementia is that there is no cure and no treatment is able to halt its progressive nature.
Non-pharmacological interventions, like physical activity, are the most favorable options for slowing down dementia-related decline. Non-pharmacological interventions are often overlooked by physicians because of little knowledge on the area, which leads to antipsychotic drugs being prescribed before exercise and other non-pharmacological interventions. Prescribing medications to dementia patients is just a temporary fix, after years on medications, disease and death result. Non-pharmacological treatments have far fewer side effects and are known for being the safer option. Physical activity is shown to have similar effects to antidepressants in reducing depressive symptoms among people with dementia. Physical activity refers to any bodily movement produced by skeletal muscles that entail energy expenditure. Exercise is shown to have a positive effect on the progressive onset of dementia, not curing or treating it, but slowing down the escalating nature.
Every sixty-five seconds someone in the United States develops dementia. Worldwide, one new case of dementia is discovered every seven seconds. Currently, forty-seven million people are living with the illness and by 2030 this number is supposed to increase to seventy-five million. This number is intended to triple by 2050. Dementia is more deadly than breast cancer and prostate cancer combined. One in three seniors die due to dementia. More than 5.4 million people with dementia may not know they have it. Dementia has no cure and nothing to stop its progressive nature. More than eighty percent of dementia patients show signs of behavioral and psychological symptoms that include aggression, agitation, apathy, anxiety, and depression. Half of adults eighty-five and older have Alzheimer’s Disease. More women are diagnosed with Alzheimer’s than men.
Dementia is the leading cause of disability in older people. The disease is also the most common reason that elders move to nursing homes. There are more than 16.1 million unpaid caregivers for people with dementia. There is an increased risk of depression, emotional stress, and financial problems in those caring for a loved one with dementia. The total cost of health care and long-term care for dementia is two-hundred seventy-seven billion dollars. The cost of dementia by 2030 is presumed to reach two trillion dollars. According to statistics from 2016, dementia cost an individual approximately three-thousand six-hundred dollars a month. An early and acute diagnosis could save up to 7.9 trillion dollars in medical and care costs.
Aerobic exercise is defined as a rapid exercise that stimulates the movement of oxygen through the bloodstream, boosts heart rate, and strengthens the heart and lungs. Aerobic exercise is widely known to improve cardiovascular health. It is executed with or in the presence of oxygen. Walking, cycling, swimming, and running are all examples of aerobic exercises. Aerobic exercise is a low-risk intervention, being that the patient is safe to exercise. Aerobic interventions are also feasible to provide in community settings.
Aerobic exercises are known for reducing the loss of grey matter within the brain. Grey matter loss is a normal part of aging among both physically active and sedentary individuals. Grey matter contains most of the brains neuronal cell bodies, which process information in the brain. Aerobic exercise is also acknowledged for increasing hippocampal volumes and spatial memory. Spatial memory is the part of the memory responsible for spatial orientation. The hippocampus is an area of the brain in charge of emotion, memory, and the autonomic nervous system, therefore, the hippocampal volume is crucial to dementia patients. The hippocampus tends to deteriorate faster in dementia patients. Reduced loss of hippocampal brain tissues is associated with the level of physical fitness in individuals.
Gregory et al. discovered that higher aerobic fitness levels are associated with greater right and left hippocampal volumes. Deficient memory ability and small hippocampal volumes tend to occur simultaneously in patients with cognitive impairments. According to Graff-Rafford et al. and Liu-Ambrose et al., one year of aerobic exercise results in remarkably larger hippocampal volume and better spatial memory. Liu-Ambrose et al. also discovered that aerobic exercise training increased hippocampal volume by two percent.
Aerobic exercise increases heart rate and the need for oxygen, which leads to the brain being fueled more efficiently. Aerobic exercise is the driving force for advances in cognition, mood, physical tasks, and behavioral complications. Exercise, specifically aerobic, decreases cognitive impairments and the risk of dementia. Aerobic exercise interventions also showed significant improvements in attention spans, processing speeds, executive function, and memory in exercise-trained individuals. Walking is one of the most highly recommended exercises for patients with dementia.
Larson et al. and Lee et al. determined that walking is advised because it is easy and associated with a low fall risk. A half an hour of walking per week is effective for improving cognitive function in patients with severe dementia. According to Larson et al., the effects of progressive aerobic training were no longer significant after the six-month re-evaluation. This shows that in order to keep the lasting effects of aerobic interventions one must continue the exercise program. With aerobic exercise improving cerebral blood flow and oxygen delivery to the brain there is no doubt it delays the onset of dementia in older adults. Liu-Ambrose et al. found that aerobic exercise interventions lead to significantly improved executive functions (EFs) in dementia patients. Gillis et al. found that aerobic exercise may be the most effective type of exercise program when the goal is to preserve cognitive health in older adults at risk for dementia.
Anaerobic exercise, also known as resistance training, is defined as short duration, high-intensity exercise that can last anywhere from seconds up to around two minutes. Anaerobic exercise causes lactate to form but is the ideal exercise for non-endurance sports to promote speed, strength, and power. Anaerobic exercises are most commonly used by bodybuilders to build muscle mass. Anaerobic exercise improves overall cardio and respiratory fitness by increasing the maximum amount of oxygen used during exercise. According to Liu-Ambrose et al., resistance training is best known for improving muscle mass and strength.
Normal aging results in a decline of N-Acetyl Aspartate (NAA) concentrations in the frontal cortex. Higher NAA concentrations are related to better working memory performance and contributors to energy production. According to Gregory et al., NAA concentrations are higher in more fit elderly individuals who engage in strength training. Elderly people facing the first signs of memory loss may be able to protect themselves from full-blown dementia by participating in resistance training. Resistance training reduces cardio-metabolic risk factors associated with cognitive impairment and promotes neurotropic factors that are beneficial for the brain.
Anaerobic exercise is also associated with increased blood levels of insulin-like growth factor-1. According to an article by Radcliffe, seniors who worked out with weights experienced greater improvements in mental functioning. Liu-Ambrose et al. and Nagamatsu et al. found that weight lifting improves selective attention, conflict resolution, associative memory, and regional patterns of functional brain plasticity. Strength training decreases levels of homocysteine, a neurotoxin, which in turn leads to better cognitive function. Lee et al. discovered that the muscle strength of the arms and legs is associated with decreased risk of dementia. Strength training leads to an improvement in cognition, independent of frequency and intensity.
Multi-component exercise is comprised of both aerobic and anaerobic interventions. Although the focus here will be on anaerobic and aerobic interventions, multi-component exercise is actually just two or more different interventions combined. There is a lot of controversy on whether or not multi-component interventions are more beneficial than single component exercise interventions. As mentioned above, aerobic and anaerobic interventions are both beneficial but in different manners. According to Gillis et al. and Sandoiu et al., combined interventions are not effective and show no positive effect on the brain or the ability to slow the onset of dementing illnesses. Bossers et al., Henskens et al., Lee et al., Liu-Ambrose et al., and Nagamatsu et al. on the other hand, found that individuals who participated in a combined aerobic and strength program experienced greater cognitive and motor improvements than those in a single exercise intervention.
Combined exercise interventions have a positive effect on brain-derived neurotrophic factors and levels of insulin-like growth factor-1. Brain-derived neurotrophic factors and insulin-like growth factor-1 mediate cell growth, proliferation, survival, and differentiation. Combining aerobic and strength training enhances cognitive performance and functional plasticity in seniors. Activities of daily living (ADLs) improved significantly with a 1-year multi-component aerobic, strength, and balance intervention. The Gillis et al. study says that the goal of the exercise intervention depends on if a single component or multi-component intervention would be best. Research seems to be limited with both the benefits of anaerobic training and multi-component training with dementia.
Another intervention that has been researched with dementing illnesses is High-Intensity Functional Exercise (HIFE). Bostrom et al., Lindelof et al., Olsen et al., and Toots et al. studied the effects that high-intensity functional exercise has on dementia. HIFE is task-specific and performed at very high intensities, almost maximum capacity. This intervention is especially beneficial for dementia patients that experience depression and balance issues, as most individuals do. HIFE usually consists of thirty-nine exercises performed in functional, mobile, and weight-bearing positions. Most programs are closely monitored while participants are performing at their highest intensity while ensuring safety. HIFE is able to account for and individualize exercises based on the specific type of dementia, unlike most other interventions.
According to Toots et al., most individuals that suffer from dementia also suffer from balance impairments. High-Intensity Function Exercise programs are able to increase balance, which in turn, leads to a positive effect on individuals performing ADLs. The Olsen et al. study claims that HIFE is a positive counteraction to physical inactivity, especially within nursing homes. HIFE provides lower limb strength, leading to better balance ability. High-Intensity Functional Exercise is commended for maximizing independence, slowing the progression of dementia, promoting sleep, and enhancing the overall quality of life and well-being. HIFE is a beneficial strategy when it comes to improving gait abnormalities and speed as well.
The downfall of HIFE is that many individuals find it difficult to participate because of the complexity of dementia symptoms. Most patients with dementia have a short leash when it comes to patience. Frustration when performing exercises, especially specific exercises at high intensity are sometimes too much for a dementia patient to handle. However, according to Lindeolf, with a positive HIFE experience, more individuals are willing and happy to participate. Depression is also a common problem in patients with dementia. Antidepressant drugs have little to no effect on dementing illnesses. Physical activity, specifically, HIFE show similar effects to antidepressant medications in alleviating depressive symptoms. HIFE or moderate to high-intensity interventions are more effective than low-intensity interventions. HIFE is significant in reducing depressive symptoms in dementia patients over other interventions.
As opposed to High-Intensity Functional Exercise, aquatic exercise is very feasible. Aquatic exercise is a low-impact, non-weight bearing intervention that removes the pressure from bones, joints and muscles. Because of the non-weight bearing property of water, intense exercises can be carried out with minimal risk of injury. Another unique property of water is buoyancy, which decreases the compressive forces on joints. Water is also beneficial in offering natural resistance, which helps to strengthen muscles. Being immersed in water also helps to lower axial loading on the body. The properties of water allow for movements that are difficult or even impossible on land. Ayan et al., Neville et al., and Schilling et al. observed the effects that aquatic exercise interventions have on dementia.
