As a result of the advances in healthcare due to medical science discoveries around the world, people are living longer. This has also brought a heightened awareness of the increase of health conditions impacting aging populations, perhaps most notably dementia.
While there are various types of dementia, Alzheimer’s Disease (AD) is by far the most common. This currently irreversible neurodegenerative disease, affecting many daily life activities and functions, is responsible for up to 70-90% of dementia cases. As life expectancy continues to increase, the frequency of AD is also expected to increase.
However, aging does not have to mean that AD is inevitable. This complex disorder has several risk factors, some of which can be altered to reduce the risk of developing AD! Some scientists say that as many as 1/3 of cases have risk factors that can be changed to reduce risk!
Researchers reviewed and compiled the results from 120 scientific studies and clinical reports to provide an “overview of current epidemiological advances related to Alzheimer’s Disease’s modifiable risk factors, highlighting the concept of early prevention.”
First, we’ll look at a few AD risk factors cited in their overview that may be altered with healthy lifestyle adaptations:
- TYPE 2 DIABETES: A higher risk of AD has been found among diabetics in numerous studies. Those whose diabetes was not well controlled have an even higher rate of AD. Interestingly, there is some evidence that usage of anti-diabetic drugs could “slow down the development of cognitive decline and reduce the risk of dementia.”
- BLOOD PRESSURE VARIABILITY: Individuals with large blood pressure variability exhibited a larger than 2-fold risk of AD.”
- MIDLIFE OBESITY: Evidence consistently pointed to a higher risk for AD among those who had a high body mass index (BMI) in middle age. Interestingly, they also found an increase in risk among those who lost a great deal of weight later in life. They suggest that adults should achieve and maintain a healthy weight in their younger years rather than delay weight loss to later adulthood.
- CARDIOVASCULAR DISEASE: Higher risk of AD was noted among those who had experienced atrial fibrillation, stroke, atherosclerosis, and arteriolosclerosis. They also note that medications and procedures utilized to limit the extent of brain injury after a stroke could “help delay or prevent the progression of AD.”
- SLEEP DISTURBANCES: Subjects with severe obstructive sleep apnea had a 66% increased risk for developing AD. Additionally, subjects who routinely slept less than 6 hours or more than 9 hours had a higher rate of AD suggesting that 6-8 hours a night is optimal in providing ample rest and protection to the brain.
- SMOKING: Smoking increased the risk of AD. It is theorized that smoking-related cerebral oxidative stress could alter the brain pathology contributing to this increase. Additionally, those who never smoked had an 18% reduction of AD compared to those who continued to smoke. Researchers suggest that the earlier one stops smoking, the greater the reduction in risk they would have.
Knowing there is an increased risk for AD associated with these alterable factors, there is even more motivation for individuals to take the steps to address them.
There are also 4 key factors which have emerged that appear to have a “protective” effect:
- HIGH EDUCATION & BILINGUALISM: Those who indulge in cognitive activity were likely to have up to a 46% reduction in AD risk. Lifelong bilinguals who did develop AD, experienced their first symptoms much later in life than their peers. Researchers suggest that the building of cognitive reserve and brain volume associated with education, bilingualism and active cognitive activities serve to protect healthy cognitive functioning.
- SOCIAL ENGAGEMENT: Having frequent social contacts with friends contributed to a modest decrease in AD risk. Specifically, community activities seemed to be of greater benefit. Those who were widowed or single, in general, tended to have less communication with others and also showed a higher rate of AD. Couples and those who engage in regular social activities experienced the protective effects on cognition.
- MEDITERRANEAN, DASH OR MIND DIETS (DASH = Dietary Approach to Stop Hypertension, MIND = Mediterranean-DASH diet Intervention for Neurodegeneration Delay): All 3 of these diets were associated with a lower risk of AD. Researchers speculate that the emphasis on the intake of antioxidant, anti-inflammatory, and anti-diabetic effects and enough mono-/poly-unsaturated fats helps protect the body tissues and protect cognition.
- PHYSICAL ACTIVITY: Increased participation of daily physical activity was related to a decrease in the risk of Alzheimer’s Disease by as much as half! Additionally, studies show that regular resistance exercise and choreographic intervention can help delay the onset in those who do develop AD.
Is Physical Activity That Important?
In 2020, another group of researchers reviewed almost 200 (181) research studies and reports specifically related to exercise and AD. Their findings are quite remarkable!
As far back as the 1970s, researchers were reporting that middle-aged sports practitioners had better response in cognitive tasks that involved a psychomotor component when compared with sedentary aged-matched subjects.
This type of scenario has been repeated through the years so that it is now generally accepted that exercise is associated with positive cognitive changes, even if the mechanisms are not yet understood.
Additionally, studies have shown that it’s never too late to start. A 2011 study found that just 1 year of moderate-intensity exercise was enough to create noticeable changes by increasing the size of the hippocampus (a portion of the brain with a major role in learning and memory), as well as increasing spatial memory.
Need more evidence? They also found that:
- 6 months of exercise (60 min duration, 3 days/week) is sufficient to increase both the gray and white matter in the anterior cingulate cortex, as measured by magnetic resonance imaging, in older, cognitively healthy subjects.
- Longer aerobic exercise training protocols (3 years’ duration) in sedentary older women have shown improvements in reaction time, motor function, and cognitive processing speed, indicating that exercise is effective in reversing or at least slowing the age-related declines in motor performance and in speed of cognitive processing.
- 6 months of resistance exercise induced improvements in memory, attention, and executive functions. Moreover, those benefits persisted 12 months after the end of the intervention period.
- 16 studies with more than 160,000 participants found a 45% reduction in the risk of developing AD due to the regular practice of physical activity
- Engaging in physical activity and lowering vascular risk may have additive protective effects on delaying the progression of AD.
Alzheimer’s disease is a complex, progressive neurodegenerative disorder that has many contributing factors. While some, such as genetics, cannot be changed, there are a number of factors that can be altered. Science does not fully understand yet how all of the factors work together or against each other, but it is clear that a healthy lifestyle can have a positive effect on a person’s Alzheimer’s Disease risk level.
For those looking to get the most benefit from lifestyle changes, a healthy diet and exercise routine are the best place to start! Not only are they associated with lower AD risk, but they also contribute to improving risk factors for everything from obesity to cardiovascular health and even mental/emotional health!
Talk to your doctor of chiropractic about changes you can begin to make now that will help you stay healthy and active longer. If additional help is needed, your chiropractor can connect you to other health professionals and work with them to provide you the best possible care. Offering a whole-person approach to care, chiropractors are skilled in providing spinal adjustments, therapeutic modalities, stretches, strengthening exercises and healthy eating & sleeping habits – focused on your health goals. Start taking action to fend off the dementia risk factors you can through health adaptions. Your body – and brain – will thank you!
Adrian De la Rosa, Gloria Olaso-Gonzalez, Coralie Arc-Chagnaud, Fernando Millan, Andrea Salvador-Pascual, Consolacion García-Lucerga, Cristina Blasco-Lafarga, Esther Garcia-Dominguez, Aitor Carretero, Angela G. Correas, Jose Viña, Mari Carmen Gomez-Cabrera, Physical exercise in the prevention and treatment of Alzheimer’s disease, Journal of Sport and Health Science, Volume 9, Issue 5, 2020, Pages 394-404, ISSN 2095-2546, https://doi.org/10.1016/j.jshs.2020.01.004.
Alzheimer’s Association “Can Alzheimer’s Disease Be Prevented?” https://www.alz.org/alzheimers-dementia/research_progress/prevention accessed 6/27/22
Radak, Zsolt et al. ‘Exercise Plays a Preventive Role Against Alzheimer’s Disease’. 1 Jan. 2010 : 777 – 783.
Zhang XX, Tian Y, Wang ZT, Ma YH, Tan L, Yu JT. The Epidemiology of Alzheimer’s Disease Modifiable Risk Factors and Prevention. J Prev Alzheimers Dis. 2021;8(3):313-321. doi: 10.14283/jpad.2021.15. PMID: 34101789.