In recent years, numerous studies have shown that changes in the brains of Alzheimer’s patients may occur many years before symptoms appear. Therefore, preventive measures against cognitive decline should not wait until old age. Experts recommend initiating preventive strategies from the age of 40 to minimize the risk.
Alzheimer’s disease is a neurodegenerative disorder that progresses slowly over time, and it is the most common form of dementia. In the United States, around 6.7 million individuals aged 65 and older have Alzheimer’s disease, and over 70 percent of them are 75 years and older.
Currently, over 55 million people worldwide suffer from dementia, with nearly 10 million new cases each year. Alzheimer’s disease accounts for approximately 60 to 70 percent of these cases. Dementia ranks as the seventh leading global cause of death and is one of the primary causes of disability and dependency among the elderly.
Alzheimer’s disease begins with the accumulation of β-amyloid protein in the brain, gradually forming “senile plaques” that lead to the destruction of nerve cells and brain atrophy.
Takashi Sakurai, director of the National Center for Geriatrics and Gerontology in Japan and a dementia expert, explained to the Japanese media, that in the early stages of Alzheimer’s disease, patients experience significant atrophy in the hippocampus. As the condition progresses, the entire brain undergoes shrinkage. Due to the damage to the nerve cells controlling memory in the hippocampus, the ability to retain memories is impaired.
Lifestyle-Related Conditions Increase the Risk of Alzheimer’s Disease
Vascular diseases are highly common in the elderly, and those diagnosed with Alzheimer’s often exhibit signs of such conditions. Mr. Sakurai explained that poor blood circulation in the brain (cerebral ischemia) can lead to increased production of β-amyloid protein. Taking measures to prevent vascular aging and enhance blood circulation can contribute to averting cerebrovascular diseases.Atherosclerosis contributes to accelerated vascular aging, and it is widely acknowledged that factors such as high blood pressure and high blood sugar play a role in its development. In fact, many dementia patients also suffer from hypertension and Type 2 diabetes.
In 2022, Scientific Reports published a large-scale observational cohort study involving 156,654 U.S. residents aged between 40 and 80. The study found that participants with dementia had a prevalence of 81.6 percent for hypertension, compared to 31.9 percent among those without dementia. Additionally, the prevalence of Type 2 diabetes was 45.9 percent for participants with dementia and 11.4 percent for those without.
Moreover, in patients with both Type 2 diabetes and dementia, more than 90 percent had hypertension.
The authors of the paper noted that the study revealed a particularly strong association between hypertension and dementia, followed by age and Type 2 diabetes. Gender, however, showed no significant correlation with dementia.
Dementia Induced by Anticholinergic Medication
Some commonly prescribed anticholinergic medications may elevate the risk of developing dementia. An article supervised by Mr. Sakurai, published in the Japanese medical magazine Pharma Style in 2022, advises pharmacists to be attentive to drug-induced dementia, as cases have been reported, particularly with benzodiazepines, antihistamines, and other anticholinergic medications. The accumulated use of benzodiazepines and antipsychotic drugs may contribute to memory impairment. Additionally, second-generation H2 blockers, upon reaching the brain, could impact cognitive function. Given that many elderly patients are on anticholinergic medications, exercising extra caution is recommended.Common anticholinergic medications include antidepressants, antihistamines, antivertigo or antiemetic drugs, antiparkinson agents, antipsychotics, skeletal muscle relaxants, bladder antimuscarinics, gastrointestinal antispasmodics, antiepileptic drugs, antiarrhythmic drugs, and antimuscarinic bronchodilators.
A study published in Scientific Reports in 2019 indicated that over a 10-year period, individuals in the group consuming the highest amount of strong anticholinergic agents had a 63 percent increased risk of developing Alzheimer’s disease compared to those in the group with the lowest consumption.
Initiating Cognitive Decline Prevention Before Aging Sets In
Mr. Sakurai mentioned that in recent years, scientists have found that individuals with Alzheimer’s disease have already built up a significant amount of β-amyloid protein at the disease’s onset. The progression from β-amyloid protein accumulation to the development of mild cognitive impairment and dementia spans a lengthy period of 20 to 30 years. This suggests, he explains, that if dementia manifests at the age of 70 to 80, β-amyloid protein has started accumulating in one’s 40s or 50s. Therefore, to lower the risk of dementia, it is advisable to implement preventive measures starting from the age of 40 or 50.A study published in the journal Neurology in 2021 offered detailed insights, revealing that the transition from β-amyloid protein negativity to positivity takes 6.4 years, and progressing to mild cognitive impairment requires an additional 13.9 years.
A report from The Lancet Commission indicated that modifying various risk factors could potentially prevent or delay around 40 percent of all cases of dementia. A few examples of these risk factors include:
1. Aim to maintain systolic blood pressure at 130 mm Hg or below from around the age of 40.
2. Prevent head injuries. A study published in The Lancet Psychiatry, tracking nearly 2.8 million individuals for an average of about 10 years, revealed that those with a history of traumatic brain injury face a 24 percent higher risk of developing all-cause dementia and a 16 percent higher risk of developing Alzheimer’s disease compared to those without such injuries. The highest risk of dementia occurs within six months after the traumatic brain injury, and the risk increases with the frequency of brain injuries.
3. Limit alcohol consumption. Excessive drinking, defined as consuming more than 21 units of alcohol per week (1 unit of alcohol = 10ml or 8g pure alcohol), is associated with an increased risk of developing dementia. A UK study, following 9,087 participants aged 35 to 55 for approximately 23 years, revealed that consuming over 21 units of alcohol per week was linked to a 17 percent higher risk of dementia compared to those who consumed less than 14 units per week. Another follow-up study spanning 30 years revealed an association between higher alcohol intake and increased odds of hippocampal atrophy.
4. Sustain physical activity in midlife or later life. A 44-year Swedish study tracking 191 women and assessing their cardiovascular fitness through exercise tests found that individuals with higher fitness levels had an 88 percent lower risk of developing all-cause dementia compared to those with moderate fitness levels, whereas those with lower fitness levels had a 41 percent higher risk. Additionally, those with higher fitness levels delayed the age of dementia onset by 9.5 years and the time to dementia onset by 5 years compared to those with moderate fitness levels.
Delaying Dementia through Social Interaction and Enjoyable Activities
Hideki Wada, a prominent Japanese psychiatric expert and psychology professor at the International University of Health and Welfare, believes that there is a widespread misconception that the lives of individuals with dementia are miserable.Mr. Wada, in his article, highlighted that many dementia patients have personal goals, such as memorizing their favorite poem every day. These individuals do not view life pessimistically but rather continue to explore ways to enjoy their remaining time.
As individuals approach the ages of 70 or 80, signs of Alzheimer’s disease often become apparent, and those who seldom engage their brains seem to be more susceptible to dementia. According to Mr. Wada, the most effective way to stimulate the brain is through social interaction. Conversation is a highly intellectual activity that requires understanding spoken words and generating immediate responses, thereby compelling the brain to function.
Mr. Wada also recommends incorporating enjoyable activities into daily life alongside mental exercises. The more one engages in fun activities, the greater the positive stimulation the brain receives. Actively engaging in preferred activities may effectively prevent or delay the onset of dementia.
