By Dr. Mary O’Brien, MD
Alzheimer’s disease is one of the most dreaded health conditions of our time. There is no cure, and current treatments don’t slow down the disease; they can only alleviate symptoms. As well as avoiding Alzheimer’s disease and age-related cognitive decline, many people want to stay as sharp as possible as they age, and, if possible, delay age-related cognitive decline. Yet are there truly preventive strategies to stave off of Alzheimer’s disease or cognitive problems associated with aging?
While there’s no definitive evidence about what can prevent or reduce the risk of Alzheimer’s disease or dementia, scientific studies have offered clues about strategies that might slow down or prevent cognitive decline. The good news is that research on the prevention and treatment of Alzheimer’s disease—which currently affect about 5.3 million Americans—is now a high priority.
In late 2015, the U.S. Congress approved the largest increase to date in federal spending for Alzheimer’s disease research and care-giver support in the 2016 federal budget—a $350 million increase over 2015. The increase in federal spending came in response to reports and studies documenting the needs and opportunities that lie ahead for Alzheimer’s disease research. By 2050, Medicare spending on Alzheimer’s disease is expected to quadruple to $589 billion annually, but one treatment delaying the onset of the disease could save Medicare $345 billion in the first 10 years of its use, according to a report from the Alzheimer’s Association.
Over the past 30 years, many advances have been made in understanding Alzheimer’s disease and dementia. We now understand the biology of Alzheimer’s disease as never before. The brains of people with Alzheimer’s disease are filled with amyloid plaques—composed of deposits of a toxic protein fragment called beta-amyloid. The brains of Alzheimer’s disease patients also have an abundance of neurofibrillary tangles or abnormal collections of twisted protein threads found inside nerve cells, composed chiefly of a protein called tau. In Alzheimer’s disease, the amyloid plaques and neurofibrillary tangles damage the brain’s neurons, interfering with their ability to function and communicate with one another. As a result, Alzheimer’s disease causes the brain to shrink and atrophy.
Scientists are now emphasizing research on the development of Alzheimer’s disease and on the symptoms and signs of early Alzheimer’s disease, which is termed mild cognitive impairment. The hope is that learning more about mild cognitive impairment can help identify patients at increased risk for the disease and for disease progression.
The symptoms of mild Alzheimer’s disease include:
- Memory loss and confusion about once familiar things or places.
- Difficulty accomplishing daily tasks, especially handling money and paying bills.
- Poor judgment that leads to bad decisions.
- Mood and personality changes, such as increased anxiety and aggression.
The symptoms of moderate Alzheimer’s are more serious, and include:
- Increasing memory loss and confusion, and shortened attention span.
- Irritability and Inappropriate outbursts of anger.
- Difficulty with language (in reading and writing) and difficulty in working with numbers.
- Trouble recognizing friends and family members.
- Difficulty organizing, planning, and thinking logically.
- Restlessness, agitation, anxiety, tearfulness, and wandering.
- Repetitive movements and statements and sometimes muscle twitches.
- Paranoia, delusions, and hallucinations.
- Loss of control over impulses.
Age and genetics are the strongest risk factors for dementia and Alzheimer’s disease. However, other risk factors have been linked to Alzheimer’s disease. Research has shown that people with heart disease, stroke, and high blood pressure may be more likely to develop Alzheimer’s disease and to have more severe diseases. Studies also show that patients with metabolic syndrome, Type 2 diabetes, and sleep apnea are at increased risk for mild cognitive impairment and Alzheimer’s disease. Whether or not successful treatment of hypertension, heart disease, diabetes and sleep apnea can affect cognitive decline is open to question, but is under study. One large trial funded by the National Institutes of Health (NIH) has compared intensive glucose-lowering treatment with standard treatment for Type 2 diabetes, but there were no significant differences between the two groups.
Hormones such as estrogen and progesterone also have effects on the brain. Yet studies on whether menopausal hormone therapy is protective against cognitive decline or Alzheimer’s disease have been conflicting. Research is continuing on estrogen and progesterone as well as other hormonal therapies that could be preventive, including testosterone, growth hormone-releasing hormone and DHEA (dehydroepiandrosterone).
Many studies have also investigated whether vitamins and dietary supplements can protect against cognitive decline and Alzheimer’s disease. Epidemiological and laboratory studies have suggested that antioxidants from food and supplements can lower the risk of Alzheimer’s disease by preventing oxidative damage from free radicals. Vitamin E, vitamin C, B vitamins, and coenzyme Q10 have been tested as treatments to slow down or prevent Alzheimer’s disease, but none have proved effective. Researchers are also investigating the effect of resveratrol—a compound found in red grapes and red wine.
Research has also revealed that healthy habits can have an important influence on the risk for Alzheimer’s disease and cognitive decline. Studies show that exercise can stimulate the brain and help to make new neuronal connections within the brain that are vital to healthy cognition. Daily aerobic exercise, for instance, can enhance recall and executive function. Research has also found that a diet rich in vegetables is associated with a reduced risk for cognitive decline, and a Mediterranean diet significantly lowers the risk for mild cognitive impairment and Alzheimer’s disease.
Keeping your mind active throughout life may also reduce the risk of Alzheimer’s disease. Large observational and epidemiological studies have associated cognitive health with the maintenance of social relationships at work, volunteering or by living with someone. Mentally stimulating activities such as reading books and magazines, playing game and going to lectures may also keep the mind sharp. Recent large studies have found that people who spend a lot of time in intellectually stimulating activities are significantly less likely to be diagnosed with Alzheimer’s disease.
For healthy people, formal cognitive training sessions also seems to have benefits for the brain. Studies on memory, reasoning, and processing speed training—all aimed at improving mental skills—show that this training can improve cognitive skills for up to 10 years. Other studies are now investigating whether the combination of exercise and cognitive training can delay or prevent age-related cognitive problems.
- National Institute on Aging. Alzheimer’s Disease: Unraveling the mystery. nia.nih.gov/
- National Institute on Aging. Alzheimer’s Disease Progress Report: Intensifying the Research Effort. nia.nih.gov
- Preventing Alzheimer’s Disease: What Do We Know? nia.nih.gov
- Alzheimer’s Association. Historic Alzheimer’s funding increase signed into law, answering Alzheimer’s Association call for action. alz.org