According to a new study, the population with Alzheimer’s Disease in the US will triple by 2050: from 4.7 millions in 2010 to 13.8 millions. This emphasizes the urgent need for more research to find preventive measures, and for more enlightened public health initiatives and individual lifestyles designed to decrease dementia risks and delay onset of symptoms.
Between 1993 and 2011, researchers followed more than 10,000 individuals 65 and older. Participants were interviewed and assessed for dementia every three years. Age, race and level of education of the participants as well as US death rates, education and population estimates from the US Census Bureau were used in the analysis.
Researchers found that in 2050 the number of people diagnosed with Alzheimer’s would likely be 13.8 millions, with 7 millions over the age of 85. This is 3 times the numbers of 2010: 4.7 millions people diagnosed, with 1.8 million over the age of 85. This increase can be explained by the aging Baby Boomer generation. Indeed, the risk of Alzheimer’s disease is highest in those over age 85. In 2050, the youngest baby boomers will be 86.
As one of the authors of the study points out, these numbers emphasize the urgent need for more research to find treatments and preventive strategies. Additionally, we need enlightened public health initiatives and individual lifestyle decisions designed to prolong cognitive vitality, delaying the onset of Alzheimer’s related symptoms.
The best study so far that looked at what may help prevent Alzheimer’s and/ or delay cognitive decline is a 2010 meta-analysis conducted by the NIH. It analyzed the results of 25 review studies and 250 single studies to understand which factors were associated with decreased risks of Alzheimer’s disease and cognitive decline. Only high-quality studies were included in the analysis, which makes its results quite reliable. The analysis looked at several factors and interventions at the same time (the Mediterranean diet, omega-3s, diabetes, drugs, physical exercise, cognitive engagement, etc.), which allowed to compare and evaluate the effects of each.
The NIH analysis identified six factors associated with both Alzheimer’s disease and cognitive decline:
- Four factors were associated with increased risks: having diabetes, having the APOE e4 gene, smoking and suffering from depression.
- Two factors were associated with decreased risks: being physically active and being cognitively active.
Of note, the authors of the analysis pointed out that other factors may also be associated with decreased risks, but could not be strongly identified because of the limited available evidence.
In sum, there may be ways to change the numbers and decrease our risks of developing Alzheimer’s disease and experiencing cognitive decline. Most of all, we need to exercise more, both our body and brain. This brings a wealth of benefits, including increasing our so-called brain reserve — that is the number of connections and neurons we have available to make our brain more resilient to damage.
The best regimen in terms of physical activity is to practice aerobic exercise at least 3 times a week for at least 30 minutes. A recent study highlighted that walking at least 5 or 6 miles per week can positively impact brain volume in healthy people (see Erikson et al., 2010) and extend such finding to individuals suffering from cognitive impairment. Aerobic exercise seems to better vascular health by increasing cerebral blood flow. It also helps create and strengthen connections between neurons (hence the increased brain volume or the reduced atrophy), by triggering the increased release of growth factors such as brain-derived neurotrophic factor (BDNF).
The best regimen in terms of mental activity is to stimulate the brain through varied and challenging activities. These activities have to be varied because we need to stimulate all brain functions: memory, language but also spatial skills, attention, social skills, etc. They also have to be challenging because it is only through attention, challenge and learning that connections in the brain can be created and strengthened.
Researchers are actively looking for the cause of Alzheimer’s disease in the hope to find curative and preventive treatments targeting the underlying pathology. As individuals, our best bet so far to decrease risks of dementia and cognitive decline is to include good amounts of physical exercise and mental challenge in our lifestyle, and to reduce those identified risk factors we have influence over (diabetes, smoking, depression).
- Hebert, L. et al. (2013). Alzheimer disease in the United States (2010–2050) estimated using the 2010 census. Neurology, Published online before print February 6, 2013, doi: 10.1212/WNL.0b013e31828726f5
- Raji et al. (2012) Walking Slows Progression of Alzheimer’s. Annual meeting of the Radiological Society of North America (RSNA).
- Williams, J. et al. (2010). Preventing Alzheimer’s Disease and Cognitive Decline. NIH Evidence Report. Evidence Reports/Technology Assessments, No. 193.
— This article was written by Pascale Michelon, PhD. Dr. Michelon was a Research Scientist at Washington University in Saint Louis, where she is now an Adjunct Faculty. She teaches memory workshops in the St Louis area, and contributes to SharpBrains.com as the Research Manager for The SharpBrains Guide to Brain Fitness.