Alzheimer’s disease has been on the minds of many over the past few weeks. From special events commemorating November as National Alzheimer’s Awareness month to Bill Gates’ recent investment in the Dementia Discovery Fund to find a cure for Alzheimer’s, the importance of brain health has increasingly been in the national spotlight.
The timing of this intensified focus provides an opportunity for each of us to reflect on the importance of our own brain health before the new year begins—and to consider the benefits of kicking off 2018 with a goal to boost brain health and minimize our risk of Alzheimer’s. In service of that important goal, for each week in January, I will share a different science-backed strategy that has been shown to reduce the risk of Alzheimer’s. This Brain Boosting Plan will also include practical, engaging tips to put the strategies into action in your daily life.
But first, let’s correct a few myths about Alzheimer’s that often unwittingly prevent us from engaging in behaviors that build better brain health and lower our risk of Alzheimer’s:
Fact: Although certain genetic factors increase the risk of developing the most common form of Alzheimer’s, there is no gene that causes it.
Approximately 96 percent of all cases of Alzheimer’s are "late onset," meaning that a person starts to show symptoms of the disease after the age of 65. It is important to note that about 60 percent of people with late-onset Alzheimer’s do not have a genetic risk factor for the disease, and many people with a genetic risk factor do not develop Alzheimer’s. Conversely, early-onset Alzheimer’s (in which symptoms begin prior to age 65) is strongly hereditary, though makes up a minority of all cases (about 4 percent).
The hereditary risk for late-onset Alzheimer’s is related to a gene on chromosome 19 called Apolipoprotein E4 (or APOE e4), which impacts the transport of cholesterol in the body and the clearing of beta-amyloid protein in the brain. (Beta-amyloid occurs naturally in the brain of all individuals but has also been linked to Alzheimer’s.) Inheriting one copy of the APOE e4 gene results in 2 to 4 times greater likelihood of developing Alzheimer’s, while inheriting two copies (one from each parent) results in a 9- to 12-fold increase in risk. However, about 50 percent of individuals with one copy of APOE e4 do not go on to develop Alzheimer’s.
Given that there are also multiple non-genetic risk factors for late-onset Alzheimer’s—including age, sex (females are twice as likely to develop Alzheimer’s), vascular health, and several lifestyle factors—many researchers have likened Alzheimer’s to other diseases that have multiple causes, and are thus unlikely to have a single cure (such as heart disease). Paradoxically, however, it is the multifaceted nature of Alzheimer’s risk factors that create opportunities to change the trajectory of lifestyle-related behaviors. This realization is much more empowering than believing the myth that Alzheimer’s is caused solely by genetic factors that are out of our control.
Fact: You can significantly lower your risk of the most common form of Alzheimer’s by engaging in certain behaviors.
There is no need to buy supplements, brain games, or other specialty products to reduce your risk of Alzheimer’s. Rather, research has shown that multiple lifestyle factors are powerful in reducing risk, including cardiovascular exercise, a brain-healthy diet, minimizing vascular risk factors (such as diabetes, high blood pressure, and cholesterol problems), maintaining a healthy weight, engagement in stimulating mental activities that promote new neuronal connections, stress management, adequate sleep, and social engagement.
Although implementing these lifestyle changes seems straightforward, research has highlighted specific strategies to use (and not use). In addition, some lifestyle strategies are more powerful than others. (I look forward to sharing details about the most effective strategies in the Brain Boosting Plan.)
Fact: Many people have had the cellular abnormalities associated with Alzheimer’s but not shown symptoms of the disease.
In their historic, long-running study of nuns, Dr. David Snowdon and colleagues found that greater numbers of abnormal cells in brain tissue at autopsy (e.g. beta-amyloid plaques and neurofibrillary tangles) were associated with greater memory impairment. However, they also noticed that about 58 percent of nuns with mild cellular abnormalities, 32 percent of nuns with moderate abnormalities, and even 8 percent of nuns with severe cellular abnormalities never exhibited Alzheimer’s symptoms. Similarly, recent research has shown that some ‘Super Agers’ (individuals between the ages 60 to 85 with memory skills similar to much younger adults) had Alzheimer’s-related cellular changes but never expressed symptoms of the disease. How are these findings possible?
The theory of "cognitive reserve" is a leading explanation. This theory was developed in the late 1980s to describe a brain’s ability to “work around” or compensate for cellular abnormalities by relying on other neural connections that were previously built through engagement in stimulating mental activities. The process of developing cognitive reserve is akin to building extra highways in the brain, with the goal that if one highway is impacted by cellular abnormalities, the brain’s traffic (neural signals) can continue to flow.
By debunking myths about Alzheimer’s, we become empowered to proactively improve our brain health and add optimism to our dialogue about Alzheimer’s. Let’s lower our risk together.