Christine Bryden was stunned in 1995 when doctors diagnosed her with Alzheimer’s. Just a year before her, the 46-year-old biochemist had won Australia’s Public Service Medal for outstanding work in science and technology. Life was for me, she writes on the YoungDementia UK website. But on that fateful afternoon, everything changed and I felt dejected in my prime.
As she looked back, Bryden began to believe that her diagnosis was somehow connected to her lifestyle. He never got enough sleep. He worked all the time. His stress levels were stratospheric. She came home at night with a lot of work, which she plunged into after hurrying to get her daughters up for the night. The next morning, Bryden woke up, she did some more work, then she got her daughters ready for the day.
Looking at his lifestyle
Perhaps the lack of sleep has damaged my brain to some extent. But a high level of stress may have also contributed to my brain damage, she writes. Bryden may not be that far off. Even though doctors have been treating Alzheimer’s for decades, they’re still stumped as to its exact causes. For the most part, scientists believe the disease is triggered by a variety of genetic and lifestyle factors. Each one impacts the brain over time. While people can’t change how old they are or the genes they’re born with, they Candies change the way they live. For starters, they can quit smoking and start eating healthier foods. They can exercise more and lose weight. They can drink less and stimulate their minds more.
A risk factor is anything that increases a person’s risk or chance of developing some type of medical condition. Some risk factors, such as age, are non-modifiable, which means they cannot be prevented. Others, however, may be able to change with certain lifestyle habits. Here, a look at some of the more commonly known risk factors for Alzheimer’s disease and what you may be able to do about them.
Non-modifiable risk factors
While some memory loss is normal as we age, Alzheimer’s is not. Experts say that between the ages of 65 and 70, the prevalence of AD is 1.5%. That means 15 out of 1,000 people will get the disease at that point in their lives. Those odds increase every year. By the time we reach age 75, the prevalence has more than doubled, to 3.5%, or 35 per 1,000. By the time we reach age 80, the prevalence of AD increases to 6.8%. As we approach our 100th birthday, the percentage skyrockets to 44.5%.
Whether we get Alzheimer’s disease could have to do with our genetics. Researchers say that if a parent or sibling has the disease, the risk increases by about 30%. And there is also a greater chance of developing AD if both parents are affected.
Some studies suggest that ethnic minorities, especially African Americans, have higher rates of dementia than Caucasians. Scientists recently identified two new genes in African Americans that may increase risk. One of the genes, ABCA7, works to produce cholesterol and lipids. Some researchers believe that Alzheimer’s may lead to abnormalities in the way our bodies metabolize fat. Other factors, such as high blood pressure and diabetes, may also play a role among older African Americans and Latinos. It is also possible that lower incomes and limited educational opportunities due to systemic discrimination against both groups contribute to disease progression.
Researchers believe that a traumatic brain injury increases the risk of Alzheimer’s and other forms of dementia. One study found that older adults who experienced a moderate head injury (loss of consciousness for more than 30 minutes) were 2.3 times more likely to develop AD than older adults who did not experience a head injury. Older adults who have suffered severe brain injury (loss of consciousness for more than 24 hours) are 4.5 times more likely to develop AD. Of course, not everyone who suffers a head injury develops Alzheimer’s or some other type of dementia. Also, there is no evidence to indicate that a mild brain injury increases your risk.
Modifiable risk factors
When it comes to Alzheimer’s, what’s bad for your heart is bad for your brain. Researchers believe that cardiovascular problems are linked to the progression of Alzheimer’s and other forms of dementia later in life. A study published in 2017 by researchers at Johns Hopkins University tracked nearly 16,000 middle-aged people in four states. Over the 25-year period since 1987, researchers have administered a series of medical, memory and cognition tests. As the study progressed, 1,500 people were diagnosed with dementia, confirming that those with midlife vascular risk factors, such as diabetes or high blood pressure, had a higher chance of developing dementia. What’s more, the researchers confirmed what other studies had only suggested that smoking cigarettes increases the risk of dementia.
Use of alcohol
For years, scientists have investigated whether alcohol use is related to Alzheimer’s. Surprisingly, one study found that drinking up to three glasses of wine a day reduced the risk of Alzheimer’s disease only in people who have the APOE e4 gene. Other studies have also described the beneficial effects of low to moderate wine consumption. As far as researchers can decipher, low-to-moderate drinking actually protects the brain by reducing the viscosity, or thickness, of blood and increasing the amount of good cholesterol, known as HDL, in the body.
That said, two major reviews of multiple research studies found that heavy drinkers and binge drinkers were more likely to develop AD and other forms of dementia than those who drank moderately. Binge drinking, according to the Centers for Disease Control and Prevention, is when men have five or more drinks in about two hours and women have four or more drinks in the same period.
Obesity causes a variety of ills, including diabetes, high blood pressure, heart problems and other cardiovascular problems. It also appears to be a major factor in AD, doubling a person’s risk of developing amyloid plaque, the boogeyman of Alzheimer’s later in life. Past research on how people’s weight affects their risk of dementia has yielded mixed results. Some studies say that if you’re obese, you’re at a high risk of dementia. Other studies, however, have linked below-average weight to increased dementia.
In 2017, however, researchers put to rest nearly all questions regarding obesity and Alzheimer’s. A 38-year study of 1.3 million adults living in the United States and Europe concluded that individuals with a high body mass index (BMI) are more likely to develop Alzheimer’s and other forms of dementia than those who have a normal body weight.
In that same study, scientists found that people with early-onset dementia and a low body mass index develop full-blown dementia more often than those at a healthy weight. The reason, the researchers concluded, is that both obesity and a low body weight during the pre-dementia phase change how the body metabolizes fat. The study suggests that maintaining a healthy weight could prevent the disease or at least stave off its effects.
How lifestyle can make a difference
In 2017, researchers in Britain announced that changing the way you live could create a roadblock in the path of Alzheimer’s disease. And while there aren’t any proven ways to stave off AD permanently, they note that some lifestyle changes could slow its progression.
The study, conducted by the Lancet Commission on Dementia Prevention, Intervention and Care, looked at nine risk factors. He concluded that more than a third of all Alzheimer’s cases are related to these risk factors and that avoiding them at any stage of life can delay or even stop memory loss. The researchers came to their conclusions by reviewing a number of previous studies on Alzheimer’s disease. Their statistical analysis found that 35% of dementia cases could be prevented by fully addressing these and many other lifestyle issues. Researchers have noted that the fight against Alzheimer’s needs to start as soon as children start going to school.
The less time a child spends in school, the higher their risk of developing Alzheimer’s later in life. In fact, the researchers found that children who were out of secondary school had a 7.5 percent increased risk of developing Alzheimer’s. That’s why researchers recommend students stay in school until age 15.
The study also recommends that people, regardless of their age, exercise more, stop smoking, become more socially involved, reduce their weight and manage their depression. Even if dementia is diagnosed later in life, brain changes usually begin to develop years earlier, with risk factors for developing the disease occurring throughout life, not just in old age, said the lead author of the study. study Gill Livingston, Ph.D., professor of elderly psychiatry at University College London. We believe that a broader approach to dementia prevention that reflects these changing risk factors will benefit our aging societies and help prevent the growing number of dementia cases globally.
The study was provocative, because the researchers based their conclusions on a statistical analysis of previous studies rather than patient research. A similar study in the United States was a little more circumspect, concluding that perhaps some lifestyle changes can boost brain health, although the study offered no definitive evidence that they would. Yet scientists are so intrigued by the lifestyle component that the Alzheimers Association in 2017 launched a $20 million clinical trial with 2,500 people to see if lifestyle changes can prevent cognitive decline and dementia.
While lifestyle changes help some people, they may not help others. And why
there are myriad reasons why some people have Alzheimer’s and others don’t. One reason is genetics, especially in early-onset cases. People who suffer from late-onset Alzheimer’s disease (in which symptoms become apparent in a person in their 60s) do so because of a series of complex brain changes that occur over decades. There is consensus among researchers that genetics, lifestyle and environmental factors all play a role.
A version of this article appeared in our partner journal Alzheimer’s: New Hope for a Cure, in 2020.