November 7, 2013
News Review From Harvard Medical School -- Being Bilingual May Delay Dementia
Speaking 2 or more languages may help delay dementia, a new study suggests. The study focused on 648 people from India. They had been diagnosed with various types of dementia. Of this group, 391 spoke at least 2 languages. They had developed symptoms of dementia an average of 4 years later than those who spoke only a single language. This delay was not related to education. It applied even to people who spoke 2 languages but could not read either of them. There was no added benefit from speaking 3 languages, researchers said. Prior research has found other factors that are linked with delays in dementia. They include more education, higher-status jobs or more thinking challenges in everyday life. Researchers say all of these things lead to greater "cognitive reserve." This reserve allows the brain to function normally despite disease or injury. Authors of the study say that speaking 2 languages may also build more cognitive reserve. The journal Neurology published the study. HealthDay News wrote about it November 6.
By Robert H. Shmerling, M.D.
Harvard Medical School
What Is the Doctor's Reaction?
If you've ever known someone with dementia, you know it's a devastating condition. That's true not only for those who suffer with it, but also for their family and friends.
The condition is increasingly common as our population ages. And, despite decades of research and remarkable advances in our understanding of dementia, treatments are limited.
Most forms of dementia affect the elderly. So medical advances that allow people to survive once-fatal conditions contribute to increasing rates of dementia. An estimated 7 million people in the United States and 36 million worldwide currently have dementia. This includes people with Alzheimer's disease, dementia related to strokes and other diseases. By 2030, the number of people with dementia is expected to nearly double, to 68 million worldwide.
There aren't many treatments for dementia. And the ones we have don't work very well. So prevention is a major focus for those researching dementia, as well as for those involved in public health.
A new study offers a novel preventive measure that could reduce the risk of developing dementia: learning a second language. The medical journal Neurology published the results.
The study included 648 older adults with dementia. Their average age was 66. About 60% of them spoke at least 2 languages, according to close relatives. Compared with those who spoke only 1 language, those who spoke 2 or more languages:
- Tended to develop dementia later in life (by more than 4 years)
- Had a later onset of dementia even if illiterate (suggesting that later dementia was not related only to better education)
- Did not have any extra protection from dementia if they spoke more than 2 languages
These conclusions remained the same even after researchers accounted for gender, job experience and other factors that might affect one's risk of dementia.
The researchers speculate that people who know a second language have better developed areas of the brain that control "executive function," such as memory and attention. These areas are among the first to fail in people with dementia. It's possible that learning a second language provides more "reserve" in these areas of the brain. That in turn may provide a measure of resistance to dementia.
In my view, this is an exciting finding. But it's hard to know what to do with it. For example:
- Should people at high risk for dementia enroll in classes to learn a second language?
- Is there a "window of opportunity" during childhood, when language skills are first acquired, when learning a second language matters most?
- Could language lessons help people who already have dementia?
What Changes Can I Make Now?
Despite the findings of this study, it's not clear that learning a new language will alter your future risk of dementia. After all, this type of study can only suggest a link between speaking multiple languages and delayed onset of dementia. It cannot prove that language skills prevent dementia.
Still, there are steps you can take to increase your chances of maintaining good brain health in the future. Here's what you can do:
- Exercise regularly. Many studies confirm the health benefits of regular exercise, including lower rates of dementia.
- Maintain a healthy weight. Excess weight is linked with diabetes, high cholesterol and other factors that may increase the risk of heart and artery disease, stroke and dementia.
- Improve your diet. Choose foods that are high in fiber, fruits, vegetables and omega-3 fatty acids.
- Keep your blood pressure and blood lipids (such as cholesterol) in a healthy range. Diet and exercise may be enough, but many people require medicines.
- Don't smoke. Talk to your doctor if you're having trouble quitting on your own.
- Keep your mind active. Having a busy social life and hobbies and engaging in mentally challenging activities may be good for brain health.
Symptoms that suggest dementia (such as poor memory) may be present in other conditions. These include depression and thyroid disease. So, if you are concerned that you or a loved one may be developing dementia, it's important to have a thorough medical evaluation.
What Can I Expect Looking to the Future?
Future research will further explore the impact of language development on when and whether people develop dementia. This may provide insights that will guide preventive measures. Perhaps these measures someday will include learning a second language. I hope that research will answer questions raised by this new study, discover the causes of dementia and find more effective approaches to prevention and treatment.