The Study
Bilingualism as a protection against the onset of symptoms of dementia.
This study looked at a group of older people with dementia and asked if they spoke two languages. It found that those who were bilingual started having symptoms later, but we cannot be sure that speaking two languages is what caused the delay, because there might be other reasons. It's like noticing that people who wear glasses often read more, but we can't say glasses make you read more.
Analysis score
Maximum 44 for a cross-sectional study.
Where the score came from
Researchers looked at people with dementia and checked if speaking two languages made a difference. They found that bilingual people started having memory problems about 4 years later than people who spoke only one language. But once dementia started, it progressed at the same speed for both groups.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 543 / 100
Quality score
Snapshots of a population at a single point in time, or descriptions of small groups. Can identify correlations and prevalence, but cannot determine cause and effect.
Key takeaways
Summary
Based on the study abstract and findings.
- 1A 4-year delay in dementia onset is significant because it could mean fewer years of disability and lower healthcare costs for individuals and society.
- 2Bilingual people showed dementia symptoms at an average age 4.1 years older than monolingual people.
- 3The decline in memory test scores after diagnosis was the same for both groups.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Related Content
Claims (4)
People who speak two languages start having thinking and memory problems about 4 years later than people who speak only one language.
People with dementia who speak two languages lose their thinking skills at the same speed as people who speak one language, when measured over four years. So speaking two languages doesn't change how fast the disease gets worse after it starts.
People who have spoken two languages their whole lives tend to start showing symptoms of dementia about 4 years later than people who only speak one language. But after diagnosis, the memory loss and thinking problems get worse at the same speed for both groups.
People who speak two languages tend to start having dementia symptoms later than people who speak only one language. On average, they start about 4 years later, according to a study done at a memory clinic.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.