Some research suggests left-handed people have an increased risk of certain health conditions, but many of these studies are small or low quality. However, there may be some genetic links, particularly for ambidextrous people.
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Not only are lefties outnumbered about 9 to 1 by righties, but they may be at greater risk of certain health conditions.
Why would being left-handed affect my health?
Although researchers observe higher rates of some conditions among left-handers, it’s not always clear why. However, there are some reasons your dominant hand may affect your health, including:
- Genetics: Genes that determine handedness may also be linked to other conditions.
- Brain connectivity: The right hemisphere of your brain controls your left hand. Scientists propose that differences in brain connectivity between lefties, righties, and people with no preference may contribute to neurological differences.
- Environment: Many tools and spaces are designed for right-handed people and bodies, meaning that left-handed people may have to make more significant adjustments or be more prone to injury.
Some older research links left-handedness to breast cancer risk. But several of those studies only examined small populations, and other variables may have affected the results.
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Researchers propose that the increased risk of breast cancer in left-handed people may be due to increased exposure to estrogen while still in the womb, which they believe contributes to left-handedness.
However, more recent research has been unable to draw a link between fetal estrogen and being left-handed.
While research on left-handedness and certain disorders is lacking, there has been a wealth of research regarding psychotic disorders and handedness, especially schizophrenia.
A 2014 meta-analysis of 50 studies concludes that people with schizophrenia were more likely to be left-handed or ambidextrous. Researchers propose this is due to genetics that predetermine how the two sides of the brain divvy up their functions, a process known as lateralization.
Researchers suggest that schizophrenia may develop due to less brain lateralization, which may be a
In a 2024 study, people with schizophrenia were more than twice as likely to be mixed-handed than people who didn’t have schizophrenia.
And in a
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- changes in mood
- anxious or nervous feelings
- irritability
- restlessness
- neuroticism
Research also links non-right-handedness to post-traumatic stress disorder (PTSD), though the link appears to be stronger for mixed-handedness.
A 2021 meta-analysis found no association between non-right-handedness and depression.
Other neurological disorders may also have links to not being right-handed (i.e., being left-handed or ambidextrous). Researchers have found left-handedness more common in people with:
There’s anecdotal evidence that left-handedness is more common in children with dyslexia, but a 2023 meta-analysis suggests that a link only exists with mixed-handedness.
Some older research suggests that left-handers consume more alcohol than right-handers.
However, a 2022 Australian study did not find a significant correlation between handedness and alcohol consumption. Researchers discuss the role stigma may have played in influencing the results of previous research.
Results of a
Researchers could not identify a cause, though, and expressed the need for future research to explore potential mechanisms.
Does being left-handed affect your life expectancy?
A 1991 report claimed that people who were left-handed died an average of 9 years earlier than people who were right-handed.
However, research since then has consistently critiqued that report, citing problems with its methodology.
Although left-handers may have some disadvantages from a health risk perspective, they may also have some advantages.
Differences in brain lateralization and connectivity in left-handers may lead to improvements in verbal fluency and recognizing and processing bodies and faces, according to
Finally, a 2017 study indicates that left-hand-dominant athletes in certain sports have a much higher representation than they do in the broader population. For example, while about 10% of people are left-handed, about 30% of the elite pitchers in baseball are lefties.
Although left-hand-dominant people represent only about 10% of the population, they appear to have higher health risks of certain conditions, including breast cancer, some mental health conditions, and even heart disease.
In some cases, there’s a stronger link between being ambidextrous (not having a preferred dominant hand) and having health conditions.
The reasons for these links aren’t always clear, though they may have to do with genetics, differences in brain connectivity, or acquired structural differences.
Still, research has shown that your dominant hand doesn’t affect your overall health or life expectancy.
While it’s interesting to consider how left-handedness might affect your risk of certain conditions, it’s important to pay attention to other known, well-established risk factors that could play a much more significant role in disease development.