In a new study, scientists found that an inability to stand on one leg for more than 20 seconds was associated with microbleeds and "silent" strokes.
Although the brain injuries were too small to cause symptoms, scientists warned they could signal later problems.
Silent strokes, or lacunar infarctions, are known to increase the risk of both full-blown strokes and dementia.
Lead researcher Dr Yasuharu Tabara, from Kyoto University in Japan, said: "Our study found that the ability to balance on one leg is an important test for brain health.
"Individuals showing poor balance on one leg should receive increased attention, as this may indicate an increased risk for brain disease and cognitive decline."
The scientists looked at 841 women and 546 men with an average age of 67 who were asked to stand with their eyes open and one leg raised for a maximum of 60 seconds.
Participants performed the test twice and the better of the two times was used in the study analysis.
They also had magnetic resonance imaging (MRI) scans to assess their levels of cerebral small vessel disease, which can interfere with blood flow in the brain.
The research, published in the journal Stroke, showed that 34.5 of those with more than two lacunar infarction lesions had trouble balancing.
The same was true for 16% of participants with one lacunar infarction lesion and 30% of men and women with more than two sites of microbleeding.
"One-leg standing time is a simple measure of postural instability and might be a consequence of the presence of brain abnormalities," said Dr Tabara.
The research is published in the American Heart Association's journal Stroke.