Foamy urine linked to higher dementia risk, Swedish study finds

A Swedish study suggests foamy urine could signal an elevated risk of developing dementia in later life. Researchers say high levels of the protein albumin in urine—an indicator of kidney damage that allows albumin to leak into urine—may be linked to brain changes associated with dementia, with the strongest association seen for vascular dementia and mixed dementia.

In four years of follow-up, the study tracked about 130,000 people aged 65 and older who did not have dementia at the start. About 7% developed dementia during the period. After accounting for kidney function and other factors, the researchers found a graded increase in risk: moderate albuminuria (30–299 mg/g) was associated with a 25% higher risk, while high albuminuria (>300 mg/g) was linked to a 37% higher risk, compared with normal levels (up to 30 mg/g).

Experts said the results underscore the importance of routine screening for albuminuria as part of early dementia risk assessment, particularly for patients with high blood pressure, diabetes, cardiovascular disease, or kidney disease. Early detection of albuminuria could potentially delay or prevent the onset of dementia.

Not everyone with albuminuria shows symptoms. When symptoms do occur, they may include foamy urine, frequent urination, and swelling around the eyes, feet, ankles, belly, or face, according to the National Kidney Foundation.

Alongside these international findings, UK context remains stark. Alzheimer’s Research UK has noted that about 74,261 people died from dementia in 2022 in Britain, up from 69,178 the year before, making dementia the country’s biggest killer. Projections by University College London researchers suggest the number of people living with dementia in the UK could rise from roughly 900,000 today to about 1.7 million in the next two decades as the population ages.

The researchers stressed that a urine test is the most effective way to diagnose albuminuria. When kidneys are functioning normally, they filter out the protein so it does not appear in urine; damage from conditions such as kidney disease can cause albumin to leak through the filtering system and into urine. The study, published in the Journal of Internal Medicine, indicates that higher albuminuria levels are linked with a greater risk of all-cause dementia, especially vascular and mixed forms, and that detecting albuminuria early could allow for more proactive management of kidney health and cognitive function, potentially delaying the onset of dementia.