A recent study indicates that heart health during middle age may be a crucial predictor of dementia risk later in life. Researchers from University College London found that individuals with elevated levels of a protein known as cardiac troponin I in their blood are more likely to develop dementia as they age. The findings, published in the European Heart Journal, suggest that heart damage can have far-reaching effects on brain health.
The study involved nearly 6,000 participants from the Whitehall II study, which has tracked British Civil Service employees since 1985. Researchers measured troponin levels in participants aged 45 to 69, all of whom were free from dementia and cardiovascular disease at the time of testing. Over an average follow-up period of 25 years, 695 participants received a dementia diagnosis. Notably, those diagnosed showed higher troponin levels compared to their unaffected counterparts, with elevated levels detectable up to 25 years prior to diagnosis.
Troponin, a protein released into the bloodstream when heart muscle sustains damage, is commonly associated with heart attacks. However, chronic, asymptomatic elevations in troponin can indicate silent heart damage that might impair blood flow to the brain over time, potentially leading to dementia.
Professor Eric Brunner, senior author and researcher at UCL Institute of Epidemiology and Health Care, emphasized the implications of poor heart health, stating, “Poor heart health in middle age puts people at increased risk of dementia in later life.” He noted that controlling risk factors associated with both heart disease and dementia, such as high blood pressure, could potentially slow or halt the progression of both conditions.
The study’s findings align with the 2024 Lancet Commission on dementia, which estimates that improving cardiovascular risk factors could prevent or delay up to 17% of dementia cases. These risk factors include managing blood pressure and cholesterol levels, promoting physical activity, and addressing obesity.
Participants were assessed for cognitive abilities at various intervals, and those with the highest troponin levels displayed a more rapid decline in memory and problem-solving skills. Specifically, their cognitive abilities at age 80 mirrored those of individuals nearly a year and a half older, while at age 90, their mental capacities aligned with those of people two years older.
Researchers also examined 641 participants who underwent MRI scans of their brains. The results indicated that individuals with higher troponin levels exhibited a smaller hippocampus, a critical area for memory retention, and reduced gray matter volume, which is essential for information processing. These brain scan findings suggested that the participants’ brains were functionally equivalent to those of individuals approximately three years older.
Lead author Dr. Simon Chen remarked, “Our study represents the longest follow-up to date to investigate links between raised cardiac troponin levels and cognitive decline and dementia.” He highlighted that midlife troponin levels may serve as a more effective biomarker for predicting dementia risk compared to levels observed later in life.
Commenting on the study, Professor Bryan Williams, Chief Scientific and Medical Officer at the British Heart Foundation, reiterated the interconnectedness of heart and brain health. He stressed the importance of maintaining heart health throughout life to support cognitive aging. “That means keeping our blood pressure under control, managing our cholesterol levels, staying active, maintaining a healthy weight, and not smoking,” he advised.
As this research paves the way for further studies, experts aim to clarify how troponin levels can be integrated into risk assessments for dementia, potentially leading to earlier interventions and improved health outcomes for future generations.
