New Hypothesis Links Metabolic Syndrome to Cognitive Impairment and Smell Dysfunction

Researchers from the University of Texas Health Science Center at San Antonio and Methodist Hospital proposed a new hypothesis in the journal Frontiers in Neuroscience. They suggest that metabolic syndrome may block the brain's waste removal pathways, leading to olfactory dysfunction, an early symptom of dementia.

The study highlights that olfactory dysfunction often precedes memory and motor impairments in neurodegenerative diseases such as Alzheimer's and Parkinson's. The researchers indicate that metabolic syndrome, characterized by conditions like hypertension and obesity, disrupts autonomic balance, causing blood vessels in the nasal cavity to swell and obstruct lymphatic drainage.

As the brain's waste disposal function becomes impaired, harmful proteins accumulate near olfactory nerves, resulting in smell dysfunction before cognitive decline. This phenomenon is not only observed in neurodegenerative diseases but also in conditions like depression and traumatic brain injury. No further timeline was disclosed at the time of publication.