Type 1 Diabetes (T1D) is associated with microvascular changes in the brain, which can cause cognitive dysfunction. Cocoa flavanols (CF) can stimulate vasodilation, resulting in enhanced cerebral blood flow and better cognitive function. This study aimed to investigate whether acute CF supplementation can improve cognitive function and the hemodynamic (BOLD) response in T1D patients.

Inclusion Criteria:

• non-smoking T1D patients or matched healthy controls
• having diabetes for more than 1 year
• males and females older than 18 years
• stable medications for more than 6 months (no use of cholinesterase inhibitors or prior use of multivitamins was allowed)
• adequate visual and auditory acuity to allow neuropsychological testing.

Exclusion Criteria:

• participant enrolled in any investigational drug study within 2 months or longer, depending on the investigational drug half-life
• history in the past 2 years of epileptic seizures or any major psychiatric disorder
• history or MRI evidence of brain damage, including significant trauma, stroke, hydrocephalus, mental retardation, or serious neurological disorder,
• significant history of alcoholism or drug abuse
• unstable cardiac, renal, lung, liver, or other severe chronic disease
• hypertension (systolic blood pressure ≥160 mmHg, diastolic blood pres-sure ≥100 mmHg) or hypotension (systolic blood pressure <100 mmHg)
• pacemaker or other medical metal devices that precludes performing MRI,
• chronic inflammatory diseases, including lupus, rheumatoid arthritis, or polymyalgia rheumatic
• macrovascular complications
• retinopathy, nephropathy or neuropathy (microvascular complications)