Targeting Neurovascular Coupling in Cognitive Decline Via Nitrate-Based Supplementation

Inclusion Criteria: * Formal diagnosis of cerebral small vessel disease (grades 1 to 3 in the Age-Related White Matter Changes Scale as assessed by Computerized Tomography or Magnetic Ressonance Imaging - MRI) and patients at high risk for cerebral small vessel disease with diabetes mellitus; * Subject has capacity and is capable of giving written informed consent; * Subject is able to read, comprehend and record information written in Portuguese. Exclusion Criteria: * Vascular diseases other than cerebral Small Vessel Disease (cSVD); * Stroke event less than 6 months ago; * Unsuitable for MRI scanning because of presence of any standard MRI contraindication (e.g presence of a cardiac pacemaker, other medical implants or devices, or the presence of ferromagnetic metal foreign bodies); * Needle phobia; * Inability or intolerance to dietary polyphenol adjustment; * Current smoker; * Alcohol abuse, drug abuse or use of drugs affecting cognitive assessment, such as sedatives, hypnotics, nootropic drugs, cholinergic drugs; * Use of medications that may be contraindicated or interact with the high nitrate diet, such as nitroglycerin or nitrate preparations used for angina, or phosphodiesterase type 5 (PDE5) inhibitors, including sildenafil (Viagral); * Patients previously diagnosed with dementia; * Presence of congenital mental retardation and severe neurological and psychiatric diseases; * Illiterate or severe visual or hearing impairment that may prevent patients from cooperating with cognitive assessment; * Relevant depression or other unrelated serious mental illness; * Severe cardiac, pulmonary, renal or hepatic insufficiency; * Patients who have participated in other interventional clinical studies within the last 3 months, or are participating in other interventional clinical studies.