Could a daily ketone drink help older adults think sharper and age healthier?

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: * Age 60 to 80 years * Postmenopausal women must be \>1 year since last menses * Able to provide informed consent * Willing and able to comply with all study procedures including randomisation into any of the experimental groups; maintenance of habitual dietary intake, exercise, medication and supplement use over the 28-day intervention period; blood draws and adipose tissue biopsies; and abstinence from alcohol (\>24 h), food (\>10 h) and strenuous exercise (\>3 d) prior to trial days. Exclusion Criteria: * Living in a residential care home * Unstable or clinically active pulmonary, cardiac, hepatic, renal, endocrine, hematologic, immunologic, neurologic, psychiatric or biliary disorders. 'Unstable' refers to complications of a condition that are not controlled by medication or lifestyle and which require frequent monitoring and testing by a health professional. Stable chronic disease is not an exclusion criterion unless specified. * Diagnosed Type 1 or Type 2 Diabetes Mellitus * Diagnosed gastrointestinal condition which would potentially impact ability to consume study drink (e.g. inflammatory bowel disease, history of gastrointestinal ulcers or bleeding) * Diagnosed autoimmune condition * Previous major cardiovascular event (e.g. heart attack, stroke) * Past or current cancer diagnosis and treatment excluding non-melanoma skin cancers * Severe hypertension (systolic blood pressure ≥180 mmHg and/or diastolic blood pressure ≥120 mmHg), as defined by blood pressure measured at Visit 1 * Current tobacco or recreational drug use * Reported changes to use of thyroid, antihypertensive, antidepressant or statin medications within 30 days of Visit 1 * Taking medications that will interfere with the study outcomes * Known negative reaction to lidocaine anaesthetic and/or taking warfarin * Currently following a ketogenic diet or taking ketone supplements * Not weight stable in the prior 3 months (\>5% weight change) * Unable to converse in English