Do Ketone Drinks Improve Immune, Metabolic and Cognitive Health in Older Adults

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 b…