The Effect of Whey Protein Supplementation on Vascular and Cognitive Function in Older Adults

The Effect of Whey Protein Supplementation on Cerebrovascular and Cognitive Function in Older Adults

The "hardening of the arteries" observed with aging raises blood pressure and contributes to poor brain blood flow and loss of cognitive function (i.e. attention, memory, solving problems, making decisions). Cognition is the most important determinant of overall health status, quality of life, functional ability and independence in older adulthood. Nutraceutical strategies have received considerable attention as they may improve cardiovascular health with far fewer side effects compared to drugs. In this regard, dairy products are particularly attractive. Higher dairy consumption is associated with lower blood pressure and improved memory in adults. Milk proteins have natural blood pressure lowering effects. Studies conducted in animals have demonstrated that whey protein (a component of milk protein) may also increase artery elasticity. This is important given the strong association between artery elasticity, brain blood flow, and risk for cognitive decline.

The investigators propose to conduct a randomized double-blind placebo controlled study comparing the effects of whey protein supplementation or carbohydrate placebo on measures of artery elasticity, brain blood flow, and cognitive function in older adults. Whey protein may be a novel dietary therapy to improve both artery health and brain health in older adults.

Participants will be randomly assigned to receive either 50 g whey protein isolate or placebo each day for 12 weeks.

Inclusion Criteria:

• ages of 60-85 years

Exclusion Criteria:

• acute or terminal illness
• Montreal Cognitive Assessment < 26 (indicating dementia)
• myocardial infarction or stroke in the previous 6 months or other symptomatic coronary or peripheral artery disease
• type I or type II diabetes mellitus
• visual impairment
• upper or lower extremity fracture in the previous 6 months
• uncontrolled hypertension (150/90 mm Hg)
• cigarette smoking
• chronic kidney disease (albumin/creatinine ratio (ACR) between 30-300 ug albumin/mg creatinine)
• liver disease
• chronic pulmonary/respiratory disease
• body mass index (kg/m2) < 21 or > 32
• recent weight loss or gain greater than 7.5% of body weight within the previous 6 months
• currently supplementing diet with whey protein products
• milk-protein allergy, or allergy to para-aminobenzoic acid (PABA)
• head injury or symptoms of concussion in the past 3 months