ABSORB (Amount of Blueberries So Older Adults Reap Benefits)

Blueberries are a rich source of anti-oxidants and dietary fiber, and are recommended to consume as a part of a healthy diet. Regular consumption of blueberries as a source of dietary antioxidants may be an effective way to lower inflammation in older adults, who commonly have higher levels of inflammatory markers. However, older adults typically have a decreased efficiency of nutrient absorption and may need a higher dose of blueberries to absorb enough of the flavonoids needed to reap their benefits on inflammation. Thus, it is important for preliminary studies to pre-determine an appropriate dose of blueberry flavonoids specifically for older adults. This study aims to evaluated the preliminary impact of freeze-dried blueberry powder consumption on flavonoid bioavailability and inflammatory biomarkers in older adults. This will be an individual-level, unblinded, randomized, cross over pilot study in 5 older adults with minor levels of depressive symptoms. Eligible participants will collect a 24 hour urine sample, and then come in for the baseline assessments and provide a blood sample. Next they will be randomized to consume either the higher dose (48 g/day, equivalent ~ 2 cups of fresh blueberries) or the lower dose (24 g/day, equivalent ~1 cup of fresh blueberries) for 3 days. After 3 days they will begin collecting a 24 hour urine sample, and come in to repeat the baseline assessments and provide a blood sample. After a two week wash out period, participants will repeat the same baseline and follow-up assessments while consuming the other powder.

Inclusion criteria

• Men and women aged 65 years and older
• Minor levels of depressive symptoms (center for epidemiological studies depression scale, ≥4 and <16 points)

Exclusion criteria

*:

• Unwilling to follow the study protocol
• Cognitive impairment (assessed via the telephone Montreal Cognitive Assessment) defined as individuals scoring <19)
• Self-reporting a history of major depression, bipolar, schizophrenia, or other psychotic or neurologic disorders
• Self-reporting of history gastro-intestinal diseases/conditions e.g., of bowel resection, inflammatory bowel disease/syndrome, Celiac disease
• Self-reporting immune disorders, e.g., rheumatoid arthritis, cancer, and other immunocompromising conditions
• Self-reporting history of type 1 or type 2 diabetes
• Self-reporting any history of substance or alcohol use disorder
• Allergy to blueberries
• Self-reporting use of anti-inflammatory (e.g., fish oil or non-steroidal anti-inflammatory drugs) or immune-suppressant drugs
• Are excessive tea or coffee consumers (e.g., >3 cups/day)
• Recent and consistent use of antibiotics
• Currently taking or advised during the intervention to take anti-depressants
• Current homicidal or suicidal ideation (assessed via the P4 Suicidality Screener

• All deviations must be approved by the study sponsor