absorb (amount of blueberries so older adults reap benefits)

Conditions: Depressive Symptoms; Aging

Summary: this randomized, cross-over, pilot study aims to compare preliminary impact of a standard dose of blueberry powder (24 g) vs a higher dose (48 g) on the bioavailability of flavonoids and inflammatory biomarkers in older adults with minor levels of depressive symptoms.

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.

Eligibility criteria:
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