(P22-041-25) Investigating the Feasibility of a Long-term Blueberry Intervention in Older Adults With Depressive Symptoms

Objectives: Inflammation is a putative contributor to depression in older adults. Since inflammation is modifiable by diet, an anti-inflammatory dietary regimen may be a strategy to reduce inflammation in older adults with mild depressive symptoms (MDS). However, such individuals often experience anhedonia (i.e., lack of interest) and may be less motivated to engage in a long-term dietary intervention. Before a full-scale trial can be conducted, the feasibility of such a trial is needed to demonstrate the practicality of such an intervention. We hypothesize that a 12-week freeze-dried blueberry powder intervention is feasible in older adults with MDS.

Methods: We conducted a single-site, randomized, double-blind, parallel pilot study in older adults with MDS, who were asked to consume either 48 g of freeze-dried blueberry powder or a nutritionally matched placebo powder each day for 12 weeks. Recruitment rate (i.e., percentage of volunteers telephone screened that were enrolled in the study), retention rate (i.e., percentage of participants randomized that ultimately completed the intervention), safety (i.e., frequency of adverse and serious adverse events), compliance (i.e., percentage of doses consumed/doses allotted on study), demographics, and depressive symptom severity (via the center for Epidemiological Studies Depression Scale-Revised, CESD-R) were calculated.

Results: Of the 145 individuals telephone screened for the study, 33 enrolled (22%). Four individuals were dropped prior to randomization due to non-compliance with the protocol (n=1) and voluntary withdrawal (n=3). Of the 29 individuals who were randomized, 22 completed the study (76%). Mean age was 73 ± 5 years, 77% female, 90% white, and CESD-R was 9.5 ± 4.2. Those who dropped out (n=7) had a mean age 70 ± 4, 86% female, 100% white, and CESD-R was 8.7 ± 3.7. There were 10 adverse and 0 serious adverse events. Mean compliance was >85% in both groups.

Conclusions: Although the drop-out rate was relatively high (i.e., 24%) a long-term blueberry intervention in older adults with MDS demonstrated sufficient safety and relatively high compliance. However, the generalizability of our findings is very limited. Future studies should account for a relatively high drop-out rate if recruiting a population of older adults with MDS for a long-term dietary intervention.

Funding Sources: This work was funded by the NIA.