A free-living parallel, single-blind, RCT will be utilized. There will be two phases: Phase 1 - to examine the effects of Blueberries on plasma markers of immune strength, and Phase 2 - to assess the response to influenza vaccine following blueberry intake. Subjects will either consume their usual diet with (Blueberry group) or a placebo(control group) blueberries for 8 weeks, receive the influenza vaccination, and continue the intervention for another 4 weeks. The test food will be freeze-dried powder (FDP) (~ to 1 cup fresh blueberries) per day with the usual diet. The control will be the placebo powder with some guidelines to restrict all berries and other polyphenol-rich foods. The entire study will last 12 weeks. Participants will attend a baseline clinic at which time they will be randomized to one of the two groups. Clinic visits will occur at baseline, weeks 4 and 8 before, and week 4 after vaccination.
This research study will test the effects of almonds on immune functions and immune response to influenza vaccine in overweight older men and postmenopausal women