(P18-016-25) Almond Intake and Cell Mediated Immunity

Objectives: Almonds are a good source of several immune-enhancing nutrients like fiber, zinc, copper, vitamin E, magnesium, selenium, folate, and polyphenols. The objectives were to determine whether almond consumption enhances immune function by assessing clinically relevant cellular and humoral immunity markers.

Methods: This was a 12-week, free living, parallel, open-label, observer-blinded, randomized, controlled, dietary intervention trial involving 58 middle-aged men and post-menopausal women. Subjects in the Almond group incorporated 1-3 oz of almonds to their daily intake (~15% of energy intake), while subjects in the Control group abstained from consuming almonds. Both groups were asked to restrict intake of other nuts. Adherence to the dietary intervention was assessed by 4 unannounced telephone 24-h diet recalls. Blood samples were taken at baseline and week 12 to measure changes in lymphocyte populations and subsets (by flow cytometry) after adjusting for CBC count of total lymphocytes, and function (by testing the ability of peripheral blood mononuclear cells [PBMC] to produce cytokines), and changes in the serum concentration of immunomodulatory markers. For each variable of interest, ANCOVA was used to test for changes over time between groups, adjusting for baseline values, age, sex, and BMI.

Results: Total T lymphocytes increased over time in both diet groups, but no differences were noted between groups. Compared to the Control group, the Almond group had greater increases in CD4+ T lymphocytes (1,547 cells/mL; p=0.019) and natural killer T cells (2,413 cells/mL; p=0.002), with decreases in naïve T (-1,257 cells/mL; p=0.029). No statistically significant differences were observed in cytotoxic T, memory T, or B cells. No changes between diet groups were observed in the serum concentrations for E-selectin, pentraxin, eotaxin, IL-1β, IL-6, MCP-1, TNFα, RANTES, or CRP; or for IFNγ, IL-1β, IL-6, IL-10, or TNFα in the PBMC supernatant.

Conclusions: This novel study suggests that almond intake may enhance immune function by boosting cell-mediated immunity, possibly by activating early immune responses, with no measurable effects on humoral immunity. This potential role in strengthening immunity and improving the ability to fight infections deserves further investigation.

Funding Sources: Almond Board of California, Modesto, CA