A new randomized controlled trial published in the American Journal of Clinical Nutrition assessed the effect of almonds on the immune response following influenza vaccination.
Researchers gave 90 healthy adults aged 40 to 64 either almonds (56 grams/day) or an equally caloric pretzel snack for eight weeks, replacing their usual snacks. All participants received a seasonal flu vaccine at week four. The almond group produced higher antibody levels against two of the four vaccine strains: antibody titers after vaccination were significantly higher for the A/Wisconsin/67/2022 (H1N1) strain, and the fold-change in antibody titers from pre- to post-vaccination was significantly greater for both that strain and the B/Yamagata strain.
The study’s primary outcome was seroconversion (the development of a measurable antibody response) against at least one vaccine strain. This did not differ significantly between the groups because nearly everyone responded well, with more than 90% of participants achieving this outcome in both the almond group and the control group. No significant differences in seroprotection were observed between groups. Thus, although some strain-specific antibody responses were enhanced, the trial did not demonstrate an overall improvement in vaccine response based on its primary outcome.
While the effects of individual nutrient supplementation on influenza vaccine responses have been widely studied, this one of the randomized controlled trial to investigate whether a whole food can influence the body’s response to vaccination. The findings open up an interesting new avenue for research into the potential role of whole foods, including nuts, in supporting immune function. As this study is one of the first of its kind, it will be interesting to see if future research provides further evidence to confirm that the observed differences in antibody responses translate into meaningful improvements in protection against influenza infection.
Funding for this study was provided by the Almond Board of California.
Reference: van der Schoot, A., Creedon, A. C., Argomaniz, N., Bajka, B., Hall, W. L., Farsi, D. N., Chrysostomou, D., Marchesi, J. R., Perucha, E., Turcanu, V., Whelan, K., & Dimidi, E. (2026). Almonds and the optimization of immune responses to influenza vaccination, compared to a control snack, in healthy adults: a randomized controlled trial. The American Journal of Clinical Nutrition, 101596. Advance online publication.
