Ganoderma lucidum (a mushroom used in traditional Chinese medicine) compounds may attenuate aging-related physiological changes and restore normal immunity. However, studies on the physiological effects of Ganoderma lucidum dry extract food supplements are few. Therefore, here, we aimed to investigate the effects of Ganoderma lucidum dry extract food supplement on the lymphocyte function of older women. This was a double-blind clinical trial (n = 60) with a final 39 older volunteers, divided into two groups, Ganoderma lucidum (n = 23) and placebo (n = 16). The Ganoderma lucidum group received 2,000 mg/day of Ganoderma lucidum dry extract for 8 weeks. We used flow cytometry to determine the lymphocyte profile. CD4+ lymphocyte gene expression was evaluated by real-time PCR. We observed that in the Ganoderma lucidum group, concanavalin A (ConA) stimulation increased lymphocyte proliferation. Further, we observed an increase in expression of FOXP3, TGF-β, IL-10, IL-6, RORγ, GATA-3, and IFN-γ genes in the Ganoderma lucidum group. Furthermore, in the Ganoderma lucidum group, ionomycin and PMA stimulation led to decrease in Th17+ cells and increase in Th2+ cells. Thus, in older women, Ganoderma lucidum regulates T lymphocyte function leading to a predominant anti-inflammatory action but does not induce T lymphocyte proliferation through CD28 signaling pathway.