Objectives: Accumulating clinical evidence from experimental and observational studies with humans suggests that edible mushrooms may have beneficial effects on markers of brain health. This study examined the effects of daily consumption of fresh Agaricus bisporus (cremini mushrooms) exposed to ultraviolet (UV) light on indices of anxiety, depression, mood, cognitive function, and well-being in middle-aged and older adults. Methods: Over a 6-week period, adults (n = 41 (19 M/22 F), age 43 ± 11 y; BMI 29.8 ± 5.9 kg/m², mean ± SD) without severe depression, cardiovascular disease, or Type 2 Diabetes consumed two daily servings (168 g/d wet weight) of cremini mushrooms intended to provide 400 IU/serving (800 IU/d) of vitamin D₂ (n = 20) or 2 tsp/d of breadcrumbs (control, n = 21). Assessments conducted at baseline and week 6 included General Anxiety Disorder-7 (GAD-7), Beck’s Depression Inventory (BDI-II), Patient Health Questionnaire (PHQ-9), Repeatable Battery for the Assessment of Neuropsychological Status (RBANS), Profile of Mood States (POMS), and Medical Outcomes Study 36-Item Short-Form Health Survey Version 2 (SF36v2). Results: Consuming UV light-exposed mushrooms did not improve brain health outcomes. Independent of mushroom consumption, over time, there were improvements in immediate memory (RBANS), language (RBANS), and depression (BDI-II and PHQ-9). Conclusions: There were no differences observed between groups in the investigated indices of brain health. However, improvements over time were observed in Beck’s Depression Inventory and the Immediate Memory and Language domains in the RBANS, independent of mushroom consumption. Overall, consuming 2 servings/d of UV-exposed mushrooms for six weeks may not improve indices of brain health.

We assessed whether consuming UV light-exposed mushrooms (UVMs) would offset the seasonal decline in circulating total 25-hydroxyvitamin D (25OHD), an index of vitamin D status. During late fall and winter, 41 adults (19 M/22 F, age 43 ± 11 y, BMI 29.8 ± 5.9 kg/m², mean ± SD) were randomized to consume either 84 g of fresh Agaricus bisporus twice/d (produced to contain 400 IU of vitamin D₂/serving; 800 IU/d total) or 1 tsp of breadcrumbs twice/d (Control) while continuing to consume their self-chosen diets. At baseline and week 6, fasting serum 25OHD₂, 25OHD₃, and total 25OHD were measured. Mushrooms were sampled weekly and vitamin D₂ content measured. From the intent-to-treat analysis (Mushroom group, n = 20, and Control group, n = 21), 25OHD₂ increased and 25OHD₃ decreased in the Mushroom group over winter months compared to Control with no differences in the decrease in total 25OHD between groups. Unexpectedly, only 67% of the UVMs contained vitamin D₂. Post hoc subgroup assessment indicated that participants consuming UVMs (n = 11) had increased 25OHD₂ and a greater decline in 25OHD₃ compared to subgroups consuming mushrooms without vitamin D₂ (n = 9) and Control (n = 21), with no differences in the decrease in total 25OHD among subgroups. Consuming UVMs increased serum 25OHD₂ but did not prevent a seasonal decline in vitamin D status due to a greater decrease in 25OHD₃.