The present disclosure relates to the synergistic combination of a sulforaphane precursor, an enzyme capable of converting the sulforaphane precursor to sulforaphane, a cofactor of the enzyme, and a glucan. The present disclosure also relates to the synergistic combination of sulforaphane or a derivative thereof and a glucan. The present disclosure also relates to the synergistic combination of a broccoli extract or powder and a glucan. The glucan may be a β-glucan. The glucan may be provided in a mushroom extract or powder selected from one or more of a maitake, a shiitake, or a reishi mushroom. Compositions and methods relating to these combinations are described.