Brassica vegetables, including broccoli, cabbage, Brussels sprouts, and kale, are rich in glucosinolates and their breakdown products, such as sulforaphane and indole-3-carbinol. There is growing scientific interest in their influence on detoxification pathways and immune modulation, which indirectly relates to lymphatic system support. The lymphatic system plays a crucial role in immune surveillance and fluid balance. Some studies suggest that compounds in Brassica vegetables enhance the activity of phase II detoxifying enzymes and promote the elimination of potential carcinogens, which can relieve some detoxification burden that also involves the lymphatic system. Additionally, Brassica phytochemicals have demonstrated anti-inflammatory and immunomodulatory effects in cell and animal studies, which may benefit lymphatic health by reducing inflammation and supporting immune cell function.

However, direct clinical evidence linking Brassica vegetable consumption specifically to improved lymphatic system function in humans is limited. Most research focuses on cancer prevention, liver detoxification, and general immune support, rather than targeted lymphatic outcomes. Nevertheless, the known effects on inflammation, immune modulation, and detoxification offer a plausible mechanistic basis for supporting lymphatic health. Thus, while there is some scientific rationale, the evidence is not direct or robust, meriting a moderate rating.