Fish and milk combination is generally fine unless allergic. No studies prove adverse effects; both are nutrient-rich and used for recovery.
Ayurveda discourages the combo due to opposing effects: milk cools, and
fish heats. The imbalance may affect digestion, and weaken immunity.
Separately, both dairy and fish are nutrient-rich, prompting their
combined use in many cultures to aid recovery. Problems arise from undercooked fish or lactose
intolerance/allergies.
Despite cultural use, caution is advised due to potential digestive
havoc. Combination lacks consensus in scientific circles, urging awareness over blind
belief.
While not toxic, the combo isn't advised, especially for the
immunocompromised. Awareness of its effects trumps blind adherence to superstition or
tradition.
Fish and milk, though not fatally harmful, may disrupt digestion and
weaken immunity, hence best avoided for overall health.