Final answer:
The proposed anti-cancer effects of foods containing plant proteins function through biological mechanisms, particularly due to the action of phytochemicals acting as antioxidants.
Step-by-step explanation:
Many of the proposed anti-cancer effects of foods containing plant protein are through biological mechanisms. Phytochemicals, a key component of plants, may protect human health through various biological pathways. One of the ways in which these compounds can exert anti-cancer effects is by acting as antioxidants that counteract cancer-causing free radicals. The research into these compounds is ongoing, and they may include as many as 4,000 different phytochemicals, which contribute to the protective effects against cancer.