The best oil to use for cutting board maintenance is mineral oil. Mineral oil is a non-penetrating oil that forms a protective barrier on the wood surface, preventing moisture and bacteria from seeping into the wood. It is also food-safe, making it suitable for use on cutting boards. According to the National Sanitation Foundation (NSF), mineral oil is one of the few oils approved for use on cutting boards due to its non-reactive nature and ability to maintain the wood's integrity. This is crucial for maintaining the longevity and hygiene of the cutting board.