According to About.com, you should use mineral oil on a wood cutting board. Food-grade mineral oil is ideal because it does not contain harmful chemicals or perfumes. Other oils that are suitable for the purpose include almond oil, coconut oil and linseed oil, as stated by TodaysHomeowner.com.
Do not use cooking oils, like olive and vegetable oil, on wooden cutting boards, as they have the potential to turn rancid. Additionally, avoid wood stains, Danish oil and polyurethane, as they may contain harmful chemicals. Using beeswax on wooden cutting boards adds protection and shine, but it tends to work better with decorative wooden surfaces that are not used often.