Betel: The International Agency for Research on Cancer (IARC) has warned that it can cause oral cancer. Betel nut and betel leaf are traditional in some Asian countries like Vietnam. When you chew it, the betel nut rubs hard against the inside of your mouth, causing the skin to peel or get scratched. Then, the toxins in betel leaves, areca nuts, figs, or tobacco can act on these damaged areas and cause cancer. Research shows that the substances in areca nuts can boost stomach acid, slow the heart rate, and stimulate nerves, which is why people often look pale after chewing betel, like they’ve had a drink.
Cold fruits: When the weather gets hot, many people choose cold fruits. But experts say most tropical fruits aren’t meant to be stored in the fridge. And the downside is that some of these fruits can produce nitrites when cold, which might give people who eat them cancer.