Many chemicals that we regard as toxic actually occur naturally in foods we live. Formaldehyde in most living things, cyanide in apples, etc. Some substances

Many chemicals that we regard as toxic actually occur naturally in foods we live. Formaldehyde in most living things, cyanide in apples, etc. Some substances should not be in our food at all, such as mercury. Other substances shouldn't be in our food above certain quantities, such as formaldehyde. So yes, there are some "toxins" that should be in our food assuming what we are eating isn't synthesised from scratch.