Speaking on a radio talk show Saturday morning, Ho said although natural toxins can be found in some plants, post-harvest processing and thorough cooking can destroy some natural toxins, or greatly reduce their toxicity.

When consuming food products, people should pay attention to their cooking or handling method and the intake amount to prevent poisoning.

For flaxseeds that are usually eaten raw, people should limit the intake to small amounts, Ho said. To prevent toxicological effects, people can cook them thoroughly in boiling water. This method can reduce more than 90 percent of cyanogenic glycosides in flaxseeds. Baking is a less effective detoxifying method because it can only reduce 10 percent of cyanogenic glycosides.

Histamine formation in fish is usually related to improper storage. It is commonly found in fish species such as tuna and sardines. Ho reminded people that tuna sandwiches, if not properly stored at four degrees Celsius or below, should be consumed within two hours after they are prepared.