Some Kitchen Habits and Cancer Risk: What Does the Evidence Show?

Dragon Media Correspondent

Not all claims linking cooking fumes, repeatedly heated oil, an unwashed pan and excessive salt to cancer are supported by evidence. Some practices may increase health risks, while a direct link has not been established for others.

The International Agency for Research on Cancer has classified emissions from high-temperature frying as probably carcinogenic to humans. Some studies have found an association between long-term exposure to cooking fumes and lung cancer. However, this classification indicates the strength of the available scientific evidence; it does not show how likely an individual is to develop cancer. Keeping the kitchen well ventilated, using an exhaust fan and avoiding heating oil until it smokes are therefore sensible precautions.

The claim that unrefined peanut oil causes intestinal cancer is not supported by the available evidence. A review by the International Agency for Research on Cancer found animal evidence concerning fumes from unrefined rapeseed oil heated to high temperatures. It would be inaccurate to extend that finding to peanut oil or intestinal cancer.

Repeatedly heating oil at high temperatures can degrade its quality and produce harmful substances. However, there is no conclusive evidence that reusing cooking oil at home causes cancer in people. Oil should be discarded if it becomes dark or foul-smelling, foams excessively or begins to smoke. Cooking several dishes in an unwashed pan can also reheat burnt food particles and leftover oil. There is no direct evidence that using an unwashed pan causes cancer, but cleaning it between dishes helps maintain hygiene and reduce smoke.

Excessive salt consumption is associated with a higher risk of high blood pressure. The US National Cancer Institute says that diets high in salted, smoked or poorly preserved foods may increase the risk of stomach cancer. This does not mean that using a small amount of salt while cooking causes cancer. Reducing total salt intake and limiting highly salted processed foods are important.

Cancer is associated with many factors. No single kitchen habit can be said to cause the disease with certainty. Reducing exposure to cooking fumes, avoiding burnt oil, not reusing degraded oil, cleaning pans and limiting salt can help reduce health risks.