Frying steak on gas hob ‘may increase risk of cancer’
Reported February 18, 2010
Using a gas hob appeared to be worse and created more of the harmful particles than using an electric one, the study conducted in Norway found.
The researchers said exposure to the fumes should be kept to a minimum and added that professional chefs were at particular risk.
Cooking fumes have been shown to cause changes in DNA that may lead to cancer and may increase the risk of lung cancer.
The International Agency for Research on Cancer recently classified high-temperature frying as ‘probably carcinogenic to humans’, the same category as diesel and some insecticides.
The researchers said an increased risk of respiratory tract cancer in cooks and bakers has been reported and the compounds which have been identified are polycyclic aromatic hydrocarbons (PAHs), heterocyclic amines and higher aldehydes.
These compounds were found in the breathing zone of cooks when frying, the research found.
The study involved frying 17 beefsteaks on a gas or electric hob consecutively for 15 minutes using margarine or soya bean oil.
The frying was conducted in a specially built kitchen desiogned to mimic a commerical restaurant kitchen with an extractor over the hob.
The study is published in the journal Occupational and Environmental Medicine found that the levels of polycyclic aromatic hydrogcarbons produced during the experiments were below accepted occupational safety thresholds.
But they added that there were other particles found in the fumes for which there is no established safe level.
Ann Kristin Sjaastad, lead author from Norwegian University of Science and Technology, in Trondheim, wrote in the journal: “The measured levels of total particles and PAHs for the cooks in our study are far below the Norwegian occupational exposure limits for nuisance dust.
“However, cooking fumes consist of a mixture of toxic and mutagenic compounds, including mutagenic aldehydes and heterocyclic amines with no known dose-response relationship, so exposure to cooking fumes should be reduced as much as possible.”
She added: “Our study shows that using a gas stove instead of an electric stove results in higher levels of PAHs, aldehydes and particles.
“This is presumed to be due to the higher temperature of the gas flame resulting in more thermal degradation products. The higher level of ultrafine particles may also be due to the gas flame itself and not just a result of the cooking process.”
Dr Deborah Jarvis, who works at the National Heart and Lung Institute and within the Medical Research Council and Health Protection Agency Centre for Environment and Health, based at Imperial College London, said: There have been large scale studies to see whether people who cook with gas have more breathing problems – such as coughs, infections and asthma – than those who cook with electricity. Results from these studies are inconsistent.
“This new study may help us understand why these inconsistencies occur. The public health message to the general public remains the same keep your kitchen well-ventilated when cooking, and make sure all your gas appliances are well maintained.
Prof Roy Harrison, Professor of Environmental Health, Birmingham University, said: There are no big surprises in this work. Cooking, and especially frying, have long been known to be a source of carcinogenic chemicals and ultrafine particles. The health consequences, if any, remain uncertain.
Source : Telegraph Media Group Limited