Consumption of well done meat and fish has been found to be associated with increased risk of breast cancer. The association is strongest for red meat (including such common dishes as hamburgers, bacon, pork chops, ribs and other fried or barbecued pork or beef), but is also evident for chicken and fish. The heightened breast cancer risk appears to be a result of polycyclic aromatic hydrocarbons (PAHs) and heterocyclic amines (HCAs) produced during cooking, especially cooking methods using high temperatures. Now a new study has reported for the first time that relatively high consumption of grilled, barbecued and/or smoked meat is associated with reduced survival after breast cancer.
Cooking methods and harmful compounds
Most consumers prefer their meat to be seared (at least at the beginning of the cooking process) or otherwise prepared so that the juices are sealed in. With some exceptions, boiled or steamed meat that has not first been seared can be unappealing. However, searing, charring and deep frying meat or fish creates PAHs and HAAs.
Based on published studies to date, the worst to the least harmful methods of cooking meat and fish appear to be grilling, barbecuing, pan frying, oven broiling, deep frying, stir frying, oven baking, and stewing. Cooking meat at high temperature until it is well done produces far higher levels of carcinogens than cooking it until it is medium rare. The char on meat and pan drippings used to make gravies have particularly high levels of HAAs. Removing the skin after frying or roasting poultry and fish greatly improves the HAA profile of the flesh that is consumed.
Latest research links grilled/barbecued/smoked meat to increased mortality
The study referenced at the beginning of this news story was designed to investigate the associations between grilled, barbecued and smoked meat consumption and survival after a diagnosis of breast cancer. Grilled, barbecued, and smoked meats are a dietary source of polycyclic aromatic hydrocarbons, which appear to be breast carcinogens, increasing breast cancer risk. The study included 1,508 women diagnosed with first primary invasive or in situ breast cancer between 1996 and 1997 (baseline). To conduct the study, the authors interviewed the women at baseline and at approximately the five-year mark to determine grilled, barbecued and smoked meat intake. The baseline interviews generated data concerning prediagnosis intake. High intake was defined as above the median intake; low intake was below the median. Study participants were followed for a median of 17.6 years.
A total of 597 deaths occurred during follow-up, of which 237 were breast cancer-specific. The authors analyzed every possible combination of high and low intake, taking account changes in postdiagnosis intake. High prediagnosis total grilled/barbecued and smoked meat intake was found to be associated with a 23% increased overall risk of death (all-cause mortality). Other associations were also found but just missed the threshold for statistical significance. These include the following: (1) high prediagnosis smoked beef/lamb/pork intake was linked to a 17% increase in all-cause mortality and a 23% increase in breast cancer-specific mortality; and (2) among women who had high grilled/barbecued and smoked meat intake both before diagnosis and five years later, all-cause mortality risk was even higher (31%). In addition, breast cancer-specific mortality was found to be lowered among women with any pre- and postdiagnosis intake of smoked poultry and/or fish. The authors conclude that high consumption of grilled, barbecued and/or smoked meat may increase mortality after breast cancer.