May 18, 2010
A diet heavy in processed meat might increase your risk of heart disease and diabetes, according to a new analysis of previous studies. Researchers say processed meats appear to be worse for you than unprocessed meat.
"Processed meats such as bacon, salami, sausages, hot dogs and processed deli meats may be the most important to avoid," said Renata Micha of the Harvard School of Public Health, lead researcher for the study.
The research concludes that consuming more than one serving of processed meat per week begins to add to the risk.
Micah said the study is different in that it examines the role of processed meat - as opposed to unprocessed meat - in heart disease. Her study was based on a systematic review of 1,600 international studies, looking for evidence of a link between eating all types of red meat and the risk of heart disease and diabetes.
For the purpose of the study, processed meat is defined as any meat that is smoked, cured, or preserved with chemicals. Processed meat includes bacon, salami, sausages, hot dogs or processed deli or luncheon meats.
The researchers found that each daily serving of processed meat was associated with a 42 percent higher risk of heart disease and a 19 percent higher risk of developing diabetes.
Not surprisingly, the American Meat Institute Foundation (AMIF) took issue with the study, saying processed meat continues to be a healthy part of a balanced diet and that nutrition decisions "should be based on the total body of evidence - not on a study that stands in contrast to other research and to the U.S. Dietary Guidelines for Americans."
"Too often, epidemiological findings are reported as 'cased closed' findings, as if a researcher has discovered the definitive cause of a disease or illness," said AMIF President James H. Hodges. "But epidemiological studies look at a multitude of diet and lifestyle factors in specific volunteer human populations and use sophisticated statistical methods to try and tease out relationships or associations between these factors and certain forms of disease. This method of comparing relationships has many limitations which are widely recognized by researchers in this field. More often than not, epidemiological studies, over time, provide more contradictions than conclusions."
Spices may help
While debate continues over potential health risks in processed meat, another study suggests ground beef would be safer with the addition of spices.
J. Scott Smith, a Kansas State University food chemistry professor, has pursued different projects in recent years seeking ways to reduce heterocyclic amines (HCAs), the carcinogenic compounds that are produced when muscle foods, such as ground beef patties, are barbecued, grilled, boiled or fried. Consuming HCAs through meat increases risk factors for colorectal, stomach, lung, pancreatic, mammary and prostate cancers, according to previous studies.
Smith, in research supported by the Food Safety Consortium, found that certain spices containing natural antioxidants would reduce HCA levels by 40 percent when applied to beef patties during cooking.
"Cooked beef tends to develop more HCAs than other kinds of cooked meats such as pork and chicken," Smith said. "Cooked beef patties appear to be the cooked meat with the highest mutagenic activity and may be the most important source of HCAs in the human diet."
Previous studies have shown that meat products cooked below 352 degrees Fahrenheit for less than four minutes had low or undetectable levels of HCAs, with HCAs increasing with higher temperatures and added cooking time. It's not a good idea to lower cooking temperatures too much, so antioxidant spices with phenolic compounds can block HCAs before they form during heating and still allow high temperatures to be maintained.
Smith's research team investigated six spices - cumin, coriander seeds, galangal, fingerroot, rosemary and tumeric - and found that the latter three had the highest levels of antioxidant activity toward inhibiting the formation of HCAs, with rosemary as the most effective.
Consumers can take advantage of the spices by integrating them into their cooking regimen, Smith says. Previous research in his laboratory has demonstrated that some commercial rosemary extracts can inhibit HCA formation by 61 to 79 percent. Smith's earlier work also showed that Thai spices can inhibit HCA formation by 40 to 43 percent.
Smith said future research in this area will investigate what some marinades or powders can do to inhibit HCAs when applied to a cooked patties. His earlier project showed that marinating steaks with certain herbs, rosemary and other antioxidant spices also reduces HCAs.
