Barbecuing meat may make it delicious, but it can also create carcinogens. In fact most methods of cooking beef produce the cancer-causing compounds heterocyclic amines (HCAs). But scientists have now shown that certain herbs and spices can reduce the levels of HCAs in meat by as much as 40%.
Although HCAs can be produced when other meats such as chicken or pork are cooked, they tend to be most prevalent in beef, and especially in hamburgers, which may be the biggest source of HCAs in our diet.
These HCAs increases risk factors for colorectal, stomach, lung, pancreatic, mammary and prostate cancers. The levels of HCAs in food can be reduced by cooking for shorter times at lower temperatures, but this can result in food poisoning if the food is undercooked.
But plants such as herbs and spices contain antioxidant compounds that can neutralize the presence of these HCAs, so chemistry professor J. Scott Smith of Kansas State University decided to investigate their effect on cooked beef.
Barbecuing meat
Smith’s research team investigated six spices — cumin, coriander seeds, galangal, fingerroot, rosemary and turmeric — 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.
Previous research in his laboratory has demonstrated that some commercial rosemary extracts, available for purchase on the Internet, can inhibit HCA formation by 61 to 79 per cent. Smith’s earlier work also showed that Thai spices can inhibit HCA formation by 40 to 43 per cent.
It seems that introducing the spices into the cooking process at an early stage, such as in a marinade, can be the most effective way to counteract the formation of HCAs during cooking.
Frying meat on a gas hob may increase your risk of cancer because of the type of fumes produced during cooking, researchers say.
Cooking fumes produced when frying at high temperatures have recently been classified as “probably carcinogenic” by the International Agency for Research on Cancer (IARC).
This is because potentially harmful chemicals such as polycyclic aromatic hydrocarbons (PAHs), heterocyclic amines, and higher aldehydes have all been found in cooking fumes, which can cause changes to DNA.
A team of researchers from the Norwegian University of Science and Technology decided to find out how the type of fat and energy source used when frying at high temperatures affected the levels of these potentially harmful chemicals.
Mirroring the cooking conditions found in a typical western restaurant kitchen, the research team fried 17 pieces of steak for 15 minutes on a gas or electric hob, using either margarine or soya bean oil.
PAHs, aldehydes and fine and ultrafine particles produced in the “breathing zone” of the cook were measured.
Frying on the gas hob resulted in the highest levels of PAH, aldehydes and ultrafine particles, regardless of the type of fat used. Napthalene – a banned chemical – was the only PAH detected in the meat samples.
And the highest levels of ultrafine particles produced during frying meat on the gas hob was found to be considerably higher compared with cooking with electricity.
Ultrafine particles are more easily absorbed into the lung.
Although the levels of PAHs and particulate matter detected were at levels regarded as safe, the researchers pointed out that the cooking fumes contained other harmful components for which there are no clear safety thresholds, and gas cooking seemed to increase exposure to these.
Professional chefs and cooks may be at a higher risk.
In the journal Occupational and Environmental Medicine, the authors concluded: “Cooking fumes consist of toxic and mutagenic compounds including mutagenic aldehydes and heterocyclic amines with no dose-response relationship, so exposure to cooking fumes should be reduced as much as possible.”
Regulary eating meat, especially if it’s well done or cooked at high temperatures, may increase your chances of developing bladder cancer, according to new research.
Past research has shown that meat cooked at high temperatures can generate cancer causing chemicals called heterocyclic amines (HCAs).
In this study, scientists wanted to find out how cooking meat, meat consumption and HCAs affected a person’s risk of developing bladder cancer.
Researchers analysed data from over 1,700 people over a 12 year period, 884 with bladder cancer.
Patients were separated into four groups, according to how much red meat they ate as part of their diet.
After adjusting for factors such as age, gender and ethnicity, the scientists found that the group who ate the most red meat were one and a half times more likely to develop bladder cancer compared with those who ate the least.
Eating steaks, pork chops and bacon raised bladder cancer risk significantly, they said. And even fried chicken and fish were found to “significantly raise the odds of cancer.”
And people whose diet included well-done meats were almost twice as likely to develop bladder cancer as those who preferred their meats rare.
The scientists also found that three specific HCAs were associated with the highest risk of bladder cancer.
In addition to diet, the scientists also analysed the DNA of patients to look for any genetic variations which may interfere with the way people metabolise red meat and increase their risk of cancer.
They found that some gene variations could increase your chances by as much as five times if they ate a lot of meat as part of their diet.
“This research reinforces the relationship between diet and cancer,” said Professor Xifeng Wu, from the University of Texas and lead author on the study.
“These results strongly support what we suspected: people, who eat a lot of red meat, particularly well-done red meat, such as fried or barbecued, seem to have a higher likelihood of bladder cancer.”
The research was presented at the annual meeting of the American Association for Cancer Research held in Washington DC.