One more reason to go easy on nyama choma

A WHO report in 2015 revealed that meat consumption leads to increased risk of developing gastric cancer. [Courtesy]

Although Kenyans love ‘nyama choma’, the grim news for backyard chefs not just in Kenya, but globally, is research points to the need to go slow, as chemicals in grilled meat - especially red meat - are potential carcinogens.

A World Health Organisation (WHO) report in 2015 revealed that meat consumption leads to increased risk of developing gastric cancer. The latest November 2021 report from a Japan Public Health Centre-based study affirms the WHO findings on the link between red meat and gastric cancer. The research was, however, inconclusive.

But another finding from a research conducted at Moi Teaching and Referral Hospital supports the WHO report, as it found that smoked, salted and grilled meat cooked over charcoal or open flame contained nitrosamines.

According to Johnston Wakhisi, a research scientist and lecturer at the Moi University’s School of Medicine, “nitrosamines are known carcinogens that cause genetic mutations” while “heterocyclic amines, polycyclic hydrocarbons and Benzopyrene (chemicals) formed in meat cooked over open flames and high temperatures are linked to esophageal cancer.”

While grilled meat is a delicious yet waistline-friendly cooking option as it does not require added fat to cook, scientists warn that when the drippings melt off and hit the fire below, the mentioned compounds are released, which then dissipate back up into the meat. 

Much of these findings are based on epidemiological studies. For example, scientists at the National Cancer Institute conducted an extensive survey of colorectal cancer cases. They found that the odds of developing the disease were closely linked to the consumption of red meat, especially when grilled or well done.

But Wakhisi says the carcinogenic chemicals are primarily produced when meat is cooked over hot coal or exposed to high temperatures. Experts recommend preheating the food in an oven to reduce the time it spends on the grate.

Covering the grill with punctured foil and avoiding charred meat also helps.

Marinating your meats has also been proved to have a powerful protective effect, a quality that experts associate with the moisture content found in marinated meats. Liquid, they believe, prevents excess burning. 

Adding dried rosemary to your marinade before grilling reduced the formation of HCAs (heterocyclic amines) by 60 per cent, according to a study in The Journal of Food Science.

Though on one hand red meat offers undisputable nutritional benefits (it is a rich source of iron, protein, and immunity supporting Vitamin B12 and Selenium), on the other, it has the potential to cause cancer, besides other lifestyle diseases.

Wakhisi concludes thus: “It all boils down to how you prepare your meat. Avoid eating the crispy, charred bits.”