I welcome the opportunity of the summer weather to let out the caveman in me through stoking up the barbecue for cooking flesh-based foods. This alfresco eating appeals to my most basic instincts, though it is well known that eating char-grilled foods is associated with an increased risk of several forms of cancer, including those of the colon and stomach.
So, while barbecuing may be in keeping with our primal past, there seem to be inherent hazards.
American scientists have recently put this down to a group of compounds known as heterocylic amines (HCAs) - potentially cancer-causing chemicals that form as a result of the action of heat on food. HCAs are formed as a result of the action of heat on amino acids (the building blocks of protein) during the cooking process. The higher the heat applied to a food, the greater the amount of HCAs that form. While many foods have some capacity to liberate HCAs, meat has the greatest potential in this respect, mainly on account of its high protein and the searing heat that is often used to cook it.
Fortunately, a few culinary tricks may help reduce the risk of us playing with fire. One of these is to keep cooking temperature relatively low - there's a lot to be said for controllable gas-fired barbecuing. However, if charcoal briquettes are used, it will help to ensure these are kept a good distance from the food. There's always a risk that liquefied fat from meat will ignite once it drips on to the hot coals, creating flames with an intense heat that are very likely to boost HCA levels, especially if they come in contact with the food. Dousing the flames with water or beer helps ensure that not too much damage is done.
How meat is prepared may also have some impact on its propensity to form HCAs. Thinner cuts are preferable to inch-thick steaks, as they cook more quickly. Marinades can affect HCA formation, too: while those based on honey boost HCA levels, teriyaki dressing and marinades containing turmeric and garlic exert a protective effect.
Another tactic for reducing the cancer-causing potential of meat is eating it with something that can counter any adverse effect in the body. Salad provides folate and carotenoid nutrients that are linked with a reduced risk of cancer. So some care in barbecuing meat and a salad accompaniment can reduce the risk of us suffering any ill effect from a sizzling summer.
· Is there anything about nutrition you would like to as Dr John Briffa? Email him at firstname.lastname@example.org and read his answers in a special Ask the Experts edition of OM at the end of July.