While grilling does create foods that have a unique flavor and texture, and grilling is pretty synonymous with summertime, we do have some concerns about it.
There are documented health risks associated with the char-broiling and gas grilling of foods. In general, these risks are associated with the formation of heterocyclic amines (HAs). Most HAs are well-documented carcinogens, and keeping their levels to a minimum in a diet can decrease our cancer risk. Here are the basic factors involved with HA formation in food:
The principles of nutrient loss from charcoaled or gas-grilled foods are very similar to the principles of all cooking: the shorter the time of exposure to heat, and the lower the heat, the less the nutrient loss. Since this cooking method does not typically involve use of water, there can be less nutrient loss from this method than from boiling or simmering. However, minimal steaming of a food would typically requiring less total cooking time and for this reason result in decreased loss of nutrients.
As noted above, most of the research on HAs has been done on meat. Therefore, it is uncertain that the grilling of vegetables and fruits may have the same level of outcomes, notably because some of the phytonutrients found in vegetables, such as the sulforaphane in broccoli, have been found to reduce the carcinogenic effect of the HAs in research studies.
The bottom line: from a health perspective, we would choose other methods of preparing foods rather than grilling, yet if you want to enjoy grilled foods on occasion, given that the rest of your diet is healthy, it may not be so detrimental. If you do choose to grill foods and use an oil to coat them, we would suggest using an oil that has a high smoke point, such as avocado oil or high-oleic safflower oil to avoid the formation of oxidative damage to the oil itself. Additionally, there are certain antioxidant-containing foods, such as rosemary, citrus fruits and green tea, which have been found to reduce HA levels. Therefore, you could consider using these foods in marinades if you are looking for ways to reduce HA formation.