Table 1. Sources of oxidative/nitrosative stress.

Sources	Effect	Method
Smoking	↑ ROS/RNS	Tar contains NO
		Induction of free radical release by immune cells
Meats	↑ ROS/RNS	Nitrates/nitrites used for meat preservation promote NO synthesis
		Heterocyclic amines (HCA) from cooking induce ROS
Pollutants	↑ ROS/RNS	Radiations, pesticides and xenobiotics damage cell structures
		Alter mitochondrial function, active ROS/RNS producing inflammatory cells, or directly generate free radicals
		Heavy metals can inactive antioxidant reactions
Obesity	↑ ROS/RNS	High fat and carbohydrate diet promote ROS
		Diminished antioxidant activity

ROS, reactive oxygen species; RNS, reactive nitrogen species.