Effects of Animal-Based and Plant-Based Nitrates and Nitrites on Human Health: Beyond Nitric Oxide Production

Nitrate (NO₃) and nitrite (NO₂) are important nitrogen compounds that play a vital role in the nitrogen cycle, contributing to plant nutrition and broader ecological functions. Nitrates are produced from nitric acid (HNO₃), while nitrites come from nitrous acid (HNO₂). These substances are commonly found in the environment, especially in food and water, due to contamination from both human and natural sources. Human activities are major contributors to the high levels of nitrates found in water, leading to environmental pollution. Although nitrogen is crucial for plant growth, excessive fertilizer use has caused ecological disruptions. In plants, nitrates tend to accumulate primarily in the leaves of non-leguminous crops, such as leafy vegetables, which are known for their high nitrate content. Furthermore, nitrates and nitrites are added to animal-based foods, especially processed meats and cheeses, to prevent bacterial growth, slow spoilage, and improve flavor and color. The concentration of these compounds in food can vary due to different factors like farming practices, climate, soil conditions, and food production methods. This review seeks to examine the differences between the plant-based and animal-based sources of these compounds and assess their potential impact on human health, considering also the paradigm that goes beyond nitric oxide production.