A rethinking of nitrate, nitrite, and nitric oxide for food preservation and human health

Nitrate and nitrite, as long-standing additives used in food industry and particularly prevalent in meat products, are often perceived negatively by consumers due to their potential to produce carcinogenic nitrosamines. Within the past decades, the importance of nitric oxide (NO) has been established for human health, including cardiovascular health, immunizing and defending system, skeletal muscle contraction and relaxation, nervous system, and cognitive function. Gradually, nitrate and nitrite, as the main NO donors, have also been demonstrated to have numerous health benefits in clinical studies. Likewise, NO has showed positive effect on postharvest fruits and vegetables. In view of different controversies, this review comprehensively discussed the effect of nitrate, nitrite on meat products and NO on fruits and vegetables, the intake of nitrate and nitrite by diet, the physiological functions, synthesis and metabolism of nitrate, nitrite, and NO in human body. It is hoped to provide some new understanding for nitrate, nitrite, and NO in food preservation and human health.