Leafy Vegetable Nitrite and Nitrate Content: Potential Health Effects

Abstract

The aim of this research was to determine the concentrations of nitrates and nitrites in different types of vegetables that are commonly represented in the diet of the inhabitants of Split and Dalmatian County. Therefore, using the method of random selection, there were 96 samples of different vegetables. The determination of the nitrate and nitrite concentrations was carried out by high-pressure liquid chromatography (HPLC) with a diode array detector (DAD). The nitrate concentrations in the range 2.1–4526.3 mg kg−1 were found in 92.7% of the analyzed samples. The highest nitrate values were found in rucola (Eruca sativa L.) followed by Swiss chard (Beta vulgaris L.). In 36.5% of the leafy vegetables intended for consumption without prior heat treatment, nitrite was found in the range of 3.3–537.9 mg kg−1. The high levels of nitrite in the vegetables intended for fresh consumption and the high nitrate values in Swiss chard indicate the need to establish maximum nitrite limits in vegetables, as well as the broadening of legal nitrate limits to wide varieties of vegetables.

Source-specific nitrate and nitrite intakes and associations with sociodemographic factors in the Danish Diet Cancer and Health cohort

“…It is hypothesized that nitrate and nitrite, when consumed as part of plant-based whole foods, should not form carcinogenic N -nitroso compounds, largely due to the concurrent presence of vitamins and polyphenols in plants ( 16 ). Recently, very high levels of nitrite have been detected in samples of rucola, lettuce and spinach from Croatia ( 5 ); the safety of consuming vegetables with very high levels of nitrite, and nitrate, is currently unknown and warrants investigation. To better understand associations with health outcomes in future studies, it is essential to examine confounders of plant-sourced nitrate/nitrite intake, given its strong correlation with plant-based food consumption and the typically healthier behaviors of such consumers, including increased health consciousness and higher education levels ( 32 ).…”

“…In plants, nitrate and nitrite hold pivotal functions, supporting growth and development ( 2 , 3 ). There is a wide variation in the nitrate and nitrite content of plants, being influenced by genetic, environmental and cultivation factors ( 4 , 5 ). In animal-sourced food products, nitrate and nitrite are both naturally occurring ( 6 ) and permitted food additives most commonly in the processing of meats ( 7 , 8 ).…”

“…In animal-sourced food products, nitrate and nitrite are both naturally occurring ( 6 ) and permitted food additives most commonly in the processing of meats ( 7 , 8 ). The nitrate and nitrite content of both plant-and animal-sourced foods is influenced by cooking ( 5 , 9 ). Drinking water is a source of nitrate being found naturally in both surface and groundwater due to drainage from soil.…”

Boosting nutritional quality of Urtica dioica L. to resist climate change

“… Rocha (2021) states that preclinical and clinical evidence suggests that a diet rich in nitrates has the potential to halt, reverse or ameliorate the physiological decline associated with aging. Nevertheless, controlling nitrate content in plant foods is crucial to ensure their safety and nutritional value, as about 80% of nitrates in the diet come from the consumption of vegetables ( Brkić et al., 2017 ; Luetic et al., 2023 ). Nitrate accumulation is very complex and is influenced by several internal and external factors, highlighting the need for careful management throughout the plant’s growth cycle to optimize the balance between nutritional value and potential risks ( Qiu et al., 2014 ).…”

Nitrite anodic oxidation at Ni(ii)/Ni(iii)-decorated mesoporous SnO2 and its analytical applications

“…Even though nitrite and its precursor saltpetre (nitrate) have been used since ancient times for meat curing and food preservation, increased concern about the effects of nitrite ingestion only arose in the mid-20 th century, once the potential of this compound to form carcinogenic nitrosamines was revealed. 1–3 As a result, constant efforts have been made to drastically reduce the role of nitrite in the food industry, 4 but the excessive use of agricultural fertilizers 5 and the uncontrolled discharge of industrial wastewater 6 continue to be possible sources of environmental nitrite contamination. Despite some controversy concerning the negative effect on human health of nitrite, 7 it is currently widely accepted that its presence at concentrations exceeding 200 ppm in meat products 8 and 3 mg L −1 in drinking water 9 can lead to the inhibition of oxygen transport, 10 to the formation of carcinogenic compounds, 11 and possibly to the occurrence of certain defects in the central nervous system during the intrauterine period.…”