DietaryN-nitroso compounds and risk of colorectal cancer: a case–control study in Newfoundland and Labrador and Ontario, Canada

Abstract

Several N-nitroso compounds (NOC) have been shown to be carcinogenic in a variety of laboratory animals, but evidence of their carcinogenicity in humans is lacking. We aimed to examine the association between NOC intake and colorectal cancer (CRC) risk and possible effect modification by vitamins C and E and protein in a large case-control study carried out in Newfoundland and Labrador, and Ontario, Canada. A total of 1760 case patients with pathologically confirmed adenocarcinoma and 2481 population controls were asked to complete a self-administered FFQ to evaluate their dietary intakes 1 year before diagnosis (for cases) or interview (for controls). Adjusted OR and 95% CI were calculated across the quintiles of NOC (measured by N-nitrosodimethylamine (NDMA)) intake and relevant food items using unconditional logistic regression. NDMA intake was found to be associated with a higher risk of CRC (highest vs lowest quintiles, OR: 1.42; 95% CI: 1.03,1.96; p-trend=0.005), specifically for rectal carcinoma (OR: 1.61; 95% CI: 1.11,2.35; p-trend=0.01). CRC risk also increased with the consumption of NDMA-containing meats when the highest tertile was compared with the lowest tertile (OR: 1.47; 95% CI: 1.03,2.10; p-trend=0.20). There was evidence of effect modification between dietary vitamin E and NDMA. Individuals with high NDMA and low vitamin E intakes had a significantly increased risk than those with both low NDMA and vitamin E intakes (OR:3.01; 95% CI: 1.43,6.51; p-interaction=0.017). The present results support the hypothesis that NOC intake may be positively associated with CRC risk in humans. Vitamin E, which inhibits nitrosation, could modify the effect of NDMA on CRC risk.

Nutrient-Gene Interaction in Colon Cancer, from the Membrane to Cellular Physiology

“…Surprisingly, miR-21 was decreased by the combination diet compared to the control diet (189, 190). This is noteworthy because, as previously noted, miR-21 is a well-known oncogenic miRNA, and its validated targets, PDCD4 and PTEN, are known tumor suppressor genes (9, 135, 229). Compared to the fish oil diet, miR-26b, miR-30b, miR-98, miR-130b, miR-182, miR-200c, and miR-203 were uniquely increased by fish oil and pectin combination feeding.…”

“…These compounds can interact with DNA to promote oncogenic mutations in driver genes (95, 119). Similar to the links of heme and heterocyclic amine with colorectal cancer, epidemiological studies have found a link between NOC and colorectal cancer (47, 125, 229). …”

Colorectal cancer risk and nitrate exposure through drinking water and diet

“…The high intake of energy, red or processed meat and alcohol, as well as physical inactivity and obesity, are established risk factors . Increased CRC risk has been suggested with dietary nitrite or dietary NOCs . Recently, a prospective study found an increased risk among subjects with high dietary nitrate and low vitamin C intake .…”

Epidemiological Study of Brain Tumours Incidence in Sudan During 2014-2017

“…Indeed the distribution of BTs in Sudan seemed to be dependent on the population (5.2 million in 2014), aging factors: most are young adult and old ones, food and dietary factors: as has been approved that N-nitroso compounds could induce neurosarcomas and potent neurocarcionogenic [26,27]; in this realm Sudanese population have focused on processed meat and fast food intake abundantly, occupational and the living style: as exposed workers to electric and magnetic fields showed significant (10% to 20%) risk increment for brain tumors [28,29]; in addition to the technology of communication specially wireless exemplar in cellular phones and electromagnetic field utilized in medical field (magnetic resonance imaging) as have been approved to induce certain brain vacuolation, atrophied hepatocytes, spleen and kidney rupture [30]. Relative to this facts: Sudanese population randomly living near high tension transformer/towers of electricity, wireless station and uncontrolled usage of cell phone (long duration chatting) that may contribute in increasing the risk factors and incidence of BTs.…”