Cured meats and childhood cancer

Dietary nitrate and nitrite: Benefits, risks, and evolving perceptions

Consumers have an illogical relationship with nitrite (and its precursor, nitrate) in food. Despite a long history of use, nitrite was nearly banned from use in foods in the 1970s due to health concerns related to the potential for carcinogenic nitrosamine formation. Changes in meat processing methods reduced those potential risks, and nitrite continued to be used in foods. Since then, two opposing movements continue to shape how consumers view dietary nitrate and nitrite. The discovery of the profound physiological importance of nitric oxide led to the realization that dietary nitrate contributes significantly to the nitrogen reservoir for nitric oxide formation. Numerous clinical studies have also demonstrated beneficial effects from dietary nitrate consumption, especially in vascular and metabolic health. However, the latest wave of consumer sentiment against food additives, the clean-label movement, has renewed consumer fear and avoidance of preservatives, including nitrite. Education is necessary but may not be sufficient to resolve this disconnect in consumer perception.

Cured meat products without direct addition of nitrate or nitrite: what are the issues?

The growing popularity of food products marketed in the United States as "natural" and "organic" has resulted in a proliferation of marketing efforts to meet consumer demands for these foods. Because natural and organic foods are not permitted to use chemical preservatives, the traditional curing agents used for cured meats, nitrate and/or nitrite, cannot be added to natural and organic processed meat products. However, alternative processes that utilize ingredients with high nitrate content, such as vegetable-based ingredients, and a nitrate-reducing starter culture can produce processed meats with very typical cured meat properties. Because it is not possible to analytically measure the amount of nitrite produced by this process, several potential issues deserve consideration. Regulations, for example, should permit labeling that accurately reflects the process and products, manufacturing procedures must be standardized to achieve product consistency, marketing efforts should clearly communicate the nature of these products to consumers, product quality must be maintained, and microbiological safety must be assured.

Associação entre fatores da dieta e tumores de cérebro em adultos: uma revisão da literatura

Desenvolveu-se uma revisão da literatura científica publicada entre 1986 e 1999, sobre a associação entre fatores da dieta e os tumores de cérebro em adultos, com o objetivo de descrever as associações observadas e discutir os aspectos metodológicos que possam influenciar os resultados observados. De um modo geral, os estudos revisados parecem apontar na direção de uma associação moderada entre os fatores da dieta e os tumores de cérebro; há evidências de que o consumo de compostos N-nitroso possa favorecer o desenvolvimento desses tumores, e de que o consumo de vegetais e frutas pode ter papel na sua inibição. A participação dos respondentes substitutos nos estudos analisados, pode ter introduzido viés de memória nas informações levantadas e contribuído para a inconsistência dos achados. As investigações epidemiológicas sobre a associação da dieta com estes tumores devem considerar a análise de outros fatores alimentares, além dos compostos N-nitroso. É necessário precisar os períodos de exposição que devem ser investigados e contar com criteriosa metodologia, de modo a prevenir a ocorrência de tendenciosidades relacionadas com a seleção dos controles e minimizar os efeitos do viés de memória.

Childhood cancer in relation to cured meat intake: review of the epidemiological evidence

Over the past two decades a series of epidemiological studies have examined the relationship between consumption of cured meats during pregnancy and the subsequent risk of brain tumors, as well as other cancers, in the offspring. The research was prompted in large part by experimental investigations showing that transplacental exposure to certain N-nitroso compounds, i.e., nitrosoureas, could produce brain tumors in laboratory animals. Fourteen such epidemiological studies, 13 of which used the case-control approach, are reviewed here. Most of the studies showed no significant association between total cured meat intake and childhood cancer risk but more found positive than negative relationships. Furthermore, several studies reported significant positive associations for maternal and sometimes childhood or paternal consumption of one or more cured meats, with odds ratios of twofold or greater reported among the highest consumers. On the other hand, a correlation analysis found no positive concordance between temporal trends from the 1970s to 1990s in childhood brain cancer rates and cured meat consumption, inasmuch as cancer rates rose over time while residual nitrite levels in cured meats fell sharply. Because of the potential for bias, especially recall bias, and/or confounding, the relatively weak magnitude of the associations reported, and the inconsistency between study findings, at this time it cannot be concluded that eating cured meat has increased the risk of childhood brain cancer or any other cancers. Moreover, although N-nitroso compounds are sometimes found in cured meats or may be formed endogenously, there is no empirical evidence that eating cured meats results in human neural nitrosourea exposure. Nevertheless, the hypothesis that eating nitrite-cured meats may influence childhood and perhaps adult brain cancer cannot be dismissed. Unbiased evaluation of the hypothesis may derive from the conduct of cohort studies, where the interview-derived information on cured meat intake precedes, or is not otherwise associated with, the diagnosis of cancer.

Evaluation of hamburgers and hot dogs for the presence of mutagens

Food products derived from heat-treated (fried, broiled, baked) meat may contain traces of mutagenic heterocyclic amine contaminants, some of which are proven carcinogens in rodents. To confirm their presence and range in Canadian foods, and estimate the average human intake of these types of mutagens from frequently consumed heat-processed foods, several commercially prepared fried-beef patties (hamburgers) and hot dogs (weiners) were analysed for their mutagenic capacity. The mutagenicity of the extracts was tested in the Salmonella/microsome assay using strain TA98 with metabolic activation. 16 samples of hamburgers and 14 samples of hot dogs, randomly obtained from 'fast food' commercial establishments or street vendors, were used in this survey. The mutagenic activity of these samples ranged from very low to 1042 revertants/g equivalent for the hamburgers and from non-detectable to 4875 revertants/g equivalent for the hot dogs. The average values were 199 and 424 revertants/g for the hamburgers and hot dogs, respectively. The wide range in mutagenicity was found even for the same type of product obtained from the same outlet at different times. This indicates possible inconsistency in cooking procedures during the preparation of these products. It also shows the difficulty in accurately assessing the intake of mutagenic heterocyclic amines from hamburgers and hot dogs prepared in 'fast food' outlets.