Implications of Helicobacter pylori infection for stomach cancer prevention

Protective effect of yoghurt consumption on Helicobacter pylori seropositivity in a Mexican population

OBJECTIVE

The aim of the study was to determine the relationship between fermented and unfermented dairy product consumption and Helicobacter pylori seropositivity in a Mexican population.

DESIGN

Dietary interviews were conducted as part of a population-based case-control study in 2005. Serum was obtained for each participant to determine H. pylori seropositivity status. Adjusted odds ratios were estimated from multivariate logistic regression models.

SETTING

Mexico City, Mexico.

SUBJECTS

A random sample of 464 healthy adult residents.

RESULTS

The overall seroprevalence of H. pylori in the study sample was 75.4%. In fully adjusted models, compared with those who did not consume yoghurt, there was a protective effect of eating up to one serving per week of yoghurt and more than one serving per week of yoghurt (odds ratio (OR) = 0.57, 95% confidence interval (CI) 0.35-0.94 and OR = 0.45, 95% CI 0.24-0.86, respectively), with a P for trend of 0.01. There were no effects for the consumption of unfermented dairy products (milk and cheese).

CONCLUSIONS

This study suggests that yoghurt consumption may have a protective effect against H. pylori seropositivity. Additional studies are needed to determine whether consumption of yoghurt or other fermented dairy products can prevent or eradicate H. pylori infection.

Dieta e câncer gástrico: aspectos históricos associados ao padrão de consumo alimentar no estado do Pará

O câncer gástrico ainda constitui importante problema de saúde pública no estado do Pará, onde as taxas de mortalidade apresentam valores acima da média brasileira. As bases históricas de ocupação de espaço na Amazônia, bem como as relações econômico-sociais estabelecidas ao longo desse processo, marcaram o padrão alimentar desse Estado. Este trabalho tem por objetivo reconstruir as principais características do padrão alimentar dessa população no século passado. Procurou-se identificar todas as publicações científicas disponíveis que relacionavam dados sobre os hábitos alimentares dos residentes do Pará no século XX. A partir dessas publicações, foi possível caracterizar o padrão alimentar da população paraense no século XX, que incluía um elevado consumo de sal, utilizado na conservação de carnes e frutos do mar, um consumo relativamente reduzido e irregular de legumes e verduras e uma importante ingestão de glicídios, a partir da farinha de mandioca, muitas vezes adicionada de corantes artificiais. O padrão de dieta retratado, provavelmente comum a outras regiões da Amazônia, pode ser caracterizado, com base na literatura científica, como potencialmente favorecedor de certas condições associadas à carcinogênese gástrica. Nesse sentido, ele poderia ter contribuído, em parte, para a alta mortalidade por essa neoplasia registrada na região Norte.

Environment and cancer in Brazil: an overview from a public health perspective

This paper presents the current pattern of cancer incidence in Brazil by analyzing the country's cancer epidemiological profile. The authors highlight the observed overlapping distribution of cancer incidence in Brazil in tumor sites normally associated with higher socioeconomic status (cancers of the breast, prostate, and colon/rectum, among others) and poverty (cervix, stomach, oral cavity, and penis). In addition to analyzing the demographic and social characteristics associated with current epidemiological distribution of cancer in Brazil, the authors present several of the most important environmental risk factors (smoking and exposure to radiation, pesticides, and other chemicals) and discuss their respective exposure levels in the Brazilian context. The article concludes with an evaluation of the principal challenges facing environmental cancer control programs in Brazil, particularly focusing on smoking and exposure to chemicals.

Cancer mortality among agricultural workers from Serrana Region, state of Rio de Janeiro, Brazil

One of the proposed hypotheses to explain the higher incidence of specific-site cancers among agricultural workers is their higher exposure to pesticides. The role of pesticide exposure in morbidity and mortality profiles in Brazil is not well known. Therefore, in order to contribute to increase knowledge on this subject, an ecological analysis aiming to investigate cancer mortality among agricultural workers in an important agricultural area of the Rio de Janeiro State, Brazil, was performed. All causes of death for male workers 30-69 years old provided by the National Mortality Information System between 1979 and 1998 were evaluated. To estimate cancer mortality risks of selected sites, mortality odds ratio (MOR) was employed, and three reference populations were used. Higher mortality of esophagus, stomach, and larynx cancer in agricultural workers 50-69 years old was observed in the period from 1979 to 1988 and of esophagus and stomach cancer from 1989 to 1998. Agricultural workers 30-49 years old showed higher, but not statistically significant, mortality by stomach, esophagus, liver, testis, and prostate cancer, and soft-tissue sarcoma in the period of 1979-1988, and by testis and penis cancer, leukemia, and soft-tissue sarcoma in the period of 1989-1998. Despite the limitations of ecological approaches concerning causality ascertainment, we believe that this study raises questions of the possible role of pesticide exposure on the cancer mortality profile among Brazilian agricultural workers.

Transmission of Helicobacter pylori among siblings

BACKGROUND

Helicobacter pylori infection causes chronic digestive diseases with a major public-health impact, yet the design of prevention measures is hampered by limited knowledge of transmission pathways. We studied the effect of family composition on H. pylori prevalence among rural Colombian children aged 2-9 years.

METHODS

684 children were screened for H. pylori with the 13C-urea breath test. For each child, birth order, birth spacing, number of 2-9-year-old siblings, and number of H-pylori-positive 2-9-year-old siblings was recorded. Odds ratios were estimated by logistic regression, controlling for hygiene-related exposures, socioeconomic indicators, and the number of children in the household.

FINDINGS

The odds of infection increased with the number of 2-9-year-old siblings in the household (odds ratios 1.4, 2.3, 2.6, and 4.3 for one, two, three, and four to five siblings, respectively). Compared with first-born children, odds ratios for children born second and third to ninth were 1.8 (95% CI 1.0-3.3) and 2.2 (1.0-4.3), respectively. Compared with children born 10 or more years after the next older household member, those born within 4 years were 4.1 times (CI 2.0-8.6) more likely to be infected; the age gap to the next younger household member displayed a weaker effect. The number of H-pylori-positive 2-9-year-old siblings had a particularly strong effect gradient (1.5, 3.2, 5.6, and 7.1, for one, two, three, and four positive siblings, respectively).

INTERPRETATION

Among rural Andean children younger than 10 years, H. pylori infection seems to be transmitted most readily among siblings who are close in age, and most frequently from older siblings to younger ones.