Iron intake with the risk of breast cancer among Chinese women: a case-control study

The predictive role of the total potassium intake and odds of breast cancer: a case-control study

BACKGROUNDS

Dietary potassium can play an important role in decreasing inflammatory factors as a protective factor for cancers. In this case-control study, we aimed to assess the possible association between dietary potassium intake and the risk of breast cancer (BC) among Iranian adult women.

METHODS

The present case-control study was conducted at Shohada and Imam Hossain hospitals, in Tehran. The study included 134 newly diagnosed cases of BC and 267 controls. A validated semi-quantitative 168-item food frequency questionnaire was used to compute the potassium intake. Logistic regression, adjusted for potential confounders, was used to estimate odds ratios(ORs) and 95% confidence intervals(CI) of BC according to tertiles of potassium intake.

RESULTS

The mean(M) ± standard deviation(SD) of age and body mass index (BMI) were 47.9 ± 10.3 years and 29.4 ± 5.5 kg/m2, respectively. Also, the M ± SD of potassium intake for the control and case groups was 1616 ± 293 and 1542 ± 338 (mg/1000 Kcal), respectively. In the multivariable-adjusted model for potential confounders, the higher total potassium intake was associated with decreased odds of BC (OR: 0.35, 95%CI: 0.19-0.62, P for trend < 0.001). Moreover, an inverse relationship was observed between potassium from plant sources (OR: 0.39, 95%CI: 0.22-0.69, P for trend = 0.001) and fruit and vegetable sources (OR: 0.49, 95%CI: 0.28-0.87, P for trend = 0.016) and odds of BC.

CONCLUSIONS

Our findings suggested that diet rich in potassium may have a predictive role to reduce the odds of BC.

Micronutrient Status and Breast Cancer: A Narrative Review

Breast cancer is one of the most common cancers worldwide, at the same time being one of the most prevalent causes of women's death. Many factors such as alcohol, weight fluctuations, or hormonal replacement therapy can potentially contribute to breast cancer development and progression. Another important factor in breast cancer onset includes micronutrient status. In this narrative review, we analyzed 23 micronutrients and their possible influence on breast cancer onset and progression. Further, the aim of this study was to investigate the impact of micronutrient status on the prevention of breast cancer and its possible influence on various therapeutic pathways. We researched meta-analyses, systemic and narrative reviews, retrospective studies, as well as original studies on human and animal models. The results of these studies indicate a possible correlation between the different levels of micronutrients and a decreased risk of breast cancer as well as a better survival rate. However, further studies are necessary to establish adequate doses of supplementation of the chosen micronutrients and the exact mechanisms of micronutrient impact on breast cancer therapy.

Association of Dietary Intake of Zinc and Selenium with Breast Cancer Risk: A Case-Control Study in Chinese Women

As major nonenzymatic antioxidant components in the body, dietary Zinc (Zn) and Selenium (Se) may have an impact on breast cancer development. This study aimed to investigate the relationship between dietary Zn, Se intake and breast cancer risk in Chinese women. The case-control study included 1591 cases and 1622 age-frequency matched controls. Dietary intake was collected using a validated food frequency questionnaire. Dietary Zn and Se were divided into four categories: Zn/Se from plants, Zn/Se from meat, Zn/Se from red meat, and Zn/Se from white meat. Unconditional logistic regression models and restricted cubic spline analyses were performed to identify potential associations. Zn from white meat intake was linearly and inversely associated with breast cancer risk, and Se from red meat intake was linearly and positively associated with breast cancer risk, with adjusted odds ratio and 95% confidence interval of 0.76 (0.61-0.95) and 1.36 (1.04-1.77), respectively. Non-linear relationships were found between total dietary Zn, Zn from meat, Zn from red meat intake and breast cancer risk (p_{non-linearity} < 0.05). In conclusion, dietary Zn and Se intake were associated with breast cancer risk in Chinese women, and the optimal intake of Zn may be beneficial for breast cancer prevention.

Pre-Clinical Insights into the Iron and Breast Cancer Hypothesis

Population studies, systematic reviews, and meta-analyses have revealed no relationship between iron status and breast cancer, a weak positive association, or a small protective effect of low iron status. However, in those studies, the authors concluded that further investigation was merited. The set of experiments reported here used preclinical models to assess the likely value of further investigation. The effects of iron status on the initiation and promotion stage of mammary carcinogenesis are reported. Using the classical model of cancer initiation in the mammary gland, 7,12 dimethyl-benz[α]anthracene-induced carcinogenesis was unaffected by iron status. Similarly, excess iron intake showed no effect on the promotion stage of 1-methyl-1-nitrosurea-induced mammary carcinogenesis, though iron deficiency exerted a specific inhibitory effect on the carcinogenic process. Though iron-mediated cellular oxidation is frequently cited as a potential mechanism for effects on breast cancer, no evidence of increased oxidative damage to DNA attributable to excess iron intake was found. The reported preclinical data fail to provide convincing evidence that the further evaluation of the iron–breast cancer risk hypotheses is warranted and underscore the value of redefining the referent group in population-based studies of iron–cancer hypotheses in other tissues.