Staple Food Fortification with Folic Acid and Iron and Gastrointestinal Cancers: Critical Appraisal of Long-Term National Fortification.

The co-occurrence of wheat flour fortification with folic acid and iron and gastrointestinal cancer incidences were critically assessed in the East Azerbaijan province in Northwest of Iran. In an ecological design, overall gastrointestinal cancer rate ratios and their 95% confidence intervals (95% CI) were calculated as primary outcome before (2004-2006) and after (2007-2015) the introduction of fortification. No consistent changes were observed in esophageal and gastric cancer, but the rate ratios of colorectal cancer increased significantly after fortification in the 35-54 years age group (women: 2.07, 95% CI: 1.79-2.49; men: 1.59, 95% CI: 1.33-1.89) and the 55-74 years age group (women 1.50, 95% CI: 1.27-1.76; men: 2.51, 95% CI: 2.13-2.95). The increased incidence of colorectal cancer was contemporary with long-term fortification; further investigation is required to establish the associations.

Folic Acid Supplement Intake and Risk of Colorectal Cancer in Women; A Case Control Study.

Background: An ongoing controversy exists on the role of folic acid supplementation in colorectal cancer risk among epidemiological studies. Objective: To assess the association between maternal folic acid supplementation and colorectal cancer risk. Methods: A paired matched case control study of 405 subjects was performed, including women residing in 135 villages of East Azerbaijan, Iran. Per area, subjects were followed regularly in local healthcare centers, where health- and social-related information have been collected prospectively in face to face interviews by well-trained health workers. We extracted folic acid supplement intake, baseline characteristics, and confounders from healthcare records. The data for study participants were linked to national cancer registry repositories, from which we retrieved the data of 135 women diagnosed with colorectal cancer between 2005 to 2015. Two hundred seventy controls were individually matched with cases in terms of residing village, age, and gender. We applied multivariate conditional logistic regression to estimate odds ratios (ORs) and 95% confidence intervals (CIs). Findings: There was no significant association between folic acid supplementation and colorectal cancer risk in those with history of folic acid intake compared to those with no history of intake (OR 0.95; 95% CI 0.59 to 1.53), in those with less than five years of folic acid (0.79; 0.45 to 1.39) or in those with ≥5 years intake (1.09; 0.52 to 2.26). This risk did not change after adjustment for covariates or further stratification. Conclusions: Maternal folic acid supplementation did not affect colorectal cancer risk in a population where supplemental folic acid is prescribed with regular intervals for women of child-bearing age.

Folic acid intake and folate status and colorectal cancer risk: A systematic review and meta-analysis.

BACKGROUND & AIMS: To evaluate the controversies among the studies assessing the association between folic acid intake or folate status and colorectal cancer risk. METHODS: PubMed, Cochrane library and references of related articles were searched from January 2000 to September 2016. Studies on folic acid intake or folate status and colorectal cancer or adenoma risk were included. Full text review was conducted for potentially eligible studies. Quality assessment was performed. Random-effects meta-analysis was used to estimate risk ratio and 95% Confidence Intervals. Analysis was conducted by Comprehensive Meta-Analysis software. RESULTS: Folic acid supplement intake showed no significant effect on colorectal cancer risk in meta-analysis of randomized controlled trials, RR: 1.07 (95% CI: 0.86-1.43). The effect on risk was not significant in cohort studies either; RR = 0.96 (95% CI: 0.76-1.21). However, there was significant reduced colorectal cancer risk in total folate intake in cohort studies; 0.71 (95% CI: 0.59-0.86). Odds Ratio was also significantly reduced in case control studies; 0.77 (95% CI: 0.62-0.95). Nevertheless once folate status was measured as Red Blood Cell folate content, no significant effect on colorectal cancer risk was observed; 1.05 (95% CI: 0.85-1.30). CONCLUSION: The differences in bioavailability and metabolism of synthetic folic acid and natural dietary folate as well as variation in the baseline characteristics of subjects and various methods of folate status assessment might be the main reasons for these controversies. Findings of present study highlight the importance of individualized folic acid supplement intake given the fact that the beneficiary effects of long term folic acid supplementation is not confirmed.

The effectiveness of acupuncture, acupressure and chiropractic interventions on treatment of chronic nonspecific low back pain in Iran: A systematic review and meta-analysis.

BACKGROUND: Low back pain (LBP) is one of the most common health problems in adults. The impact of LBP on the individual can cause loss of health status and function related to pain in the back. To reduce the impact of LBP on adults, drug therapy is the most frequently recommended intervention. But over the last decade, a substantial number of randomized clinical trials of non-pharmacological intervention for LBP have been published. OBJECTIVE: To determine the effectiveness of acupuncture, acupressure and chiropractic (non-pharmacological) interventions on the treatment of chronic nonspecific low back pain in Iran. STUDY DESIGN: Systematic review and meta-analysis. METHODS: A systematic literature search was completed without date restrictions up to May 2013 in five major databases (Medline, CINAHL, Science Direct, CAJ Full-text Database, and Cochrane databases). Only randomized controlled trials published in Persian (Farsi) or English languages were included. Two independent reviewers extracted the data. The quality of the papers was assessed using the Cochrane Back Review Risk of Bias criteria. RESULTS: Initial searches revealed 415 papers, 382 of which were excluded on the basis of abstract alone. After excluding 23 papers due to duplication, the remaining 10 trial papers were subjected to a more detailed analysis of the full text, which resulted in three being excluded. The seven remaining trials had a lack of methodological and clinical homogeneity, precluding a meta-analysis. The trials used different comparators with regards to the primary outcomes, the number of treatments, the duration of treatment and the duration of follow-up. CONCLUSION: This systematic review demonstrates that acupuncture, acupressure and chiropractic may have a favorable effect on self-reported pain and functional limitations on NSCLBP. However, the results should be interpreted in the context of the limitations identified, particularly in relation to the heterogeneity in the study characteristics and the low methodological quality in many of the included studies.