Effects of dietary beef, pork, chicken and salmon on intestinal carcinogenesis in A/J Min/+ mice

A comparative analysis of factors influencing colorectal cancer’s age standardized mortality ratio among Korean women in the hot and cold spots

The study aimed at exploring factors that most influence colorectal cancer (CRC) age standardized mortality ratio (ASMR) among Korean women, as reported in previous studies. The factors used the data of 250 municipalities from the Korean Statistical Information Service (KOSIS) from 2010 to 2018. In the exploratory survey, over 70% of women aged 65 and above died of colorectal cancer. After investigating the existing literature and theories, 250 regions were classified into hot and cold spots according to age standardized mortality ratio (ASMR). The Nearest Neighbor Index (NNI), Moran’s I index and The Durbin-Watson test were also utilized. The ASMR’s regional cluster analysis showed that the inland areas were the hot spots and the cold spots were in the southwest coastal areas. The result also showed the differences in dwellers’ lifestyles between these two regions as well as the mean difference between the two. In addition, there was no significant difference in ASMR for breast cancer, CRC deaths, and agricultural product shipments between the two regions. In the multiple regression model, CRC mortality, diabetes, and CRC age standardized incidence ratio (ASIR) were analyzed as major influencing factors, demonstrated a significant result with 30.6% by examining the adjusted R-squared. However, this study showed that factors such as smoking, alcohol consumption, abdominal obesity, breast cancer, and food consumption indicated to have less influence on the occurrence of CRC. The aging rate, amount of food consumption, seafood production, livestock product shipments, and drinking rate were higher in the cold spot than in the hot spot.

Fish Consumption and Colorectal Cancer Risk: Meta-Analysis of Prospective Epidemiological Studies and Review of Evidence from Animal Studies

Background: Epidemiological studies on the association between fish consumption and colorectal cancer (CRC) risk have yielded inconsistent results, despite evidence from preclinical studies that long-chain ω-3 polyunsaturated fatty acids inhibit colorectal carcinogenesis. We conducted a meta-analysis of prospective epidemiological studies investigating the association between fish consumption and CRC risk among humans and reviewed studies examining the link between fish components and colorectal carcinogenesis in animal models. Methods: We included studies published until November 2020. We calculated the summary risk ratio (SRR) and 95% confidence intervals (CI) through random effects meta-analysis models in order to summarize evidence from studies among humans. Results: Twenty-five prospective epidemiological studies encompassing 25,777 CRC cases were included. Individuals in the highest (vs. lowest) category of fish consumption had a significantly reduced risk of CRC (SRR 0.94, 95%CI 0.89-0.99). In dose-response meta-analysis, a 50-g increment in the daily consumption of fish was associated with a statistically significant 4% reduction in CRC risk (SRR 0.96, 95%CI 0.92-0.99). Preclinical studies (n = 25) identified multiple mechanisms of action of fish and fish components on colorectal carcinogenesis. Conclusions: Dietary recommendations for cancer prevention should take into account the evidence from epidemiological and preclinical studies that increasing fish consumption may be effective in preventing CRC.

Maternal exposure to a human relevant mixture of persistent organic pollutants reduces colorectal carcinogenesis in A/J Min/+ mice

An increased risk of developing colorectal cancer has been associated with exposure to persistent organic pollutants (POPs) and alteration in the gut bacterial community. However, there is limited understanding about the impact of maternal exposure to POPs on colorectal cancer and gut microbiota. This study characterized the influence of exposure to a human relevant mixture of POPs during gestation and lactation on colorectal cancer, intestinal metabolite composition and microbiota in the A/J Min/+ mouse model. Surprisingly, the maternal POP exposure decreased colonic tumor burden, as shown by light microscopy and histopathological evaluation, indicating a restriction of colorectal carcinogenesis. ¹H nuclear magnetic resonance spectroscopy-based metabolomic analysis identified alterations in the metabolism of amino acids, lipids, glycerophospholipids and energy in intestinal tissue. In addition, 16S rRNA sequencing of gut microbiota indicated that maternal exposure modified fecal bacterial composition. In conclusion, the results showed that early-life exposure to a mixture of POPs reduced colorectal cancer initiation and promotion, possibly through modulation of the microbial and biochemical environment. Further studies should focus on the development of colorectal cancer after combined maternal and dietary exposures to environmentally relevant low-dose POP mixtures.