The effect of serum carotenoids on atrophic gastritis among the inhabitants of a rural area in Hokkaido, Japan

Astaxanthin and β-carotene in Helicobacter pylori-induced Gastric Inflammation: A Mini-review on Action Mechanisms

Helicobacter pylori is a dominant bacterium living in the human gastric tissues. In H. pylori-infected tissues, the infiltrated inflammatory cells produce reactive oxygen species (ROS), leading to gastric inflammation with production of various mediators. According to numerous epidemiological studies, dietary carotenoids may prevent gastric inflammation due to their antioxidant properties. Recent studies showed that antioxidant and anti-inflammatory effects of astaxanthin and β-carotene may contribute to inhibition of H. pylori-induced gastric inflammation. Astaxanthin changes H. pylori-induced activation of T helper cell type 1 response towards T helper cell type 2 response in the infected tissues. Astaxanthin inhibits the growth of H. pylori. Even though astaxanthin reduces H. pylori-induced gastric inflammation, it does not reduce cytokine levels in the infected tissues. β-Carotene suppresses ROS-mediated inflammatory signaling, including mitogen-activated protein kinases and redox-sensitive transcription factors, and reduces expression of inflammatory mediators, including interleukin-8, inducible nitric oxide synthase, and cyclooxygenase-2 in the infected tissues. Therefore, consumption of astaxanthin- and β-carotene-rich foods may be beneficial to prevent H. pylori-induced gastric inflammation. This review will summarize anti-inflammatory mechanisms of astaxanthin and β-carotene in H. pylori-mediated gastric inflammation.

The CAPN2/CAPN8 Locus on Chromosome 1q Is Associated with Variation in Serum Alpha-Carotene Concentrations

BACKGROUND/AIMS

Alpha-carotene is a provitamin A carotenoid present in fruits and vegetables. Higher serum concentrations of α-carotene have been associated with lower risk of cancer and all-cause mortality. Previous studies have suggested that genetic variants influence serum concentrations of provitamin A carotenoids, but to date no variants have been robustly associated with serum α-carotene concentrations. The aim of this study was to identify genetic associations with serum α-carotene concentrations using the genome-wide association study (GWAS) approach.

METHODS

A GWAS of serum α-carotene concentrations was conducted in 433 Old Order Amish adults who had consumed a 6-day controlled diet. Linear regression models adjusting for age, gender, and family structure were utilized to evaluate associations between genetic variants and serum α-carotene concentrations.

RESULTS

Genome-wide significant associations with α-carotene concentrations were observed for loci on chromosome 1q41 between the genes CAPN2 and CAPN8 (rs12137025, p = 3.55 × 10-8), chromosome 2p21 in PRKCE (rs2594495, p = 1.01 × 10-8), and chromosome 4q34 (rs17830069, p = 2.89 × 10-8).

CONCLUSIONS

We identified 3 novel loci associated with serum α-carotene concentrations among a population that consumed a controlled diet. While replication is necessary, the CAPN2/CAPN8 locus provides compelling evidence for an association with serum α-carotene concentrations and may suggest a relationship with the development and progression of cancers.

Prevalence of gastric precancerous conditions: a systematic review and meta-analysis

Several reports of estimates for precancerous conditions for gastric adenocarcinoma can be found in the current literature. Our aim was to systematically review and estimate the prevalence of gastric precancerous conditions. Four databases (PubMed, Scopus, Web of Knowledge and EBSCO Academic Search Complete) were searched for original manuscripts addressing the presence of chronic atrophic gastritis (CAG) or intestinal metaplasia (IM). Subgroup analysis was carried out on methods of diagnosis, type of population, incidence of gastric cancer, sex, Helicobacter pylori status, age and extent of conditions. Overall, 107 studies were included. The worldwide prevalence of CAG in the general population was 33% (95% confidence interval: 26-41%) when considering biopsies (n=20 912) and 24% (19-29%) if serology (n=51 886) was used, whereas IM was found in 25% (19-30%) (n=30 960). Estimates for CAG were higher in countries with a high incidence of gastric cancer (42 vs. 23%), men (32 vs. 28%), H. pylori positive (46 vs. 17%) and if aged 40 years or older (48 vs. 22%). The prevalence of extensive conditions was 16% (12-20%) for CAG and 13% (9.0-17%) for IM. When comparing countries with high versus low to moderate incidence of gastric cancer, significant differences were achieved for CAG: 27% (12-36%) versus 7.3% (5.6-9.0%). Worldwide, one-third and one-fourth of individuals may harbour CAG and IM, respectively. In countries with a high incidence of gastric cancer, the prevalence of extensive conditions may increase up to 27% and these patients represent a high-risk population to whom endoscopic surveillance should be offered according to recent guidelines.