Dietary antioxidants, fruits, and vegetables and the risk of Barrett's esophagus

Barrett's esophagus

Barrett's esophagus is an acquired metaplastic abnormality in which the normal stratified squamous epithelium lining of the esophagus is replaced by an intestinal-like columnar epithelium. While in itself a benign and asymptomatic disorder, the clinical importance of this relatively common condition relates to its role as a precursor lesion to esophageal adenocarcinoma, the incidence of which has dramatically increased in Western populations in recent years. Although known to arise as a consequence of chronic gastroesophageal reflux, the cellular and molecular mechanisms underlying development Barrett's esophagus and its progression to cancer remain unclear.

[Surveillance in Barrett's esophagus]

Barrett's esophagus (BE) is a consequence of chronic gastroesophageal reflux. Barrett's esophagus is a well-established risk factor for adenocarcinoma. There is no effective method available to prevent the malignant transformation of Barrett's esophagus. Endoscopy is therefore the only means of patients' screening and monitoring. Endoscopic surveillance is recommended to detect precancerous or cancerous lesions at an early stage, where curative treatment can be proposed.

Barrett's esophagus, esophageal and esophagogastric junction adenocarcinomas: the role of diet

Identification of modifiable risk factors is an attractive approach to primary prevention of esophageal adenocarcinoma (EAC) and esophagogastric junction adenocarcinoma (EGJAC). We conducted a review of the literature to investigate the association between specific dietary components and the risk of Barrett’s esophagus (BE), EAC and EGJAC, supposing diet might be a risk factor for these tumors. Consumption of meat and high-fat meals has been found positively associated with EAC and EGJAC. An inverse association with increased intake of fruit, vegetables and antioxidants has been reported but this association was not consistent across all studies reviewed. Few studies have examined the association between diet and BE. Additional research is needed to confirm the aforementioned association and clarify the mechanisms by which dietary components affect the risk of developing EAC and EGJAC. Future studies could advance our knowledge by emphasizing prospective designs to reduce recall bias, by using validated dietary intake questionnaires and biological measures and by considering important confounders such as gastro-esophageal reflux disease (GERD) symptoms, tobacco and alcohol use, biometrics, physical activity, and socioeconomic factors.

Iron intake and markers of iron status and risk of Barrett's esophagus and esophageal adenocarcinoma

OBJECTIVE

To investigate the association between iron intake and iron status with Barrett's esophagus (BE) and esophageal adenocarcinoma (EAC).

METHODS

A total of 220 BE patients, 224 EAC patients, and 256 frequency-matched controls completed a lifestyle and food frequency questionnaire and provided serum and toenail samples between 2002 and 2005. Using multiple logistic regression, odds ratios (OR) and 95% confidence intervals (95% CI) were calculated within quartiles of intake/status.

RESULTS

Comparing the fourth to the first quartile, ferritin (OR 0.47; 95% CI: 0.23, 0.97) and transferrin saturation (OR 0.41; 95% CI: 0.20, 0.82) were negatively associated with BE; while total iron binding capacity was positively associated per 50 μg/dl increment (OR 1.47; 95% CI: 1.12, 1.92). Comparing the fourth to the first quartile, iron intake (OR 0.50; 95% CI: 0.25, 0.98), non-heme iron intake per 10 mg/day increment (OR 0.29; 95% CI: 0.08, 0.99), and toenail iron (OR 0.40; 95% CI: 0.17, 0.93) were negatively associated with EAC; while heme iron intake was positively associated (OR 3.11 95% CI: 1.46, 6.61).

PRINCIPAL CONCLUSION

In contrast to the hypothesis that increased iron intakes and higher iron stores are a risk factor for BE and EAC, this study suggests that higher iron intakes and stores may have a protective association with BE and EAC, with the exception of what was found for heme iron intake.

Dietary antioxidant and mineral intake in humans is associated with reduced risk of esophageal adenocarcinoma but not reflux esophagitis or Barrett's esophagus

The role of antioxidants in the pathogenesis of reflux esophagitis (RE), Barrett's esophagus (BE), and esophageal adenocarcinoma (EAC) remains unknown. We evaluated the associations among dietary antioxidant intake and these diseases. We performed an assessment of dietary antioxidant intake in a case control study of RE (n = 219), BE (n = 220), EAC (n = 224), and matched population controls (n = 256) (the Factors Influencing the Barrett's Adenocarcinoma Relationship study) using a modification of a validated FFQ. We found that overall antioxidant index, a measure of the combined intake of vitamin C, vitamin E, total carotenoids, and selenium, was associated with a reduced risk of EAC [odds ratio (OR) = 0.57; 95% CI = 0.33-0.98], but not BE (OR = 0.95; 95% CI = 0.53-1.71) or RE (OR = 1.60; 95% CI = 0.86-2.98), for those in the highest compared with lowest category of intake. Those in the highest category of vitamin C intake had a lower risk of EAC (OR = 0.37; 95% CI = 0.21-0.66; P-trend = 0.001) and RE (OR = 0.46; 95% CI = 0.24-0.90; P-trend = 0.03) compared with those in the lowest category. Vitamin C intake was not associated with BE, and intake of vitamin E, total carotenoids, zinc, copper, or selenium was not associated with EAC, BE, or RE. In conclusion, the overall antioxidant index was associated with a reduced risk of EAC. Higher dietary intake of vitamin C was associated with a reduced risk of EAC and RE. These results suggest that antioxidants may play a role in the pathogenesis of RE and EAC and may be more important in terms of progression rather than initiation of the disease process.

Dietary factors and the risks of oesophageal adenocarcinoma and Barrett's oesophagus

Incidence rates for oesophageal adenocarcinoma have increased by over 500% during the past few decades without clear reasons. Gastro-oesophageal reflux disease, obesity and smoking have been identified as risk factors, although the demographic distribution of these risk factors is not consistent with the demographic distribution of oesophageal adenocarcinoma, which is substantially more common among whites and males than any other demographic groups. Numerous epidemiological studies have suggested associations between dietary factors and the risks of oesophageal adenocarcinoma and its precursor, Barrett's oesophagus, though a comprehensive review is lacking. The main aim of the present review is to consider the evidence linking dietary factors with the risks of oesophageal adenocarcinoma, Barrett's oesophagus, and the progression from Barrett's oesophagus to oesophageal adenocarcinoma. The existing epidemiological evidence is strongest for an inverse relationship between intake of vitamin C, β-carotene, fruits and vegetables, particularly raw fruits and vegetables and dark green, leafy and cruciferous vegetables, carbohydrates, fibre and Fe and the risk of oesophageal adenocarcinoma and Barrett's oesophagus. Patients at higher risk for Barrett's oesophagus and oesophageal adenocarcinoma may benefit from increasing their consumption of fruits and vegetables and reducing their intake of red meat and other processed food items. Further research is needed to evaluate the relationship between diet and the progression of Barrett's oesophagus to oesophageal adenocarcinoma. Evidence from cohort studies will help determine whether randomised chemoprevention trials are warranted for the primary prevention of Barrett's oesophagus or its progression to cancer.

Barrett's oesophagus and oesophageal adenocarcinoma: time for a new synthesis

The public health importance of Barrett's oesophagus lies in its association with oesophageal adenocarcinoma. The incidence of oesophageal adenocarcinoma has risen at an alarming rate over the past four decades in many regions of the Western world, and there are indications that the incidence of this disease is on the rise in Asian populations in which it has been rare. Much has been learned of host and environmental risk factors that affect the incidence of oesophageal adenocarcinoma, and data indicate that patients with Barrett's oesophagus rarely develop oesophageal adenocarcinoma. Given that 95% of oesophageal adenocarcinomas arise in individuals without a prior diagnosis of Barrett's oesophagus, what strategies can be used to reduce late diagnosis of oesophageal adenocarcinoma?

Effects of dietary fiber, fats, and meat intakes on the risk of Barrett's esophagus

Animal and human models suggest associations between fat intake, fiber intake, and the risk of esophageal adenocarcinoma. We evaluated whether these factors may act early in the carcinogenic pathway as a risk factor for Barrett's esophagus, a potentially premalignant precursor to esophageal adenocarcinoma using a case-control design within the Kaiser Permanente, Northern California population. Incident Barrett's esophagus cases (n = 296) were matched to persons with gastroesophageal reflux disease (GERD) (n = 308) and to population controls (n = 309). Higher intakes of omega-3-fatty-acids [cases vs. population controls; OR = 0.46, 95% CI = 0.22-0.97, 4th vs. 1st quartiles of intake], polyunsaturated fat, total fiber (OR = 0.34, 95% CI = 0.15-0.76), and fiber from fruits and vegetables (OR = 0.47 95% CI = 0.25-0.88) were associated with a lower risk of Barrett's esophagus. Higher meat intakes were associated with a lower risk of long-segment Barrett's esophagus (OR = 0.25, 95% CI = 0.09-0.72). In contrast, higher trans-fat intakes were associated with increased risk (OR = 1.11; 95% CI = 1.03-1.21 per g/day). Total fat intake, barbecued foods, and fiber intake from sources other than fruits and vegetables were not associated with Barrett's esophagus. Future studies to evaluate whether dietary interventions might influence the risk of Barrett's esophagus or esophageal adenocarcinoma in high risk persons are needed.

Vegetable and fruit intakes and risk of Barrett's esophagus in men and women

BACKGROUND

Barrett's esophagus (BE) is a risk factor for esophageal adenocarcinoma. Modifiable risk factors for BE are largely unknown.

OBJECTIVE

The purpose of this study was to determine whether vegetable and fruit intakes are associated with BE risk.

DESIGN

In a case-control study based in western Washington State, we compared the vegetable and fruit intakes of 170 patients with newly diagnosed BE with those of 182 controls from the general population. Relations between vegetable and fruit intakes and BE were examined by using unconditional logistic regression to compute odds ratios (ORs) and corresponding 95% CIs.

RESULTS

Participants in the second (adjusted OR: 0.40; 95% CI: 0.23, 0.71) and third (adjusted OR: 0.33; 95% CI: 0.17, 0.63) tertiles of vegetable intake appeared to have a lower risk of BE (P for trend = 0.048) than did participants in the first tertile of vegetable intake. Similarly, participants in the second (adjusted OR: 0.49; 95% CI: 0.28, 0.86) and third (adjusted OR: 0.39; 95% CI: 0.21, 0.75) tertiles of combined vegetable and fruit intakes had a lower risk of BE (P for trend = 0.047) than did participants in the first tertile of vegetable and fruit intakes. Similar results were obtained in subanalyses limited to patients with visible and with long-segment BE.

CONCLUSIONS

The results support previous findings that increased intakes of vegetables and of vegetables and fruit are associated with a lower risk of BE in men and women. Prospective data that examine relations between diet and BE are needed.