Dietary antioxidant intake and the risk of developing Barrett's oesophagus and oesophageal adenocarcinoma.

BACKGROUND: We investigated in a cohort study, for the first time using 7-day food diaries (7-DFDs), for age-dependent inverse associations with antioxidants, which have anti-carcinogenic properties, and development of Barrett's oesophagus (BO) and oesophageal adenocarcinoma (OAC). METHODS: A total of 24,068 well individuals completed 7-DFDs and donated blood. Vitamins C and E, carotenes, zinc and selenium intakes, and plasma vitamin C were measured. Participants were monitored for 15 years for BO and OAC. Hazard ratios (HRs) were estimated for: quintiles of intake and in participants younger and >=65 years at recruitment, the midpoint of BO peak prevalence. RESULTS: A total of 197 participants developed BO and 74 OAC. There were no significant associations between antioxidants and BO or OAC in the whole cohort or if >65 years at recruitment. In participants <65 years, for BO, there was an inverse trend across plasma vitamin C quintiles (trend HR = 0.82; 95% CI = 0.71-0.96, P = 0.01), OAC for plasma vitamin C (trend HR = 0.58; 95% CI = 0.37-0.92, P = 0.02) and for dietary vitamins C and E (trend HR = 0.71 95% CI = 0.51-0.99, P = 0.04 and trend HR = 0.70; 95% CI = 0.51-0.96; P = 0.03). CONCLUSIONS: Data supports a role for dietary antioxidants prevent BO and OAC, perhaps at the earlier stages of carcinogenesis.

Dietary Polyphenols in the Aetiology of Crohn's Disease and Ulcerative Colitis-A Multicenter European Prospective Cohort Study (EPIC).

BACKGROUND: Oxidative stress may be involved in the aetiology of inflammatory bowel disease and whether dietary polyphenols, which possess antioxidants properties, prevent its development is unknown. METHODS: A total of 401,326 men and women aged 20 to 80 years from 8 countries were recruited between 1991 and 1998 and at baseline completed validated food frequency questionnaires. Dietary polyphenol intake was measured using Phenol-Explorer, a database with information on the content of 502 polyphenols. Incident cases of Crohn's diseases (CD) and ulcerative colitis (UC) were identified during the follow-up period of up to December 2010. A nested case-control study using conditional logistic regression estimated the odds ratios (ORs), and 95% confidence intervals, for polyphenol intake (categories based on quartiles) and developing CD or UC. RESULTS: In total, 110 CD (73% women) and 244 UC (57% women) cases were identified and matched to 440 and 976 controls, respectively. Total polyphenol intake was not associated with CD (P trend = 0.17) or UC (P trend = 0.16). For flavones and CD, there were reduced odds for all quartiles, which were statistically significant for the third (OR3rd versus 1st quartile = 0.33; 95% confidence interval, 0.15-0.69) and there was an inverse trend across quartiles (P = 0.03). Similarly, for resveratrol, there was an inverse association with CD (OR4th versus 1st quartile = 0.40; 95% confidence interval, 0.20-0.82) with an inverse trend across quartiles (P = 0.02). No significant associations between subtypes of polyphenols and UC were found. Effect modification by smoking in CD was documented with borderline statistical significance. CONCLUSIONS: The data supports a potential role of flavones and resveratrol in the risk of developing CD; future aetiological studies should investigate these dietary components and further examine the potential for residual confounding.

Is there a role for vitamin C in preventing osteoporosis and fractures? A review of the potential underlying mechanisms and current epidemiological evidence.

Osteoporosis and related fractures are a major global health issue, but there are few preventative strategies. Previously reported associations between higher intakes of fruits and vegetables and skeletal health have been suggested to be partly attributable to vitamin C. To date, there is some evidence for a potential role of vitamin C in osteoporosis and fracture prevention but an overall consensus of published studies has not yet been drawn. The present review aims to provide a summary of the proposed underlying mechanisms of vitamin C on bone and reviews the current evidence in the literature, examining a potential link between vitamin C intake and status with osteoporosis and fractures. The Bradford Hill criteria were used to assess reported associations. Recent animal studies have provided insights into the involvement of vitamin C in osteoclastogenesis and osteoblastogenesis, and its role as a mediator of bone matrix deposition, affecting both the quantity and quality of bone collagen. Observational studies have provided some evidence for this in the general population, showing positive associations between dietary vitamin C intake and supplements and higher bone mineral density or reduced fracture risk. However, previous intervention studies were not sufficiently well designed to evaluate these associations. Epidemiological data are particularly limited for vitamin C status and for fracture risk and good-quality randomised controlled trials are needed to confirm previous epidemiological findings. The present review also highlights that associations between vitamin C and bone health may be non-linear and further research is needed to ascertain optimal intakes for osteoporosis and fracture prevention.

Dietary antioxidants and the aetiology of pancreatic cancer: a cohort study using data from food diaries and biomarkers.

OBJECTIVE: To investigate whether the dietary antioxidants vitamins C and E, selenium and zinc decrease the risk of developing pancreatic cancer, for the first time using 7-day food diaries, the most accurate dietary methodology in prospective work. DESIGN: 23,658 participants, aged 40-74 years, recruited into the EPIC-Norfolk Study completed 7-day food diaries which recorded foods, brands and portion sizes. Nutrient intakes were calculated in those later diagnosed with pancreatic cancer and in 3970 controls, using a computer program with information on 11,000 foods. Vitamin C was measured in serum samples. The HRs of developing pancreatic cancer were estimated across quartiles of intake and thresholds of the lowest quartile (Q1) against a summation of the three highest (Q2-4). RESULTS: Within 10 years, 49 participants (55% men), developed pancreatic cancer. Those eating a combination of the highest three quartiles of all of vitamins C and E and selenium had a decreased risk (HR=0.33, 95% CI 0.13 to 0.84, p<0.05). There were threshold effects (Q2-4 vs Q1) for selenium (HR=0.49, 95% CI 0.26 to 0.93, p<0.05) and vitamin E (HR=0.57, 95% CI 0.29 to 1.09, p<0.10). The HRs of quartiles for antioxidants, apart from zinc, were <1, but not statistically significant. For vitamin C, there was an inverse association with serum measurements (HR trend=0.67, 95% CI 0.49 to 0.91, p=0.01), but the threshold effect from diaries was not significant (HR=0.68, 95% CI 0.37 to 1.26). CONCLUSION: The results support measuring antioxidants in studies investigating the aetiology of pancreatic cancer. If the association is causal, 1 in 12 cancers might be prevented by avoiding the lowest intakes.

Dietary n-3 polyunsaturated fatty acids and the aetiology of ulcerative colitis: a UK prospective cohort study.

OBJECTIVES: The aetiology of ulcerative colitis (UC) is largely unknown, although it is plausible that dietary n-3 polyunsaturated fatty acids (PUFAs) may be protective. Metabolites derived from n-3 PUFAs are less proinflammatory than those from n-6 PUFAs. Earlier, no prospective cohort studies have investigated this hypothesis, using dietary information collected from food diaries. The aim of this study was to investigate the total dietary intake of n-3 PUFAs and the specific n-3 PUFAs, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) on the risk of developing incident UC. METHODOLOGY: Twenty-five thousand six hundred and thirty-nine participants, living in Norfolk UK, aged 45-74 years (median age at recruitment of 59.2 years), completed 7-day food diaries. These were interpreted using a computer programme, which converted food items into nutrients, including n-3 PUFAs. The cohort was monitored for participants who developed UC. Each case was matched with four controls and an analysis performed using conditional logistic regression. RESULTS: In the cohort, 22 incident cases of UC were identified after a median follow-up time of 4.2 years (range 1.8-8.3 years). A statistically significant protective odds ratio (OR) for the trend across tertiles was found for DHA [OR = 0.43, 95% confidence interval (CI)=0.22-0.86, P = 0.02] and borderline statistically significant differences for trends for total total n-3 PUFAs (OR = 0.56, 95% CI=0.28-1.13, P = 0.10) and EPA (OR = 0.53, 95% CI=0.27-1.03, P = 0.06) after adjusting for age, sex, total energy intake, smoking, and other fatty acids. CONCLUSION: Total dietary n-3 PUFAs, EPA, and DHA, particularly DHA were associated with protection from UC in a cohort aged over 45 years. If the association is causal, then increasing the population's intake of n-3 PUFAs from oily fish may help prevent UC.

Increased consumption of fatty and lean fish reduces serum C-reactive protein concentrations but not inflammation markers in feces and in colonic biopsies.

Fish consumption is associated with a reduced colorectal cancer risk. A possible mechanism by which fish consumption could decrease colorectal cancer risk is by reducing inflammation. However, thus far, intervention studies investigating both systemic and local gut inflammation markers are lacking. Our objective in this study was to investigate the effects of fatty and lean fish consumption on inflammation markers in serum, feces, and gut. In an intervention study, participants were randomly allocated to receive dietary advice (DA) plus either 300 g of fatty fish (salmon) or 300 g of lean fish (cod) per week for 6 mo, or only DA. Serum C-reactive protein (CRP) concentrations were measured pre- and postintervention (n = 161). In a subgroup (n = 52), we explored the effects of the fish intervention on fecal calprotectin and a wide range of cytokines and chemokines in fecal water and in colonic biopsies. Serum CRP concentrations were lower in the salmon (-0.5 mg/L; 95% CI -0.9, -0.2) and cod (-0.4 mg/L; 95% CI -0.7, 0.0) groups compared with the DA group. None of the inflammation markers in fecal water and colonic biopsies differed between the DA group and the groups that consumed extra fish. In conclusion, increasing salmon or cod consumption for 6 mo resulted in lower concentrations of the systemic inflammation marker CRP. However, exploratory analysis of local markers of inflammation in the colon or feces did not reveal an effect of fish consumption.