Gerda K. Pot

No effect of fish oil supplementation on serum inflammatory markers and their interrelationships: a randomized controlled trial in healthy, middle-aged individuals.

Background:A high intake of n-3 polyunsaturated fatty acids (PUFAs), mainly present in fish, may be associated with decreased inflammation. Previous intervention studies on fish PUFA and inflammatory markers in healthy individuals did not analyze a broad spectrum of inflammatory cytokines, chemokines and cell adhesion molecules, or their interrelationships. Therefore, we determined the effects of fish oil supplementation on 19 serum inflammatory markers and their interrelationships in healthy, middle-aged individuals.Methods:Individuals (n=77) aged 50–70 years completed a randomized, double-blind placebo-controlled intervention study. Participants received 3.5 g/day fish oil (1.5 g/day total n-3 PUFA) (n=39) or placebo (high oleic sunflower oil) (n=38) for 12 weeks. Serum concentrations of 19 inflammatory markers were determined using a multiplex immunoassay before and after intervention. Changes in concentrations were analyzed using analysis of covariance and differences in patterns in inflammatory markers between the fish oil and placebo group were analyzed by principal component analysis.Results:Fish oil supplementation did not significantly affect serum concentrations of cytokines, chemokines or cell adhesion molecules as compared with placebo. However, there was a trend for all inflammatory markers to increase after fish oil supplementation. PCA did not result in markedly distinctive patterns of inflammatory markers for the fish oil and placebo group.Conclusion:In conclusion, this 12-week randomized, double-blind placebo-controlled intervention trial did not show that 1.5 g/day n-3 PUFA significantly affected the serum inflammatory response in healthy individuals, nor did patterns of inflammatory markers. Thus, a healthy middle-aged population may not benefit from fish oil as an anti-inflammatory agent.

Opposing associations of serum n‐3 and n‐6 polyunsaturated fatty acids with colorectal adenoma risk: An endoscopy‐based case–control study

Several human and animal studies have shown that n‐3 polyunsaturated fatty acids (PUFA) might be associated with a decreased risk, whereas other studies showed that n‐6 PUFA may be associated with an increased risk of colorectal cancer. However, results from these studies are not consistent. We evaluated the associations between serum n‐3 and n‐6 PUFA levels and colorectal adenoma risk in an endoscopy‐based case–control study, conducted in The Netherlands between 1997 and 2002. We included 363 cases of colorectal adenomas and 498 adenoma‐free controls. Serum fatty acids were measured in cholesteryl esters. Logistic regression models were used to calculate odds ratios (OR), which were adjusted for age, gender and alcohol intake. Total serum n‐3 PUFA levels were inversely associated with colorectal adenoma risk, the OR comparing the third tertile with the first tertile was 0.67 [95% confidence interval (CI) 0.46–0.96, p for trend = 0.03]. Serum eicosapentaenoic acid (EPA; C20:5n‐3) and docosahexaenoic acid (DHA; C22:6n‐3) and the n‐3/n‐6 ratio were inversely associated with colorectal adenoma risk, but these were not statistically significant. In contrast, the risk of colorectal adenomas was increased by total n‐6 PUFA with an OR of 1.68 (95% CI, 1.17–2.42, p for trend = 0.006) and by linoleic acid (LA; C18:2n‐6) with an OR of 1.65 (95% CI, 1.15–2.38, p for trend = 0.007). This is the first observational study that simultaneously finds an inverse association of serum n‐3 PUFA and a positive association of n‐6 PUFA with colorectal adenoma risk.

Fish consumption and markers of colorectal cancer risk: a multicenter randomized controlled trial

BACKGROUND Diet is a major factor in the etiology of colorectal cancer, with high fish consumption possibly decreasing colorectal cancer risk, as was shown in several observational studies. To date, no intervention trials have examined the possible beneficial effects of fish intake on colorectal cancer risk. OBJECTIVE The objective was to investigate the effects of a 6-mo intervention with oil-rich or lean fish on apoptosis and mitosis within the colonic crypt. DESIGN In a multicenter, randomized, controlled intervention trial, patients with colorectal polyps, inactive ulcerative colitis, or no macroscopic signs of disease were recruited (n = 242) and randomly allocated to receive dietary advice plus either 300 g oil-rich fish (salmon) per week (n = 82), 300 g lean fish (cod) per week (n = 78), or only dietary advice (DA) (n = 82). Apoptosis and mitosis were measured in colonic biopsy samples collected before and after intervention (n = 213). RESULTS The total number of apoptotic cells per crypt did not increase in the salmon or cod group: -0.10 (95% CI: -0.36, 0.16) and -0.06 (95% CI: -0.32, 0.20), respectively, compared with the DA group. The total number of mitotic cells per crypt decreased nonsignificantly in the salmon group (-0.87; 95% CI: -2.41, 0.68) and in the cod group (-1.04; 95% CI: -2.62, 0.53) compared with the DA group. Furthermore, the distribution of mitosis within the crypt did not significantly change in either group. CONCLUSION An increase in the consumption of either oil-rich or lean fish to 2 portions weekly over 6 mo does not markedly change apoptotic and mitotic rates in the colonic mucosa. This trial was registered at www.clinicaltrials.gov as NCT00145015.

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.

Efficacy of fish intake on vitamin D status: a meta-analysis of randomized controlled trials

BACKGROUND It is well known that fish is the major natural source of vitamin D in the diet; therefore, this meta-analysis investigated the influence of fish consumption in randomized controlled trials (RCTs) on serum 25-hydroxyvitamin D [25(OH)D] concentrations. OBJECTIVE A literature search was carried out in Medline, Embase, Web of Science, and the Cochrane Library (up to February 2014) for RCTs that investigated the effect of fish consumption on 25(OH)D concentrations in comparison to other dietary interventions. RESULTS Seven articles and 2 unpublished study data sets with 640 subjects and 14 study groups met the inclusion criteria and were included in this meta-analysis. Compared with controls, the consumption of fish increased 25(OH)D concentrations, on average, by 4.4 nmol/L (95% CI: 1.7, 7.1 nmol/L; P < 0.0001, I(2) = 25%; 9 studies).The type of the fish also played a key role: the consumption of fatty fish resulted in a mean difference of 6.8 nmol/L (95% CI: 3.7, 9.9 nmol/L; P < 0.0001, I(2) = 0%; 7 study groups), whereas for lean fish the mean difference was 1.9 nmol/L (95% CI: -2.3, 6.0 nmol/L; P < 0.38, I(2) = 37%; 7 study groups). Short-term studies (4-8 wk) showed a mean difference of 3.8 nmol/L (95% CI: 0.6, 6.9 nmol/L; P < 0.02, I(2) = 38%; 10 study groups), whereas in long-term studies (∼6 mo) the mean difference was 8.3 nmol/L (95% CI: 2.1, 14.5 nmol/L; P < 0.009, I(2) = 0%; 4 study groups). CONCLUSION As the major food source of vitamin D, fish consumption increases concentrations of 25(OH)D, although recommended fish intakes cannot optimize vitamin D status.

Development of the Eating Choices Index (ECI): a four-item index to measure healthiness of diet.

OBJECTIVE Current indices of diet quality generally include intakes of specific foods or nutrients. We sought to develop an index that discriminates healthy and unhealthy eating choices for use in large surveys as a short questionnaire and as a measure in existing studies with adequate dietary data. DESIGN The Eating Choices Index (ECI) score included four components: (i) consumption of breakfast, (ii) consumption of two portions of fruit per day, (iii) type of milk consumed and (iv) type of bread consumed, each providing a score from 1 to 5. In analysis of 5 d food records, the ECI score was examined in relation to macronutrients, fibre, vitamin C, Fe, Ca and folate using Pearson correlations. Variation with sex, BMI, socio-economic status, marital status, smoking status and physical activity were also investigated. SETTING Medical Research Council National Survey of Health and Development. SUBJECTS Individuals (n 2256) aged 43 years. RESULTS The ECI score (mean 12·3 (sd 3·5)) was significantly positively associated with protein, carbohydrate, fibre, vitamin C, Fe, Ca and folate (r = 0·2-0·5; P < 0·001) and significantly negatively associated with fat intake (r = -0·2; P < 0·001); ECI scores were not correlated with total energy intake. Individuals with a lower ECI score were more likely to be men (P < 0·001), overweight or obese (P < 0·001), have lower socio-economic status (P < 0·001), smoke more (P < 0·001) and be less physically active (P < 0·001). CONCLUSIONS ECI scores correlated with nutrient profiles consistent with a healthy diet. It provides a simple method to rank diet healthiness in large observational studies.

Chrono-nutrition: a review of current evidence from observational studies on global trends in time-of-day of energy intake and its association with obesity.

The importance of the circadian rhythm in regulating human food intake behaviour and metabolism has long been recognised. However, little is known as to how energy intake is distributed over the day in existing populations, and its potential association with obesity. The present review describes global trends in time-of-day of energy intake in the general population based on data from cross-sectional surveys and longitudinal cohorts. Evidence of the association between time-of-day of energy intake and obesity is also summarised. Overall, there were a limited number of cross-sectional surveys and longitudinal cohorts that provided data on time-of-day of energy intake. In the identified studies, a wide variation in time-of-day of energy intake was observed, with patterns of energy distribution varying greatly by country and geographical area. In relation to obesity, eight cross-sectional surveys and two longitudinal cohorts were identified. The association between time-of-day of energy intake and obesity varied widely, with several studies reporting a positive link between evening energy intake and obesity. In conclusion, the current review summarises global trends in time-of-day of energy intake. The large variations across countries and global regions could have important implications to health, emphasising the need to understand the socio-environmental factors guiding such differences in eating patterns. Evidence of the association between time-of-day of energy intake and BMI also varied. Further larger scale collaborations between various countries and regions are needed to sum data from existing surveys and cohorts, and guide our understanding of the role of chrono-nutrition in health.

The effects of partial sleep deprivation on energy balance: A systematic review and meta-analysis

Background/Objectives:It is unknown whether short sleep duration causatively contributes to weight gain. Studies investigating effects of partial sleep deprivation (PSD) on energy balance components report conflicting findings. Our objective was to conduct a systematic review and meta-analysis of human intervention studies assessing the effects of PSD on energy intake (EI) and energy expenditure (EE).Subjects/Methods:EMBASE, Medline, Cochrane CENTRAL, Web of Science and Scopus were searched. Differences in EI and total EE following PSD compared with a control condition were generated using the inverse variance method with random-effects models. Secondary outcomes included macronutrient distribution and resting metabolic rate. Heterogeneity was quantified with the I2-statistic.Results:Seventeen studies (n=496) were eligible for inclusion in the systematic review, and 11 studies (n=172) provided sufficient data to be included in meta-analyses. EI was significantly increased by 385 kcal (95% confidence interval: 252, 517; P<0.00001) following PSD compared with the control condition. We found no significant change in total EE or resting metabolic rate as a result of PSD. The observed increase in EI was accompanied by significantly higher fat and lower protein intakes, but no effect on carbohydrate intake.Conclusions:The pooled effects of the studies with extractable data indicated that PSD resulted in increased EI with no effect on EE, leading to a net positive energy balance, which in the long term may contribute to weight gain.

Identification of a dietary pattern associated with greater cardiometabolic risk in adolescence

Background and aims Energy dense, high fat, low fibre diets may contribute to obesity in young people, however their relationships with other cardiometabolic risk factors are unclear. We examined associations between an ‘energy-dense, high-fat and low-fibre’ dietary pattern (DP) and cardiometabolic risk factors, and the tracking of this DP in adolescence. Methods and results Data was sourced from participants in the Western Australian Pregnancy (Raine) Cohort Study. At 14 and 17 y, dietary intake, anthropometric and biochemical data were measured and z-scores for an ‘energy dense, high fat and low fibre’ DP were estimated using reduced rank regression (RRR). Associations between DP z-scores and cardiometabolic risk factors were examined using regression models. Tracking of DP z-scores was assessed using Pearsons correlation coefficient. A 1 SD unit increase in DP z-score between 14 and 17 y was associated with a 20% greater odds of high metabolic risk (95% CI: 1.01, 1.41) and a 0.04 mmol/L higher fasting glucose in boys (95% CI: 0.01, 0.08); a 28% greater odds of a high-waist circumference (95% CI: 1.00, 1.63) in girls. An increase of 3% and 4% was observed for insulin and HOMA (95% CI: 1%, 7%), respectively, in boys and girls, for every 1 SD increase in DP z-score and independently of BMI. The DP showed moderate tracking between 14 and 17 y of age (r = 0.51 for boys, r = 0.45 for girls). Conclusion An ‘energy dense, high fat, low fibre’ DP is positively associated with cardiometabolic risk factors and tends to persist throughout adolescence.

Irregular consumption of energy intake in meals is associated with a higher cardiometabolic risk in adults of a British birth cohort.

Background/Objectives:A potential risk factor for cardiometabolic diseases is irregular or inconsistent eating, however, research on this topic is scarce. We aimed to study associations between irregular consumption of energy intake in meals and cardiometabolic risk factors.Subject and Methods:Dietary intake data were derived from 5-day estimated diet diaries of 1768 participants of the National Survey of Health and Development. Energy intakes during predefined meals (breakfast, lunch, dinner, between meals) and daily totals were analyzed using a score for irregularity based on the deviation from the 5-day mean energy intake. Logistic regression models were used to calculate odds ratios (ORs) and 95% confidence intervals (CIs) for having the metabolic syndrome or one of its components. Models were adjusted for sex, physical activity, socioeconomic status, marital status and smoking.Results:Irregularity scores of energy intake ranged from 0–160 and were highest for between meals. An increased risk of the metabolic syndrome was associated with more irregular energy intake during breakfast (OR=1.34 (0.99, 1.81); P trend=0.04) and between meals (OR=1.36 (1.01, 1.85); P trend=0.04). Moreover, increased waist circumference was associated with irregular energy intake during breakfast (OR=1.90 (1.47, 2.45); P trend <0.01), evening meal (OR=1.36 (1.06, 1.75); P trend=0.02) and daily total (OR=1.34 (1.04, 1.72); P trend=0.01). No significant associations were found for the other components of the metabolic syndrome.Conclusions:Individuals with a more irregular intake of energy, especially during breakfast and between meals, appeared to have an increased cardiometabolic risk.