Current level of fish and omega-3 fatty acid intakes and risk of Type 2 diabetes in China

Excessive oil absorption and maillard reaction products in fried muscle foods: Formation mechanisms, potential health risks and mitigation strategies

Fried muscle foods are popular among consumers for their golden color, fried flavor, and crispy exterior paired with a tender interior. However, physicochemical reactions occurring during frying lead to the formation of harmful components. This review focuses on the formation mechanisms of excessive oil and Maillard reaction products (advanced glycation end products, and heterocyclic amines) in fried muscle foods including protein oxidation, starch gelatinization, and generation of carbonyls and free radicals. The gastrointestinal digestion, absorption, and potential health risks of these components are discussed. It also summarizes the measures to inhibit oil absorption in four ways, including reducing initial moisture content, controlling moisture migration, reducing frying oil usage, and reducing interfacial tension between oil and food. Finally, it reviews mitigation strategies of Maillard reaction products from two aspects: reducing precursors, and trapping intermediates. This review may help produce healthier fried muscle foods.

Higher docosahexaenoic acid proportions in blood are inversely associated with the prevalence of prediabetes: Evidence from the UK Biobank

Prediabetes and type 2 diabetes mellitus are growing global health concerns, predisposing individuals to various vascular complications. Lifestyle modifications, including dietary interventions, offer promising avenues for prevention and management. Using a multivariable-adjusted model, we analyzed the cross-sectional associations between plasma proportions (% of total fatty acids) of omega-3 polyunsaturated fatty acids (n3 PUFA, including total n3 PUFA, docosahexaenoic acid [DHA], non-DHA n3 PUFA), and glycated hemoglobin A1c (HbA1c) as well as the prevalence of prediabetes in a sample from the UK Biobank cohort. Our hypothesis was that proportions of n3 PUFA, especially DHA, would by inversely associated with the prediabetes prevalence. The sample (n = 92,762; 54.5% females) had an average age of 56 years and was overweight (mean body mass index = 27). The mean plasma DHA proportion in the sample was 2.03% (standard deviation [SD] = 0.67%), non-DHA n3 PUFA was 2.41% (SD = 1.02%) and total n3 PUFA was 4.43% (SD = 1.56%). Prediabetic individuals were identified by blood HbA1c proportions between 5.7% and 6.4% (39-46 mmol/mol) according to American Diabetes Association criteria. Each of the three n3 PUFA biomarkers was inversely associated with HbA1c proportions. In particular, DHA showed the strongest inverse association, with an OR of 0.62 (95% confidence intervals: 0.58, 0.67; P < .001) when comparing quintiles 5 to 1 in a fully adjusted model. These findings suggest a potential protective role of n3 PUFA, particularly DHA, in mitigating the risk of having prediabetes. Further prospective investigations are needed to clarify whether long-chain n3 PUFA could function as modifiable factors for prediabetes.

Associations between cooking method of food and type 2 diabetes risk: A prospective analysis focusing on cooking method transitioning

Cooking process for food significantly impacts household air and increases exposure to endocrine disruptors such as acrylamide, consequently affecting human health. In the past 30 years, the transformation of cooking methods to high-temperature thermal processing has occurred widely in China. Yet the transition of cooking methods on the onset of type 2 diabetes (T2D) remains unclear, which may hinder health-based Sustainable Development Goals. We aimed to estimate the associations between dietary intake with different cooking methods and T2D risk. We included 14,745 participants (>20 y) from the China Health and Nutrition Survey (1991-2015). Food consumption was calculated using three consecutive 24-h dietary recalls combined with both individual participant level and household food inventory. Cooking methods, including boiling, steaming, baking, griddling, stir-frying, deep-frying, and raw eating, were also recorded. The consumption of baked/griddled and deep-fried foods was positively associated with 39% and 35% higher of T2D risk by comparing the highest with the lowest category of food consumption, respectively. The use of unhealthy cooking methods for processing foods including baked/griddled and deep-fried foods was attributable for 15 million T2D cases of the total T2D burden in 2011, resulting in a medical cost of $2.7 billion and was expected to be attributable for 39 million T2D cases in 2030, producing a medical cost of $223.8 billion. Replacing one serving of deep-fried foods and baked/griddle foods with boiled/steamed foods was related to 50% and 20% lower risk of T2D, respectively. Our findings recommend healthy driven cooking methods for daily diet for nourishing sustainable T2D prevention in China.

Seafood intake in childhood/adolescence and the risk of obesity: results from a Nationwide Cohort Study

BACKGROUND & AIMS

Obesity has been linked to various detrimental health consequences. While there is established evidence of a negative correlation between seafood consumption and obesity in adults, the current research on the association between seafood intake in childhood/adolescence and the risk of obesity is lacking. Our aim was to evaluate the association between seafood intake in childhood/adolescence and the risk of obesity in a Chinese nationwide cohort.

METHODS

We utilized data from the China Health and Nutrition Survey (CHNS) from the year of 1997 to 2015. Seafood consumption was evaluated through 3-day 24-hour recalls. In our study, overweight/obesity status was determined based on the Chinese Criteria of Overweight and Obesity in School-age Children and Adolescents (WS/T 586-2018), while abdominal obesity status was determined according to the Chinese Criteria of Waist Circumference Screening Threshold among Children and Adolescents (WS/T 611-2018).

RESULTS

During an average follow-up of 7.9 years, 404 cases developed overweight/obesity among 2206 participants in the seafood-overweight/obesity analysis, while 381 cases developed abdominal obesity among 2256 participants in the seafood-abdominal-obesity analysis. The high-consumer group was associated with 35% lower risk of overweight/obesity risk and 26% lower risk of abdominal obesity after fully adjusting for sociodemographic and lifestyle factors, compared with the non-consumer group. Considering different cooking methods, boiled seafood consumption was associated with 43% lower risk of overweight/obesity and 23% lower risk of abdominal obesity in the fully adjusted model, while stir-fried seafood did not demonstrate a statistical significance.

CONCLUSION

Higher intake of seafood in childhood/adolescents, particularly in a boiled way, was associated with lower obesity risk.

Serum bile acid and unsaturated fatty acid profiles of non-alcoholic fatty liver disease in type 2 diabetic patients

BACKGROUND

The understanding of bile acid (BA) and unsaturated fatty acid (UFA) profiles, as well as their dysregulation, remains elusive in individuals with type 2 diabetes mellitus (T2DM) coexisting with non-alcoholic fatty liver disease (NAFLD). Investigating these metabolites could offer valuable insights into the pathophy-siology of NAFLD in T2DM.

AIM

To identify potential metabolite biomarkers capable of distinguishing between NAFLD and T2DM.

METHODS

A training model was developed involving 399 participants, comprising 113 healthy controls (HCs), 134 individuals with T2DM without NAFLD, and 152 individuals with T2DM and NAFLD. External validation encompassed 172 participants. NAFLD patients were divided based on liver fibrosis scores. The analytical approach employed univariate testing, orthogonal partial least squares-discriminant analysis, logistic regression, receiver operating characteristic curve analysis, and decision curve analysis to pinpoint and assess the diagnostic value of serum biomarkers.

RESULTS

Compared to HCs, both T2DM and NAFLD groups exhibited diminished levels of specific BAs. In UFAs, particular acids exhibited a positive correlation with NAFLD risk in T2DM, while the ω-6:ω-3 UFA ratio demonstrated a negative correlation. Levels of α-linolenic acid and γ-linolenic acid were linked to significant liver fibrosis in NAFLD. The validation cohort substantiated the predictive efficacy of these biomarkers for assessing NAFLD risk in T2DM patients.

CONCLUSION

This study underscores the connection between altered BA and UFA profiles and the presence of NAFLD in individuals with T2DM, proposing their potential as biomarkers in the pathogenesis of NAFLD.

Substitution of animal-based with plant-based foods on cardiometabolic health and all-cause mortality: a systematic review and meta-analysis of prospective studies

BACKGROUND

There is growing evidence that substituting animal-based with plant-based foods is associated with a lower risk of cardiovascular diseases (CVD), type 2 diabetes (T2D), and all-cause mortality. Our aim was to summarize and evaluate the evidence for the substitution of any animal-based foods with plant-based foods on cardiometabolic health and all-cause mortality in a systematic review and meta-analysis.

METHODS

We systematically searched MEDLINE, Embase, and Web of Science to March 2023 for prospective studies investigating the substitution of animal-based with plant-based foods on CVD, T2D, and all-cause mortality. We calculated summary hazard ratios (SHRs) and 95% confidence intervals (95% CI) using random-effects meta-analyses. We assessed the certainty of evidence (CoE) using the GRADE approach.

RESULTS

In total, 37 publications based on 24 cohorts were included. There was moderate CoE for a lower risk of CVD when substituting processed meat with nuts [SHR (95% CI): 0.73 (0.59, 0.91), n = 8 cohorts], legumes [0.77 (0.68, 0.87), n = 8], and whole grains [0.64 (0.54, 0.75), n = 7], as well as eggs with nuts [0.83 (0.78, 0.89), n = 8] and butter with olive oil [0.96 (0.95, 0.98), n = 3]. Furthermore, we found moderate CoE for an inverse association with T2D incidence when substituting red meat with whole grains/cereals [0.90 (0.84, 0.96), n = 6] and red meat or processed meat with nuts [0.92 (0.90, 0.94), n = 6 or 0.78 (0.69, 0.88), n = 6], as well as for replacing poultry with whole grains [0.87 (0.83, 0.90), n = 2] and eggs with nuts or whole grains [0.82 (0.79, 0.86), n = 2 or 0.79 (0.76, 0.83), n = 2]. Moreover, replacing red meat for nuts [0.93 (0.91, 0.95), n = 9] and whole grains [0.96 (0.95, 0.98), n = 3], processed meat with nuts [0.79 (0.71, 0.88), n = 9] and legumes [0.91 (0.85, 0.98), n = 9], dairy with nuts [0.94 (0.91, 0.97), n = 3], and eggs with nuts [0.85 (0.82, 0.89), n = 8] and legumes [0.90 (0.89, 0.91), n = 7] was associated with a reduced risk of all-cause mortality.

CONCLUSIONS

Our findings indicate that a shift from animal-based (e.g., red and processed meat, eggs, dairy, poultry, butter) to plant-based (e.g., nuts, legumes, whole grains, olive oil) foods is beneficially associated with cardiometabolic health and all-cause mortality.

Associations between the inflammatory potential of diets with adherence to plant-based dietary patterns and the risk of new-onset cardiometabolic diseases in Chinese adults: findings from a nation-wide prospective cohort study

Aims: convincing evidence is still limited for the validation of associations between the inflammatory potential of diets, based on the dietary inflammatory index (DII), and cardiometabolic outcomes. We aimed to investigate the associations between the DII with adherence to plant-based dietary patterns and the risk of new-onset cardiometabolic diseases (CMDs), including stroke, type 2 diabetes mellitus (T2DM) and myocardial infarction (MI). Methods: adults (N = 14 652) from the China Health and Nutrition Survey (1997-2015) were included in the current analysis. Dietary intake data were collected using a combination of 3 day consecutive 24 h dietary recalls and the food weighing method. The DII was calculated with established and validated methods. CMDs were identified using validated self-reported questionnaires. The Cox proportional hazard regression model was used for statistical analysis. Results: during a mean follow-up of 10 years, a total of 404 new-onset stroke, 1051 new-onset T2DM and 280 new-onset MI cases were identified. Lower PDI, hPDI, ERD, WISH and PHDI scores and higher uPDI scores were associated with higher DII scores (all P-trend < 0. 0001). A pro-inflammatory diet, as reflected by relatively higher DII scores, was positively associated with an increased risk of stroke (Q5 vs. Q1: HR = 1.90; 95% CI: 1.26-2.88; P-trend = 0.0006), T2DM (Q5 vs. Q1: HR = 2.08; 95% CI: 1.61-2.69; P-trend < 0.0001) and MI (Q5 vs. Q1: HR = 1.70; 95% CI: 1.04-2.76; P-trend = 0.0114) in the entire cohort. Sex and BMI significantly modified the association between the DII and the risk of T2DM, and sex significantly modified the association between the DII and the risk of MI. Conclusions: lower adherence to healthy and sustainable plant-based dietary patterns and higher adherence to unhealthy plant-based dietary patterns were associated with higher DII scores. With the use of the DII, we reported long-term positive associations between a pro-inflammatory diet and an increased risk of new-onset stroke, T2DM and MI in Chinese adults who were free from CMDs and cancer at the baseline. These findings provided evidence for the validation of associations between the DII and cardiometabolic health, and contributed to the current literature suggesting careful evaluations of whether the DII should be incorporated into dietary guidelines and utilized as an effective tool for improving the diet quality and CMD prevention in the Chinese population.

Evaluating the distinct pleiotropic effects of omega-3 fatty acids on type 2 diabetes mellitus: a mendelian randomization study

BACKGROUND

Observational studies and conventional Mendelian randomization (MR) studies showed inconclusive evidence to support the association between omega-3 fatty acids and type 2 diabetes. We aim to evaluate the causal effect of omega-3 fatty acids on type 2 diabetes mellitus (T2DM), and the distinct intermediate phenotypes linking the two.

METHODS

Two-sample MR was performed using genetic instruments derived from a recent genome-wide association study (GWAS) of omega-3 fatty acids (N = 114,999) from UK Biobank and outcome data obtained from a large-scale T2DM GWAS (62,892 cases and 596,424 controls) in European ancestry. MR-Clust was applied to determine clustered genetic instruments of omega-3 fatty acids that influences T2DM. Two-step MR analysis was used to identify potential intermediate phenotypes (e.g. glycemic traits) that linking omega-3 fatty acids with T2DM.

RESULTS

Univariate MR showed heterogenous effect of omega-3 fatty acids on T2DM. At least two pleiotropic effects between omega-3 fatty acids and T2DM were identified using MR-Clust. For cluster 1 with seven instruments, increasing omega-3 fatty acids reduced T2DM risk (OR: 0.52, 95%CI 0.45-0.59), and decreased HOMA-IR (β = - 0.13, SE = 0.05, P = 0.02). On the contrary, MR analysis using 10 instruments in cluster 2 showed that increasing omega-3 fatty acids increased T2DM risk (OR:1.10; 95%CI 1.06-1.15), and decreased HOMA-B (β = - 0.04, SE = 0.01, P = 4.52 × 10^-5). Two-step MR indicated that increasing omega-3 fatty acid levels decreased T2DM risk via decreasing HOMA-IR in cluster 1, while increased T2DM risk via decreasing HOMA-B in cluster 2.

CONCLUSIONS

This study provides evidence to support two distinct pleiotropic effects of omega-3 fatty acids on T2DM risk influenced by different gene clusters, which could be partially explained by distinct effects of omega-3 fatty acids on insulin resistance and beta cell dysfunction. The pleiotropic feature of omega-3 fatty acids variants and its complex relationships with T2DM need to be carefully considered in future genetic and clinical studies.

Associations between Conventional and Emerging Indicators of Dietary Carbohydrate Quality and New-Onset Type 2 Diabetes Mellitus in Chinese Adults

Dietary glycemic index (GI), carbohydrate to fiber ratio (CF) and carbohydrate quality index (CQI) are conventional and emerging indicators for carbohydrate quality. We aimed to investigate the associations between these indicators and new-onset type 2 diabetes mellitus (T2DM) risk among Chinese adults. This prospective cohort study included 14,590 adults from the China Health and Nutrition Survey without cardiometabolic diseases at baseline. The associations between dietary GI, CF and CQI and T2DM risk were assessed using Cox proportional hazard regression analysis and dose-response relationships were explored using restricted cubic spline and threshold analysis. After a mean follow-up duration of 10 years, a total of 1053 new-onset T2DM cases occurred. There were U-shaped associations between dietary GI and CF and T2DM risk (both P-nonlinear < 0.0001), and T2DM risk was lowest when dietary GI was 72.85 (71.40, 74.05) and CF was 20.55 (17.92, 21.91), respectively (both P-log likelihood ratio < 0.0001). Inverse associations between CQI and T2DM risk specifically existed in participants < 60 y or attended middle school or above (both P-trend < 0.05). These findings indicated that moderate dietary GI and CF range and a higher dietary CQI score may be suggested for T2DM prevention in Chinese adults.

Nutritional significance and health benefits of omega-3, -6 and -9 fatty acids in animals

The balance between omega-3 (ω-3), omega-6 (ω-6) and omega-9 (ω-9) fatty acids (FAs) is very important because these types of oils constitute essential components for the formation of the cell membrane, also they are precursors for a large number of substances in the body. One of the most important strategies for improving the increment of polyunsaturated FAs in poultry and animal meat is the dietary administration of these FAs. Additionally, the different sources of ω-3 or 6 in the diet improve the performance, public health and physiological aspects including anti-oxidative properties and immunity. ω-3 FAs have anti-inflammatory characteristics due to their ability to reduce cytokines liberation. High-level of ω-6 FAs is always associated with an increased incidence of dangerous disorders like depression and heart disease. These FAs showed a tremendous series of beneficial impacts like improved cholesterol levels and a decreased occurrence of coronary heart diseases. This article includes some information on the use of ω-3, ω-6 and ω-9 FAs in animal and human diets. These oils are vital for the physiological and health aspects, and the information mentioned here will improve our understanding of the functions and roles of these FAs in the body.

Types of diet, obesity, and incident type 2 diabetes: Findings from the UK Biobank prospective cohort study

AIM

To investigate the associations between types of diet and incident type 2 diabetes and whether adiposity mediated these associations.

MATERIALS AND METHODS

In total, 203 790 participants from UK Biobank (mean age 55.2 years; 55.8% women) without diabetes at baseline were included in this prospective study. Using the dietary intake data self-reported at baseline, participants were categorized as vegetarians (n = 3237), fish eaters (n = 4405), fish and poultry eaters (n = 2217), meat eaters (n = 178 004) and varied diet (n = 15 927). The association between type of diet and incident type 2 diabetes was investigated using Cox-proportional hazards models with a 2-year landmark analysis. The mediation role of adiposity was tested under a counterfactual framework.

RESULTS

After excluding the first 2 years of follow-up, the median follow-up was 5.4 (IQR: 4.8-6.3) years, during which 5067 (2.5%) participants were diagnosed with type 2 diabetes. After adjusting for lifestyle factors, fish eaters (HR 0.52 [95% CI: 0.39-0.69]) and fish and poultry eaters (HR 0.62 [95% CI: 0.45-0.88]) had a lower risk of incident type 2 diabetes compared with meat eaters. The association for vegetarians was not significant. Varied diet had a higher risk of type 2 diabetes. Obesity partially mediated the association of fish (30.6%), fish and poultry (49.8%) and varied (55.2%) diets.

CONCLUSIONS

Fish eaters, as well as fish and poultry eaters, were at a lower risk of incident type 2 diabetes than meat eaters, partially attributable to lower obesity risk.

Dietary Copper and Selenium Intakes and the Risk of Type 2 Diabetes Mellitus: Findings from the China Health and Nutrition Survey

The long-term associations between dietary copper (Cu) and selenium (Se) intakes and type 2 diabetes mellitus (T2DM) risk are unclear. We aimed to examine the prospective associations between dietary Cu and Se intakes and T2DM risk in Chinese adults. A total of 14,711 adults from the China Health and Nutrition Survey (1997–2015) were included. Nutrient intakes were assessed by 3 consecutive 24 h recalls and food-weighing methods. T2DM was identified by a validated questionnaire and laboratory examination. Cox regression models were used for statistical analysis. A total of 1040 T2DM cases were diagnosed during 147,142 person-years of follow-up. In fully adjusted models, dietary Cu or Se intake was not associated with T2DM risk. Dietary Se intake significantly modified the association between dietary Cu intake and T2DM risk, and dietary Cu intake was positively associated with T2DM risk when Se intake was lower than the median (p-interaction = 0.0292). There were no significant effect modifications on the associations by age, sex, BMI, or region. Although dietary Cu or Se intake was not independently associated with T2DM risk in Chinese adults free from cardiometabolic diseases and cancer at the baseline, there was a significant interaction between dietary Cu and Se intakes on T2DM risk.

Polyunsaturated fatty acid intake and incidence of type 2 diabetes in adults: a dose response meta-analysis of cohort studies

BACKGROUND

To evaluate the association and dose-response relationship between polyunsaturated fatty acid (PUFA) intake and incidence of type 2 diabetes (T2D) in adults.

METHODS

PubMed, Embase, Cochrane Library, and Web of Science databases were searched for cohort studies that examined the association between PUFA and T2D incidence published up to September 6, 2021. Relative risk (RR) or hazard ratio (HR) was used as the effect indicator, each effect size was expressed by 95% confidence interval (CI). The presence of heterogeneity of effect size between studies was assessed by the Q-test and I² statistics. If I² ≥ 50%, the random-effects model was applied, otherwise the fixed effects model was used. Sensitivity analysis was performed for all models. Potential publication bias was assessed. We conducted linear and nonlinear dose-response meta-analyses, calculated summary relative risk (SRR).

RESULTS

Twenty-five articles were selected including 54,000 patients in this study. Our estimates observed no linear associations between total PUFA and the incidence of T2D. However, the summary dose-response curve of T2D risk increased in a nonlinear pattern with the consumption of omega-3 PUFA (P_nonlinearity < 0.001) and docosahexaenoic acid (DHA) (P_nonlinearity = 0.040). Our subgroup analysis showed that total PUFA intake was associated with increased incidence of T2D in Europe (RR: 1.040, 95% CI 1.009 to 1.072), and Australia (RR: 1.188, 95% CI 1.113 to 1.269). However, total PUFA intake was associated with decreased T2D incidence in Asia (RR: 0.897, 95% CI 0.860 to 0.936). Subgroup analysis based on PUFA types showed that DHA intake was associated with decreased T2D incidence (RR: 1.164, 95% CI 1.048 to 1.294) while linoleic acid (LA) decreased T2D incidence (RR: 0.956, 95% CI 0.930 to 0.983). Regarding the sex subgroup, women's intake of total PUFA would increase the risk of T2D (RR: 1.049, 95% CI 1.019 to 1.079) while total PUFA intake decreased the risk of T2D in men (RR: 0.955, 95% CI 0.913 to 0.999).

CONCLUSION

For specific PUFA, dose-response curves show nonlinear significant associations between PUFA intakes and T2D. It may be necessary to pay attention to the effects of PUFA and type of intake on T2D. Trial registration Not applicable.

Longitudinal study of the relationship between coffee consumption and type 2 diabetes in Chinese adult residents: Data from China Health and Nutrition Survey

BACKGROUND

Increasing coffee intake was inversely associated with risk of type 2 diabetes in Western countries. However, in China where coffee consumption and diabetes population has been growing fast in recent years, studies on the impact of coffee intakes on the onset of type 2 diabetes are lacking. This study attempts to determine the associations between coffee consumption and type 2 diabetes in Chinese adults.

METHODS

This longitudinal study analyzed 10447 adults who had participated in at least two rounds of the China Health and Nutrition Survey (CHNS), which is a survey database of multistage, random cluster process during 1993-2011. Coffee consumption and type 2 diabetes incidence were measured in the survey. Body mass index (BMI), age, sex, place of residence, waves, education level, smoking, drinking alcohol and tea drinking frequency were adjusted as covariate. We used longitudinal fixed effects regression models to assess changes within person.

RESULTS

After adjusting confounding factors, lower risk of diabetes is observed among Chinese adults who drink coffee occasionally (Adjusted Odds Ratio (AOR)  = 0.13, 95% CI = 0.05, 0.34) and drink almost every day (AOR = 0.61, 95% CI = 0.45, 0.83), compared with those who do not or hardly drink. In the subgroup analysis, among women aged 45-59 who drink coffee one to three times a week (AOR = 0.21, 95% CI = 0.08, 0.52) and men over 60 who drink coffee almost every day (AOR = 0.19, 95% CI = 0.07, 0.53), protective effects were found. For young men aged 19-29, drinking coffee almost every day showed a risk effect (AOR = 20.21, 95% CI = 5.96-68.57).

CONCLUSIONS

Coffee drinking habit is an independent protective factor for adult on type 2 diabetes in China. And it varies among people with different ages and genders. The rapid growth of coffee consumption in China in recent years may help reduce the risk of type 2 diabetes, but at the same time, the risk of type 2 diabetes in adolescents needs attention.

Heterogeneity of Associations between Total and Types of Fish Intake and the Incidence of Type 2 Diabetes: Federated Meta-Analysis of 28 Prospective Studies Including 956,122 Participants

The association between fish consumption and new-onset type 2 diabetes is inconsistent and differs according to geographical location. We examined the association between the total and types of fish consumption and type 2 diabetes using individual participant data from 28 prospective cohort studies from the Americas (6), Europe (15), the Western Pacific (6), and the Eastern Mediterranean (1) comprising 956,122 participants and 48,084 cases of incident type 2 diabetes. Incidence rate ratios (IRRs) for associations of total fish, shellfish, fatty, lean, fried, freshwater, and saltwater fish intake and type 2 diabetes were derived for each study, adjusting for a consistent set of confounders and combined across studies using random-effects meta-analysis. We stratified all analyses by sex due to observed interaction (p = 0.002) on the association between fish and type 2 diabetes. In women, for each 100 g/week higher intake the IRRs (95% CIs) of type 2 diabetes were 1.02 (1.01-1.03, I2 = 61%) for total fish, 1.04 (1.01-1.07, I2 = 46%) for fatty fish, and 1.02 (1.00-1.04, I2 = 33%) for lean fish. In men, all associations were null. In women, we observed variation by geographical location: IRRs for total fish were 1.03 (1.02-1.04, I2 = 0%) in the Americas and null in other regions. In conclusion, we found evidence of a neutral association between total fish intake and type 2 diabetes in men, but there was a modest positive association among women with heterogeneity across studies, which was partly explained by geographical location and types of fish intake. Future research should investigate the role of cooking methods, accompanying foods and environmental pollutants, but meanwhile, existing dietary regional, national, or international guidelines should continue to guide fish consumption within overall healthy dietary patterns.

Association of Oily and Nonoily Fish Consumption and Fish Oil Supplements With Incident Type 2 Diabetes: A Large Population-Based Prospective Study

OBJECTIVE

To evaluate associations of oily and nonoily fish consumption and fish oil supplements with incident type 2 diabetes (T2D).

RESEARCH DESIGN AND METHODS

We included 392,287 middle-aged and older participants (55.0% women) in the UK Biobank who were free of diabetes, major cardiovascular disease, and cancer and had information on habitual intake of major food groups and use of fish oil supplements at baseline (2006-2010). Of these, 163,706 participated in one to five rounds of 24-h dietary recalls during 2009-2012.

RESULTS

During a median 10.1 years of follow-up, 7,262 incident cases of T2D were identified. Compared with participants who reported never consumption of oily fish, the multivariable-adjusted hazard ratios of T2D were 0.84 (95% CI 0.78-0.91), 0.78 (0.72-0.85), and 0.78 (0.71-0.86) for those who reported <1 serving/week, weekly, and ≥2 servings/week of oily fish consumption, respectively (P-trend < 0.001). Consumption of nonoily fish was not associated with risk of T2D (P-trend = 0.45). Participants who reported regular fish oil use at baseline had a 9% (95% CI 4-14%) lower risk of T2D compared with nonusers. Baseline regular users of fish oil who also reported fish oil use during at least one of the 24-h dietary recalls had an 18% (8-27%) lower risk of T2D compared with constant nonusers.

CONCLUSIONS

Our findings suggest that consumption of oily fish but not nonoily fish was associated with a lower risk of T2D. Use of fish oil supplements, especially constant use over time, was also associated with a lower risk of T2D.

Investigation of enhanced oxidation stability of microencapsulated enzymatically produced tuna oil concentrates using complex coacervation

Tuna oil was selectively hydrolysed using Thermomyces lanuginosus lipase for 6 h to prepare omega-3 acylglycerol concentrate with the DHA content significantly increased from 24.9% in tuna oil to 36.3% in the acylglycerol concentrate. The acylglycerol concentrate was subsequently encapsulated into the "multi-core" microcapsules using gelatin-sodium hexametaphosphate complex coacervates as the shell material. Rancimat, Oxipres and thermogravimetric analyses all showed that the microencapsulated acylglycerol concentrate had unexpectedly improved oxidation stability, compared to those produced using tuna oil, even though the concentrated oils themselves were significantly less stable than tuna oil. The incorporation of enzymatic tuna oil acylglycerol concentrate also significantly improved the oxidation stability of microencapsulated standard refined unconcentrated tuna oil. A wide range of characteristics including lipid and fatty acid composition, oil-in-water (O/W) emulsion properties, morphology, nanomechanical strength and physicochemical stability of acylglycerol, acylglycerol oil-in-water (O/W) emulsion and final microcapsules were investigated throughout the preparation. The result suggests that high levels of monoacylglycerol (about 35%) and diacylglycerol (about 8.5%) were produced in the acylglycerol. The acylglycerol O/W emulsion exhibited significantly smaller droplet size, lower zeta-potential and higher surface hydrophobicity, which contributed to the formation of the microcapsule with a significantly smoother surface and more compact structure, finally leading to improved oxidative stability compared to those prepared from native tuna oil.

Fatty acids and cardiometabolic health: a review of studies in Chinese populations

Rapid nutrition transition from plant-based traditional diet to westernized diet has led to dramatically heightening burdens of cardiometabolic diseases in China in past decades. Recently, national surveys reported that poor dietary quality including low marine n-3 fatty acids and high intakes of red meat and processed meat was associated with considerably elevated cardiometabolic deaths. Previous studies mainly from Western population-based cohorts have indicated that not only fat quantity but also quality linked with different cardiometabolic outcomes. Compared with Western peoples, Asian peoples, including Chinese, are known to have different dietary patterns and lifestyle, as well as genetic heterogeneities, which may modify fatty acid metabolism and disease susceptibility in certain degree. To date, there were limited prospective studies investigating the relationships between fatty acids and cardiometabolic disease outcomes in Chinese, and most existing studies were cross-sectional nature and within one or two region(s). Notably, shifting dietary patterns could change not only amount, types, and ratio of fatty acids accounting for overall energy intake, but also their food sources and ratio to other macronutrients. Moreover, large geographic and urban-rural variations in prevalence of cardiometabolic diseases among Chinese may also reflect the effects of socioeconomic development and local diets on health status. Therefore, current review will summarize available literatures with more focus on the Chinese-based studies which may extend current knowledge about the roles of fatty acids in pathogenesis of cardiometabolic diseases for Asian populations and also provide useful information for trans-ethnic comparisons with other populations.