Interactions of ethanol drinking with n -3 fatty acids in rats: potential consequences for the cardiovascular system

Relationship Between Fish Oil Use and Incidence of Primary Liver Cancer: Findings From a Population-Based Prospective Cohort Study

Background: N-3 long-chain polyunsaturated fatty acids (LCPUFAs) prevented non-alcoholic steatohepatitis (NASH) and hepatocellular carcinoma (HCC) in studies of mouse models. We examined prospective relationships between fish oil use and risk of primary liver cancer and the major histological subtypes, such as HCC and intrahepatic cholangiocarcinoma (ICC).

Methods: We included 434,584 middle-aged and older men and women who were free of cancer at recruitment of the UK Biobank (2006–2010). Information on fish oil use and other dietary habits was collected via questionnaires. Cox proportional hazards models were used to compute the hazard ratio (HR) and 95% CI of liver cancer associated with fish oil use, with adjustment for socio-demographic, lifestyle, dietary, and other clinical risk factors.

Results: At baseline, 31.4% of participants reported regular use of fish oil supplements. During a median of 7.8 years of follow-up, 262 incident liver cancer cases were identified, among which 127 were HCC and 110 were ICC cases. As compared with non-users, fish oil users had a significantly 44% (95% CI: 25–59%) lower risk of total liver cancer, and 52% (95% CI: 24–70%) and 40% (95% CI: 7–61%) lower risk of HCC and ICC, respectively. Higher intake of oily fish also was associated with a lower risk of HCC (≥2 vs. <1 serving/week: HR = 0.46; 95% CI: 0.23–0.96; P-trend = 0.027) but not ICC (P-trend = 0.96).

Conclusion: Habitual use of fish oil supplements was associated lower risk of primary liver cancer regardless of cancer histological subtypes, potentially supporting a beneficial role of dietary n-3 LCPUFAs in liver cancer prevention.

Fat-1 Transgenic Mice With Augmented n3-Polyunsaturated Fatty Acids Are Protected From Liver Injury Caused by Acute-On-Chronic Ethanol Administration

Alcohol-associated liver disease (ALD) is the leading cause of liver disease worldwide, and alcohol-associated hepatitis (AH), a severe form of ALD, is a major contributor to the mortality and morbidity due to ALD. Many factors modulate susceptibility to ALD development and progression, including nutritional factors such as dietary fatty acids. Recent work from our group and others showed that modulation of dietary or endogenous levels of n6-and n3-polyunsaturated fatty acids (PUFAs) can exacerbate or attenuate experimental ALD, respectively. In the current study, we interrogated the effects of endogenous n3-PUFA enrichment in a mouse model which recapitulates features of early human AH using transgenic fat-1 mice which endogenously convert n6-PUFAs to n3-PUFAs. Male wild type (WT) and fat-1 littermates were provided an ethanol (EtOH, 5% v/v)-containing liquid diet for 10 days, then administered a binge of EtOH (5 g/kg) by oral gavage on the 11^th day, 9 h prior to sacrifice. In WT mice, EtOH treatment resulted in liver injury as determined by significantly elevated plasma ALT levels, whereas in fat-1 mice, EtOH caused no increase in this biomarker. Compared to their pair-fed controls, a significant EtOH-mediated increase in liver neutrophil infiltration was observed also in WT, but not fat-1 mice. The hepatic expression of several cytokines and chemokines, including Pai-1, was significantly lower in fat-1 vs WT EtOH-challenged mice. Cultured bone marrow-derived macrophages isolated from fat-1 mice expressed less Pai-1 and Cxcl2 (a canonical neutrophil chemoattractant) mRNA compared to WT when stimulated with lipopolysaccharide. Further, we observed decreased pro-inflammatory M1 liver tissue-resident macrophages (Kupffer cells, KCs), as well as increased liver T regulatory cells in fat-1 vs WT EtOH-fed mice. Taken together, our data demonstrated protective effects of endogenous n3-PUFA enrichment on liver injury caused by an acute-on-chronic EtOH exposure, a paradigm which recapitulates human AH, suggesting that n3-PUFAs may be a viable nutritional adjuvant therapy for this disease.

Circulating fatty acids in relation to alcohol consumption: Cross-sectional results from a cohort of 60-year-old men and women

BACKGROUND & AIMS

Alcohol consumption is considered to affect circulating fatty acids (FAs) but knowledge about specific associations is limited. We aimed to assess the relation between alcohol consumption and serum FAs in 60-year-old Swedish men and women.

METHODS

In a random sample of 1917 men and 2058 women residing in Stockholm county, cross-sectional associations between different categories of alcohol consumption and FAs were assessed using linear regression; β₁ coefficients with 95% confidence interval (CI) were calculated. Self-reported alcohol consumption was categorized as none, low (≤9.9 g/day) (reference), moderate (10-29.9 g/day) and high (≥30 g/day). Moderate alcohol consumption was further subdivided into consumption of beer, wine, liquor and their combinations. Thirteen serum cholesterol ester FAs were measured by gas chromatography and individual FAs were expressed as percentage of total FAs.

RESULTS

Increasing alcohol consumption was associated to linear increase of saturated myristic acid, monounsaturated FAs and n-6 polyunsaturated (PUFA) arachidonic acid, whereas linear decrease was noted for saturated pentadecanoic acid and for n-6 PUFA linoleic acid. With non-linear associations, increasing alcohol consumption also associated to decreased saturated stearic acid, n-6 PUFA dihomo-gamma-linolenic acid, and n-3 PUFA docosahexaenoic acid and increased saturated palmitic acid, n-6 PUFA gamma-linolenic acid and n-3 PUFA eicosapentaenoic acid. Among types of beverages, wine consumption was associated with n-6 PUFA arachidonic acid (β₁ 0.59; 95% CI: 0.30;0.88) and the n-3 PUFAs eicosapentaenoic acid (β₁ 0.54; 95% CI: 0.30;0.78), and docosahexaenoic acid (β₁ 0.06; 95% CI: 0.00;0.12).

CONCLUSIONS

These findings may give important basis for further investigations to better understand biological mechanisms behind the dose-dependent associations between alcohol consumption and health outcomes observed in many previous studies.

Chronic ethanol consumption increases myocardial mitochondrial DNA mutations: a potential contribution by mitochondrial topoisomerases

AIMS

Alcoholic cardiomyopathy (ACM) presents as decreased myocardial contractility, arrhythmias and secondary non-ischemic dilated cardiomyopathy leading to heart failure. Mitochondrial dysfunction is known to have a significant role in the development and complications of ACM. This study investigated if chronic ethanol feeding promoted myocardial mitochondrial topoisomerase dysfunction as one underlying cause of mitochondrial DNA (mtDNA) damage and mitochondrial dysfunction in ACM.

METHODS

The impact of chronic ethanol exposure on the myocardial mitochondria was examined in both neonatal cardiomyocytes using 50 mM ethanol for 6 days and in rats assigned to control or ethanol feeding groups for 4 months.

RESULTS

Chronic ethanol feeding led to significant (P < 0.05) decreases in M-mode Fractional Shortening, ejection fraction, and the cardiac output index as well as increases in Tau. Ethanol feeding promoted mitochondrial dysfunction as evidenced by significantly decreased left ventricle cytochrome oxidase activity and decreases in mitochondrial protein content. Both in rats and in cultured cardiomyocytes, chronic ethanol presentation significantly increased mtDNA damage. Using isolated myocardial mitochondria, both mitochondrial topoisomerase-dependent DNA cleavage and DNA relaxation were significantly altered by ethanol feeding.

CONCLUSION

Chronic ethanol feeding compromised cardiovascular and mitochondrial function as a result of a decline in mtDNA integrity that was in part the consequence of mitochondrial topoisomerase dysfunction. Understanding the regulation of the mitochondrial topoisomerases is critical for protection of mtDNA, not only for the management of alcoholic cardiomyopathy, but also for the many other clinical treatments that targets the topoisomerases in the alcoholic patient.

Consumption of Chinese tea-flavor liquor improves circulating insulin levels without affecting hepatic lipid metabolism-related gene expression in Sprague-Dawley rats

Objective. To examine the effect of two Chinese liquors with quite different nonalcoholic components on insulin sensitivity, tissue polyunsaturated fatty acids (PUFA), and hepatic lipid metabolism in SD rats. Methods. Thirty-three SD rats were randomized into four groups and maintained in each treatment for 10 weeks: Chinese tea-flavor liquor (TFL, n = 9), traditional Chinese liquor (TCL, n = 8), ethanol control (EC, n = 8), and water control (WC, n = 8). Results. TFL significantly decreased plasma insulin (P = 0.009) and marginally decreased Homeostatic Model Assessment-Insulin Resistance (HOMA-IR) (P = 0.05), compared with WC. Hepatic total and n-6 PUFA compositions were significantly decreased in TFL, TCL, and EC groups compared with WC group (P < 0.05). TFL significantly increased kidney n-6 PUFA (P = 0.05) and total PUFA (P = 0.039), compared with EC group. EC group showed significant higher gene expressions of acetyl-CoA carboxylase and steroid response element-binding protein (1c and 2), while there were no significant differences of these gene expressions in TFL or TCL group compared with WC. Conclusions. TFL has a beneficial effect on metabolic disorder in relation to improved circulating insulin levels without affecting hepatic lipid metabolism-related gene expressions in rats.

Dietary flavonoids increase plasma very long-chain (n-3) fatty acids in rats

Flavonoids probably contribute to the health benefits associated with the consumption of fruit and vegetables. However, the mechanisms by which they exert their effects are not fully elucidated. PUFA of the (n-3) series also have health benefits. Epidemiological and clinical studies have suggested that wine flavonoids may interact with the metabolism of (n-3) PUFA and increase their blood and cell levels. The present studies in rats were designed to assess whether flavonoids actually increase plasma levels of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), the main very long-chain (n-3) PUFA. Rats were fed a corn-derived anthocyanin (ACN)-rich (ACN-rich) or ACN-free diet with constant intakes of plant and marine (n-3) PUFA for 8 wk (Expt. 1). Plasma fatty acids were measured by GC. The ACN-rich diet contained ~0.24 ± 0.01 mg of ACN/g pellets. There were no significant differences between groups in the main saturated, monounsaturated, and (n-6) fatty acids. In contrast, plasma EPA and DHA were greater in the ACN-rich diet group than in the ACN-free diet group (P < 0.05). We obtained similar results in 2 subsequent experiments in which rats were administered palm oil (80 μL/d) and consumed the ACN-rich or ACN-free diet (Expt. 2) or were supplemented with fish oil (60 mg/d, providing 35 mg DHA and 12 mg EPA) and consumed the ACN-rich or ACN-free diet (Expt. 3). In both experiments, plasma EPA and DHA were significantly greater in the ACN-rich diet group. These studies demonstrate that the consumption of flavonoids increases plasma very long-chain (n-3) PUFA levels. These data confirm previous clinical and epidemiological studies and provide new insights into the health benefits of flavonoids.

Alcohol consumption and risk of heart failure: a meta-analysis

BACKGROUND

Heart failure is highly prevalent among older adults and is associated with high treatment costs. Identifying modifiable determinants of heart failure may help in prevention. Alcohol consumption has emerged as a modifiable risk factor for cardiovascular diseases. Although many studies have suggested a positive association between heavy drinking and cardiomyopathy, the association between infrequent or light-to-moderate drinking and heart failure risk has been less conclusive.

PURPOSE

To examine the relation between various levels of alcohol intake and incident heart failure.

METHODS

We conducted a meta-analysis of 6 studies obtained through a PubMed literature search. Alcohol drinkers were classified as never, former, and current drinkers of 0.1 to 0.9, 1 to 7, 8 to 14, and > 14 drinks per week.

RESULTS

Compared with never drinkers, the pooled relative risks were 1.16 (95% confidence interval [CI], 0.90-1.51) for former drinkers, 0.90 (95% CI, 0.83-0.98), 0.80 (95% CI, 0.73-0.88), 0.78 (95% CI, 0.65-0.95), and 0.77 (95% CI, 0.63-0.95) for current drinkers of 0.1 to 0.9, 1 to 7, 8 to 14, and > 14 drinks per week, respectively, in a random effects model.

CONCLUSION

These data suggest that infrequent and light-to-moderate drinking is associated with a lower risk of heart failure.

A variety of food and drink improves CVD profile

An inverse association between alcohol consumption and risk of CHD in diverse populations has been reported in over forty prospective studies(1).