Effect of Alcohol Combined With High Fat Diet: Two Wrongs Don't Make a Right but They Could Make a Good Excuse

Dynamic Alterations to Hepatic MicroRNA-29a in Response to Long-Term High-Fat Diet and EtOH Feeding

MicroRNA-29a (miR-29a) is a well characterized fibro-inflammatory molecule and its aberrant expression is linked to a variety of pathological liver conditions. The long-term effects of a high-fat diet (HFD) in combination with different levels of EtOH consumption on miR-29a expression and liver pathobiology are unknown. Mice at 8 weeks of age were divided into five groups (calorie-matched diet plus water (CMD) as a control group, HFD plus water (HFD) as a liver disease group, HFD plus 2% EtOH (HFD + 2% E), HFD + 10% E, and HFD + 20% E as intervention groups) and fed for 4, 13, 26, or 39 weeks. At each time point, analyses were performed for liver weight/body weight (BW) ratio, AST/ALT ratio, as well as liver histology assessments, which included inflammation, estimated fat deposition, lipid area, and fibrosis. Hepatic miR-29a was measured and correlations with phenotypic traits were determined. Four-week feeding produced no differences between the groups on all collected phenotypic traits or miR-29a expression, while significant effects were observed after 13 weeks, with EtOH concentration-specific induction of miR-29a. A turning point for most of the collected traits was apparent at 26 weeks, and miR-29a was significantly down-regulated with increasing liver injury. Overall, miR-29a up-regulation was associated with a lower liver/BW ratio, fat deposition, inflammation, and fibrosis, suggesting a protective role of miR-29a against liver disease progression. A HFD plus increasing concentrations of EtOH produces progressive adverse effects on the liver, with no evidence of beneficial effects of low-dose EtOH consumption. Moreover, miR-29a up-regulation is associated with less severe liver injury.

Which drinkers have changed their alcohol consumption due to energy content concerns? An Australian survey

Background

Alcohol is a discretionary, energy dense, dietary component. Compared to non-drinkers, people who consume alcohol report higher total energy intake and may be at increased risk of weight gain, overweight, and obesity, which are key preventable risk factors for illness. However, accurate consumer knowledge of the energy content in alcohol is low. To inform future behaviour change interventions among drinkers, this study investigated individual characteristics associated with changing alcohol consumption due to energy-related concerns.

Methods

An online survey was undertaken with 801 Australian adult drinkers (18–59 years, 50.2% female), i.e. who consumed alcohol at least monthly. In addition to demographic and health-related characteristics, participants reported past-year alcohol consumption, past-year reductions in alcohol consumption, frequency of harm minimisation strategy use (when consuming alcohol), and frequency of changing alcohol consumption behaviours because of energy-related concerns.

Results

When prompted, 62.5% of participants reported changing alcohol consumption for energy-related reasons at least ‘sometimes’. Women, those aged 30–44 years, metropolitan residents, those with household income $80,001–120,000, and risky/more frequent drinkers had increased odds of changing consumption because of energy-related concerns, and unemployed respondents had reduced odds.

Conclusions

Results indicate that some sociodemographic groups are changing alcohol consumption for energy-related reasons, but others are not, representing an underutilised opportunity for health promotion communication. Further research should investigate whether messaging to increase awareness of alcohol energy content, including through systems-based policy actions such as nutritional/energy product labelling, would motivate reduced consumption across a broader range of drinkers.

High-Fat Diet Augments the Effect of Alcohol on Skeletal Muscle Mitochondrial Dysfunction in Mice

Previous studies have shown that chronic heavy alcohol consumption and consumption of a high-fat (HF) diet can independently contribute to skeletal muscle oxidative stress and mitochondrial dysfunction, yet the concurrent effect of these risk factors remains unclear. We aimed to assess the effect of alcohol and different dietary compositions on mitochondrial activity and oxidative stress markers. Male and female mice were randomized to an alcohol (EtOH)-free HF diet, a HF + EtOH diet, or a low-Fat (LF) + EtOH diet for 6 weeks. At the end of the study, electron transport chain complex activity and expression as well as antioxidant activity and expression, were measured in skeletal muscles. Complex I and III activity were diminished in muscles of mice fed a HF + EtOH diet relative to the EtOH-free HF diet. Lipid peroxidation was elevated, and antioxidant activity was diminished, in muscles of mice fed a HF + EtOH diet as well. Consumption of a HF diet may exacerbate the negative effects of alcohol on skeletal muscle mitochondrial health and oxidative stress.