Surplus dietary isoleucine intake enhanced monounsaturated fatty acid synthesis and fat accumulation in skeletal muscle of finishing pigs

Background: Isoleucine(Ile) has been implicated in the regulation of energy homeostasis and adipogenesis.However,the impact of surplus dietary Ile intake on muscle lipogenesis remains unknown.The present study aimed to investigate the impact of dietary supplementation of extra-Ile on lipogenesis,fatty acid profile and lipid accumulation in skeletal muscle in finishing pigs.Methods: Forty-eight barrows with initial body weight of 77.0 ± 0.1 kg were allotted to one of two groups and fed diets containing 0.39%,0.53% standardized ileal digestible(SID) Ile with six replicates per treatment and four pigs per replicate for 30 d.Results: Dietary Ile intake significantly improved the intramuscular fat(IMF) content and monounsaturated fatty acid(MUFA) concentration in the skeletal muscle(P < 0.05),and decreased the drip loss and shear force(P < 0.05) without influencing the growth performance of pigs(P > 0.05).Moreover,the phosphorylation of adenosine monophosphate activated protein kinase α(AMPKα) and acetyl coenzyme A carboxylase(ACC) proteins that monitor lipid metabolism were decreased in skeletal muscle of pigs offered extra-Ile diet(P < 0.05).The mRNA expression of adipose-specific genes adipocyte determination and differentiation factor 1(ADD1),fatty acid synthase(FAS),and stearoyl-CoA desaturase(SCD) were upregulated and the activity of SCD was increased as well(P < 0.05).Conclusions: Surplus dietary Ile intake could increase IMF accumulation and MUFA synthesis in skeletal muscle through depressing the phosphorylation of AMPKα-ACC and stimulating the expression and activity of SCD,and increasing the capability of lipogenesis in skeletal muscle.

Associations between Avocado Intake and Lower Rates of Incident Type 2 Diabetes in US Adults with Hispanic/Latino Ancestry

Background/Purpose: Hispanic/Latinos in the US are at increased risk for type 2 diabetes (T2D). Data suggest that avocado intake is associated with better glycemic control, but whether this translates to protection from T2D has not been studied. The goal of the current analyses was to examine whether consuming avocados at baseline is associated with lower incident T2D over a six-year period, compared to not consuming avocados at baseline. Subjects/Methods: Using data from a large population of US adults with Hispanic ancestry, without known or unknown T2D at baseline (N = 6159), participants were classified as avocado consumers (N = 983) or non-consumers (N = 5176) based on the mean of two 24-hour dietary recalls. Cox proportional hazard models estimated the association of avocado consumption with incident T2D (N = 656 cases) over a six-year follow-up period, in the population as a whole, and separately in those with normoglycemia vs. prediabetes at baseline. A set of three sequential models were run: the first controlling only for sociodemographic factors (“minimally adjusted” models), the second for these and health behaviors (“fully adjusted” models), and a third for both sets of covariates and also body mass index (BMI;“fully adjusted + BMI” models). Results: In the population as a whole, avocado intake at baseline was associated with reduced incident T2D in both the minimally adjusted (hazard ratio [HR] (±95% confidence intervals [CIs]): 0.70 (0.52 - 0.94), P = 0.04) and the fully adjusted models (HR: 0.72 (0.54 - 0.97), P = 0.03). This association was observed in both those with prediabetes and with normoglycemia at baseline, but only reached significance in those with prediabetes (minimally adjusted model: HR: 0.68 (0.48 - 0.97), P = 0.03;fully adjusted model: HR: 0.69 (0.48 - 0.98), P = 0.04), not in those with normoglycemia (minimally adjusted model: HR: 0.86 (0.45 - 1.65), P = 0.65;fully adjusted model: HR: 0.80 (0.41 - 1.55), P = 0.50). In models which additionally controlled for BMI (“fully adjusted + BMI model”), the associations were slightly attenuated (overall population: HR: 0.79 (0.59 - 1.06), P = 0.60;normoglycemia: HR: 0.83 (0.42 - 1.64), P = 0.60;prediabetes: HR = 0.75 (0.54 - 1.05), P = 0.09). Conclusions: In our longitudinal analyses, adults with Hispanic/Latino ancestry who consumed avocado were less likely to develop T2D than those who did not consume avocado at baseline, especially if they had prediabetes at baseline.

Olive oil consumption and non-alcoholic fatty liver disease

The clinical implications of non-alcoholic fatty liver diseases(NAFLD)derive from their potential to progress to fibrosis and cirrhosis.Inappropriate dietary fat intake,excessive intake of soft drinks,insulin resistance and increased oxidative stress results in increased free fatty acid delivery to the liver and increased hepatic triglyceride(TG)accumulation.An olive oil-rich diet decreases accumulation of TGs in the liver,improves postprandial TGs,glucose and glucagonlike peptide-1 responses in insulin-resistant subjects, and upregulates glucose transporter-2 expression in the liver.The principal mechanisms include:decreased nuclear factor-kappaB activation,decreased lowdensity lipoprotein oxidation,and improved insulin resistance by reduced production of inflammatory cytokines(tumor necrosis factor,interleukin-6)and improvement of jun N-terminal kinase-mediated phosphorylation of insulin receptor substrate-1.The beneficial effect of the Mediterranean diet is derived from monounsaturated fatty acids,mainly from olive oil.In this review,we describe the dietary sources of the monounsaturated fatty acids,the composition of olive oil,dietary fats and their relationship to insulin resistance and postprandial lipid and glucose responses in non-alcoholic steatohepatitis,clinical and experimental studies that assess the relationship between olive oil and NAFLD,and the mechanism by which olive oil ameliorates fatty liver,and we discuss future perspectives.

Role of abnormal lipid metabolism in development,progression,diagnosis and therapy of pancreatic cancer

There is growing evidence that metabolic alterations play an important role in cancer development and progression.The metabolism of cancer cells is reprogrammed in order to support their rapid proliferation.Elevated fatty acid synthesis is one of the most important aberrations of cancer cell metabolism.An enhancement of fatty acids synthesis is required both for carcinogenesis and cancer cell survival,as inhibition of key lipogenic enzymes slows down the growth of tumor cells and impairs their survival.Based on the data that serum fatty acid synthase(FASN),also known as oncoantigen 519,is elevated in patients with certain types of cancer,its serum level was proposed as a marker of neoplasia.This review aims to demonstrate the changes in lipid metabolism and other metabolic processes associated with lipid metabolism in pancreatic ductal adenocarcinoma(PDAC),the most common pancreatic neoplasm,characterized by high mortality.We also addressed the influence of some oncogenic factors and tumor suppressors on pancreatic cancer cell metabolism.Additionally the review discusses the potential role of elevated lipid synthesis in diagnosis and treatment of pancreatic cancer.In particular,FASN is a viable candidate for indicator of pathologic state,marker of neoplasia,as well as,pharmacological treatment target in pancreatic cancer.Recent research showed that,in addition to lipogenesis,certain cancer cells can use fatty acids from circulation,derived from diet(chylomicrons),synthesized in liver,or released from adipose tissue for their growth.Thus,the interactions between de novo lipogenesis and uptake of fatty acids from circulation by PDAC cells require further investigation.

Relationship between high dietary fat intake and Parkinson’s disease risk: a meta-analysis

OBJECTIVE: To assess whether dietary fat intake influences Parkinson’s disease risk. DATA SOURCES: We systematically surveyed the Embase and PubMed databases, reviewing manuscripts published prior to October 2018. The following terms were used:(“Paralysis agitans” OR “Parkinson disease” OR “Parkinson” OR “Parkinson’s” OR “Parkinson’s disease”) AND (“fat” OR “dietary fat” OR “dietary fat intake”). DATA SELECTION: Included studies were those with both dietary fat intake and Parkinson’s disease risk as exposure factors. The Newcastle-Ottawa Scale was adapted to investigate the quality of included studies. Stata V12.0 software was used for statistical analysis. OUTCOME MEASURES: The primary outcomes included the relationship between high total energy intake, high total fat intake, and Parkinson’s disease risk. The secondary outcomes included the relationship between different kinds of fatty acids and Parkinson’s disease risk. RESULTS: Nine articles met the inclusion criteria and were incorporated into this meta-analysis. Four studies scored 7 and the other five studies scored 9 on the Newcastle-Ottawa Scale, meaning that all studies were of high quality. Meta-analysis results showed that high total energy intake was associated with an increased risk of Parkinson’s disease (P = 0.000, odds ratio (OR)= 1.49, 95% confidence interval (CI): 1.26–1.75);in contrast, high total fat intake was not associated with Parkinson’s disease risk (P = 0.123, OR = 1.07, 95% CI: 0.91–1.25). Subgroup analysis revealed that polyunsaturated fatty acid intake (P = 0.010, OR = 1.03, 95% CI: 0.88–1.20) reduced the risk of Parkinson’s disease, while arachidonic acid (P = 0.026, OR = 1.15, 95% CI: 0.97–1.37) and cholesterol (P = 0.002, OR = 1.09, 95% CI: 0.92–1.29) both increased the risk of Parkinson’s disease. Subgroup analysis also demonstrated that, although the results were not significant, consumption of n-3 polyunsaturated fatty acids (P = 0.071, OR = 0.88, 95% CI: 0.73–1.05),α-linolenic acid (P = 0.06, OR = 0.86, 95% CI: 0.72–1.02), and the n-3 to n-6 ratio (P = 0.458, OR = 0.89, 95% CI: 0.75–1.06) were all linked with a trend toward reduced Parkinson’s disease risk. Monounsaturated fatty acid (P = 0.450, OR = 1.06, 95% CI: 0.91–1.23), n-6 polyunsaturated fatty acids (P = 0.100, OR = 1.15, 95% CI: 0.96–1.36) and linoleic acid (P = 0.053, OR = 1.11, 95% CI: 0.94–1.32) intakes were associated with a non-significant trend toward higher PD risk. Saturated fatty acid (P = 0.619, OR = 1.01, 95% CI: 0.87–1.18) intake was not associated with Parkinson’s disease. CONCLUSION: Dietary fat intake affects Parkinson’s disease risk, although this depends on the fatty acid subtype. Higher intake of polyunsaturated fatty acids may reduce the risk of Parkinson’s disease, while higher cholesterol and arachidonic acid intakes may elevate Parkinson’s disease risk. However, further studies and evidence are needed to validate any link between dietary fat intake and Parkinson’s disease.

Dietary Fats and Oils: Some Evolutionary and Historical Perspectives Concerning Edible Lipids for Human Consumption

Consumption of fats and oils in the ancient world was examined as a window to human nutritional needs and compared with lipid usage in the modern world, post-1900. In earlier periods, the natural and only source of edible fats and oils came from both animals and plants. These fats and oils played a vital role in the evolution of the human body structure, supporting many biochemical functions. Artifacts from prehistoric periods and the ancient world had indicated that humans were evolutionarily adapted to consume saturated lipids. They also consumed unsaturated fats and oils extracted from animals and plants, now identified as omega-3 to omega-6 in the fatty acid ratio of 1:1, commonly derived from naturally consumed unprocessed products and food sources. These fats and oils assisted in providing the ingredients for the building up of cells and maintaining their structural integrity in tissues, including the brain and other important internal organs, as well as providing energy for many biochemical processes in the body. The double bonds distributed throughout fatty acid carbon chains are a characteristic of unsaturated vegetable oils. They are more structurally diverse in polyunsaturated fats and oils with the greater preponderance for carbon-to-carbon double bonds distributed in the carbon chains. These double bonds are susceptible to generating free radicals. This article considers potential problems that proponents of the prevailing diet-heart cholesterol paradigm of the past 60 years may have neglected. It also presents the possible consequences of abandoning the evolutionarily inherited foods containing extracted natural saturated and monounsaturated fats and oils. Furthermore, the article addresses the contribution of docosahexaenoic and eicosapentaenoic acids to immunity and the possible connection of excess consumption of omega-6 fatty acid to the marked rise in obesity and other non-communicable diseases in modern civilization.

Food for Thought: Have We Been Giving the Wrong Dietary Advice?

Background: Since 1984 UK citizens have been advised to reduce total dietary fat intake to 30% of total energy and saturated fat intake to 10%. The National Institute of Clinical Excellence [NICE] suggests a further benefit for Coronary Heart Disease [CHD] prevention by reducing saturated fat [SFA] intake to 6% - 7% of total energy and that 30,000 lives could be saved by replacing SFAs with Polyunsaturated fats [PUFAs]. Methods: 20 volumes of the Seven Countries Study, the seminal work behind the 1984 nutritional guidelines, were assessed. The evidence upon which the NICE guidance was based was reviewed. Nutritional facts about fat and the UK intake of fat are presented and the impact of macronutrient confusion on public health dietary advice is discussed. Findings: The Seven Countries study classified processed foods, primarily carbohydrates, as saturated fats. The UK government and NICE do the same, listing biscuits, cakes, pastries and savoury snacks as saturated fats. Processed foods should be the target of public health advice but not natural fats, in which the UK diet is deficient. With reference to the macro and micro nutrient composition of meat, fish, eggs, and dairy foods the article demonstrates that dietary trials cannot change one type of fat for another in a controlled study. Interpretation: The evidence suggests that processed food is strongly associated with the increase in obesity, diabetes, CHD, and other modern illness in our society. The macro and micro nutrients found in meat, fish, eggs and dairy products, are vital for human health and consumption of these nutritious foods should be encouraged.