A highly saturated fat-rich diet is more obesogenic than diets with lower saturated fat content

Global deletion of G protein-coupled receptor 55 impairs glucose homeostasis during obesity by reducing insulin secretion and β-cell turnover

AIM

To investigate the effect of G protein-coupled receptor 55 (GPR55) deletion on glucose homeostasis and islet function following diet-induced obesity.

METHODS

GPR55-/- and wild-type (WT) mice were fed ad libitum either standard chow (SC) or a high-fat diet (HFD) for 20 weeks. Glucose and insulin tolerance tests were performed at 9/10 and 19/20 weeks of dietary intervention. Insulin secretion in vivo and dynamic insulin secretion following perifusion of isolated islets were also determined, as were islet caspase-3/7 activities and β-cell 5-bromo-20-deoxyuridine (BrdU) incorporation.

RESULTS

GPR55-/- mice fed a HFD were more susceptible to diet-induced obesity and were more glucose intolerant and insulin resistant than WT mice maintained on a HFD. Islets isolated from HFD-fed GPR55-/- mice showed impaired glucose- and pcacahorbol 12-myristate 13-acetate-stimulated insulin secretion, and they also displayed increased cytokine-induced apoptosis. While there was a 5.6 ± 1.6-fold increase in β-cell BrdU incorporation in the pancreases of WT mice fed a HFD, this compensatory increase in β-cell proliferation in response to the HFD was attenuated in GPR55-/- mice.

CONCLUSIONS

Under conditions of diet-induced obesity, GPR55-/- mice show impaired glucose handling, which is associated with reduced insulin secretory capacity, increased islet cell apoptosis and insufficient compensatory increases in β-cell proliferation. These observations support that GPR55 plays an important role in positively regulating islet function.

Metabolite Predictors of Breast and Colorectal Cancer Risk in the Women's Health Initiative

Metabolomics has been used extensively to capture the exposome. We investigated whether prospectively measured metabolites provided predictive power beyond well-established risk factors among 758 women with adjudicated cancers [n = 577 breast (BC) and n = 181 colorectal (CRC)] and n = 758 controls with available specimens (collected mean 7.2 years prior to diagnosis) in the Women's Health Initiative Bone Mineral Density subcohort. Fasting samples were analyzed by LC-MS/MS and lipidomics in serum, plus GC-MS and NMR in 24 h urine. For feature selection, we applied LASSO regression and Super Learner algorithms. Prediction models were subsequently derived using logistic regression and Super Learner procedures, with performance assessed using cross-validation (CV). For BC, metabolites did not increase predictive performance over established risk factors (CV-AUCs~0.57). For CRC, prediction increased with the addition of metabolites (median CV-AUC across platforms increased from ~0.54 to ~0.60). Metabolites related to energy metabolism: adenosine, 2-hydroxyglutarate, N-acetyl-glycine, taurine, threonine, LPC (FA20:3), acetate, and glycerate; protein metabolism: histidine, leucic acid, isoleucine, N-acetyl-glutamate, allantoin, N-acetyl-neuraminate, hydroxyproline, and uracil; and dietary/microbial metabolites: myo-inositol, trimethylamine-N-oxide, and 7-methylguanine, consistently contributed to CRC prediction. Energy metabolism may play a key role in the development of CRC and may be evident prior to disease development.

Associations of major dietary patterns with cardiometabolic risk factors among Iranian patients with type 1 diabetes

Objective

To examine the associations between dietary patterns and cardiometabolic risk factors among type 1 diabetic (T1D) patients.

Methods

This cross-sectional study was conducted on 229 Iranian T1D patients. Data on dietary intakes were collected using a 168-item food frequency questionnaire. To identify major dietary patterns, we merged data on the 168 food items to obtain 23 food groups. Then, we constructed major dietary patterns using factor analysis with varimax rotation. We used binary logistic regression to assess the association between dietary patterns and cardiometabolic risk factors, in which potential confounders were adjusted.

Results

Four dietary patterns were identified: Western, unhealthy, traditional, and semi-healthy patterns. After adjusting for confounders including demographic variables, physical activity, energy intake, and medical history, participants in the highest tertile of the Western dietary pattern had 2.53 (95 % CI: 1.03-6.22) and 3.37 (95 % CI: 1.18-9.63) times more odds of elevated HbA1c and low estimated glucose disposal rate (eGDR), respectively, compared with those in the lowest tertile. Such the positive association was also seen for elevated fasting blood glucose (FBG). Moreover, individuals in the top tertile of unhealthy diet had more odds of elevated LDL-c and abdominal obesity than those in the lowest tertile. Regarding the semi-healthy diet, higher adherence was associated with 51 % lower odds of elevated FBG (OR: 0.49, 95 % CI: 0.24-0.99). For other outcomes, no significant association was found.

Conclusion

We found that T1D patients may take benefit from adherence to a semi-healthy diet with a low amount of unhealthy and Western-related foods.

Low-Carbohydrate Diet Macronutrient Quality and Weight Change

Importance

The associations of low-carbohydrate diets (LCDs) with long-term weight management remains unclear, and the source and quality of macronutrients within LCDs are less explored.

Objectives

To prospectively examine associations between changes in LCD indices and weight change among US adults.

Design, Setting, and Participants

This prospective cohort study included initially healthy participants at baseline from the Nurses' Health Study (NHS; 1986-2010), Nurses' Health Study II (NHSII; 1991-2015), and Health Professionals Follow-up Study (HPFS; 1986-2018). Data analysis was performed between November 2022 and April 2023.

Exposures

Five LCD indices were examined: (1) a total LCD (TLCD) emphasizing overall lower carbohydrate intake; (2) an animal-based LCD (ALCD) that emphasized animal-sourced protein and fat; (3) a vegetable-based LCD (VLCD) that emphasized plant-sourced protein and fat; (4) a healthy LCD (HLCD) emphasizing less refined carbohydrates, more plant protein, and healthy fat; and (5) an unhealthy LCD (ULCD) emphasizing less healthful carbohydrates, more animal protein, and unhealthy fat.

Main Outcomes and Measures

The outcome of interest was 4-year changes in self-reported body weight.

Results

A total of 123 332 participants (mean [SD] age, 45.0 [9.7] years; 103 320 [83.8%] female) were included in this study. The median carbohydrate intake (as a percentage of energy) of the highest quintiles of TLCD score at baseline ranged from 38.3% in HPFS to 40.9% in NHSII. Mean weight gain over 4-year intervals among participants varied from 0.8 kg in the HPFS to 1.8 kg in the NHSII. After adjusting for demographics and baseline and concomitant changes of selected lifestyle factors, each 1-SD increase in TLCD score was associated with 0.06 (95% CI, 0.04-0.08) kg more weight gain over the 4-year periods. Similarly, participants gained 0.13 (95% CI, 0.11 to 0.14) kg per each 1-SD increase in ALCD score and 0.39 (95% CI, 0.37 to 0.40) kg per each 1-SD change in ULCD score. In contrast, each 1-SD increase in VLCD score was associated with 0.03 (95% CI, 0.01 to 0.04) kg less weight gain, and each 1-SD increase in HLCD score was associated with 0.36 (95% CI, 0.35 to 0.38) kg less weight gain. The associations were more pronounced among obese individuals (per 1-SD increase in HLCD score: BMI ≥30, 0.88 [95% CI, 0.80, 0.97] kg less weight gain; BMI <25, 0.23 [95% CI, 0.20, 0.26] kg less weight gain; P for interaction < .001).

Conclusions and Relevance

These findings suggest that the quality of LCDs may play a critical role in modulating long-term weight change. Only LCDs that emphasized high-quality protein, fat, and carbohydrates from whole grains and other plant-based foods were associated with less weight gain.

Physical activity in a swimming pool attenuates memory impairment by reducing glutamate and inflammatory cytokines and increasing BDNF in the brain of mice with type 2 diabetes

Type 2 diabetes is a risk factor for the development of cognitive impairment. Increasing evidence suggests that regular exercise is beneficial for the treatment of clinical symptoms in diabetic patients. The current study aimed to evaluate whether increasing physical activity through swimming training can reduce memory impairment in an animal model of type 2 diabetes. Diabetes and non-diabetes mice underwent swimming training for four weeks, and then working, spatial, and recognition memory were evaluated using three behavioral tests. Body weight, glucose, and insulin resistance were monitored. We also measured inflammatory cytokines (interleukin (IL)- 6, IL-1β, and tumor-necrosis-factor (TNF)-α), an anti-inflammatory cytokine (IL-10), and brain-derived-neurotrophic-factor (BDNF), and glutamate levels in the hippocampus or prefrontal cortex of mice. The findings showed that diabetes increased body weight, glucose, and insulin resistance, impaired working, spatial and recognition memory, increased levels of IL-6, IL-1β, TNF-α, and glutamate levels, and decreased BDNF in the hippocampus of diabetic mice. While higher physical activity was associated with reduced body weight, glucose, and insulin resistance, attenuated memory impairment, IL-6, IL-1β, TNF-α, and glutamate, and increased BDNF levels in the hippocampus and prefrontal cortex of diabetic mice. This study shows that swimming training can normalize body weight and glucose-insulin axis and reduce inflammation and glutamate in the hippocampus and enhance the neurotrophic system in both the hippocampus and prefrontal cortex of diabetic mice. This study also suggests that higher physical activity through swimming training can improve cognitive impairment in a mouse model of type 2 diabetes.

Ultra-processed food consumption and obesity indicators in individuals with and without type 1 diabetes mellitus: a longitudinal analysis of the prospective Coronary Artery Calcification in Type 1 Diabetes (CACTI) cohort study

OBJECTIVE

To evaluate the associations of ultra-processed food (UPF) consumption and obesity indicators among individuals with and without type 1 diabetes mellitus (T1DM) from the Coronary Artery Calcification in Type 1 Diabetes cohort study.

DESIGN

A secondary analysis. The consumption of UPF was assessed using the dietary data collected with the Harvard FFQ, and each food item was categorised according to the NOVA food processing classification. Height, weight and waist circumference were measured at baseline and after a mean of 14·6-year follow-up. Generalised estimating equations stratified by diabetes status were used to assess the associations between UPF intake and obesity indicators over 14 years of follow-up.

SETTING

USA.

PARTICIPANTS

A total of 600 adults (256 T1DM and 344 non-diabetic controls) aged 39 ± 9·1 years at baseline and followed up for over 14 years were included.

RESULTS

Participants with T1DM consumed significantly more UPF than non-diabetic controls at baseline: 7·6 ± 3·8 v. 6·6 ± 3·4 servings per day of UPF, respectively (P < 0·01). Participants with T1DM and with the highest UPF intake had the highest weight (βQ4 v. Q1 = 3·07) and BMI (βQ4 v. Q1 = 1·02, all P < 0·05) compared with those with the lowest UPF intake. Similar positive associations were observed in non-diabetic controls.

CONCLUSIONS

Individuals with T1DM may consume more UPF than non-diabetic controls. Positive associations between UPF consumption and obesity indicators suggest that limiting UPF can be recommended for obesity prevention and management. Further research is needed to confirm these findings.

Effects of Exercise Intensity on Cardiometabolic Parameters of Ovariectomized Obese Mice

The aim of this study was to compare the effects of continuous-moderate vs. high-intensity interval aerobic training on cardiovascular and metabolic parameters in ovariectomized high-fat-fed mice. C57BL/6 female ovariectomized were divided into four groups (n=8): low-fat-fed sedentary (SLF); high-fat-fed sedentary (SHF); high-fat-fed moderate-intensity continuous trained (MICT-HF); and high-fat-fed high-intensity interval aerobic trained (HIIT-HF). The high-fat diet lasted 10 weeks. Ovariectomy was performed in the fourth week. The exercise training was carried out in the last four weeks of protocol. Fasting glycemia, oral glucose tolerance, arterial pressure, baroreflex sensitivity, and cardiovascular autonomic modulation were evaluated. Moderate-intensity continuous training prevented the increase in arterial pressure and promoted a reduction in HR at rest, associated with an improvement in the sympathovagal balance in MICT-HF vs. SHF. The high-intensity interval training reduced blood glucose and glucose intolerance in HIIT-HF vs. SHF and MICT-HF. In addition, it improved sympathovagal balance in HIIT-HF vs. SHF. Moderate-intensity continuous training was more effective in promoting cardiovascular benefits, while high-intensity interval training was more effective in promoting metabolic benefits.

Macauba (Acrocomia aculeata) Pulp Oil Prevents Adipogenesis, Inflammation and Oxidative Stress in Mice Fed a High-Fat Diet

Macauba is a palm tree native to Brazil, which fruits are rich in oil. Macauba pulp oil has high contents of oleic acid, carotenoids, and tocopherol, but its effect on health is unknown. We hypothesized that macauba pulp oil would prevent adipogenesis and inflammation in mice. Thus, the purpose of this study was to evaluate the effects of macauba pulp oil on the metabolic changes in C57Bl/6 mice fed a high-fat diet. Three experimental groups were used (n = 10): control diet (CD), high-fat diet (HFD), and high-fat diet with macauba pulp oil (HFM). The HFM reduced malondialdehyde and increased SOD activity and antioxidant capacity (TAC), showing high positive correlations between total tocopherol, oleic acid, and carotenoid intakes and SOD activity (r = 0.9642, r = 0.8770, and r = 0.8585, respectively). The animals fed the HFM had lower levels of PPAR-γ and NF-κB, which were negatively correlated with oleic acid intake (r = -0.7809 and r = -0.7831, respectively). Moreover, the consumption of macauba pulp oil reduced inflammatory infiltrate, adipocyte number and length, (mRNA) TNF-α, and (mRNA) SREBP-1c in the adipose tissue, and it increased (mRNA) Adiponectin. Therefore, macauba pulp oil prevents oxidative stress, inflammation, and adipogenesis and increases antioxidant capacity; these results highlight its potential against metabolic changes induced by an HFD.

Implication of saturated fats in the aetiology of childhood attention deficit/hyperactivity disorder - A narrative review

Attention Deficit/Hyperactivity Disorder (ADHD) is the most common mental health disorder in the paediatric population. ADHD is highly comorbid with obesity, and has also been associated with poor dietary patterns such as increased consumption of refined carbohydrates and saturated fats. Although ADHD in children was associated with high consumption of saturated fats, so far there has been no evidence-based attempt to integrate dietary strategies controlling for intake of saturated fats into the etiological framework of the disorder. Evidence from human studies and animal models has shown that diets high in saturated fats are detrimental for the development of dopaminergic neurocircuitries, synthesis of neurofactors (e.g. brain derived neurotrophic factor) and may promote brain inflammatory processes. Notably, animal models provide evidence that early life consumption of a high saturated fats diet may impair the development of central dopamine pathways. In the present paper, we review the impact of high saturated fats diets on neurobiological processes in human studies and animal models, and how these associations may be relevant to the neuropathophysiology of ADHD in children. The validation of this relationship and its underlying mechanisms through future investigative studies could have implications for the prevention or exacerbation of ADHD symptoms, improve the understanding of the pathogenesis of the disorder, and help design future dietary studies in patients with ADHD.

Maternal diet disrupts the placenta-brain axis in a sex-specific manner

High maternal weight is associated with detrimental outcomes in offspring, including increased susceptibility to neurological disorders such as anxiety, depression and communicative disorders. Despite widespread acknowledgement of sex biases in the development of these disorders, few studies have investigated potential sex-biased mechanisms underlying disorder susceptibility. Here, we show that a maternal high-fat diet causes endotoxin accumulation in fetal tissue, and subsequent perinatal inflammation contributes to sex-specific behavioural outcomes in offspring. In male offspring exposed to a maternal high-fat diet, increased macrophage Toll-like receptor 4 signalling results in excess microglial phagocytosis of serotonin (5-HT) neurons in the developing dorsal raphe nucleus, decreasing 5-HT bioavailability in the fetal and adult brains. Bulk sequencing from a large cohort of matched first-trimester human samples reveals sex-specific transcriptome-wide changes in placental and brain tissue in response to maternal triglyceride accumulation (a proxy for dietary fat content). Further, fetal brain 5-HT levels decrease as placental triglycerides increase in male mice and male human samples. These findings uncover a microglia-dependent mechanism through which maternal diet can impact offspring susceptibility for neuropsychiatric disorder development in a sex-specific manner.

Comparing of the effects of sesame oil and rapeseed oil versus suet oil and animal butter on the reproductive system of male rats

BACKGROUND

The aim of this study was to compare the effect of vegetable oils and animal oils on the reproductive system of male rats.

METHODS

This study was a random and observational study conducted on 36 male rats with the age of 6 weeks weighing 200 ± 20 grams. Different groups were fed by sesame oil, suet oil, rapeseed oil and animal butter. The control group was fed by standard food used normally to feed animals in the laboratories. At the end of six weeks, testosterone level changes and weight changes were compared among different groups. Data were analyzed by SPSS-IBM version 16.

RESULT

Weight changes among groups did not show a dramatic statistical difference (P = .571 > 0.005). Average weight in control group was 202 and about the male rats fed by 10% of animal butter and by sesame oil were 206.5 and 99, respectively. Weight changes among groups were significant (P value = 0.005 > 0.0004). The average testosterone level in the control group was 2.4. This value in the different groups fed by 10% oils, the maximum was 12.2 and the minimum was 1.35 assigned to animal butter and rapeseed oil, respectively. So we concluded that using 10% of different oils causes an increase in testosterone level (P value = 0.001 > 0.05). The maximum testosterone level was 3.6 in the rapeseed 20% group and lowest 0.45 in the sesame 20% group.

CONCLUSION

We found that animal oil-containing diet has no significant harmful effect on male rat reproductive system in comparison with plant oils.

Individual SFA intake and risk of overweight/obesity: findings from a population-based nationwide cohort study

The relationship between SFA consumption and the risk of overweight/obesity remains unclear. Epidemiological evidence is lacking among Chinese population. This study aimed to investigate the association between individual dietary SFA intake and the risk of overweight/obesity in Chinese adults. Data from 8465 adults with BMI < 24 kg/m² at entry in the China Health and Nutrition Survey (1989-2011) were analysed. Three-day 24-h dietary records were used to collect dietary data. Cox proportional hazards regression models were constructed to estimate hazard ratios (HR) and 95 % CI for the risk of developing overweight or obesity. A total of 3171 incident cases of overweight/obesity were identified (1649 for women and 1522 for men) during a median of 11 years of follow-up. Compared with the lowest category, the intake of total SFA (TSFA) showed no significant association with the risk of overweight/obesity. However, an increased risk of overweight/obesity was observed with a higher intake of medium chain SFA (MCSFA) (P_trend = 0·004), especially decanoic acid (10:0) (HR was 1·25 (95 % CI 1·10, 1·42) comparing the highest category with the reference group; P_trend < 0·001), whereas an inverse relationship was observed for hexanoic acid (6:0) consumption; compared with non-consumers, 6:0 intake was associated with 32 % lower risk of overweight/obesity (HR: 0·68 (95 % CI 0·56, 0·84); P_trend < 0·001). Overall, the intake of subtypes of MCSFA but not TSFA was associated with the risk of overweight/obesity. Increasing hexanoic acid (6:0) and limiting decanoic acid (10:0) consumption may be protective for overweight/obesity among Chinese population.

Morphological, biochemical and histological effects of aqueous extracts of peanut (Arachis hypogaea) on swiss mice in different diets

PURPOSE

To evaluate the morphological, biochemical, and histological effects of aqueous extracts of peanut (skinless and added to 1% skin) in Swiss mice submitted to a high-fat diet.

METHODS

Forty male Swiss mice were divided into four groups (n=10 per group): GI) normocaloric diet; GII) high-fat diet; GIII) high-fat diet + 0.5 mL of peanut extract; GIV) high-fat diet + 0.5 mL of peanut extract + 1% peanut skin. The animals were weighed weekly and euthanized after 12 weeks for histopathological and biochemical analyses. The study was approved by the Animal Use Ethics Committee.

RESULTS

The animals in the GIV group had higher body weight when compared to the other ones. Increase in total cholesterol in GIII, increase in blood glucose in groups GII, GIII and GIV, decrease in serum low-density lipoprotein (LDL) concentration in groups GI and GIV and increase in serum concentration of C-reactive protein in GII were seen. The presence of vacuolar fat deposits was found in animal livers from GII.

CONCLUSIONS

The extracts improved the plasma concentrations of animals that received a high-fat diet, including preventing morphological damage to liver tissue. These benefits were enhanced by the association of peanut shells with the extract.

Anxiety Sensitivity and Fast-Food Ordering Habits Among Black Adults

Background

Black adults experience high rates of overweight/obesity, which is linked to chronic diseases and is exacerbated by fast-food consumption. Anxiety sensitivity, a relative stable fear of anxiety-related sensations, has been linked to high caloric intake. Here, we examine whether anxiety sensitivity is associated with fast-food ordering habits within a convenience sample of Black adults.

Methods

Of 124 adults (79.4% women; M_age=49.3±11.6; 84.8% overweight/obese), 107 (86.3%) reported eating from a fast-food restaurant in the last month. Participants completed the Anxiety Sensitivity-Index 3, which has a total score and physical, cognitive, and social concerns subscales. Investigator-generated items queried frequency of ordering "supersized" quantities of fast-food (e.g., cheeseburgers, fries), and healthy items (e.g., salads, oatmeal, yogurt), respectively, from "never" to "always." Covariate-adjusted ordinal logistic regression models were used to assess relations between measures of interest.

Results

Anxiety sensitivity (total and physical concerns) was associated with greater odds of more frequently ordering supersized unhealthy fast-food; and anxiety sensitivity (total and cognitive concerns) was associated with lower odds of more frequently ordering healthy items from fast-food restaurants.

Conclusions

Results suggest that adults with greater anxiety sensitivity may engage in fast-food ordering habits that can contribute to the overweight/obesity epidemic. Future studies should replicate results and determine the potential for anxiety sensitivity-reduction interventions to affect dietary choices that contribute to overweight/obesity.

Gut Microbiome Composition and Metabolic Status Are Differently Affected by Early Exposure to Unhealthy Diets in a Rat Model

Childhood is a critical stage of development during which diet can have profound influence on the microbiota–host interactions, leading to potentially lifelong impacts. This study aimed to investigate whether the consumption of cafeteria diet (CAFD) and sugary drinks during early rat life alters the structure of the gut microbial community and the metabolic activity. Four-week-old male Wistar rats (n = 27) were fed a standard chow diet with ad libitum access to water (CD) or to sucrose solution (HSD), and a third group was fed with CAFD and a sucrose solution for 14 weeks. HSD and CAFD consumption induced alterations in Firmicutes to Bacteroidetes ratio, Proteobacteria, and Verrucomicrobia. HSD increased the abundance of Barnesiella, whereas CAFD induced a depletion of Saccharibacteria. CAFD increased total white adipose tissue (WAT) weight (p < 0.0005) compared to CD. When CAFD was compared to HSD, a significant difference was found only for retroperitoneal WAT (p < 0.0005). Unhealthy diet-fed groups presented higher glucose (p < 0.0005), total cholesterol and creatinine serum levels (p < 0.005) compared to the CD rats. Early-life consumption of HSD, and of CAFD even more so, can have long-lasting negative effects on metabolic function. The gut microbiota communities were distinctively perturbed by diet composition.

Combination of cafeteria diet with intraperitoneally streptozotocin in rats. A type-2 diabetes model

Purpose

To develop a model of induction of type-2 diabetes (DM2) by combining low doses of streptozotocin (STZ) and a cafeteria diet.

Methods

Forty male Wistar rats (200 g) were allocated into four groups: control (non-diabetic, n = 10); STZ 30 mg/kg (diabetic, n = 10); STZ 35 mg/kg (diabetic,n = 10); and STZ 40 mg/kg (diabetic, n = 10). DM2 was induced with a single intraperitoneal injection of STZ after four weeks of cafeteria diet in the three diabetic groups. All animals were evaluated as for anthropometric, and biochemical analyses, as well as liver, kidney and pancreas histological analyses.

Results

Lower weight gain, higher water intake, higher Lee index, hyperglycemia and modified total protein, urea, alpha-amylase, as well as insulin resistance, hepatic steatosis, pancreas, and kidney injury were observed in animals treated with 35 and 40 mg/kg of STZ.

Conclusions

The results show that the experimental model using cafeteria diet associated with 35 mg/kg of STZ is a low-cost model and efficient in order to develop DM2, confirmed by the presence of polydipsia, hyperglycemia, altered biochemical tests, insulin resistance and damages to the liver, pancreas and kidney, which is similar to the disease found in humans.

High fat diet and its effects on cognitive health: alterations of neuronal and vascular components of brain

It has been well recognized that intake of diets rich in saturated fats could result in development of metabolic disorders such as type 2 diabetes mellitus, obesity and cardiovascular diseases. Recent studies have suggested that intake of high fat diet (HFD) is also associated with cognitive dysfunction. Various preclinical studies have demonstrated the impact of short and long term HFD feeding on the biochemical and behavioural alterations. This review summarizes studies and the protocols used to assess the impacts of HFD feeding on cognitive performance in rodents. Further, it discuss the key mechanisms that are altered by HFD feeding, such as, insulin resistance, oxidative stress, neuro-inflammation, transcriptional dysregulation and loss of synaptic plasticity. Along with these, HFD feeding also alters the vascular components of brain such as loss of BBB integrity and reduced cerebral blood flow. It is highly possible that these factors are responsible for the development of cognitive deficits as a result of HFD feeding.

A Differential Threshold of Breakfast, Caffeine and Food Groups May Be Impacting Mental Well-Being in Young Adults: The Mediation Effect of Exercise

Diet and exercise are known to influence mental health. However, the interaction between diet, dietary practices, and exercise and its impact on the mood of young adults (YA) is poorly understood. YA are inherently at risk for mental distress. They tend to consume a low-quality diet and are generally active. The purpose of the study was to assess these relationships through validating causal loop diagrams (CLD) that describe these connections by using a system dynamic (SD) modeling methodology. Adults 18-29 years were invited to complete the Food-Mood questionnaire. The anonymous questionnaire link was distributed to several institutional listservs and via several social media platforms targeting young adults. A multi-level analysis, including machine learning techniques, was used to assess these relationships. The key findings were then built into gender based CLD, which suggest that a differential repertoire may be needed to optimize diet quality, exercise, and mental well-being. Additionally, a potential net threshold for dietary factors and exercise may be needed to achieve mental well-being in young adults. Moreover, our findings suggest that exercise may boost the enhancing effect of food groups on mental well-being and may lessen the negative impact of dietary impediments of mental well-being.

Customization of Diet May Promote Exercise and Improve Mental Wellbeing in Mature Adults: The Role of Exercise as a Mediator

Diet, dietary practices and exercise are modifiable risk factors for individuals living with mental distress. However, these relationships are intricate and multilayered in such a way that individual factors may influence mental health differently when combined within a pattern. Additionally, two important factors that need to be considered are gender and level of brain maturity. Therefore, it is essential to assess these modifiable risk factors based on gender and age group. The purpose of the study was to explore the combined and individual relationships between food groups, dietary practices and exercise to appreciate their association with mental distress in mature men and women. Adults 30 years and older were invited to complete the food–mood questionnaire. The anonymous questionnaire link was circulated on several social media platforms. A multi-analyses approach was used. A combination of data mining techniques, namely, a mediation regression analysis, the K-means clustering and principal component analysis as well as Spearman’s rank–order correlation were used to explore these research questions. The results suggest that women’s mental health has a higher association with dietary factors than men. Mental distress and exercise frequency were associated with different dietary and lifestyle patterns, which support the concept of customizing diet and lifestyle factors to improve mental wellbeing.

Dietary agrobiodiversity for improved nutrition and health outcomes within a transitioning indigenous Solomon Island food system

Indigenous food systems of Pacific Small Island Developing Countries contain vast biological and cultural diversity. However, a nutrition transition is underway, characterized by shifts away from traditional diets in favour of imported and modern foods, contributing to some of the highest rates of obesity and Diabetes Type 2 Mellitus in the world. Using a mixed method approach, this study aimed to assess dietary agrobiodiversity’s relationship with nutrition indicators related to diet quality and anthropometrics within the context of the rural and Indigenous food system of Baniata village, located in the Western Province of Solomon Islands (Melanesia). A secondary aim was to evaluate the contribution of agrobiodiversity from the local food system to diet quality. A comprehensive nutrition survey was administered to the women primarily responsible for cooking of randomly selected households (n = 30). Additionally, 14 participatory focus group discussions captured the historical narrative of food system transitions, were hosted over a period of seven days, and included men, women and youth. Dietary intakes of the participants were reported below the estimated average requirement (EAR) for several essential nutrients, including protein (53%), calcium (96.6%), vitamin B1 (86.6%), vitamin B2 (80%), vitamin A (80%), zinc (40%) and fibre (77%). Focus group participants built a timeline of key historical and climatic transitions perceived to be drivers of dietary shifts away from traditional foods and towards imported and processed foods. Participants identified 221 species and varieties of agrobiodiverse foods available for cultivation or wild collection. Based on 24 h diet recalls, 87 were found to be utilised. Participants who consumed foods of a wider diversity of species richness had a higher probability of achieving recommended nutrition intakes and a lower body fat percentage (r2 = 0.205; p = 0.012). Our results suggest a nutrition transition is underway, and strategies harnessing traditional knowledge of nutrient-dense, agrobiodiverse foods can help improve food and nutrition security.

Study of Probiotic Effects of Bifidobacterium animalis subsp. lactis BB-12 and Lactobacillus plantarum 299v Strains on Biochemical and Morphometric Parameters of Rabbits after Obesity Induction

Simple Summary

On the basis of the extensive literature, two main strategies have been used to manipulate intestinal microbial composition and selectively stimulate the growth and activity of certain species, these being the administration of either prebiotics or food supplements containing living bacteria such as probiotics. Several animal studies have indicated that certain probiotics, including Lactobacilli and Bifidobacteria, can suppress body weight gain in rodents, while some probiotics strains have little effect or promote weight gain. The potential anti-obesity effect of probiotics seems to depend on the strains used and the underlying mechanisms, leading to their effects remaining not fully understood. It is in this context that this study was designed to investigate the potential of two probiotics strains, these being Bifidobacterium animalis subsp. lactis BB-12^® and Lactobacillus plantarum 299v^® in rabbits, whereby obesity and metabolic syndrome was first induced in a first experiment, and the animals were then used in a second experiment to test the hypothesis of probiotics effect on biochemical and morphometric parameters. The model of obesity induced by giving a “cafeteria” diet for 14 weeks in this trial demonstrated a change in the biochemical and morphometric parameters investigated in the ITELV2006 rabbit strain. This study revealed that B. animalis subsp. lactis BB-12 and L. plantarum 299v strains could exert beneficial effects in reducing the incidence of obesity and metabolic syndrome in the ITELV2006 rabbit strain.

Abstract

This study aimed first to develop an experimental model of obesity and metabolic syndrome over 14 weeks using a diet called “cafeteria”, which is a high-fat diet, to evaluate its consequences on the biochemical and morphometric parameters in ITELV2006 strain rabbits. Second, the trial aimed to evaluate the effect of two strains of probiotics, these being Bifidobacterium animalis subsp. lactis BB-12^® and Lactobacillus plantarum 299v^®, on the obesity and MetS induced during the first experiment. Overall, the results of the “cafeteria” diet demonstrated significant changes in numerous biochemical and morphometric parameters, reproducing obesity and the main clinical manifestations of the metabolic syndrome in humans. The administration of the two probiotic strains demonstrated an impact on certain parameters of obesity and induced MetS. This study makes it possible to conclude that probiotics could be useful in the treatment of obesity and metabolic syndrome of rabbits, but in a dependent manner. Furthermore, this study evidenced the importance of selecting specific probiotic strains and dosages to achieve desirable results on rabbits or other species.

High Fat Rodent Models of Type 2 Diabetes: From Rodent to Human

Poor dietary habits contribute to increased incidences of obesity and related co-morbidities, such as type 2 diabetes (T2D). The biological, genetic, and pathological implications of T2D, are commonly investigated using animal models induced by a dietary intervention. In spite of significant research contributions, animal models have limitations regarding the translation to human pathology, which leads to questioning their clinical relevance. Important considerations include diet-specific effects on whole organism energy balance and glucose and insulin homeostasis, as well as tissue-specific changes in insulin and glucose tolerance. This review will examine the T2D-like phenotype in rodents resulting from common diet-induced models and their relevance to the human disease state. Emphasis will be placed on the disparity in percentages and type of dietary fat, the duration of intervention, and whole organism and tissue-specific changes in rodents. An evaluation of these models will help to identify a diet-induced rodent model with the greatest clinical relevance to the human T2D pathology. We propose that a 45% high-fat diet composed of approximately one-third saturated fats and two-thirds unsaturated fats may provide a diet composition that aligns closely to average Western diet macronutrient composition, and induces metabolic alterations mirrored by clinical populations.

Sestrins in Physiological Stress Responses

Sestrins are a family of proteins that respond to a variety of environmental stresses, including genotoxic, oxidative, and nutritional stresses. Sestrins affect multiple signaling pathways: AMP-activated protein kinase, mammalian target of rapamycin complexes, insulin-AKT, and redox signaling pathways. By regulating these pathways, Sestrins are thought to help adapt to stressful environments and subsequently restore cell and tissue homeostasis. In this review, we describe how Sestrins mediate physiological stress responses in the context of nutritional and chemical stresses (liver), physical movement and exercise (skeletal muscle), and chemical, physical, and inflammatory injuries (heart). These findings also support the idea that Sestrins are a molecular mediator of hormesis, a paradoxical beneficial effect of low- or moderate-level stresses in living organisms.

Sinapine-enriched rapeseed oils reduced fatty liver formation in high-fat diet-fed C57BL/6J mice

Oil enrichment with trace amounts of components has significant effects on animal nutrition and health. In this work, the potential impact of sinapine, a trace amount of polyphenol naturally present in rapeseeds, was investigated in high-fat diet (HF)-fed C57BL/6J mice. The mice were fed with different diets including chow diet (LF), HF diet, rapeseed oil-containing HF diet (RO), and rapeseed oils enriched with sinapine (500 mg kg-1 oil, high-fat diet, RP) for 12 weeks. Here, it was demonstrated that sinapine supplementation significantly reduced (P < 0.05) body weight increase, fat accumulation, and fatty liver formation in mice when compared with those fed with a high-fat diet. The TG, LDL-C, ALT and AST levels in the RP group were significantly reduced (P < 0.05) by 15.67%, 73.62%, 20.67%, and 31.58%, respectively, compared with that in the HF group. Besides, the addition of sinapine prevented the degeneration of mouse adipocytes and lipid accumulation in the liver. Moreover, this change was achieved by downregulating SREBP-1c and FAS and upregulating PPAR-α and ACOX1 gene expression levels. Our results indicate that sinapine can be used as a prebiotic to enhance the nutritional function of vegetable oils to prevent obesity-related chronic diseases such as NAFLD.

Serum triglycerides in Alzheimer disease: Relation to neuroimaging and CSF biomarkers

OBJECTIVE

To investigate the association of triglyceride (TG) principal component scores with Alzheimer disease (AD) and the amyloid, tau, neurodegeneration, and cerebrovascular disease (A/T/N/V) biomarkers for AD.

METHODS

Serum levels of 84 TG species were measured with untargeted lipid profiling of 689 participants from the Alzheimer's Disease Neuroimaging Initiative cohort, including 190 cognitively normal older adults (CN), 339 with mild cognitive impairment (MCI), and 160 with AD. Principal component analysis with factor rotation was used for dimension reduction of TG species. Differences in principal components between diagnostic groups and associations between principal components and AD biomarkers (including CSF, MRI and [¹⁸F]fluorodeoxyglucose-PET) were assessed with a generalized linear model approach. In both cases, the Bonferroni method of adjustment was used to correct for multiple comparisons.

RESULTS

The 84 TGs yielded 9 principal components, 2 of which, consisting of long-chain, polyunsaturated fatty acid-containing TGs (PUTGs), were significantly associated with MCI and AD. Lower levels of PUTGs were observed in MCI and AD compared to CN. PUTG principal component scores were also significantly associated with hippocampal volume and entorhinal cortical thickness. In participants carrying the APOE ε4 allele, these principal components were significantly associated with CSF β-amyloid_1-42 values and entorhinal cortical thickness.

CONCLUSION

This study shows that PUTG component scores were significantly associated with diagnostic group and AD biomarkers, a finding that was more pronounced in APOE ε4 carriers. Replication in independent larger studies and longitudinal follow-up are warranted.

Metabolic Biomarkers in Aging and Anti-Aging Research

Although human life expectancy has increased significantly over the last two centuries, this has not been paralleled by a similar rise in healthy life expectancy. Thus, an important goal of anti-aging research has been to reduce the impact of age-associated diseases as a way of extending the human healthspan. This review will explore some of the potential avenues which have emerged from this research as the most promising strategies and drug targets for therapeutic interventions to promote healthy aging.

Does gender influence cardiovascular remodeling in C57BL/6J mice fed a high-fat, high-sucrose and high-salt diet?

Animal models are widely used to study the physiopathology of human diseases. However, the influence of gender on modern society diet style-induced cardiovascular disease has not thus far been explored in these models. Thus, this study investigated cardiovascular remodelling in C57BL/6J mice fed a diet rich in saturated fat, sucrose and salt, evaluating gender effect on this process. Male and female C57BL/6J mice were fed AIN93M diet or a modified AIN93M rich in fat, sucrose and salt (HFSS) for 12 weeks. Body mass, water and food intake and cardiovascular remodelling were assessed. The HFSS diet did not lead to body mass gain or glucose metabolism disturbance as assessed by serum glucose, insulin and oral glucose tolerance test. However, female mice on a HFSS diet had increased visceral and subcutaneous adiposity. Only male mice displayed heart hypertrophy. The left ventricle was not hypertrophied in either male or female mice, but its lumen was dilated. Intramyocardial arteries and the thoracic aorta showed media thickening in male mice, but in the female it was only observed in the thoracic aorta. Finally, intramyocardial artery dilation was present in both genders, but not in the aorta. Therefore changes in LV dimensions and arterial remodelling were influenced by both gender and the HFSS diet. In conclusion, male and female C57BL/6J mice suffered cardiovascular remodelling after 12 weeks of HFSS feeding, although they did not develop obesity or diabetes. Sexual dimorphism occurred in response to diet for body adiposity, heart hypertrophy and intramyocardial artery remodelling.

High-Fish Oil and High-Lard Diets Differently Affect Testicular Antioxidant Defense and Mitochondrial Fusion/Fission Balance in Male Wistar Rats: Potential Protective Effect of ω3 Polyunsaturated Fatty Acids Targeting Mitochondria Dynamics

High-fat diets rich in fish oil (HFO diet, mainly ω3-PUFAs), in contrast to high-fat diets rich in lard (HL diet, mainly saturated fatty acids) have been shown to induce improvement in mitochondrial function and fusion processes associated with a reduction in reactive oxygen species production in both liver and skeletal muscle. High-fat diets may also impair testicular function, and mitochondria represent important cellular organelles with a pivotal role in reproductive function. Mitochondria are dynamic organelles that frequently undergo fission/fusion processes. A shift toward mitochondrial fusion process has been associated with improvement of mitochondrial function, as well as with ω3-PUFAs protective effects. The present study aimed to analyze the effect of chronic overfeeding (six weeks) with HFO or HL diet on testicular tissue histology, oxidative stress, antioxidant defenses, and mitochondrial fusion (mitofusin 2) and fission (dynamic related protein 1) protein. Our results showed that HFO diet induced less testicular histology impairment, oxidative stress, and apoptosis compared to a HL diet. This finding was associated with an increase in antioxidant activities and a shift toward mitochondrial fusion processes induced by HFO diet compared to HL diet, suggesting that ω3-PUFAs may act as bioactive compound targeting mitochondria dynamics to prevent testicular impairment.

Food hypersensitivity-induced chronic gastrointestinal inflammation in a non-human primate model of diet-induced obesity

Experimental non-human primate models of obesity are induced through the introduction of atypically calorically rich diets. Studies in captive-bred macaques show the development of obesity and diabetes with similar complications to humans including eye and kidney diseases, nerve damage associated with pain and blood vessel damage. Diets differ in outcomes and here we document inflammation of the gastrointestinal tract that can be exacerbated through these dietary interventions. Following baseline physiological evaluation of body composition, Southern pigtail macaques were given a high-fat diet (HFD) for three months. This HFD consisted of lard, grains (including gluten), dairy and fructose that was otherwise omitted from a standard macaque diet (Chow). Physiological parameters were then reassessed before animals were reverted back to standard Chow for a further three months (remission). Consumption of the HFD resulted in food-mediated hypersensitivity marked by chronic weight loss, alopecia, malabsorption, protein-losing enteropathy and gross diffuse intestinal villi atrophy and lamina propria hypertrophy. Physiological changes were more highly pronounced in female macaques suggesting sex-specific differences but could be fully reversed through change of diet. Care should be taken in choosing non-human primate HFD diets for creating experimental models of obesity because they can induce severe food-driven chronic inflammation of the gastrointestinal tract that can eventuate to diet-induced chronic wasting and mortality.

High-fat diet and streptozotocin in the induction of type 2 diabetes mellitus: a new proposal

Our objective was to establish a diabetes mellitus type 2 (DM2) model in rats using a high-fat diet and streptozotocin (HF-STZ). Male Wistar rats (240-250g) were divided into a control group (commercial feed), and HF-STZ group, (66.5%-commercial feed, 13.5%-lard, and 20%-sugar). STZ (40mg/kg i.p.) or vehicle was administered on the 13th day. An oral glucose tolerance test (OGTT) was performed (2.5mg of glucose/kg v.o.) on both groups. After 39 days of treatment, blood and tissue samples were collected for analyses. The weight gain after STZ administration was lower in the HF-STZ group than in the control group with reductions in muscle mass and adipose tissue. The HF-STZ group showed hyperglycemia after STZ administration (glucose on day 39: HF-STZ: 499 ± 60; control: 134 ± 9mg/dL). Serum glucagon was 23% lower, and insulin levels were unaltered. The HOMA index was 4-times higher in the HF-STZ. The HF-STZ group showed increased post-prandial (330%) and fasting (125%) triglycerides, and while glycogen content in the liver and muscles decreased (70-80%). The area under the curve (OGTT) was 282% higher in the HF-STZ group. The combination of high-fat diet with STZ (i.p) generated rats with hyperglycemia associated with hypertriglyceridemia and introduced many other alterations present in human DM2.

Body composition and dairy intake in sedentary employees who participated in a healthy program based on nutrition education and Zumba

BACKGROUND & AIMS

The dairy intake is associated with body composition; however, its effect is controversial and remains unknown in relation to exercise interventions as Zumba Fitness^®. Thus, we analyzed the body composition and its relation to dairy intake in sedentary employees who participated in a healthy program based on nutrition education and Zumba Fitness^®.

METHODS

Sixty-nine sedentary employees (age = 38.41 ± 7.45-yr, 81.16% women) participated in a healthy program (16-weeks) based on nutrition education (2 sessions, 1st and 10th week) and Zumba Fitness^® (ZF) exercise programs [2 interventions: a) ZF, 1 h of ZF/3 day/week; b) ZF + BW, 1 h of ZF/3 day/week plus 20 min of bodyweight training]. Body composition (body weight, height, BMI, waist-hip index, ∑6-skinfolds, fat mass and muscle mass), blood pressure and dairy intake (milk, yogurt and cheese) were assessed at baseline and after interventions. Participants were categorized into normal weight (NW, BMI = 18.5-24.9 Kg/m²) and excess weight (EW, BMI ≥ 25 Kg/m²). Dairy intake and changes in BMI (ΔBMI = BMI after intervention-BMI at baseline) were divided into tertiles (T).

RESULTS

Only muscle mass (Kg) differed between ZF and ZF + BW (baseline and 16-weeks). Anthropometric indicators of adiposity were lower in NW than EW group (baseline). The ∑6-skinfolds and fat-mass decreased, while muscle mass increased in ZF and ZF + BW, and in NW and EW groups (16-weeks). The most consumed dairy was milk (baseline). Participants of T1 of cheese intake (baseline) had a higher reduction in BMI (0.42 ± 0.56 vs 0.62 ± 1.42 Kg/m²) and in ∑6-skinfolds (40.23 ± 13.13 vs 23.51 ± 10.84 mm) than individuals in T3 (16-weeks). Employees who presented higher weight loss (T3, BMI decrease > 0.50 Kg/m²) consumed lower cheese than the weight gain group (T1, BMI increase ≥ 0.33 Kg/m²) (baseline).

CONCLUSIONS

Healthy programs based on nutrition education and Zumba Fitness^® improve body composition both in EW and NW sedentary employees. ZF is as effective as ZF + BW. A lower cheese intake, at baseline, but not milk or yogurt, was related to a weight loss.

High Fat Diet Upregulates Fatty Acid Oxidation and Ketogenesis via Intervention of PPAR-γ

Background/Aims:

Systemic hyperlipidemia and intracellular lipid accumulation induced by chronic high fat diet (HFD) leads to enhanced fatty acid oxidation (FAO) and ketogenesis. The present study was aimed to determine whether activation of peroxisome proliferator-activated receptor-γ (PPAR-γ) by surplus free fatty acids (FA) in hyperlipidemic condition, has a positive feedback regulation over FAO and ketogenic enzymes controlling lipotoxicity and cardiac apoptosis.

Methods:

8 weeks old C57BL/6 wild type (WT) or PPAR-γ^−/− mice were challenged with 16 weeks 60% HFD to induce obesity mediated type 2 diabetes mellitus (T2DM) and diabetic cardiomyopathy. Treatment course was followed by echocardiographic measurements, glycemic and lipid profiling, immunoblot, qPCR and immunohistochemistry (IHC) analysis of PPAR-γ and following mitochondrial metabolic enzymes 3-hydroxy-3- methylglutaryl-CoA synthase (HMGCS2), mitochondrial β-hydroxy butyrate dehydrogenase (BDH1) and pyruvate dehydrogenase kinase isoform 4 (PDK4). In vivo model was translated in vitro, with neonatal rat cardiomyocytes (NRCM) treated with PPAR-γ agonist/antagonist and PPAR-γ overexpression adenovirus in presence of palmitic acid (PA). Apoptosis was determined in vivo from left ventricular heart by TUNEL assay and immunoblot analysis.

Results:

We found exaggerated circulating ketone bodies production and expressions of the related mitochondrial enzymes HMGCS2, BDH1 and PDK4 in HFD-induced diabetic hearts and in PA-treated NRCM. As a mechanistic approach we found HFD mediated activation of PPAR-03B3 is associated with the above-mentioned mitochondrial enzymes. HFD-fed PPAR-γ^−/− mice display decreased hyperglycemia, hyperlipidemia associated with increased insulin responsiveness as compared to HFD-fed WT mice PPAR-γ^−/−−HFD mice demonstrated a more robust functional recovery after diabetes induction, as well as significantly reduced myocyte apoptosis and improved cardiac function.

Conclusions:

PPAR-γ has been described previously to regulate lipid metabolism and adipogenesis. The present study suggests for the first time that increased PPAR-γ expression by HFD is responsible for cardiac dysfunction via upregulation of mitochondrial enzymes HMGCS2, BDH1 and PDK4. Targeting PPAR-γ and its downstream mitochondrial enzymes will provide novel strategies in preventing metabolic and myocardial dysfunction in diabetes mellitus.

Why Do Mice Overeat High-Fat Diets? How High-Fat Diet Alters the Regulation of Daily Caloric Intake in Mice

OBJECTIVE

Ad libitum high-fat diets (HFDs) spontaneously increase caloric intake in rodents, which correlates positively with weight gain. However, it remains unclear why rodents overeat HFDs. This paper investigated how changing the proportion of diet that came from HFDs might alter daily caloric intake in mice.

METHODS

Mice were given 25%, 50%, or 90% of their daily caloric need from an HFD, along with ad libitum access to a low-fat rodent chow diet. Food intake was measured daily to determine how these HFD supplements impacted total daily caloric intake. Follow-up experiments addressed the timing of HFD feeding.

RESULTS

HFD supplements did not alter total caloric intake or body weight. In a follow-up experiment, mice consumed approximately 50% of their daily caloric need from an HFD in 30 minutes during the light cycle, a time when mice do not normally consume food.

CONCLUSIONS

An HFD did not disrupt regulation of total daily caloric intake, even when up to 90% of total calories came from the HFD. However, HFDs increased daily caloric intake when provided ad libitum and were readily consumed by mice outside of their normal feeding cycle. Ad libitum HFDs appear to induce overconsumption beyond the mechanisms that regulate daily caloric intake.

Rapeseed oil fortified with micronutrients can reduce glucose intolerance during a high fat challenge in rats

Background

Better choices of dietary lipid sources and substitution of refined by fortified oils could reduce the intake of saturated fatty acids (FA) and increase the intake of omega 3 FA concomitantly to healthy bioactive compounds.

Methods

The development of obesity and metabolic disturbances was explored in rats fed during 11 weeks with a high fat diet (HFD) in which the amount of saturated and polyunsaturated FA was respectively reduced and increased, using rapeseed oil as lipid source. This oil was used in a refined form (R) or fortified (10 fold increase in concentration) with endogenous micronutrients (coenzyme Q10 + tocopherol only (RF) only and also with canolol (RFC)). The effect of substituting palm by rapeseed oil was analysed using a student t test, oil fortification was analysed using ANOVA statistical test.

Results

Despite a similar weight gain, diets R, RF and RFC improved glucose tolerance (+ 10%) of the rats compared to a standard HFD with palm and sunflower oils as lipid source. Plasma glucose was lowered in RF and RFC groups (- 15 and 23% respectively), although triacylglycerol level was only reduced in group RFC (- 33%) compared to R. The fortification with canolol promoted the activation of Akt and AMP-activated protein kinase (AMPK) in skeletal muscle and subcutaneous adipose tissue respectively. Canolol supplementation also led to reduce p38 MAPK activation in skeletal muscle.

Conclusions

This study suggests that the presence of endogenous micronutrients in rapeseed oil promotes cellular adaptations to reverse glucose intolerance and improve the metabolism of insulin sensitive tissues.

Effect of Antioxidants on Testicular iNOS and eNOS after High-Fat Diet in Rat

BACKGROUND AND OBJECTIVE

Spermatogenesis is a process by which germ cells produce spermatozoa and can be disturbed at every level. Nitric Oxide Synthases (NOS), implicate in interactions with Oxidative Stress (OS) which is one of the main factors in the etiology of male infertility. The High Fat Diet (HFD) is a major factor of obesity which in turn is important for enhancing OS. Antioxidants and garlic could attenuate or reverse effects of HFD. The aim of the study was to investigate the effects of dietary antioxidants and garlic on testicular inducible NOS (iNOS) and endothelial NOS (eNOS) in Wistar albino rats fed on HFD.

MATERIALS AND METHODS

Groups (each n = 8) were: SD (100% access to standard diet), F-HFD, (100% access to HFD) and R-HFD (70% access to HFD), F-HFD +antioxidants, F-HFD+garlic and R-HFD+antioxidants. The HFD consisted of a 60% fatty diet in 3 forms: Without antioxidants, with antioxidants and with garlic. The testicular iNOS and eNOS were studied by immunohistochemical (IHC) method. Also used ANOVA, repeated measures ANOVA, t-tests and Tukey's test (where necessary) to analyze the data (p<0.05).

RESULTS

The iNOS increased in the F-HFD and R-HFD+antioxidants groups. The eNOS increased in R-HFD,F-HFD and F-HFD+garlic groups. The H-E evaluation in R-HFD group showed a decrease in spermatogenesis score count and seminiferous tubules diameters (μm) in comparison with the SD and F-HFD groups. R-HFD+antioxidants group had lower score than F-HFD+antioxidants and F-HFD+garlic groups.

CONCLUSION

Restricted fat diet consumption causes increase in weight and impairs spermatogenesis. Results of this study reveal that adding the antioxidants can't improve histological changes of testis. The iNOS expression in seminiferous tubules in restricted fat diet along with antioxidants, suggest a potential role of iNOS in spermatogenesis and male infertility.

Estradiol Uses Different Mechanisms in Astrocytes from the Hippocampus of Male and Female Rats to Protect against Damage Induced by Palmitic Acid

An excess of saturated fatty acids can be toxic for tissues, including the brain, and this has been associated with the progression of neurodegenerative diseases. Since palmitic acid (PA) is a free fatty acid that is abundant in the diet and circulation and can be harmful, we have investigated the effects of this fatty acid on lipotoxicity in hippocampal astrocytes and the mechanism involved. Moreover, as males and females have different susceptibilities to some neurodegenerative diseases, we accessed the responses of astrocytes from both sexes, as well as the possible involvement of estrogens in the protection against fatty acid toxicity. PA increased endoplasmic reticulum stress leading to cell death in astrocytes from both males and females. Estradiol (E2) increased the levels of protective factors, such as Hsp70 and the anti-inflammatory cytokine interleukin-10, in astrocytes from both sexes. In male astrocytes, E2 decreased pJNK, TNFα, and caspase-3 activation. In contrast, in female astrocytes E2 did not affect the activation of JNK or TNFα levels, but decreased apoptotic cell death. Hence, although E2 exerted protective effects against the detrimental effects of PA, the mechanisms involved appear to be different between male and female astrocytes. This sexually dimorphic difference in the protective mechanisms induced by E2 could be involved in the different susceptibilities of males and females to some neurodegenerative processes.

Comparative effects of high oleic acid vs high mixed saturated fatty acid obesogenic diets upon PUFA metabolism in mice

Emerging evidence indicates that the fatty acid composition of obesogenic diets influences physiologic outcomes. There are scant data regarding how the content of non-essential fatty acids like monounsaturated fatty acids (MUFA) and saturated fatty acids (SFAs) impact the metabolism of polyunsaturated fatty acids (PUFAs). In this work, we tested the hypothesis that obesogenic diets enriched in oleic acid (OA; 18:1n-9) reduce polyunsaturated fatty acid (PUFA) levels vs an obesogenic diet enriched in SFAs. Adult male mice were fed for eight weeks either (1) a control 16% fat energy (en) diet with 5.7% en OA and 4.4% en SFA, (2) a 50% fat en diet with 33% en OA and 9.9% en SFA, or (3) a 50% en diet with a high SFA diet with 33% en SFA and 9.1% en OA. Dietary levels and intake of linoleic acid (LA; 18:2n-6) and α-linolenic acid (ALA; 18:3n-3) were constant between the experimental groups. Several peripheral organs (liver, heart, kidney, and adipose) were analyzed for lipid composition and oxylipin analysis was performed for liver and adipose. Our data demonstrate that a high OA diet reduced tissue content of LA and ALA (≥30%) in phospholipid and neutral lipid fractions, reduced the content of some LA-derived and ALA-derived oxylipins in liver and adipose, and conversely, elevated hepatic content of PGF_2α. In all tissues examined, except for adipose, levels of arachidonic acid (ARA; 20:4n-6) and docosahexaenoic acid (DHA; 22:6n-3) were either elevated or unaffected by the obesogenic diets. Our data indicate that the non-essential fatty content of obesogenic diets impacts PUFA content in peripheral tissues and influences the levels of bioactive oxylipins.

The role of dietary fat in obesity-induced insulin resistance

Consumption of excess calories results in obesity and insulin resistance and has been intensively studied in mice and humans. The objective of this study was to determine the specific contribution of dietary fat rather than total caloric intake to the development of obesity-associated insulin resistance. We used an intragastric feeding method to overfeed excess calories from a low-fat diet (and an isocalorically matched high-fat diet) through a surgically implanted gastric feeding tube to generate obesity in wild-type mice followed by hyperinsulinemic-euglycemic clamp studies to assess the development of insulin resistance. We show that overfeeding a low-fat diet results in levels of obesity similar to high-fat diet feeding in mice. However, despite a similar body weight, obese high-fat diet-fed mice are more insulin resistant than mice fed an isocaloric low-fat diet. Therefore, increased proportion of calories from dietary fat further potentiates insulin resistance in the obese state. Furthermore, crossover diet studies revealed that reduction in dietary fat composition improves glucose tolerance in obesity. In the context of the current obesity and diabetes epidemic, it is particularly important to fully understand the role of dietary macronutrients in the potentiation and amelioration of disease.

Niacin and olive oil promote skewing to the M2 phenotype in bone marrow-derived macrophages of mice with metabolic syndrome

Metabolic syndrome (MetS) is associated with obesity, dyslipemia, type 2 diabetes and chronic low-grade inflammation.

An Overview of Murine High Fat Diet as a Model for Type 2 Diabetes Mellitus

Type 2 diabetes mellitus (T2DM) is a worldwide epidemic, which by all predictions will only increase. To help in combating the devastating array of phenotypes associated with T2DM a highly reproducible and human disease-similar mouse model is required for researchers. The current options are genetic manipulations to cause T2DM symptoms or diet induced obesity and T2DM symptoms. These methods to model human T2DM have their benefits and their detractions. As far as modeling the majority of T2DM cases, HFD establishes the proper etiological, pathological, and treatment options. A limitation of HFD is that it requires months of feeding to achieve the full spectrum of T2DM symptoms and no standard protocol has been established. This paper will attempt to rectify the last limitation and argue for a standard group of HFD protocols and standard analysis procedures.

Metabolic and testicular effects of the long-term administration of different high-fat diets in adult rats

Purpose:

To evaluate the effects of different high-fat diets on body mass, carbohydrate metabolism and testicular morphology in rats seven months old.

Materials and Methods:

Male Wistar rats were divided into four groups: SC (standard chow), HF-S (high fat diet rich in saturated fatty acids), HF-P (high fat diet rich in polyunsaturated fatty acids), HF-SP (high fat diet rich in saturated and polyunsaturated fatty acids). The rats were fed for 16 weeks. Blood samples, testes and genital fat deposits were collected for analysis. Data were analyzed by one-way ANOVA and Bonferroni post hoc test, considering p<0.05 as statistically significant.

Results:

Different high-fat diets promoted an increase in the body mass (p<0.0001). The genital fat deposits were higher in the high-fat groups (HF-S, HF-P, HF-SP) (p=0.0004). Regarding serum parameters, the animals in the HF-S and HF-SP groups presented hyperglycemia (p=0.0060), hyperinsulinemia (p=0.0030) and hypercholesterolemia (p=0.0021). All of the hyperlipidemic groups showed hyperleptinemia (p=0.0019). Concerning the testis, the HF-S group showed a reduction on the seminiferous epithelium height (p=0.0003) and cell proliferation (p=0.0450). Seminiferous tubule diameter was lower in the HF-SP than in the SC group (p=0.0010).

Conclusions:

The high fat diet administration, independent of the lipid quality, promotes overweight. Diet rich in saturated fatty acids (lard) alters the carbohydrate metabolism and the testicular morphology with reductions of seminiferous epithelium height, seminiferous tubule diameter and cell proliferation which could be related to a disturbance of spermatogenesis.

Fat Quality Influences the Obesogenic Effect of High Fat Diets

High fat and/or carbohydrate intake are associated with an elevated risk for obesity and chronic diseases such as diabetes and cardiovascular diseases. The harmful effects of a high fat diet could be different, depending on dietary fat quality. In fact, high fat diets rich in unsaturated fatty acids are considered less deleterious for human health than those rich in saturated fat. In our previous studies, we have shown that rats fed a high fat diet developed obesity and exhibited a decrease in oxidative capacity and an increase in oxidative stress in liver mitochondria. To investigate whether polyunsaturated fats could attenuate the above deleterious effects of high fat diets, energy balance and body composition were assessed after two weeks in rats fed isocaloric amounts of a high-fat diet (58.2% by energy) rich either in lard or safflower/linseed oil. Hepatic functionality, plasma parameters, and oxidative status were also measured. The results show that feeding on safflower/linseed oil diet attenuates the obesogenic effect of high fat diets and ameliorates the blood lipid profile. Conversely, hepatic steatosis and mitochondrial oxidative stress appear to be negatively affected by a diet rich in unsaturated fatty acids.

Folic acid supplementation during high-fat diet feeding restores AMPK activation via an AMP-LKB1-dependent mechanism

AMPK is an endogenous energy sensor that regulates lipid and carbohydrate metabolism. Nonalcoholic fatty liver disease (NAFLD) is regarded as a hepatic manifestation of metabolic syndrome with impaired lipid and glucose metabolism and increased oxidative stress. Our recent study showed that folic acid supplementation attenuated hepatic oxidative stress and lipid accumulation in high-fat diet-fed mice. The aim of the present study was to investigate the effect of folic acid on hepatic AMPK during high-fat diet feeding and the mechanisms involved. Male C57BL/6J mice were fed a control diet (10% kcal fat), a high-fat diet (60% kcal fat), or a high-fat diet supplemented with folic acid (26 mg/kg diet) for 5 wk. Mice fed a high-fat diet exhibited hyperglycemia, hepatic cholesterol accumulation, and reduced hepatic AMPK phosphorylation. Folic acid supplementation restored AMPK phosphorylation (activation) and reduced blood glucose and hepatic cholesterol levels. Activation of AMPK by folic acid was mediated through an elevation of its allosteric activator AMP and activation of its upstream kinase, namely, liver kinase B1 (LKB1) in the liver. Consistent with in vivo findings, 5-methyltetrahydrofolate (bioactive form of folate) restored phosphorylation (activation) of both AMPK and LKB1 in palmitic acid-treated HepG2 cells. Activation of AMPK by folic acid might be responsible for AMPK-dependent phosphorylation of HMG-CoA reductase, leading to reduced hepatic cholesterol synthesis during high-fat diet feeding. These results suggest that folic acid supplementation may improve cholesterol and glucose metabolism by restoration of AMPK activation in the liver.

Stochastic effects in adaptive reconstruction of body damage: implied the creativity of natural selection

After an injury occurs, mechanical/biochemical loads on muscles influence the composition and structure of recovering muscles; this effect likely occurs in other tissues, cells and biological molecules as well owing to the similarity, interassociation and interaction among biochemical reactions and molecules. The 'damage and reconstruction' model provides an explanation for how an ideal cytoarchitecture is created by reducing components not suitable for bearing loads; in this model, adaptive changes are induced by promoting the stochasticity of biochemical reactions. Biochemical and mechanical loads can direct the stochasticity of biochemical reactions, which can in turn induce cellular changes. Thus, mechanical and biochemical loads, under natural selection pressure, modify the direction of cell- and tissue-level changes and guide the formation of new structures and traits, thereby influencing microevolution. In summary, the 'damage and reconstruction' model accounts for the role of natural selection in the formation of new organisms, helps explain punctuated equilibrium, and illustrates how macroevolution arises from microevolution.