The influence of dietary fat on insulin resistance

Dietary Patterns and Physical Activity Levels Among People With Type 2 Diabetes

Objective

The aim of our study was to assess the association of eating habits with the dietary patterns of people with diabetes.

Methods

This cross-sectional study was conducted at National Institute of Diabetes and Endocrinology (NIDE), Dow University Hospital in Karachi, Pakistan. A total 301 patients aged >18 with type 2 diabetes came to Outpatient department were recruited. Structured questionnaire was used to assess general characteristics, Anthropometric measurements, biochemical markers, and dietary intake.

Results

A total of 301 patients with type 2 diabetes mellitus were included in this study. The average age of patients was 51.6 (SD ± 11.1) years which ranged from 21 to 80 years whereas the average BMI was 27.2 kg / m2 (SD ± 5.6). Overall, 42% of patients were found to often have less than 1 serving of fruit, and 45% had less than 3 servings of vegetables daily. Of all, 77 (26%) patients often distributed carbohydrates all over the day. Results revealed that HbA1c was higher in those patients who took more than 3 roti (approximately each roti weight 60-80 g) (P-value < .001) and full plate rice approximately 300 to 355 g cooked weight in a whole day (P-value < .001) as compared to those patients whose intake of roti was 3 or less than 3 and rice was a half plate. Moreover, out of 301 patients, 102 were found physically active (52% females and 48% males), while 199 were not active. Pain in legs and lack of motivation were common barrier to physical activity.

Conclusion

Our study revealed that patients' fruits and vegetable intake was not optimum, diet was not balanced and the quantity of starchy carbohydrates was not controlled which may affect their HBA1C levels. Proper counseling and awareness about the importance of a balanced diet and portion control in diabetes are needed.

A Randomized Double-Blind Placebo-Controlled Clinical Study to Evaluate the Effect on the Weight of a Medical Device with Polyglucosamine L112 in a Group of Overweight and Obese Subjects

BACKGROUND

Overweight and obesity have reached epidemic proportions and safe treatments are needed to heal these diseases.

OBJECTIVE

The objective of this study is to examine the activity of a medical device based on polyglucosamine polymers (PG) on body weight (BW) reduction, insulin resistance, and the serum levels of fat-soluble vitamins and glucosamine.

METHODS

A double-blind placebo-controlled interventional study comparing PG and a placebo (PL) was conducted. One hundred and fifty overweight or obese cases were treated, divided into two groups for a period of 90 days at the dosage of 3 g/day.

RESULTS

One hundred and nineteen cases (58 with PG and 61 with PL, respectively) concluded the treatment. PG was more effective than the PL on the reduction of BW and insulin resistance. No modification of fat-soluble vitamins (Vit A, E, D3, K1) and glucosamine levels was shown. Total cholesterol levels were significantly more reduced in the PG group compared to the PL group as it was for subjects with a BW decrease of >5%.

CONCLUSIONS

PG acts as a safe medical device, is not absorbed, and binds lipids in the upper gastrointestinal tract, reducing their availability, with a significant activity on the reduction of BW, insulin resistance, and cholesterol levels without the modification of fat-soluble vitamins.

Non-conventional therapeutical approaches to acne vulgaris related to its association with metabolic disorders

The ever-increasing frequency of metabolic syndrome (MetS) is still a major challenge of the public health care system, worldwide. In recent years, researchers have been drawn to the uncommon (at first look) link between skin illnesses and MetS. Because of the pro-inflammatory mechanisms and insulin resistance (IR) that are upregulated in metabolic syndrome, many skin disorders are correlated to metabolic dysfunctions, including acne vulgaris. A comprehensive understanding of the link between MetS and acne vulgaris may contribute to the development of new treatment strategies. The current review focuses on dietary and therapeutic interventions and assesses the effect of various approaches such as improving diet by avoiding certain food products (i.e., milk and chocolate) or increasing the intake of others (i.e., food products rich in omega-3 fatty acids), metformin administration, therapy with plant extracts, plant essential oils, and probiotic supplementation on the improvement of certain acne vulgaris severity parameters. These therapeutic approaches, when combined with allopathic treatment, can improve the patients' quality of life.

Dysmetabolism and Neurodegeneration: Trick or Treat?

Accumulating evidence suggests the existence of a strong link between metabolic syndrome and neurodegeneration. Indeed, epidemiologic studies have described solid associations between metabolic syndrome and neurodegeneration, whereas animal models contributed for the clarification of the mechanistic underlying the complex relationships between these conditions, having the development of an insulin resistance state a pivotal role in this relationship. Herein, we review in a concise manner the association between metabolic syndrome and neurodegeneration. We start by providing concepts regarding the role of insulin and insulin signaling pathways as well as the pathophysiological mechanisms that are in the genesis of metabolic diseases. Then, we focus on the role of insulin in the brain, with special attention to its function in the regulation of brain glucose metabolism, feeding, and cognition. Moreover, we extensively report on the association between neurodegeneration and metabolic diseases, with a particular emphasis on the evidence observed in animal models of dysmetabolism induced by hypercaloric diets. We also debate on strategies to prevent and/or delay neurodegeneration through the normalization of whole-body glucose homeostasis, particularly via the modulation of the carotid bodies, organs known to be key in connecting the periphery with the brain.

Trends in Prediabetes and Non-Alcoholic Fatty Liver Disease Associated with Abdominal Obesity among Korean Children and Adolescents: Based on the Korea National Health and Nutrition Examination Survey between 2009 and 2018

Investigations on the trends of prediabetes and non-alcoholic fatty liver disease (NAFLD) among children are scarce. We aimed to analyze the trends of prediabetes and NAFLD, as well as their association, among Korean children and adolescents from 2009 to 2018. This study investigated the prevalence of prediabetes, NAFLD, and abdominal obesity among 6327 children and adolescents aged 10–18 years according to age, sex, and body mass index (BMI) using a nationally representative survey. The prevalence of prediabetes, NAFLD, and abdominal obesity increased from 5.14%, 8.17%, and 5.97% respectively, in 2009 to 10.46%, 12.05%, and 10.51% respectively, in 2018. In age-specific analyses, an adverse trend in NAFLD was significant only in participants aged 16–18 years while the prevalence of prediabetes worsened significantly in all age groups. In BMI-specific analyses, the prevalence of prediabetes and NAFLD increased significantly only in participants with normal BMI. In logistic regression analysis, the odds ratio of prediabetes for NAFLD was 1.85 and those of abdominal obesity for prediabetes and NAFLD was 1.85 and 9.34, respectively. Our results demonstrated that the prevalence of prediabetes and NAFLD was increasing in association with abdominal obesity in Korean children and adolescents.

The Impact of Diet on Bone and Fracture Risk in Diabetes

PURPOSE OF REVIEW

The purpose of this review is to summarize the recently published scientific evidence on the effects of diet on diabetes and skeletal health.

RECENT FINDINGS

The impact of diet on overall health has been a growing topic of interest among researchers. An inappropriate eating habit is a relatively modified risk factor for diabetes in adults. Parallel with the significant increase in the incidence of diabetes mellitus worldwide, many studies have shown the benefits of lifestyle modifications, including diet and exercise for people with, or at risk of developing, diabetes. In the last years, accumulating evidence suggests that diabetes is a risk factor for bone fragility. As lifestyle intervention represents an effective option for diabetes management and treatment, there is potential for an effect on bone health. Healthy lifestyle is critical to prevent bone fragility. However, more studies are needed to fully understand the impact of diet and weight loss on fracture risk in diabetics.

Effect of dietary fat intake and genetic risk on glucose and insulin-related traits in Brazilian young adults

PURPOSE

The development of metabolic diseases such as type 2 diabetes (T2D) is closely linked to a complex interplay between genetic and dietary factors. The prevalence of abdominal obesity, hyperinsulinemia, dyslipidaemia, and high blood pressure among Brazilian adolescents is increasing and hence, early lifestyle interventions targeting these factors might be an effective strategy to prevent or slow the progression of T2D.

METHODS

We aimed to assess the interaction between dietary and genetic factors on metabolic disease-related traits in 200 healthy Brazilian young adults. Dietary intake was assessed using 3-day food records. Ten metabolic disease-related single nucleotide polymorphisms (SNPs) were used to construct a metabolic-genetic risk score (metabolic-GRS).

RESULTS

We found significant interactions between the metabolic-GRS and total fat intake on fasting insulin level (Pinteraction = 0.017), insulin-glucose ratio (Pinteraction = 0.010) and HOMA-B (Pinteraction = 0.002), respectively, in addition to a borderline GRS-fat intake interaction on HOMA-IR (Pinteraction = 0.051). Within the high-fat intake category [37.98 ± 3.39% of total energy intake (TEI)], individuals with ≥ 5 risk alleles had increased fasting insulin level (P = 0.021), insulin-glucose ratio (P = 0.010), HOMA-B (P = 0.001) and HOMA-IR (P = 0.053) than those with < 5 risk alleles.

CONCLUSION

Our study has demonstrated a novel GRS-fat intake interaction in young Brazilian adults, where individuals with higher genetic risk and fat intake had increased glucose and insulin-related traits than those with lower genetic risk. Large intervention and follow-up studies with an objective assessment of dietary factors are needed to confirm our findings.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s40200-021-00863-7.

Canola oil compared with sesame and sesame-canola oil on glycaemic control and liver function in patients with type 2 diabetes: A three-way randomized triple-blind cross-over trial

BACKGROUND

This study aimed to compare the effects of sesame (SO), canola (CO), and sesame-canola (SCO: a blend) oils on glycaemic control markers and liver function enzymes in adults with type 2 diabetes.

METHODS

In this randomized, triple-blind, three-way, cross-over clinical trial, participants replaced their usual oil with the intervention oils for 9 weeks. Serum fasting blood sugar, fasting serum insulin (FSI), insulin resistance (HOMA2-IR), beta-cell function (HOMA2-%B), insulin sensitivity (HOMA2-%S), quantitative insulin sensitivity check index (QUICKI), as well as serum liver function enzymes were measured at baseline and end of intervention periods.

RESULTS

Ninety-two participants completed all treatment periods. After adjusting for confounders, all treatment oils resulted in significant improvements in FSI and HOMA2-%S (p < 0.05). SO and SCO led to favourable changes in HOMA2-IR and QUICKI (p < 0.05). Following CO and SCO, there was a significant decrease in HOMA2-%B (p < 0.05). The sex-stratified analysis revealed that FSI and HOMA2-IR were decreased after SO compared to CO in males (p = 0.024). Serum gamma-glutamyltransferase (GGT) was significantly lower following SO compared to CO in females (p = 0.02), however, the difference in change values was not significant (p = 0.058).

CONCLUSIONS

SO consumption appears to improve glycaemic control markers in males and serum GGT in females compared with CO in patients with type 2 diabetes (registration code: IRCT2016091312571N6).

Binahong (Anredera cordifolia (Tenore) Steen.) Leaf Extract Modulates Fatty Acids and Amino Acids to Lower Blood Glucose in High-Fat Diet-Induced Diabetes Mellitus Rats

Patients with diabetes are 1.6 times more likely to use complementary alternative medicine than nondiabetic patients. Previous studies have shown that Anredera cordifolia (Tenore) Steen. (A. cordifolia) leaf extract has the capacity to lower blood glucose, but the actual mechanisms are unclear. Therefore, in this study, we explored the effect of A. cordifolia leaf extract on the metabolism of fatty acids and amino acids. Six-week-old male Wistar rats were randomly divided into six experimental groups (n = 5 per group). Two groups were fed with a regular diet or a high-fat diet (HFD) for six weeks. The regular diet and HFD groups were administered with 0.5% carboxymethylcellulose as a vehicle, and HFD rats were also fed with a suspension of glibenclamide (0.51 mg/kg body weight (BW)) or A. cordifolia leaf extract (25, 50, and 100 mg/kg BW). During the whole treatment, BW and food intake were recorded weekly. The rats were euthanized seven weeks after treatment. Blood glucose was evaluated by spectrophotometry, while fatty acids and amino acids were evaluated using a gas chromatography/flame ionization detector (GC/FID). All doses of A. cordifolia administration reduced blood glucose significantly, and 50 mg/kg BW was most effective in lowering blood glucose, similar to the effects of glibenclamide. A. cordifolia leaf extract affected the levels of medium-chain fatty acids, especially at 50 mg/kg BW. In contrast, glibenclamide affected long-chain fatty acids (LCFAs) to lower blood glucose. Based on the analysis conducted, we conclude that administration of A. cordifolia leaf extract can decrease blood glucose levels by regulating fatty acid metabolism and that a dose of 50 mg/kg BW in rats was the optimal dose.

Maternal and developmental toxicity induced by Nanoalumina administration in albino rats and the potential preventive role of the pumpkin seed oil

Although Nanoalumina is widely used in many biomedical applications, its potential toxic effect on pregnant women and developing embryos/fetuses has not been reported. In this investigation, the maternal and developmental toxicity caused by Nanoalumina during gestation and the potential preventive role of the pumpkin seed oil (PSO) were evaluated. Four groups of pregnant rats were orally administered during days 5–19 of gestation as follows: control group, Nanoalumina group (70 mg/kg b.w), PSO- group (4 ml/kg b.w.), and Nanoalumina plus PSO- group. Nanoalumina induced detrimental impacts in pregnancy outcomes, fetal growth retardation, morphological anomalies, hepatic and neural DNA damage, and histopathological changes in hepatic and neural tissues of both mother and fetus, respectively. Furthermore, the level of MDA is significantly increased and activities of GSH and CAT are significantly reduced in both tissues of nanoalumina‐administered rats. PSO co administration improved pregnancy outcomes, fetal growth parameters, DNA damage, antioxidant defenses the histopathological changes of nanoalumina‐gavaged rats and significantly diminished MDA level. Finally, PSO has a preventive role against the detrimental impacts of nanoalumina in dams and fetuses probably via its potential to prevent reactive oxygen species.

A selanylimidazopyridine (3-SePh-IP) reverses the prodepressant- and anxiogenic-like effects of a high-fat/high-fructose diet in mice

OBJECTIVE

While chronic feeding with high-fat or high-sugar diets is known related to obesity and type 2 diabetes, later data have indicated that it is also related to depression and anxiety appearance. In this regard, multi-target drugs raise considerable interest as promising therapeutic solutions to complex diseases. Considering the pharmacological effects of the imidazopyridine-derivative moiety imidazo[1,2-a]pyridine and the organoselenium molecules, the combination of both could be a feasible strategy to develop efficient drugs to handle obesity and related comorbidities, for example dyslipidemia and mood disorders.

METHODS

The antidepressant- and anxiolytic-like properties of a selanylimidazopyridine compound, 2-Phenyl-3-(phenylselanyl)imidazo[1,2-a]pyridine (3-SePh-IP), were evaluated on high-fat/high-fructose diet (HFFD)-fed female Swiss mice.

KEY FINDINGS

Our results showed that a short-term HFFD (16 days) could promote a significant body weight gain, hypercholesterolemia, glucose intolerance, and anxiety- and depressive-like behaviour in mice. Concomitant treatment with 3-SePh-IP (10 mg/kg; i.p.) attenuated the HFFD-induced increase in cholesterol levels and blunted the anxiety- and depressive-like behaviour in mice.

CONCLUSIONS

3-SePh-IP holds multimodal pharmacological properties, which provide a rationale for further studies, for example to assess the underlying mechanisms linked to its anxiolytic- and antidepressive-like activities.

Unravelling the involvement of gut microbiota in type 2 diabetes mellitus

Type 2 diabetes mellitus is the most prevalent metabolic disorder characterized by hyperglycemia, hyperlipidemia as well as insulin resistance and is affecting the lives of a huge population across the globe. Genetic mutations, obesity and lack of physical activity constitute the possible factors that can lead to onset and progression of this disorder. However, there is another major factor that can be the root cause of type 2 diabetes mellitus and that is an imbalance in the microorganisms that inhabit the gut. The gut microbiome is a vital component that needs to be given significant attention because any "dysbiosis" in the colonic microorganisms can transform the host from a state of health to a state of disease. This transformation is quite obvious since the gut barrier integrity, host metabolism such as sensitivity to insulin and maintaining blood glucose level are carried out by the tiny organisms inhabiting our intestine. In fact, the normal functioning of the human body is accredited to the microbes, particularly the bacteria, because they generate their metabolites that communicate with host cells and maintain normal physiology. Giving importance to gut health is, therefore, necessary to prevent metabolic diseases that can be maintained by the intake of prebiotics, probiotics, synbiotics along with healthy diet. The tiny microorganisms in the gut that keep our body free of disorders such as type 2 diabetes mellitus need to be in a state of 'eubiosis', else the consequences of disturbance in gut microbes can progress to serious complications in the host.

Calorie restriction for enhanced longevity: The role of novel dietary strategies in the present obesogenic environment

Calorie restriction (CR) is a potent modulator of longevity in multiple species. A growing body of evidence shows that sustained periods of CR without malnutrition improves risk factors involved in the pathophysiology of type 2 diabetes, cardiovascular diseases, cancer, and neurological disorders in humans. Innovative dietary strategies such as intermittent fasting and protein restriction have recently emerged as alternative approaches that improve markers of aging. Some of these newer strategies might provide benefits for healthy aging with little to no CR and therefore, compared to traditional CR, may be easier to follow. Further to providing an update of CR studies in humans, the present narrative review appraises the influence of these contemporary dietary strategies on mechanisms posited to drive CR-induced longevity in humans, including those involving energy metabolism, oxidative damage, inflammation, glucose homeostasis, and functional changes in the neuroendocrine systems. The review also discusses the utilization of these diets for populations in the current obesogenic environment, and comments on whether current research can inform an optimal diet that attenuates aging, can be easily followed, and promises to improve longevity in humans.

Variables to Be Monitored via Biomedical Sensors for Complete Type 1 Diabetes Mellitus Management: An Extension of the "On-Board" Concept

Type 1 diabetes mellitus (DM1) is a growing disease, and a deep understanding of the patient is required to prescribe the most appropriate treatment, adjusted to the patient's habits and characteristics. Before now, knowledge regarding each patient has been incomplete, discontinuous, and partial. However, the recent development of continuous glucose monitoring (CGM) and new biomedical sensors/gadgets, based on automatic continuous monitoring, offers a new perspective on DM1 management, since these innovative devices allow the collection of 24-hour biomedical data in addition to blood glucose levels. With this, it is possible to deeply characterize a diabetic person, offering a better understanding of his or her illness evolution, and, going further, develop new strategies to manage DM1. This new and global monitoring makes it possible to extend the "on-board" concept to other features. This well-known approach to the processing of variable "insulin" describes some inertias and aggregated/remaining effects. In this work, such analysis is carried out along with a thorough study of the significant variables to be taken into account/monitored-and how to arrange them-for a deep characterization of diabetic patients. Lastly, we present a case study evaluating the experience of the continuous and comprehensive monitoring of a diabetic patient, concluding that the huge potential of this new perspective could provide an acute insight into the patient's status and extract the maximum amount of knowledge, thus improving the DM1 management system in order to be fully functional.

MaFOS-GDM trial: Maternal fish oil supplementation in women with gestational diabetes and cord blood DNA methylation at insulin like growth factor-1 (IGF-1) gene

BACKGROUND

To evaluate the effects of maternal fish oil supplementation in women with gestational diabetes mellitus (GDM) on birthweight and DNA methylation at insulin like growth factor-1 (IGF-1) gene in their offspring.

METHODS

Randomized controlled trial. A total of 120 women with GDM were randomized to one of the two groups between 24 and 28 weeks of the pregnancy: Group 1 (n = 52) received fish oil liquid softgel (Ocean plus®) and Group 2 (Placebo) (n = 68) sunflower oil liquid softgel. The birthweight and DNA methylation at IGF-1 gene of the offsprings were assessed.

RESULTS

We observed a significant inverse association between fish oil use during pregnancy and birthweight (β = -0.18, s.e.:125, P = .04), corresponding to a 250 g lower birthweight among infants born to fish oil users. This association didn't persist in multivariate analysis. Cord blood IGF-1 was lower in fish oil group (P = .001). Cord blood DNA methylation percentages at CpG-1044 and CpG-611 sites of IGF-1 gene promoter 1 (P1) region were higher in fish oil group compared to placebo group (P = .02 and P = .001, respectively). However, CpG-1044 and CpG-611 methylations were not associated to birthweight (β = 0.04, s.e: 25.1, P = .66 and β = 0.04, s.e: 22.7, P = 0.66, respectively).

CONCLUSIONS

Maternal fish oil use has small effects on birthweight and DNA methylation when given to mothers with GDM at late pregnancy. Future studies are needed to show associations between maternal fish oil use and neonatal DNA methylations.

CLINICAL TRIAL REGISTRATION

"Fish Oil Supplementation in Women with Gestational Diabetes".

IDENTIFIER

NCT02371343.

Associations between Nut Consumption and Health Vary between Omnivores, Vegetarians, and Vegans

Regular nut consumption is associated with reduced risk factors for chronic disease; however, most population-based studies lack consideration of effect modification by dietary pattern. The UK Women’s Cohort Study (UKWCS) provides an ideal opportunity to examine relationships between nut consumption and chronic disease risk factors in a large sample with diverse dietary patterns. Nut and nutrient intake from 34,831 women was estimated using a food frequency questionnaire among self-identified omnivores, vegetarians and vegans. In this cross-sectional analysis, higher nut consumption was associated with lower body weight (difference between highest and lowest consumption categories from adjusted model: 6.1 kg; 95% CI: 4.7, 7.6) body mass index (BMI, 2.4 units difference; 95% CI: 1.9, 2.9), and waist circumference (2.6 cm difference; 95% CI: 1.4, 3.8) (all p for linear trend < 0.001). Higher nut consumption was also associated with reduced prevalence of high cholesterol and high blood pressure; having a history of heart attack, diabetes and gallstones; and markers of diet quality (all adjusted p for linear trend ≤ 0.011). Higher nut consumption appeared overall to be associated with greater benefits amongst omnivores compared to vegetarians and vegans. Findings support existing literature around beneficial effects of nut consumption and suggest that benefits may be larger among omnivores. Nut promotion strategies may have the highest population impact by specifically targeting this group.

Cardio-Metabolic Benefits of Plant-Based Diets

Cardio-metabolic disease, namely ischemic heart disease, stroke, obesity, and type 2 diabetes, represent substantial health and economic burdens. Almost one half of cardio-metabolic deaths in the U.S. might be prevented through proper nutrition. Plant-based (vegetarian and vegan) diets are an effective strategy for improving nutrient intake. At the same time, they are associated with decreased all-cause mortality and decreased risk of obesity, type 2 diabetes, and coronary heart disease. Evidence suggests that plant-based diets may reduce the risk of coronary heart disease events by an estimated 40% and the risk of cerebral vascular disease events by 29%. These diets also reduce the risk of developing metabolic syndrome and type 2 diabetes by about one half. Properly planned vegetarian diets are healthful, effective for weight and glycemic control, and provide metabolic and cardiovascular benefits, including reversing atherosclerosis and decreasing blood lipids and blood pressure. The use of plant-based diets as a means of prevention and treatment of cardio-metabolic disease should be promoted through dietary guidelines and recommendations.

An obesogenic diet enriched with blue mussels protects against weight gain and lowers cholesterol levels in C57BL/6 mice

Obesity is linked to several health complications, such as cardiovascular disease, insulin resistance, and hypertension. Dyslipidemia in obesity is one of the prime causes for health complications. We have previously shown that blue mussels (BM) are a rich source of omega (n)-3 polyunsaturated fatty acids (PUFA) and increase the mRNA expression of peroxisome-proliferator activated receptor and adiponectin, thereby inducing anti-obesity and insulin sensitizing effects in vitro. However, the in vivo effects of BM on obesity and metabolic regulation are not known. We hypothesized that dietary intake of BM will prevent weight gain and improve lipid profile of C57BL/6 mice fed a high-fat diet (HFD). Mice were fed a HFD supplemented with 5% w/w BM (BM-HFD) for 4 weeks, and then switched to a HFD for 4 weeks. Mice fed a BM-HFD showed significantly lower body weight gain and abdominal fat, compared to the HFD. Furthermore, a BM-HFD significantly reduced plasma and hepatic total and low-density lipoprotein (LDL)-cholesterol, compared to HFD. The decrease in cholesterol levels coincided with inhibition of hepatic sterol regulatory element-binding protein-2 and HMG-CoA reductase mRNA expression, and an increase in LDL-receptor gene expression in the BM-HFD group, compared to the HFD group. In conclusion, our findings have established that BM reduces body weight gain in mice. BM may have potential to lower cholesterol levels by inhibiting cholesterol synthesis, thereby protecting against obesity and perhaps heart disease.

The effects of high-fat diets composed of different animal and vegetable fat sources on the health status and tissue lipid profiles of male Japanese quail (Coturnix coturnix japonica)

Objective

The current study aimed to investigate the impact of high-fat diets composed of different animal and vegetable fat sources on serum metabolic health markers in Japanese quail, as well as the overall lipid content and fatty acid profiles of the edible bird tissues following significantly increased dietary lipid supplementation.

Methods

Fifty seven male quail were divided into six groups and fed either a standard diet or a diet enriched with one of five different fats (22% coconut oil, lard, palm oil, soybean oil, or sunflower oil) for 12 weeks. The birds were subjected to an oral glucose tolerance test following the feeding period, after which they were euthanized and blood, liver, breast, and thigh muscle samples collected. Total fat content and fatty acid profiles of the tissue samples, as well as serum uric acid, triglyceride, cholesterol, total protein, albumin, aspartate transaminase, and total bilirubin concentrations were assessed.

Results

High-fat diet feeding had no significant effects on the glucose tolerance of the birds. Dietary fatty acid profiles of the added fats were reflected in the lipid profiles of both the liver and breast and thigh muscle tissues, indicating successful transfer of dietary fatty acids to the edible bird tissues. The significantly increased level of lipid inclusion in the diets of the quail used in the present study was unsuccessful in increasing the overall lipid content of the edible bird tissues. Serum metabolic health markers in birds on the high-fat diets were not significantly different from those observed in birds on the standard diet.

Conclusion

Thus, despite the various high-fat diets modifying the fatty acid profile of the birds’ tissues, unlike in most mammals, the birds maintained a normal health status following consumption of the various high-fat diets.

The Evidence Is In: Lifestyle Interventions Can Prevent Diabetes

Early epidemiological and clinical trials suggested that type 2 diabetes could be prevented or delayed by lifestyle modifications. The Finnish Diabetes Prevention Study and the Diabetes Prevention Programs provided conclusive evidence that type 2 diabetes could be prevented or delayed with modest lifestyle changes—5% to 7% loss of body weight and 150 min/week of physical activity. Both used intensive intervention strategies and continued support and follow-up to achieve study goals. Other smaller studies made similar observations. Various medications—metformin, acarbose, troglitazone and pioglitazone, orlistat, and rosiglitazone—and bariatric surgery have also been effective for the prevention or delay of diabetes. Nutrient factors studied include the contribution of a high dietary fat intake, especially saturated fat, to the development of diabetes and increased intake of fiber, whole grains, and alcohol to decreased risk. A review of the evidence led the American Diabetes Association to conclude that lifestyle interventions should be the first choice for prevention or delay of diabetes and that drug therapy should not be a substitute for lifestyle interventions—healthy and appropriate food choices and physical activity.

Protective effect of combined pumpkin seed and ginger extracts on sperm characteristics, biochemical parameters and epididymal histology in adult male rats treated with cyclophosphamide

Reproductive toxicity is one of the side effects of cyclophosphamide (CP) in cancer treatment. Pumpkin seeds and Zingiber officinale are natural sources of antioxidants. We investigated the possible protective effect of combined pumpkin seed and Zingiber officinale extracts on sperm characteristics, epididymal histology and biochemical parameters of CP-treated rats. Male adult Wistar rats were divided randomly into six groups. Group 1, as a control, received an isotonic saline solution injection intraperitoneally (IP). Group 2 were injected IP with a single dose of CP (100 mg/kg) once. Groups 3 and 4 received CP plus 300 and 600 mg/kg combined pumpkin seed and Zingiber officinale extract (50:50). Groups 5 and 6 received only 300 and 600 mg/kg combined pumpkin seed and Zingiber officinale extract. Six weeks after treatment, sperm characteristics, histopathological changes and biochemical parameters were assessed. In CP-treated rats, motile spermatozoa were decreased, and abnormal or dead spermatozoa increased significantly (P < 0.001) but administration of the mixed extract improved sperm parameters. Epididymal epithelium and fibromascular thickness were also improved in extract-treated rats compared to control or CP groups. Biochemical analysis showed that the administration of combined extracts could increase the total antioxidant capacity (TAC) level significantly in groups 3, 4, 5 and 6. Interestingly, the mixed extract could decrease most of the side effects of CP such as vacuolization and separation of epididymal tissue. Our findings indicated that the combined extracts might be used as a protective agent against CP-induced reproductive toxicity.

Effects of Fish Oil Supplementation on Gestational Diabetes Mellitus (GDM): A Systematic Review

Context

One of the most common complications of pregnancy is gestational diabetes mellitus (GDM), which is increasing worldwide. Experimental and epidemiological studies have shown that higher intake of n-3 long-chain polyunsaturated fatty acids may decrease the risk of various diseases such as diabetes. The objective of this study was to assess the effect of fish oil supplementation on the prevention and treatment of GDM.

Evidence Acquisition

This systematic review was performed by searching several databases, including PubMed, Scopus, Google Scholar, the Cochrane Library, ProQuest, Science Direct SID, Magiran and IranMedex since 1983. The researchers also searched for references in reviewed clinical trial articles in which fish oil supplementation was compared with placebo or no supplementation.

Results

Only two published and in-press articles are included in this review. Based on these studies, docosahexaenoic acid (DHA)-enriched fish oil (800 mg/d) had no effect on prevention of GDM [0.97 (95% CI: 0.74, 1.27)]. Furthermore, omega-3 fatty acid supplementation containing 180 mg of eicosapentaenoic acid (EPA) and 120 mg DHA had beneficial effects on insulin resistance in women with GDM (change from baseline: 1.5 ± 7.5 vs ‏3.5 ± 8.5 mIU/mL, P = 0.02) but did not influence fasting plasma glucose, homeostatic model assessment-Beta cell function (HOMA-B), the quantitative insulin sensitivity check index (QUICKI), or lipid profiles (P > 0.05).

Conclusions

There is not enough evidence to support or refute the routine use of fish oil supplements during pregnancy for the prevention or treatment of diabetes. It is suggested that further randomized controlled trials be conducted to evaluate the role of fish oil supplementation in pregnancy.

Prevalence, Awareness, Treatment and Control of Diabetes Mellitus-A Population Based Study in Shanghai, China

In this study, we aimed to investigate the prevalence, awareness, treatment, and control of diabetes in Shanghai, China. A sample of 3600 residents aged from 18 to 80 years selected by a randomized stratified multiple-stage sampling method in Shanghai was investigated, with blood samples collected. Diabetes was defined as fasting plasma glucose (FPG) ≥ 7.0 mmol/L, or glycated haemoglobin (HbA1c) ≥ 6.5% (48 mmol/mol), or previous diagnosis by a physician. Adequate control of diabetes was taken as a level of HbA1c < 7.0% (53 mmol/mol) among people with treated diabetes. Multivariable regression analysis was used to explore associated factors for diabetes and prediabetes. In the 3136 participants suitable for analysis, the prevalences of diabetes, prediabetes, and previously diagnosed diabetes were 15.91%, 37.37%, and 4.46%, respectively. Among those with diabetes, only 28.06% were aware of their condition, 25.85% were currently undergoing medication treatment, and 12.42% achieved glycaemic control. Logistic regression showed that old age, preobesity, obesity, elevated triglyceride (TG), elevated C-reactive protein (CRP), and lower education level were associated with an increased risk of diabetes; old age, obesity, elevated TG, and elevated low-density lipoprotein (LDL) were associated with an increased risk of prediabetes, while male sex and rural residence were associated with a decreased risk of prediabetes. In summary, the state of diabetes in China is alarming; the rates of awareness, treatment, and control were relatively low. More efforts should be made to promote the prevention and control of diabetes in china.

Potential Bioactive Compounds from Seaweed for Diabetes Management

Diabetes mellitus is a group of metabolic disorders of the endocrine system characterised by hyperglycaemia. Type II diabetes mellitus (T2DM) constitutes the majority of diabetes cases around the world and are due to unhealthy diet, sedentary lifestyle, as well as rise of obesity in the population, which warrants the search for new preventive and treatment strategies. Improved comprehension of T2DM pathophysiology provided various new agents and approaches against T2DM including via nutritional and lifestyle interventions. Seaweeds are rich in dietary fibres, unsaturated fatty acids, and polyphenolic compounds. Many of these seaweed compositions have been reported to be beneficial to human health including in managing diabetes. In this review, we discussed the diversity of seaweed composition and bioactive compounds which are potentially useful in preventing or managing T2DM by targeting various pharmacologically relevant routes including inhibition of enzymes such as α-glucosidase, α-amylase, lipase, aldose reductase, protein tyrosine phosphatase 1B (PTP1B) and dipeptidyl-peptidase-4 (DPP-4). Other mechanisms of action identified, such as anti-inflammatory, induction of hepatic antioxidant enzymes’ activities, stimulation of glucose transport and incretin hormones release, as well as β-cell cytoprotection, were also discussed by taking into consideration numerous in vitro, in vivo, and human studies involving seaweed and seaweed-derived agents.

Effect of Omega-3 Fatty Acid on the Fatty Acid Content of the Erythrocyte Membrane and Proteinuria in Patients with Diabetic Nephropathy

Diabetic nephropathy is the leading cause of end-stage renal disease and is associated with an increased risk of cardiovascular events. Dietary omega-3 fatty acid (FA) has cardioprotective effect and is associated with a slower deterioration of albumin excretion in patients with diabetic nephropathy. In this study, we evaluated the effect of omega-3 FA on proteinuria in diabetic nephropathy patients who are controlling blood pressure (BP) with angiotensin converting enzyme inhibitor (ACEi) or angiotensin II receptor blocker (ARB). In addition, we identified changes in erythrocyte membrane FA contents. A total of 19 patients who were treated with ACEi or ARB for at least 6 months were treated for 12 weeks with omega-3 FA (Omacor, 3 g/day) or a control treatment (olive oil, 3 g/day). Proteinuria levels were unchanged after 12 weeks compared with baseline values in both groups. The erythrocyte membrane contents of omega-3 FA and eicosapentaenoic acid (EPA) were significantly increased, and oleic acid, arachidonic acid : EPA ratio, and omega-6 : omega-3 FA ratio were significantly decreased after 12 weeks compared with the baseline values in the omega-3 FA group. Although omega-3 FA did not appear to alter proteinuria, erythrocyte membrane FA contents, including oleic acid, were altered by omega-3 FA supplementation.

Impact of maternal dietary fat supplementation during gestation upon skeletal muscle in neonatal pigs

BACKGROUND

Maternal diet during pregnancy can modulate skeletal muscle development of the offspring. Previous studies in pigs have indicated that a fat supplemented diet during pregnancy can improve piglet outcome, however, this is in contrast to human studies suggesting adverse effects of saturated fats during pregnancy. This study aimed to investigate the impact of a fat supplemented (palm oil) "high fat" diet on skeletal muscle development in a porcine model. Histological and metabolic features of the biceps femoris muscle obtained from 7-day-old piglets born to sows assigned to either a commercial (C, n = 7) or to an isocaloric fat supplementation diet ("high fat" HF, n = 7) during pregnancy were assessed.

RESULTS

Offspring exposed to a maternal HF diet demonstrated enhanced muscular development, reflected by an increase in fractional growth rate, rise in myofibre cross-sectional area, increased storage of glycogen and reduction in lipid staining of myofibres. Although both groups had similar intramuscular protein and triglyceride concentrations, the offspring born to HF mothers had a higher proportion of arachidonic acid (C20:4n6) and a reduction in α-linolenic acid (C18:3n3) compared to C group offspring. The HF group muscle also exhibited a higher ratio of C20:3n6 to C20:4n6 and total n-6 to n-3 in conjunction with up-regulation of genes associated with free fatty acid uptake and biogenesis.

CONCLUSION

In conclusion, a HF gestational diet accelerates the maturation of offspring biceps femoris muscle, reflected in increased glycolytic metabolism and fibre cross sectional area, differences accompanied with a potential resetting of myofibre nutrient uptake.

Association of the ADIPOQ T45G polymorphism with insulin resistance and blood glucose: a meta-analysis

Results of published studies on the association of the ADIPOQ T45G polymorphism with insulin resistance (IR) and blood glucose are conflicting. In this study, we performed a meta-analysis to further investigate such an association. Articles that evaluate the effect of the T45G polymorphism on IR and blood glucose were identified from the PubMed and Embase databases. Five indices, including fasting blood glucose (FBG), fasting insulin (F-insulin), 2-h blood glucose (2-h BG), 2-h insulin, and homeostasis model assessment insulin resistance index (HOMA-IR), were used to assess the effects of the T45G polymorphism on IR and blood glucose under a dominant model. 24 articles involving 7630 subjects were included. Twenty-two studies on FBG, 17 on F-insulin, 20 on HOMA-IR, and 3 on 2-h BG were included. No study on 2-h insulin was found. This meta-analysis revealed no significant association between the ADIPOQ T45G polymorphism and IR and blood glucose in the overall population and subgroup subjects under a dominant model, regardless of whether FBG, F-insulin, 2-h BG, or HOMA-IR was used. The present meta-analysis indicated that the mutation allele may have no function in IR development. The ADIPOQ T45G polymorphism is not associated with IR and blood glucose.

A comparative study of effects of omega-3 Fatty acids, alpha lipoic Acid and vitamin e in type 2 diabetes mellitus

BACKGROUND

Diabetes Mellitus is a metabolic disorder characterized by abnormal lipid and glucose metabolism. Various modes of adjuvant therapy have been advocated to ameliorate insulin resistance.

AIM

This study was intended to assess the effects of antioxidants; alpha lipoic acid (ALA), omega 3 fatty acid and vitamin E on parameters of insulin sensitivity (blood glucose and HbA1c) in patients of type 2 diabetes mellitus with documented insulin resistance.

SUBJECTS AND METHODS

It was a prospective, randomized, double blind, placebo controlled, single centered study. 104 patients with type 2 diabetes mellitus with insulin resistance were recruited. They were given ALA, omega 3 fatty acid, vitamin E or placebo. Fasting blood glucose and HbA1c were measured at first visit (V1) and after 90 days (V2). Statistical analysis was carried out by paired t-test by using SPSS software version 11 (SPSS, Chicago, USA).

RESULTS

Analysis of baseline (V1) vs. end of treatment period (V2) parameters, showed significant decrease in HbA1c in the three treatment group. We also observed decrease in fasting blood glucose in the three treatment group but it was not statistically significant (Gr. I = 0.51, Gr. II = 0.05, Gr. III = 0.22, Gr. IV = 0.88).

CONCLUSION

ALA, Omega 3 fatty acid and vitamin E can be used as add on therapy in patients with type 2 diabetes mellitus to improve insulin sensitivity and lipid metabolism.

Relationships between Dietary Habits and Allostatic Load Index in Metabolic Syndrome Patients

BACKGROUND

Allostatic load (AL) measures overall physiological wear and tear on one's body, as a preclinical marker of pathophysiologic processes that precede the onset of disease. We studied the association of dietary habits with AL.

METHODS

Consecutive patients visiting a tertiary hospital Health Promotion Center from September 2009 to February 2010, older than 20 years with metabolic syndrome were selected for study (n = 204). By multivariable linear regression analysis, we investigated the association of various dietary habits evaluated by questionnaires.

RESULTS

In male, multivariable linear regression showed a significant negative association between fat preference and AL with BMI ≥ 30 (1st quartile [Q] vs. 2Q: β = -3.71; 95% confidence interval [CI], -6.26 to -1.16), a significant negative association between salt preference and AL with BMI 25-30 (β = -1.36; 95% CI, -2.46 to -0.26), a negative association between appetite control and AL with BMI < 25 (1Q vs. 3Q: β = -1.54; 95% CI, -3.00 to -0.096), a significant positive association between appetite control and AL with BMI 25-30 (1Q vs. 3Q: β = 1.30; 95% CI, 0.12 to 2.48), and a significant positive association between eating in response to food cues and AL in males with BMI 25-30 (1Q vs. 4Q: β = 1.09; 95% CI, 0.020 to 2.15).

CONCLUSION

Our results suggest that metabolic syndrome patients should be discouraged from eating fat and eating in response to food cues, and should be educated about nutrition and balanced diet.

Fasting substrate oxidation in relation to habitual dietary fat intake and insulin resistance in non-diabetic women: a case for metabolic flexibility?

Background

Metabolic flexibility described as “the capacity of the body to match fuel oxidation to fuel availability” has been implicated in insulin resistance. We examined fasting substrate oxidation in relation to dietary macronutrient intake, and markers of insulin resistance in otherwise healthy women, with and without a family history of diabetes mellitus (FH DM).

Methods

We measured body composition (dual x-ray absorptiometry), visceral and subcutaneous adipose tissue area (VAT, SAT, using Computerised Tomography), fasting [glucose], [insulin], [free fatty acids], [blood lipids], insulin resistance (HOMA-IR), resting energy expenditure (REE), respiratory exchange ratio(RER) and self-reported physical activity in a convenience sample of 180 women (18-45 yrs). A food frequency questionnaire was used to assess energy intake (EI) and calculate the RER: Food Quotient (FQ) ratio. Only those with EI:REE (1.05 -2.28) were included (N=140). Insulin resistance was defined HOMA-IR (>1.95).

Results

The Insulin Resistant (IR) group had higher energy, carbohydrate and protein intakes (p < 0.05) and lower PA levels than Insulin Sensitive (IS) group (P < 0.001), but there were no differences in RER or RER:FQ between groups. However, nearly 50% of the variance in HOMA-IR was explained by age, body fat %, VAT, RER:FQ and FH DM (adjusted R² = 0.50, p < 0.0001). Insulin-resistant women, and those with FH DM had a higher RER:FQ than their counterparts (p < 0.01), independent of body fat % or distribution.

Conclusion

In these apparently healthy, weight-stable women, insulin resistance and FH DM were associated with lower fat oxidation in relation to dietary fat intake, suggesting lower metabolic flexibility.

Study of comparative effects of antioxidants on insulin sensitivity in type 2 diabetes mellitus

OBJECTIVES

This study intended to assess the effects of the antioxidants; Alpha Lipoic Acid (ALA), omega 3 fatty acids and vitamin E on the parameters of insulin sensitivity, oxidative stress, lipid metabolism and glycaemic control in patients of type 2 diabetes mellitus.

METHODS

This was a prospective, randomized, double blind, placebo controlled, single centred study. One hundred four patients with type 2 diabetes mellitus with insulin resistance were recruited for the study. They were given ALA, omega 3 fatty acids, vitamin E or placebo. Their weight, Body Mass Index (BMI) and Waist circumference were measured. The investigations which were fasting glucose and fasting total cholesterol. The insulin resistance was calculated on the basis of the BMI and the waist circumference.

RESULTS

In the intra group analysis at the baseline (V1) vs at the end of the treatment period (V5), we observed a significant decrease in the BMI, waist circumference and the total cholesterol in the three treatment groups. In the intergroup analysis at V5, ALA, omega 3 fatty acids and vitamin E showed a significant improvement in the total cholesterol as compared to the placebo and vitamin E showed the maximum improvement.

CONCLUSION

ALA, omega 3 fatty acids and vitamin E showed the improvement in insulin sensitivity. Since they differ in improving different parameters all of these three can be used as an add on therapy in patients with type 2 diabetes mellitus to improve their insulin sensitivity and lipid metabolism.

Intramyocellular Lipid Content and Molecular Adaptations in Response to a 1-Week High-Fat Diet

OBJECTIVE

To investigate molecular adaptations that accompany the elevation of intramyocellular lipid (IMCL) content on a high-fat (HF) diet for 1 week.

RESEARCH METHODS AND PROCEDURES

Ten subjects consumed a normal-fat (NF) diet for 1 week, followed by an HF diet for another week. After both dietary periods, we determined the IMCL content by proton magnetic resonance spectroscopy in the vastus lateralis muscle and quantified changes in gene expression, protein content, and activity in biopsy samples. We investigated genes involved in carbohydrate and fatty acid handling [lipoprotein lipase, acetyl-coenzyme A carboxylase (ACC) 2, hormone-sensitive lipase, hexokinase II, and glucose transporter 4] and measured protein levels of CD36 and phosphorylated and unphosphorylated ACC2 and the activity of adenosine monophosphate-activated kinase.

RESULTS

IMCL content was increased by 54% after the HF period. Lipoprotein lipase mRNA concentration was increased by 33%, whereas ACC2 mRNA concentration tended to be increased after the HF diet. Hexokinase II, glucose transporter 4, and hormone-sensitive lipase mRNA were unchanged after the HF diet. ACC2 and CD36 protein levels, phosphorylation status of ACC2, and adenosine monophosphate-activated kinase activity did not change in response to the HF diet.

DISCUSSION

We found that IMCL content in skeletal muscle increased after 1 week of HF feeding, accompanied by molecular adaptations that favor fat storage in muscle rather than oxidation.

RTEF-1 attenuates blood glucose levels by regulating insulin-like growth factor binding protein-1 in the endothelium

RATIONALE

Related transcriptional enhancer factor-1 (RTEF-1) plays an important role in endothelial cell function by regulating angiogenesis; however, the mechanism underlying the role of RTEF-1 in the endothelium in vivo is not well defined.

OBJECTIVE

We investigated the biological functions of RTEF-1 by disrupting the gene that encodes it in mice endothelium -specific RTEF-1-deficient transgenic mice (RTEF-1(-/-)).

METHODS AND RESULTS

RTEF-1(-/-) mice showed significantly increased blood glucose levels and insulin resistance, accompanied by decreased levels of insulin-like growth factor binding protein-1 (IGFBP-1) mRNA in the endothelium and decreased serum IGFBP-1 levels. Additionally, the RTEF-1(-/-) phenotype was exacerbated when the mice were fed a high-fat diet, which correlated with decreased IGFBP-1 levels. In contrast, vascular endothelial cadherin/RTEF-1-overexpressing(1) transgenic mice (VE-Cad/RTEF1) demonstrated improved glucose clearance and insulin sensitivity in response to a high-fat diet. Furthermore, we demonstrated that RTEF-1 upregulates IGFBP-1 through selective binding and promotion of transcription from the insulin response element site. Insulin prevented RTEF-1 expression and significantly inhibited IGFBP-1 transcription in endothelial cells in a dose-dependent fashion.

CONCLUSIONS

To the best of our knowledge, this is the first report demonstrating that RTEF-1 stimulates promoter activity through an insulin response element and also mediates the effects of insulin on gene expression. These results show that RTEF-1-stimulated IGFBP-1 expression may be central to the mechanism by which RTEF-1 attenuates blood glucose levels. These findings provide the basis for novel insights into the transcriptional regulation of IGFBP-1 and contribute to our understanding of the role of vascular endothelial cells in metabolism.

Type 2 diabetes mellitus: a review of current trends

Type 2 diabetes mellitus (DM) is a chronic metabolic disorder in which prevalence has been increasing steadily all over the world. As a result of this trend, it is fast becoming an epidemic in some countries of the world with the number of people affected expected to double in the next decade due to increase in ageing population, thereby adding to the already existing burden for healthcare providers, especially in poorly developed countries. This review is based on a search of Medline, the Cochrane Database of Systemic Reviews, and citation lists of relevant publications. Subject heading and key words used include type 2 diabetes mellitus, prevalence, current diagnosis, and current treatment. Only articles in English were included. Screening and diagnosis is still based on World Health Organization (WHO) and American Diabetes Association (ADA) criteria which include both clinical and laboratory parameters. No cure has yet been found for the disease; however, treatment modalities include lifestyle modifications, treatment of obesity, oral hypoglycemic agents, and insulin sensitizers like metformin, a biguanide that reduces insulin resistance, is still the recommended first line medication especially for obese patients. Other effective medications include non-sulfonylurea secretagogues, thiazolidinediones, alpha glucosidase inhibitors, and insulin. Recent research into the pathophysiology of type 2 DM has led to the introduction of new medications like glucagon-like peptide 1 analogoues: dipeptidyl peptidase-IV inhibitors, inhibitors of the sodium-glucose cotransporter 2 and 11ß-hydroxysteroid dehydrogenase 1, insulin-releasing glucokinase activators and pancreatic-G-protein-coupled fatty-acid-receptor agonists, glucagon-receptor antagonists, metabolic inhibitors of hepatic glucose output and quick-release bromocriptine. Inhaled insulin was licensed for use in 2006 but has been withdrawn from the market because of low patronage.

ω-3 polyunsaturated fatty acid supplementation does not influence body composition, insulin resistance, and lipemia in women with type 2 diabetes and obesity

To evaluate the influence of ω-3 polyunsaturated fatty acid (ω-3 PUFA) supplementation on body composition, insulin resistance, and lipemia of women with type 2 diabetes, the authors evaluated 41 women (60.64 ± 7.82 years) with high blood pressure and diabetes mellitus in a randomized and single-blind longitudinal intervention study. The women were divided into 3 groups: GA (2.5 g/d fish oil), GB (1.5 g/d fish oil), and GC (control). The capsules with the supplement contained 21.9% of eicosapentaenoic acid and 14.1% of docosapentaenoic acid. Biochemical (glucose, glycated hemoglobin, total and fractional cholesterol, triglycerides, and insulin) and anthropometric (body mass, stature, waist circumference [WC], and body composition) evaluations were performed before and after the 30 days of intervention. Homeostasis model assessment-insulin resistance and the Quantitative Insulin Sensitivity Check Index were used to evaluate the insulin resistance and insulin sensitivity (IS), respectively. GB presented a greater loss of body mass and WC (P < .05), greater frequency of glycemic and total cholesterol reduction, and an increase of high-density lipoprotein cholesterol compared with GA. Thus, a high dose of ω-3 PUFA can reduce IS. A lower dose of ω-3 PUFA positively influenced body composition and lipid metabolism.

Foods for the prevention of diabetes: how do they work?

With the diabetes epidemic reaching menacing proportions worldwide, there is an urgent need for the development of cost-efficient prevention strategies to be effective at the population level. Great potential in this direction lies in properly designed, large-scale dietary interventions. The macronutrient composition and the caloric content of our diet are major determinants of glucose homeostasis and there is a continuously growing list of foods, nutrients or individual compounds that have been associated with an increased or reduced incidence of diabetes mellitus. These include fat, carbohydrates, fibre, alcohol, polyphenols and other micronutrients or individual dietary compounds, which have been shown to either promote or prevent a progression towards a (pre-)diabetic state. This review aims to briefly summarize relevant epidemiological data linking foods to diabetes and to provide insights into the mechanisms through which these effects are mediated. These include improvement of insulin sensitivity or promotion of insulin resistance, regulation of inflammatory pathways, regulation of glucose transport and tissue glucose uptake, aggravation or attenuation of postprandial glycaemia/insulinaemia, interactions with hormonal responses and β-cell-dependent mechanisms.

Nutritional modulation of insulin resistance

Insulin resistance has been proposed as the strongest single predictor for the development of Type 2 Diabetes (T2DM). Chronic oversupply of energy from food, together with inadequate physical activity, have been recognized as the most relevant factors leading to overweight, abdominal adiposity, insulin resistance, and finally T2DM. Conversely, energy reduced diets almost invariably to facilitate weight loss and reduce abdominal fat mass and insulin resistance. However, sustained weight loss is generally difficult to achieve, and distinct metabolic characteristics in patients with T2DM further compromise success. Therefore, investigating the effects of modulating the macronutrient composition of isoenergetic diets is an interesting concept that may lead to additional important insights. Metabolic effects of various different dietary concepts and strategies have been claimed, but results from randomized controlled studies and particularly from longer-term-controlled interventions in humans are often lacking. However, some of these concepts are supported by recent research, at least in animal models and short-term studies in humans. This paper provides an update of the current literature regarding the role of nutrition in the modulation of insulin resistance, which includes the discussion of weight-loss-independent metabolic effects of commonly used dietary concepts.

Eicosanoids, β-cell function, and diabetes

Arachidonic acid (AA) is metabolized by cyclooxygenase (COX), lipoxygenase (LOX), and cytochrome P450 (CYP) enzymes into eicosanoids, which are involved in diverse diseases, including type 1 and type 2 diabetes. During the last 30 years, evidence has been accumulated that suggests important functions for eicosanoids in the control of pancreatic β-cell function and destruction. AA metabolites of the COX pathway, especially prostaglandin E(2) (PGE(2)), appear to be significant factors to β-cell dysfunction and destruction, participating in the pathogenesis of diabetes and its complications. Several elegant studies have contributed to the sorting out of the importance of 12-LOX eicosanoids in cytokine-mediated inflammation in pancreatic β cells. The role of CYP eicosanoids in diabetes is yet to be explored. A recent publication has demonstrated that stabilizing the levels of epoxyeicosatrienoic acids (EETs), CYP eicosanoids, by inhibiting or deleting soluble epoxide hydrolase (sEH) improves β-cell function and reduces β-cell apoptosis in diabetes. In this review we summarize recent findings implicating these eicosanoid pathways in diabetes and its complications. We also discuss the development of animal models with targeted gene deletion and specific enzymatic inhibitors in each pathway to identify potential targets for the treatment of diabetes and its complications.

Almond consumption improved glycemic control and lipid profiles in patients with type 2 diabetes mellitus

Almond consumption is associated with ameliorations in obesity, hyperlipidemia, hypertension, and hyperglycemia. The hypothesis of this 12-week randomized crossover clinical trial was that almond consumption would improve glycemic control and decrease the risk for cardiovascular disease in 20 Chinese patients with type 2 diabetes mellitus (T2DM) (9 male, 11 female; 58 years old; body mass index, 26 kg/m²) with mild hyperlipidemia. After a 2-week run-in period, patients were assigned to either a control National Cholesterol Education Program step II diet (control diet) or an almond diet for 4 weeks, with a 2-week washout period between alternative diets. Almonds were added to the control diet to replace 20% of total daily calorie intake. Addition of approximately 60 g almonds per day increased dietary intakes of fiber, magnesium, polyunsaturated fatty acid, monounsaturated fatty acid, and vitamin E. Body fat determined with bioelectrical impedance analysis was significantly lower in patients consuming almonds (almonds vs control: 29.6% vs 30.4%). The almond diet enhanced plasma α-tocopherol level by a median 26.8% (95% confidence intervals, 15.1-36.6) compared with control diet. Furthermore, almond intake decreased total cholesterol, low-density lipoprotein cholesterol, and the ratio of low-density lipoprotein cholesterol to high-density lipoprotein cholesterol by 6.0% (1.6-9.4), 11.6% (2.8-19.1), and 9.7% (0.3-20.9), respectively. Plasma apolipoprotein (apo) B levels, apo B/apo A-1 ratio, and nonesterified fatty acid also decreased significantly by 15.6% (5.1-25.4), 17.4% (2.8-19.9), and 5.5% (3.0-14.4), respectively. Compared with subjects in the control diet, those in the almond diet had 4.1% (0.9-12.5), 0.8% (0.4-6.3), and 9.2% (4.4-13.2) lower levels of fasting insulin, fasting glucose, and homeostasis model assessment of insulin resistance index, respectively. Our results suggested that incorporation of almonds into a healthy diet has beneficial effects on adiposity, glycemic control, and the lipid profile, thereby potentially decreasing the risk for cardiovascular disease in patients with type 2 diabetes mellitus.

Intake of fatty acids and antioxidants and pancreatic cancer in a large population-based case-control study in the San Francisco Bay Area

There are no well-established modifiable risk factors for pancreatic cancer except smoking. Some dietary factors have been associated with pancreatic cancer risk and require further study. We examined the associations among intake of specific fatty acids and antioxidants and risk of pancreatic cancer in a large population-based case-control study in the San Francisco Bay Area. Unconditional logistic regression models were used to compute odds ratios (ORs) and 95% confidence intervals (CI) as estimates of relative risk. Positive associations were observed for high levels of the 8 individual saturated fatty acids (4th vs. 1st quartile: ORs ranged from 1.6 to 2.6; all p(trend) < 0.01), monounsaturated palmitoleic and oleic fatty acids [OR = 1.6 (95% CI: 1.2-2.1) and 1.4 (95% CI: 1.1-1.9); both p(trend) < 0.01], and polyunsaturated linolenic acid [OR = 1.5 (95% CI: 1.1-2.0); p(trend) = 0.02]. Inverse associations were observed for high levels of gadolic acid [4th vs. 1st quartile: OR = 0.68 (95% CI: 0.50-0.92); p(trend) = 0.007] and omega-3 fatty acids [>or=0.85 g/day vs. 1st quartile: OR = 0.47 (95% CI: 0.25-0.90)]. An inverse association was also observed for high total intake of vitamin C [4th vs. 1st quartile: OR = 0.69 (95% CI: 0.51-0.94); p(trend) = 0.004] and of vitamin E [OR = 0.67 (95% CI: 0.49-0.92); p(trend) = 0.01]. Although similar decreased risks were also observed for high supplemental intake of these 2 vitamins (both p(trend) < 0.01), no association was observed for intake from food alone. These results support the hypotheses that a high intake of saturated and certain monounsaturated fatty acids may increase the risk of pancreatic cancer, whereas greater intake of omega-3 fatty acids, vitamins C and E may reduce the risk.

Association of the fatty acid-binding protein 2 gene Ala54Thr polymorphism with insulin resistance and blood glucose: a meta-analysis in 13451 subjects

BACKGROUND

The results from the published studies on the association of fatty acid-binding protein 2 (FABP2) Ala54Thr polymorphism with insulin resistance and blood glucose are conflicting. In this meta-analysis, we investigated the association of the FABP2 Ala54Thr polymorphism with insulin resistance and blood glucose.

METHODS

We collected data on fasting blood glucose and fasting insulin, 2-h blood glucose (2-h BG) and 2-h insulin (2-h insulin), and homeostasis model assessment insulin resistance index. A dominant model was used for this meta-analysis.

RESULTS

Thirty-one studies with 13 451 subjects were included in this meta-analysis. The carriers of Thr54 allele have significantly higher homeostasis model assessment insulin resistance index and marginally higher fasting insulin than the non-carriers: standardized mean difference (SMD) = 0.07, 95% confidence interval (CI, 0.02, 0.12), p = 0.007, p(heterogeneity) = 0.19 and SMD = 0.08, 95% CI (-0.01, 0.17), p = 0.07, p(heterogeneity) < 0.00001, respectively. A borderline significant association between the FABP2 Ala54Thr polymorphism and an increased 2-h BG was also detected under the dominant model: SMD = 0.10, 95% CI (0.00, 0.20), p = 0.05, p(heterogeneity) = 0.09. In addition, a borderline association between this polymorphism and an increased fasting blood glucose in populations of other ethnic origins was detected under the dominant model: SMD = 0.11, 95% CI (-0.00, 0.23), p = 0.06, p(heterogeneity) = 0.03.

CONCLUSIONS

Our meta-analysis suggests that the Thr54 allele of the FABP2 Ala54Thr is weakly associated with a higher degree of insulin resistance, higher level of fasting insulin and higher level of 2-h BG. Our meta-analysis also suggests a weak association between this polymorphism and an increased fasting blood glucose in populations of other ethnic origins under the dominant model.