Oleic acid from cooking oils is associated with lower insulin resistance in the general population (Pizarra study)

Recent Advances on Sex Hormone-Binding Globulin Regulation by Nutritional Factors: Clinical Implications

Sex hormone-binding globulin (SHBG) is a homodimeric glycoprotein produced by the human liver and secreted into the systemic circulation where it binds with high affinity sex steroids regulating their availability in blood and accessibility to target tissues. Plasma SHBG levels are altered in metabolic disorders such as obesity, anorexia, and insulin resistance. Several reports have shown that diets in terms of total calories or fat, fiber, or protein content can alter plasma SHBG levels. However, there are many components in a diet that can affect SHBG gene expression in the liver. In order to unravel the molecular mechanisms by which diets regulate SHBG production, it would be necessary to analyze single diet components and/or nutritional factors. This review summarizes the recent advances in identifying different nutritional factors regulating SHBG production and the related molecular mechanism, as well as the clinical implications.

Simultaneous Dual-Band Hyperspectral Stimulated Raman Scattering Microscopy with Femtosecond Optical Parametric Oscillators

Stimulated Raman scattering (SRS) microscopy is a label-free quantitative optical technique for imaging molecular distributions in cells and tissues by probing their intrinsic vibrational frequencies. Despite its usefulness, existing SRS imaging techniques have limited spectral coverage due to either a wavelength tuning constraint or narrow spectral bandwidth. High-wavenumber SRS imaging is commonly used to map lipid and protein distribution in biological cells and visualize cell morphology. However, to detect small molecules or Raman tags, imaging in the fingerprint region or "silent" region, respectively, is often required. For many applications, it is desirable to collect SRS images in two Raman spectral regions simultaneously for visualizing the distribution of specific molecules in cellular compartments or providing accurate ratiometric analysis. In this work, we present an SRS microscopy system using three beams generated by a femtosecond oscillator to acquire hyperspectral SRS image stacks in two arbitrary vibrational frequency bands, between 650-3280 cm-1, simultaneously. We demonstrate potential biomedical applications of the system in investigating fatty acid metabolism, cellular drug uptake and accumulation, and lipid unsaturation level in tissues. We also show that the dual-band hyperspectral SRS imaging system can be adapted for the broadband fingerprint region hyperspectral imaging (1100-1800 cm-1) by simply adding a modulator.

Serum Metabolomic Profiling in Aging Mice Using Liquid Chromatography-Mass Spectrometry

BACKGROUND

The process of aging and metabolism are intricately linked, thus rendering the identification of reliable biomarkers related to metabolism crucial for delaying the aging process. However, research of reliable markers that reflect aging profiles based on machine learning is scarce.

METHODS

Serum samples were obtained from aged mice (18-month-old) and young mice (3-month-old). LC-MS was used to perform a comprehensive analysis of the serum metabolome and machine learning was used to screen potential aging-related biomarkers.

RESULTS

In total, aging mice were characterized by 54 different metabolites when compared to control mice with criteria: VIP ≥ 1, q-value < 0.05, and Fold-Change ≥ 1.2 or ≤0.83. These metabolites were mostly involved in fatty acid biosynthesis, cysteine and methionine metabolism, D-glutamine and D-glutamate metabolism, and the citrate cycle (TCA cycle). We merged the comprehensive analysis and four algorithms (LR, GNB, SVM, and RF) to screen aging-related biomarkers, leading to the recognition of oleic acid. In addition, five metabolites were identified as novel aging-related indicators, including oleic acid, citric acid, D-glutamine, trypophol, and L-methionine.

CONCLUSIONS

Changes in the metabolism of fatty acids and conjugates, organic acids, and amino acids were identified as metabolic dysregulation related to aging. This study revealed the metabolic profile of aging and provided insights into novel potential therapeutic targets for delaying the effects of aging.

Association between Adherence to the Mediterranean Diet and Anthropometric and Health Variables in College-Aged Males

The present study aimed to verify the association between adherence to the Mediterranean diet (MD) and anthropometric and health variables. Four-hundred-and-ninety-five college-aged males aged 18–25 participated in this cross-sectional research. The KIMED (Mediterranean Diet Quality Index for children and adolescents) was used to assess the adherence to MD. The following variables were also assessed: body mass (BM), height (HE), body mass index (BMI), body fat percentage (%FAT), lean mass (LEAN), abdominal girth (AG), waist-to-hip ratio (WHR), oxygen saturation (SPO2), systolic blood pressure (SBP), diastolic blood pressure (DBP), double product (DP), and fasting blood glucose (GLU). The results showed that adherence to MD presented a strong negative correlation with most of the anthropometric parameters (BM: r = −0.571; BMI: r = −0.614; %FAT: r = −0.558; and AG: r = −0.564), a moderate or weak correlation with most of the health variables (GLU: r = −0.407; SBP: r = −0.238; DBP: r = −0.217, and DP: r = −0.265) and LEAN (r = −0.497), and a very weak correlation with WHR (r = −0.090). Many anthropometric parameters (BM, BMI, %FAT, LEAN, AG, WHR) present significant correlations with health variables (SBP, DBP, DP, and GLU). We conclude that greater adherence to Mediterranean diet is associated with healthier values of the selected anthropometric and health parameters. Since most of the anthropometric and health parameters present significant correlations among themselves, this finding could be useful in medical diagnosis, health monitoring, and risk detection. Based on the level of adherence to Mediterranean diet and the KIDMED found in the present study, and considering the prevalence of obesity in the Middle East, it is imperative to implement nutritional interventions with the target population of this research to prevent nutrition-related diseases and promote public health.

Nanocarriers System for Vitamin D as Nutraceutical in Type 2 Diabetes: A Review

Incidence of diabetes are common among population around the world. Diabetes may lead to other complication and increasing morbidity and mortality. Many ways have been done to treat and prevent the development of diabetes. In addition of conventional pharmacotherapy, therapeutic therapy shown good opportunity to maintain and improve diabetic conditions. Vitamin D3 is known as nutraceutical and has good opportunity to develop the medication of type 2 diabetes. In another way, vitamin D3 naturally easy to damage by environmental condition. To overcome this weakness, researcher around the world have developed the method for protecting unstable compound as vitamin D3 with encapsulation. Liprotide is one of the various materials which can be used for encapsulation. Combination of lipid and protein molecules is expected to be a carrier and protector of vitamin D3 in gastrointestinal system. Here we review the research advances of liprotide as nanocarriers and vitamin D3 as nutraceuticals to discuss in applied on type 2 diabetes.

Effects of combined Garcinia kola and Kigelia africana on Insulin and Paraoxonase 1 (PON1) levels in type 2 diabetic rats

BACKGROUND

Several reports of individual extracts of Garcina kola and Kigelia africana beneficial effects against several factors related with development of diabetes mellitus abound. However, there is still lack of information about the combined effects of these extracts on Insulin and Paraoxonase 1 (PON-1) in Streptozotocin-Nicotinamide induced type-2 diabetic Wistar rats.

METHODS

Forty-two young male rats (180-200g) were randomly divided into six groups (n=7/group). Diabetes was intraperitoneally induced with 110 mg/kg of nicotinamide constituted in distilled water andfifteen minutes after with 65mg/kg of streptozocin freshly prepared in 0.1M citrate buffer (pH of 4.5) and treated for six weeks as follows: the control rats received either 0.9% normal saline (NS) or 250mg/kg extract by gavage. The remaining animals were diabetic induced and subsequently treated with either NS, graded doses of the extract (250mg/kg and 500mg/kg) or 5mg/kg Glibenclamide + 100mg/kg Metformin. Gas chromatography mass spectrometry (GCMS) of the combined extracts was also analyzed to identify the bioactive compounds present. Insulin, PON-1 levels, lipid profiles and atherogenic index were assessed.

RESULTS

Our findings show that Insulin and PON-1 levels in the plasma of diabetic rats treated with the combined extracts were significantly increased when compared to the control rats. Moreover, the GCMS of the extract show the presence of both monosaturated (oleic acid) and polyunsaturated (linoleic acid) fatty acids.

CONCLUSION

The current findings suggest that the extract may help improve glucose homeostasis, prevent atherosclerosis through established mechanism of the identified bioactive compounds.

The association between consumption of monounsaturated fats from animal- v. plant-based foods and the risk of type 2 diabetes: a prospective nationwide cohort study

Although higher dietary intake of MUFA has been shown to improve glycaemic control and lipid profiles, whether MUFA consumption from different sources is linked to the development of type 2 diabetes (T2D) remains unclear. We aimed to prospectively assess the associations of plant-derived MUFA (P-MUFA) and animal-derived MUFA (A-MUFA) intakes with T2D risk in a nationwide oriental cohort. Overall, 15 022 Chinese adults, aged ≥20 years, from the China Health and Nutrition Survey (CHNS 1997–2011) were prospectively followed up for a median of 14 years. Consumption of MUFA from plant and animal sources was assessed using 3-d 24-h recalls in each survey, and the cumulative average of intake was calculated. Multivariable-adjusted Cox models were constructed to estimate the hazard ratios (HR) of T2D according to quartiles of MUFA intake. P-MUFA were mainly consumed from cooked vegetable oils, fried bread sticks and rice, while A-MUFA were mainly consumed from pork, lard and eggs. Intake of P-MUFA was associated with a higher risk of T2D (HRQ4 v. Q1 1·50 (95 % CI 1·18, 1·90); Ptrend = 0·0013), whereas A-MUFA showed no significant association (HRQ4 v. Q1 0·84 (95 % CI 0·59, 1·20); Ptrend = 0·30). When further considering the cooking method of food sources, consumption of P-MUFA from fried foods was positively associated with T2D risk (HRQ4 v. Q1 1·60 (95 % CI 1·26, 2·02); Ptrend = 0·0006), whereas non-fried P-MUFA were not associated. Intake of MUFA from fried plant-based foods may elevate T2D risk among the Chinese population.

Virgin Olive Oil and Health: Summary of the III International Conference on Virgin Olive Oil and Health Consensus Report, JAEN (Spain) 2018

The Mediterranean diet is considered as the foremost dietary regimen and its adoption is associated with the prevention of degenerative diseases and an extended longevity. The preeminent features of the Mediterranean diet have been agreed upon and the consumption of olive oil stands out as the most peculiar one. Indeed, the use of olive oil as the nearly exclusive dietary fat is what mostly characterizes the Mediterranean area. Plenty of epidemiological studies have correlated that the consumption of olive oil was associated with better overall health. Indeed, extra virgin olive oil contains (poly)phenolic compounds that are being actively investigated for their purported biological and pharma-nutritional properties. On 18 and 19 May 2018, several experts convened in Jaen (Spain) to discuss the most recent research on the benefits of olive oil and its components. We reported a summary of that meeting (reviewing several topics related to olive oil, not limited to health) and concluded that substantial evidence is accruing to support the widespread opinion that extra virgin olive oil should, indeed, be the fat of choice when it comes to human health and sustainable agronomy.

Extra virgin olive oil diet intervention improves insulin resistance and islet performance in diet-induced diabetes in mice

Dietary composition plays an important role in the pathophysiology of type 2 diabetes. Monounsaturated fatty acid consumption has been positively associated with improved insulin sensitivity and β-cell function. We examined whether an extra virgin olive oil (EVOO) high fat diet (HFD) can improve glucose homeostasis. C57BL/6J mice were fed a standard diet or a lard-based HFD to induce type 2 diabetes. Then, HFD mice were fed with three different based HFD (lard, EVOO and EVOO rich in phenolic compounds) for 24 weeks. HFD-EVOO diets significantly improved glycemia, insulinemia, glucose tolerance, insulin sensitivity and insulin degradation. Moreover, EVOO diets reduced β-cell apoptosis, increased β-cell number and normalized islet glucose metabolism and glucose induced insulin secretion. No additional effects were observed by higher levels of phenolic compounds. Thus, EVOO intake regulated glucose homeostasis by improving insulin sensitivity and pancreatic β-cell function, in a type 2 diabetes HFD animal model.

Dietary oleic acid is inversely associated with pancreatic cancer - Data from food diaries in a cohort study

BACKGROUND

Dietary oleic acid may prevent pancreatic ductal adenocarcinoma (PDA) by reducing hyperinsulinaemia which can otherwise promote DNA damage and tumour growth. Results from previous epidemiological studies investigating oleic acid are inconsistent. This study aims to clarify the relationship between dietary oleic acid intake and the risk of developing PDA using nutritional information from food diaries plus published serum biomarker data from HbA1c.

METHODS

23,658 participants, aged 40-74 years, were recruited into EPIC-Norfolk and completed 7-day food diaries which recorded; foods, brands and portion sizes to calculate nutrient intakes. Serum HbA1c was measured at recruitment in 11,147 participants (48.7% of cohort). Hazard ratios (HRs) for quintiles of dietary oleic acid intake and serum HbA1c were estimated using Cox regression. Additional analyses were made according to whether body mass index (BMI) was greater or less than 25 kg/m² as this influences hyperinsulinaemia.

RESULTS

88 participants (55% women) developed PDA after a mean follow-up of 8.4 years (SD = 3.9) (mean age at diagnosis = 72.6 years, SD = 8.8). A decreased risk of PDA was associated with increased dietary oleic acid intake (highest vs lowest quintile, HR = 0.29, 95% CI = 0.10-0.81, P trend across quintiles = 0.011), with statistical significance maintained when BMI>25 kg/m² but not if BMI<25 kg/m². An elevated serum HbA1c was associated with increased risk of disease (highest vs lowest quintiles, HR = 6.32, 95% CI = 1.38-28.89, P for trend = 0.004).

CONCLUSIONS

The data supports a protective role of oleic acid against development of PDA in those with higher BMIs possibly through influencing hyperinsulinaemia. Oleic acid intake should be accurately measured in future aetiological studies.

Relation between plasma phospholipid oleic acid and risk of heart failure

BACKGROUND AND AIMS

Although the association between monounsaturated fatty acids (MUFA) and risk factors for heart failure (HF) has been reported, it is unclear whether oleic acid, the predominant MUFA in olive oil, plays a role in the development of HF. Consequently, we sought to examine the relation of plasma phospholipid oleic acid with HF in a male cohort. In a secondary analysis, we examined the relation of the ratio of plasma monounsaturated-to-saturated fatty acids (MUFA: SFA) with HF.

METHODS

This prospective nested case-control study was based on 788 incident HF cases and 788 controls from the Physicians' Health Study. Plasma phospholipid fatty acids were measured using gas chromatography and incident HF was self-reported via annual follow-up questionnaires and validated in a subsample using medical records.

RESULTS

The mean age was 58.7 years at blood collection. In a conditional logistic regression, multivariable adjusted-odds ratios (95% confidence interval) for HF across consecutive quartiles of oleic acid were 1.0 (reference), 1.10 (0.79-1.54), 1.02 (0.72-1.44), and 1.05 (0.72-1.54). For MUFA:SFA ratio, corresponding odds ratios (95% CI) for HF were 1.0 (ref), 1.12 (0.80-1.58), 1.19 (0.84-1.68), and 0.97 (0.66-1.42).

CONCLUSIONS

Our data do not lend support to an association between plasma phospholipid oleic acid or MUFA: SFA ratio and the risk of HF. These results warrant confirmation in the general population including women and other ethnic groups.

Virgin Olive Oil as Frying Oil

Frying is one of the oldest cooking procedures and is still among the most popular ones for food preparation. Due to their unique sensory characteristics, fried foods are consumed often and with pleasure. During frying, part of the oil is absorbed by the food, thereby becoming part of our diet; most interestingly, in the Mediterranean area approximately 50% of total fat intake is provided by cooking fats. Olive oil is the key lipid component of the Mediterranean diet, the health-promoting effects of which have been largely attributed to olive oil intake. Olive oil is unique among vegetable oils due to its desirable lipid profile and some of its minor components. Scientific evidence now indicates that during frying olive oil behavior is usually equal or superior to that of refined vegetable oils. Herein, an overview of virgin olive oil performance under frying is given, with special reference to the fate of olive oil microconstituents. The compositional changes of foods fried in olive oil are also reviewed and discussed in detail.

Analysis using national databases reveals a positive association between dietary polyunsaturated fatty acids with TV watching and diabetes in European females

In recent years, dietary polyunsaturated fatty acids (PUFA) have increased in parallel to sedentary behavior and diabetes across the world. To test any putative association between dietary PUFA and sedentary behavior or diabetes in females, we obtained country-specific, cross-sectional data on sedentary activity and diabetes prevalence from European Cardiovascular Statistics 2012. Age and gender-specific, nutritional data from each country were obtained from nutritional surveys as well. Socioeconomic (GDP), physical environment (urbanization index) and climatic confounders were accounted for each country. Upon analysis, we found a strong, positive association between sedentary lifestyle in 11-yr old girls (> = 2 hours of TV/ weekday) and dietary PUFA across 21 European countries. Further, a weak association of dietary PUFA and a strong relationship of per-capita GDP was established with elevated fasting blood glucose [(> = 7.0 mmol/L; or on medication] among 25+ year old adult females across 23 countries in Europe. In summary, we present novel ecological evidence that dietary PUFA is strongly associated with sedentary behavior among pre-teen girls and weakly associated with diabetes among adult women across Europe. In the latter group, per-capita GDP was a significant predictor for diabetes as well. Therefore, we recommend that prospective randomized controlled trials (RCTs) be implemented to evaluate if ubiquitous presence of dietary PUFA and low socioeconomic status are possible confounders when intervening to treat/prevent sedentary lifestyle or diabetes in female subjects in Western nations.

Effect of interactions of polymorphisms in the Melanocortin-4 receptor gene with dietary factors on the risk of obesity and Type 2 diabetes: a systematic review

AIM

To perform a systematic review of the effect of interaction between Melanocortin-4 receptor (MC4R) single nucleotide polymorphisms and diet on the development of obesity and Type 2 diabetes.

BACKGROUND

Environmental factors, such as nutrient intakes or feeding behaviours, can modulate the association of polymorphism in the MC4R gene with obesity and Type 2 diabetes mellitus.

METHODS

A systematic literature search was conducted in the PubMed, Scopus and Google Scholar databases, with a combination of the following keywords: Diet*, nutr*, melanocortin receptor, melanocortin 4 receptor and MC4R. To assess the quality of observational studies, we used a 12-item quality checklist, derived from the STREGA statement.

RESULTS

A total of 14 articles were selected based on the inclusion and exclusion criteria. Consumption of highly salty foods and adherence to a Mediterranean dietary pattern can modulate the association between MC4R polymorphisms and the risk of obesity or Type 2 diabetes. Despite the highly contradictory results of intervention studies, after short-term lifestyle interventions, children with variant alleles of MC4R single nucleotide polymorphisms can lose more body weight, compared with non-carriers, although they may have difficulty in maintaining this weight loss in the long-term. To interpret the results of studies on adults, we need further studies.

CONCLUSIONS

The interaction between MC4R genes with dietary factors plays a significant role in the development of obesity or Type 2 diabetes phenotypes. Early detection of MC4R risk alleles in individuals and modification of their diet based on these results could be an efficient strategy to prevent obesity or diabetes in these subgroups.

Effect of an avocado oil-enhanced diet ( Persea americana ) on sucrose-induced insulin resistance in Wistar rats

A number of studies have been conducted to evaluate the effects of vegetable oils with varying percentages of monounsaturated and polyunsaturated fatty acids on insulin resistance. However, there is no report on the effect of avocado oil on this pathologic condition. The aim of this work was to evaluate the effect of avocado oil on sucrose-induced insulin resistance in Wistar rats. An experimental study was carried out on Wistar rats that were randomly assigned into six groups. Each group received a different diet over an 8-week period (n = 11 in each group): the control group was given a standard diet, and the other five groups were given the standard feed plus sucrose with the addition of avocado oil at 0%, 5%, 10%, 20%, and 30%, respectively. Variables were compared using Student t test and analysis of variance. Statistically significant difference was considered when p < 0.05. Rats that were given diets with 10% and 20% avocado oil showed lower insulin resistance (p = 0.022 and p = 0.024, respectively). Similar insulin resistance responses were observed in the control and 30% avocado oil addition groups (p = 0.85). Addition of 5–30% avocado oil lowered high sucrose diet-induced body weight gain in Wistar rats. It was thus concluded that glucose tolerance and insulin resistance induced by high sucrose diet in Wistar rats can be reduced by the dietary addition of 5–20% avocado oil.

Skeletal intramyocellular lipid metabolism and insulin resistance

Lipids stored in skeletal muscle cells are known as intramyocellular lipid (IMCL). Disorders involving IMCL and its causative factor, circulatory free fatty acids (FFAs), induce a toxic state and ultimately result in insulin resistance (IR) in muscle tissue. On the other hand, intramuscular triglyceride (IMTG), the most abundant component of IMCL and an essential energy source for active skeletal muscle, is different from other IMCLs, as it is stored in lipid droplets and plays a pivotal role in skeletal muscle energy homeostasis. This review discusses the association of FFA-induced ectopic lipid accumulation and IR, with specific emphasis on the relationship between IMCL/IMTG metabolism and IR.

Sunflower Oil but Not Fish Oil Resembles Positive Effects of Virgin Olive Oil on Aged Pancreas after Life-Long Coenzyme Q Addition

An adequate pancreatic structure is necessary for optimal organ function. Structural changes are critical in the development of age-related pancreatic disorders. In this context, it has been reported that different pancreatic compartments from rats were affected according to the fat composition consumed. Since there is a close relationship between mitochondria, oxidative stress and aging, an experimental approach has been developed to gain more insight into this process in the pancreas. A low dosage of coenzyme Q was administered life-long in rats in order to try to prevent pancreatic aging-related alterations associated to some dietary fat sources. According to that, three groups of rats were fed normocaloric diets containing Coenzyme Q (CoQ) for two years, where virgin olive, sunflower, or fish oil was included as unique fat source. Pancreatic samples for microscopy and blood samples were collected at the moment of euthanasia. The main finding is that CoQ supplementation gives different results according to fat used in diet. When sunflower oil was the main fat in the diet, CoQ supplementation seems to improve endocrine pancreas structure and in particular β-cell mass resembling positive effects of virgin olive oil. Conversely, CoQ intake does not seem to improve the structural alterations of exocrine compartment previously observed in fish oil fed rats. Therefore CoQ may improve pancreatic alterations associated to the chronic intake of some dietary fat sources.

Does cooking with vegetable oils increase the risk of chronic diseases?: a systematic review

Overweight/obesity, CVD and type 2 diabetes are strongly associated with nutritional habits. High consumption of fried foods might increase the risk of these disorders. However, it is not clear whether the use of vegetables oils for cooking increases the risk of chronic diseases. We systematically searched for published studies that assessed the association between vegetable oil consumption including fried food consumption and the risk of overweight/obesity or weight gain, T2DM or the metabolic syndrome, and CVD or hypertension in the following databases: PubMed; Web of Science; Google Scholar. Keywords such as 'fried food' or 'vegetable oil' or 'frying' or 'frying oils' or 'dietary fats' and 'weight gain' or 'overweight' or 'obesity' or 'CHD' or 'CVD' or 'type 2 diabetes' or 'metabolic syndrome' were used in the primary search. Additional published reports were obtained through other sources. A total of twenty-three publications were included based on specific selection criteria. Based on the results of the studies included in the present systematic review, we conclude that (1) the myth that frying foods is generally associated with a higher risk of CVD is not supported by the available evidence; (2) virgin olive oil significantly reduces the risk of CVD clinical events, based on the results of a large randomised trial that included as part of the intervention the recommendation to use high amounts of virgin olive oil, also for frying foods; and (3) high consumption of fried foods is probably related to a higher risk of weight gain, though the type of oil may perhaps modify this association.

Effect of mediterranean diet in diabetes control and cardiovascular risk modification: a systematic review

BACKGROUND

Over the past few years, there has been a worldwide significant increase in the incidence of type II diabetes mellitus with both increase in morbidity and mortality. Controlling diabetes through life style modifications, including diet and exercise has always been the cornerstone in diabetes management. Increasing evidence suggests that the Mediterranean diet could be of benefit in diseases associated with chronic inflammation, including metabolic syndrome, diabetes, obesity as well as atherosclerosis, cancer, pulmonary diseases, and cognition disorders As a matter of fact, a number of studies addressed the relationship between Mediterranean diet and diabetes control. The result of these studies was conflicting. Some were able to elicit a protective role, while others showed no added benefit. As a result; we decided to conduct a systematic review to have a better understanding of the relationship between adherence to Mediterranean diet and diabetes control.

METHODS

A systematic review was conducted on the effect of Mediterranean diet in diabetes control and cardiovascular risk modification as well as the possible mechanism through which this diet might exhibit its beneficial role. We did a comprehensive search of multiple electronic databases such as Medline, Google Scholars, PubMed, and the Cochrane central register data until May 2014. We included cross-sectional, prospective, and controlled clinical trials that looked at the associations between Mediterranean diet and indices of diabetes control such HbA1c, fasting glucose, and homeostasis model assessment, in addition to cardiovascular and peripheral vascular outcomes.

OUTCOME/CONCLUSION

Most of the studies showed favorable effects of Mediterranean diet on glycemic control and CVD, although a certain degree of controversy remains regarding some issues, such as obesity. Important methodological differences and limitations in the studies make it difficult to compare results, thus further longer term studies are needed to evaluate the long-term efficacy of the Mediterranean diet along with the possibility of explaining its mechanism.

Variable patterns of obesity and cardiometabolic phenotypes and their association with lifestyle factors in the Di@bet.es study

BACKGROUND AND AIM

Prevalence rates of "metabolically healthy obese" (MHO) subjects vary depending on the criteria used. This study examined the prevalence and characteristics of MHO subjects and metabolically abnormal normal-weight subjects and compared the findings with the NHANES 1999-2004 study. The aims of the present study were, first, to determine the prevalence rates of MHO and MNHNO subjects using the same criteria as those of the National Health and Nutrition Examination Survey (NHANES) (1999-2004) study, and second to compare the prevalence and correlates of obese subjects who are resistant to the development of adiposity-associated cardiometabolic abnormalities (CA) and normal-weight individuals who display cardiometabolic risk factor clustering between the Spanish and the US populations.

METHODS AND RESULTS

Di@bet.es study is a national, cross-sectional population-based survey of 5728 adults conducted in 2009-2010. Clinical, metabolic, sociodemographic, and anthropometric data and information about lifestyle habits, such as physical activity, smoking habit, alcohol intake and food consumption, were collected. Subjects were classified according to their body mass index (BMI) (normal-weight, <25 kg/m(2); overweight, 25-29.9 kg/m(2); and obese, >30 kg/m(2)). CA included elevated blood pressure; elevated levels of triglycerides, fasting glucose, and high-sensitivity C-reactive protein (hs-CRP); and elevated homeostasis model assessment of insulin resistance (HOMA-IR) value and low high-density lipoprotein cholesterol (HDL-c) level. Two phenotypes were defined: metabolically healthy phenotype (0-1 CA) and metabolically abnormal phenotype (≥2 CA). The prevalence of metabolically abnormal normal-weight phenotype was slightly lower in the Spanish population (6.5% vs. 8.1%). The prevalence of metabolically healthy overweight and MHO subjects was 20.9% and 7.0%, respectively, while in NHANES study it was 17.9% and 9.7%, respectively. Cigarette smoking was associated with CA in each phenotype, while moderate physical activity and moderate alcohol intake were associated with being metabolically healthy. Olive oil intake was negatively associated with the prevalence of CA.

CONCLUSIONS

Smoking, physical activity level, and alcohol intake contribute to the explanation of the prevalence of CA in the Spanish population, as in the US population. However in Spain, olive oil intake contributes significantly to the explanation of the variance in the prevalence of CA.

Oleic acid increases hepatic sex hormone binding globulin production in men

SCOPE

Low circulating sex hormone-binding globulin (SHBG) is an independent risk factor for cardiovascular disease. Mediterranean diet has been associated with a decreased risk of cardiovascular disease. We aimed to test the hypothesis that the increase of circulating MUFA associated with olive oil consumption (primary fat source in Mediterranean diet) increases SHBG serum levels.

METHODS AND RESULTS

A total of 315 men were included. In these patients, nutrition data and plasma samples for SHBG assessment were obtained. In vitro studies to examine the effects of oleic and linoleic acid on SHBG production using HepG2 cells were performed. We provided evidence that SHBG serum levels were significantly higher in subjects using olive oil for cooking in comparison with subjects using sunflower oil. The SHBG levels correlated positively with MUFA (p < 0.001) and negatively with saturated fatty acids (p = 0.003). In the multiple regression analysis, MUFA were independently associated with SHBG levels and accounted for the 20.4% of SHBG variance. In vitro studies revealed that oleoyl-CoA increases SHBG production by downregulating PPAR-γ levels in HepG2 cells.

CONCLUSION

Olive oil consumption is associated with elevated SHBG serum levels. PPAR-γ downregulation induced by oleoyl-CoA is an important underlying mechanism of such regulation.

Comparative analysis of pancreatic changes in aged rats fed life long with sunflower, fish, or olive oils

An adequate pancreatic structure is necessary for optimal organ function. Structural changes are critical in the development of age-related pancreatic disorders. We aimed to study the effect of oil consumption on pancreas histology in order to find aging-related signs. To this end, three groups of rats were fed an isocaloric diet for 2 years, where virgin olive, sunflower, or fish oil was included. Pancreatic samples for microscopy and blood samples were collected at the moment of sacrifice. As a result, the sunflower oil-fed rats presented higher β-cell numbers and twice the insulin content than virgin olive oil-fed animals. In addition, rats fed with fish oil developed acinar fibrosis and macrophage infiltrates in peri-insular regions, compared with counterparts fed with virgin olive oil. Inflammation signs were less prominent in the sunflower group. The obtained data emphasize the importance of dietary fatty acids in determining pancreatic structure.

Polymorphisms in the SCD1 gene are associated with indices of stearoyl CoA desaturase activity and obesity: a prospective study

SCOPE

The serum fatty acid (FA) composition is influenced by dietary fat and the endogenous production of FAs. Stearoyl CoA desaturase 1 (SCD1) is the rate-limiting enzyme catalyzing the synthesis of MUFAs from saturated FAs. Variations in SCD1 activity have been associated with obesity, diabetes, or inflammation. We evaluated the associations between genetic variation of the SCD1 gene, SCD1 activity, intake of oil, and obesity in a population-based prospective study in southern Spain.

METHODS AND RESULTS

We collected phenotypic, metabolic, nutritional, and genetic information. The type of dietary fat was assessed from samples of cooking oil taken from the participants' kitchens and analyzed by GC. A total of nine single nucleotide polymorphisms (SNPs) of the SCD1 gene were analyzed by SNPlex technology. We found a significant association between SCD1 genetic variation and enzyme activity in four of nine polymorphisms studied. An interaction between rs10883463 and olive oil intake on the [18:1/18:0] desaturase index was found (p = 0.009). We also showed that genetic variations in the SCD1 gene were associated with obesity.

CONCLUSION

Our results show a relationship between genetic variation of the SCD1 gene, enzyme activity, and the risk of obesity, an association that is not independent of the type of oil consumed.

Olive oil has a beneficial effect on impaired glucose regulation and other cardiometabolic risk factors. Di@bet.es study

BACKGROUND

Despite the marked increase in cardiovascular risk factors in Spain in recent years, the prevalence and incidence of cardiovascular diseases have not risen as expected. Our objective is to examine the association between consumption of olive oil and the presence of cardiometabolic risk factors in the context of a large study representative of the Spanish population.

SUBJECTS AND METHODS

A population-based, cross-sectional, cluster sampling study was conducted. The target population was the whole Spanish population. A total of 4572 individuals aged ≥ 18 years in 100 clusters (health centers) were randomly selected with a probability proportional to population size. The main outcome measures were clinical and demographic structured survey, lifestyle survey, physical examination (weight, height, body mass index, waist, hip and blood pressure) and oral glucose tolerance test (OGTT) (75 g).

RESULTS

Around 90% of the Spanish population use olive oil, at least for dressing, and slightly fewer for cooking or frying. The preference for olive oil is related to age, educational level, alcohol intake, body mass index and serum glucose, insulin and lipids. People who consume olive oil (vs sunflower oil) had a lower risk of obesity (odds ratio (OR)=0.62 (95% confidence interval (CI)=0.41-0.93, P=0.02)), impaired glucose regulation (OR=0.49 (95% CI=0.28-0.86, P=0.04)), hypertriglyceridemia (OR=0.53 (95% CI=0.33-0.84, P=0.03)) and low HDL cholesterol levels (OR=0.40 (95% CI=0.26-0.59, P=0.0001)).

CONCLUSIONS

The results show that consumption of olive oil has a beneficial effect on different cardiovascular risk factors, particularly in the presence of obesity, impaired glucose tolerance or a sedentary lifestyle.

White rice consumption and risk of type 2 diabetes

BACKGROUND & AIM

Recent studies suggest that white rice consumption increases risk of diabetes.

AIM

to assess the association between white rice intake and the incidence of diabetes in a population from Southern Spain.

METHODS

A population-based cohort study was undertaken in Pizarra, Spain. At baseline and follow-up, participants underwent an interview and a standardized clinical examination which included an oral glucose tolerance test in those subjects without known diabetes. Incidence and odds ratio (OR) for diabetes were calculated. Multivariate analysis was performed using stepwise logistical regression.

RESULTS

Thirty eight percent of subjects reported rice consumption 2-3 times a week, 58.5% once or less a week, and 3.6% no rice consumption. In subjects who reported rice intake 2-3 times a week, incidence of diabetes after 6 years follow-up was 12.0%, and in those who reported once or less a week, 20.2% (p = 0.04, non adjusted). Subjects who ate rice frequently had lower risk to develop diabetes 6 years later (OR = 0.43, p = 0.04; adjusted for age, sex, obesity, and presence of impaired fasting glucose and/or impaired glucose tolerance at baseline).

CONCLUSIONS

A negative association was found between white rice intake in the way it is consumed in Southern Spain, and the 6 years incidence of diabetes.

Vascular smooth muscle cell alterations triggered by mice adipocytes: role of high-fat diet

AIM

Inherent mechanisms leading to vascular smooth muscle cells (VSMC) alterations in obesitylinked type 2 diabetes (T2D) situation remain to be clarified. This study evaluates the impact of supernatant of adipocytes extracted from mice fed high-fat-diets (HFD) on the proliferation and apoptosis of VSMC.

METHODS

Adipocytes were extracted from visceral white fat pads of male and female C57Bl6 mice showing different stages of metabolic alterations after 20 weeks of vegetal or animal HFD feeding. These cells were stimulated or not with insulin or glucose to condition VSMC media. After 24h of stimulation with adipocyte supernatants (AdS), VSMC proliferation and sustainability were assessed in the absence and presence of AdS. CD36 and insulin receptor mRNA levels were also evaluated.

RESULTS

Proliferation and viability of VSMC were significantly modulated by the nature of the AdS used and the gender of mice from which adipocytes have been extracted. The most extensive effects on VSMC were triggered by adipocytes from males fed animal HFD and females fed vegetal HFD. These effects were concurrent with increased leptin concentration and decreased adiponectin levels in AdS. In addition, adipocytes of HFD-fed mice increased caspase-3 activity and apoptosis in VSMC. Significant up-regulation of CD36 mRNA was also found in these cells.

CONCLUSION

Adipocytes of HFD-fed mice induce VSMC alterations. These changes involved mouse gender, most probably correlated to the diet-induced adipocyte secretion profile. Greater sensitivity to AdS effects in VSMC raises concerns about the more frequent cardiovascular events associated with obesity in the presence of T2D, which impairs adipocyte activity.

ELOVL6 genetic variation is related to insulin sensitivity: a new candidate gene in energy metabolism

Background

The elongase of long chain fatty acids family 6 (ELOVL6) is an enzyme that specifically catalyzes the elongation of saturated and monounsaturated fatty acids with 12, 14 and 16 carbons. ELOVL6 is expressed in lipogenic tissues and it is regulated by sterol regulatory element binding protein 1 (SREBP-1).

Objective

We investigated whether ELOVL6 genetic variation is associated with insulin sensitivity in a population from southern Spain.

Design

We undertook a prospective, population-based study collecting phenotypic, metabolic, nutritional and genetic information. Measurements were made of weight and height and the body mass index (BMI) was calculated. Insulin resistance was measured by homeostasis model assessment. The type of dietary fat was assessed from samples of cooking oil taken from the participants' kitchens and analyzed by gas chromatography. Five SNPs of the ELOVL6 gene were analyzed by SNPlex.

Results

Carriers of the minor alleles of the SNPs rs9997926 and rs6824447 had a lower risk of having high HOMA_IR, whereas carriers of the minor allele rs17041272 had a higher risk of being insulin resistant. An interaction was detected between the rs6824447 polymorphism and the intake of oil in relation with insulin resistance, such that carriers of this minor allele who consumed sunflower oil had lower HOMA_IR than those who did not have this allele (P = 0.001).

Conclusions

Genetic variations in the ELOVL6 gene were associated with insulin sensitivity in this population-based study.

Research in olive oil: challenges for the near future

Olive oil, a traditional food product with thousands of years of history, is continually evolving toward a more competitive global market. Being one of the most studied foods across different disciplines, olive oil still needs intensive research activity to face some vulnerabilities and challenges. This perspective describes some of them and shows a vision of research on olive oil for the near future, bringing together those aspects that are more relevant for better understanding and protection of this edible oil. To accomplish the most urgent challenges, some possible strategies are outlined, taking advantage of the latest analytical advances, considering six areas: (i) olive growing; (ii) processing, byproduct, and environmental issues; (iii) virgin olive oil sensory quality; (iv) purity, authentication, and traceability; (v) health and nutrition; (vi) consumers. The coming research, besides achieving those challenges, would increase the understanding of some aspects that are still the subject of debate and controversy among scientists focused on olive oil.

Intake and home use of olive oil or mixed oils in relation to healthy lifestyles in a Mediterranean population. Findings from the prospective Pizarra study

Discordances exist in epidemiological studies regarding the association between the intake of nutrients and death and disease. We evaluated the social and health profile of persons who consumed olive oil in a prospective population cohort investigation (Pizarra study) with a 6-year follow-up. A food frequency questionnaire and a 7 d quantitative questionnaire were administered to 538 persons. The type of oil used in food preparation was determined by direct measurement of the fatty acids in samples obtained from the kitchens of the participants at baseline and after follow-up for 6 years. The fatty acid composition of the serum phospholipids was used as an endogenous marker of the type of oil consumed. Total fat intake accounted for a mean 40 % of the energy (at baseline and after follow-up). The concordance in intake of MUFA over the study period was high. The fatty acid composition of the serum phospholipids was significantly associated with the type of oil consumed and with fish intake. The concentration of polar compounds and polymers, indicative of degradation, was greater in oils from the kitchens where sunflower oil or refined olive oil was used, in oils used for deep frying and in oils that had been reused for frying five times or more. Consumption of olive oil was directly associated with educational level. Part of the discordance found in epidemiological studies between diet and health may be due to the handling of oils during food preparation. The intake of olive oil is associated with other healthy habits.

Olive oil consumption and non-alcoholic fatty liver disease

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

Voluntary consumption of ethyl oleate reduces food intake and body weight in rats

Previous studies have shown that administration of the fatty acids, linoleic and oleic acid, either by intragastric or intraintestinal infusion, suppresses food intake and body weight in rats. While still not fully understood, gut-mediated satiety mechanisms likely are potential effectors of this robust response to gastrointestinal fatty acid infusions. The objective of this study was to assess the effects of voluntary access to an oleic acid derivative, ethyl oleate (EO), on subsequent food intake and body weight in rats. Animals were randomized either to a 12.5% EO diet or a soybean oil diet as a "breakfast," followed either by two one-hour or one five-hour access periods to standard rodent diet, and food intake and body weights were collected. Across 14 days access, rats consuming EO on both feeding schedules gained less weight and consumed less total kilocalories than rats consuming the SO diet. Further, plasma levels of glucose and insulin were comparable in both EO and SO diet groups. In summary, EO was found to increase weight loss in rats maintained on a 75% food-restriction regimen, and attenuate weight-gain upon resumption of an ad-libitum feeding regimen. These data indicate that voluntary access to EO promoted short-term satiety, compared to SO diet, and that these effects contributed to an important and novel attenuated weight gain in EO-fed animals.

The potential role of olive oil-derived MUFA in insulin sensitivity

Dietary fatty acids play an important role in the development of insulin resistance, the prelude to type 2 diabetes mellitus. This review addresses the potential role of olive oil-derived MUFA in insulin sensitivity, particularly how dietary fat interacts with insulin resistance looking at whole body metabolic measures, as well as molecular effects. The review focuses on the role of non-esterified fatty acids, fatty acid composition in vivo and dietary fat modification on insulin resistance in the metabolic syndrome. Particular emphasis is placed on the role of olive oil within the context of dietary modification to improve insulin sensitivity and for the prevention of the metabolic syndrome.

Obesity and the metabolic syndrome in Mediterranean countries: A hypothesis related to olive oil

In Mediterranean countries people would previously have consumed a diet with a high proportion of MUFA. Physical activity would have been intense with a low level of stress. The stearoyl-CoA desaturase (SCD1) system selected over thousands of years of this type of behavior must have adapted to a particular capacity of self regulation. Now, this pattern, called the "Mediterranean diet", has been broken and many people living by the Mediterranean consume a high quantity of calories, mainly from saturated or n-6-rich fats and the relative intake of MUFA has decreased. Simultaneously, physical activity has decreased and the pattern of stress has changed towards what is called a western lifestyle. In this new context, if people have a favorable, genetically conditioned SCD1 activity that will let them confront the new situation or else have some other compensatory mechanism, such as being keen on sport, etc, then they can prevent the appearance of some of the complications associated with the metabolic syndrome. If, on the other hand, the SCD1 pattern is genetically unfavorable for this new situation and they have a new cultural context, then they do not have the alternative compensatory mechanisms and the probability of developing the metabolic syndrome is high.

Effect of the interaction between the fatty acid binding protein 2 gene Ala54Thr polymorphism and dietary fatty acids on peripheral insulin sensitivity: a cross-sectional study

BACKGROUND

The intestinal fatty acid-binding protein (FABP2) is involved in the intracellular transport and metabolism of fatty acids and may affect insulin sensitivity and glucose metabolism.

OBJECTIVE

The objective was to study the effect of interaction between the Ala54Thr polymorphism of the FABP2 gene (FABP2) and the type of dietary cooking oil used on peripheral insulin sensitivity in a population from southern Spain.

DESIGN

The study was cross-sectional. Anthropometric measurements were obtained for 1226 persons aged 18-65 y selected randomly from the municipal census of Pizarra, Spain. An oral-glucose-tolerance test was given to 1020 of these persons. Insulin resistance was measured by homeostasis model assessment. Samples of the cooking oil being used were taken from the kitchens of a random subset of 538 persons.

RESULTS

Persons who consumed sunflower oil and who also had the Thr54 variant had higher insulin resistance than did those who consumed olive oil (P = 0.01). We detected an interaction between the Ala54Thr polymorphism and the type of oil consumed that accounted for the variance in insulin resistance (P = 0.02).

CONCLUSIONS

The effect of dietary fatty acids on the populational pattern of insulin resistance is not independent of the Ala54Thr polymorphism of FABP2. An interaction existed between this polymorphism and the intake of dietary fats in a population with a high intake of monounsaturated fatty acids.

Upregulation of cellular triacylglycerol - free fatty acid cycling by oleate is associated with long-term serum-free survival of human breast cancer cells

We previously showed that exogenous oleate protects human breast cancer cells against palmitate-induced apoptosis in part by increasing esterification of this free fatty acid (FFA) into triacylglycerol (TG). Here, we studied the mechanism whereby oleate protects these cells against apoptosis induced by serum withdrawal. The metabolism of FFA, TG, and glucose, in parallel with long-term cell survival in the absence of serum, was investigated in a panel of human breast cancer cell lines and in nontransformed MCF-10A cells after treatment with exogenous oleate. Short-term (3-24 h) exposure of MDA-MB-231 human breast cancer cells to exogenous oleate resulted in a dose-dependent long-term (10 day) serum-free survival that correlated with the accumulation of TG in lipid droplets and with upregulation of lipolysis. Both effects persisted for several days after oleate removal. Rapid TG lipolysis and FFA re-esterification, supported by high rates of glycolysis that provide the glycerol backbone for TG synthesis, are consistent with the presence of very active TG-FFA cycling in human breast cancer cells. Only the cancer cell lines capable of accumulating TG showed long-term serum-free survival after oleate treatment. The results suggest that upregulation of TG-FFA cycling induced by oleate may be involved in maintenance of human breast cancer cell survival.

Intake of fried foods is associated with obesity in the cohort of Spanish adults from the European Prospective Investigation into Cancer and Nutrition

BACKGROUND

Consumption of fried food has been suggested to promote obesity, but this association has seldom been studied.

OBJECTIVE

We aimed to assess the association of energy intake from fried food with general and central obesity in Spain, a Mediterranean country where frying with oil is a traditional cooking procedure.

DESIGN

This was a cross-sectional study of 33 542 Spanish persons aged 29-69 y who were participating in the European Prospective Investigation into Cancer and Nutrition between 1992 and 1996. Dietary intake was assessed by a diet history questionnaire. Height, weight, and waist circumference were measured by trained interviewers. Analyses were performed with logistic regression and were adjusted for total energy intake and other confounders.

RESULTS

The prevalence of general obesity [body mass index (in kg/m(2)) >or= 30] was 27.6% in men and 27.7% in women. Respective figures for central obesity (waist circumference >or= 102 cm in men and >or= 88 cm in women) were 34.5% and 42.6%. The average proportion of energy intake from fried food was 15.6% in men and 12.6% in women. The adjusted odds ratios for general obesity in the highest versus the lowest quintile of fried food intake were 1.26 (95% CI: 1.09, 1.45; P for trend < 0.001) in men and 1.25 (1.11, 1.41; P for trend < 0.001) in women. The corresponding values for central obesity were 1.17 (1.02, 1.34; P for trend < 0.003) in men and 1.27 (1.13, 1.42; P for trend < 0.001) in women.

CONCLUSION

Fried food was positively associated with general and central obesity only among subjects in the highest quintile of energy intake from fried food.

The Association between Adherence to the Mediterranean Diet and Fasting Indices of Glucose Homoeostasis: The ATTICA Study

OBJECTIVE

We investigated the association between adherence to Mediterranean diet and fasting indices of glucose homoeostasis, in a Greek adult population.

METHODS

During 2001-2002 we randomly enrolled 1514 men and 1528 women (18-89 years old) without history of CVD, from the Attica area. Diabetes mellitus (type 2) and impaired fasting glucose (IFG) were defined according to the established ADA criteria. Insulin resistance was evaluated by HOMA-IR. Dietary habits were assessed through a validated food frequency questionnaire and a diet score (range 0-55) was developed (higher values means greater adherence to the Mediterranean diet).

RESULTS

The overall prevalence of diabetes type 2 was 7.9% in men and 6.0% in women (P = 0.05). Mean diet score was 26.3 +/- 6.8 in normoglycemic, 25.7 +/- 6.4 in IFG and 22.2 +/- 5.8 in diabetic subjects (p < 0.001). In normoglycemic subjects who were in the upper tertile of the diet score we observed 7% lower glucose (p < 0.05), 5% lower insulin (p < 0.05) and 15% lower HOMA-IR (p < 0.01) levels compared to subjects in the lower tertile of the diet score. Additionally, in diabetic/IFG participants who where in the upper tertile of the diet score we observed 15% lower glucose (p < 0.05), 15% lower insulin (p < 0.05) and 27% lower HOMA-IR (p < 0.01) levels compared to those in the lower tertile. However, multiple regression analysis, adjusted for age, sex, BMI, waist-to-hip ratio, physical activity, smoking status, and presence of hypertension and hypercholesterolemia, confirmed the previous associations in normoglycemic, but not in diabetic/IFG people.

CONCLUSION

An inverse association was observed between adherence to Mediterranean diet and indices of glucose homeostasis, only in normoglycemic people.

Mediterranean diet and metabolic syndrome: a cross-sectional study in the Canary Islands

Objective

Assessment of relation between metabolic syndrome (MS) and Mediterranean diet (MD) adherence.

Design

Cross-sectional study. ATP III definition of MS was used. Adherence to MD was assessed with a Food Frequency Questionnaire. Intakes of cereal, fruit, legumes, vegetables, fish, nuts, monounsaturated to saturated ratio, alcohol from red wine, whole-fat dairy products and red meat were considered.

Setting

Representative sample of population from the Canary Islands (Spain) participating in the Canarian Nutrition Survey (ENCA).

Subjects

578 adults>18 years.

Results

Of the subjects, 24.4% presented MS. Once adjusted, MD adherence was not related to MS prevalence, but subjects in the third tertile of adherence presented 70% lower prevalence of the blood pressure criteria and 2.5 times more prevalence of the glycaemia criteria with respect to the first tertile. Red meat intake was associated with higher prevalence of blood pressure criteria. Moderate alcohol intake from red wine was associated with lower prevalence of these criteria in women and lower prevalence of HDL cholesterol criteria in men. Fruit intake showed a protective effect on triglyceride criteria, whereas vegetable intake was associated with higher prevalence of this criterion. Cereals' intake showed a protective effect over insulin resistance measured by high insulinaemia level. Fruit intake showed a significative protective effect over high Homeostasis Model Assessment index. Whole-fat dairy products showed a significant protective effect on the glycaemia criteria. High monounsaturated to saturated fatty acid intake showed a protective effect on insulin resistance.

Conclusions

Some components of the MD showed a protective effect on the MS and its components.

Effects of milk enriched with omega-3 fatty acid, oleic acid and folic acid in patients with metabolic syndrome

BACKGROUND & AIMS

Patients with metabolic syndrome (MS) have increased cardiovascular risk factors. Dietary modifications mainly polyunsatturated fatty acids intake, can improve them. The present study was performed to assess the effects of enriched milk with omega-3 and oleic fatty acids, folic acid and vitamin E, in these patients.

METHODS

We performed a randomized, placebo-controlled and open clinical trial, among 72 patients with MS for 3 months. Thirty-six of them consumed 500 cm(3) per day of semi-skimmed milk (control group), and the others consumed 500 cm(3) per day of enriched milk (test group). Daily supplements in this group were 5.7 g of oleic acid, 0.2g of omega-3 fatty acid, 150 microg of folic acid and 7.5mg of vitamin E. Serum for total and HDL cholesterol, triglycerol, Apo B, glucose, insulin, hs-CRP, homocysteine and fatty acids contents in serum phospholipids, was obtained at the beginning and at the end of the study. LDL cholesterol was calculated by Friedewald formula.

RESULTS

Four patients in the test group, and two in the control group dropped out. In the test group a decrease in serum total cholesterol (-6.2%, P=0.006), LDL cholesterol (-7.5%, P=0.032), triglycerol (-13.3%, P=0.016), Apo B (-5.7%, P=0.036), glucose (-5.3%, P=0.013), and homocysteine (-9.5%, P=0.00) was observed. Any of these parameters changed in the control group.

CONCLUSIONS

Dietary supplementation with 500 cm(3) of enriched milk with omega-3 fatty acid, oleic acid and folic acid, reduces serum tryglicerides, total and LDL cholesterol, Apo B, glucose and homocysteine in patients with MS. This milk is well tolerated and accepted by the patients.

Dietary fatty acids and insulin secretion: a population-based study

OBJECTIVE

Few epidemiological studies have examined the relationship of dietary fatty acids, especially MUFA, with the interrelation between insulin secretion and insulin resistance. We assessed the relation of dietary fatty acids with insulin secretion in a free-living population.

DESIGN AND SETTING

This cross-sectional, population-based study was undertaken in Pizarra, a small town in Spain.

SUBJECTS AND METHODS

Anthropometrical data were collected for 1226 persons selected randomly from the municipal census, 538 of whom (randomly chosen) were given a prospective, quantitative, 7-day nutritional questionnaire. The fatty acid composition of the serum phospholipids was used as a biological marker of the type of fat consumed. Beta-cell function (betaCFI) and insulin-resistance index (IRI) were estimated by the Homeostasis Model Assessment.

RESULTS

To determine which factors influence the variability of the betaCFI, we analyzed the variance of the betaCFI according to sex, the presence of carbohydrate metabolism disorders and the different components of the diet, adjusting the models for age, body mass index (BMI) and IRI. The dietary MUFA and polyunsaturated fatty acids (PUFA) contributed to the variability of the betaCFI, whereas only the proportion of serum phospholipid MUFA, but neither the saturated fatty acids nor the PUFA accounted for part of the variability of the betaCFI in a multiple regression analysis.

CONCLUSION

The results of this population-based study corroborate the results of other clinical and experimental studies suggesting a favorable relationship of MUFA with beta-cell insulin secretion.

SPONSORSHIP

Fondo de Investigación Sanitaria, Junta de Andalucía and the Asociación Maimónides.