Dietary carbohydrate restriction induces a unique metabolic state positively affecting atherogenic dyslipidemia, fatty acid partitioning, and metabolic syndrome

Postprandial changes in cardiometabolic disease risk in young Chinese men following isocaloric high or low protein diets, stratified by either high or low meal frequency - a randomized controlled crossover trial

BACKGROUND

Cardio-Metabolic Disease (CMD) is the leading cause of death globally and particularly in Asia. Postprandial elevation of glycaemia, insulinaemia, triglyceridaemia are associated with an increased risk of CMD. While studies have shown that higher protein intake or increased meal frequency may benefit postprandial metabolism, their combined effect has rarely been investigated using composite mixed meals. We therefore examined the combined effects of increasing meal frequency (2-large vs 6-smaller meals), with high or low-protein (40 % vs 10 % energy from protein respectively) isocaloric mixed meals on a range of postprandial CMD risk markers.

METHODS

In a randomized crossover study, 10 healthy Chinese males (Age: 29 ± 7 years; BMI: 21.9 ± 1.7 kg/m(2)) underwent 4 dietary treatments: CON-2 (2 large Low-Protein meals), CON-6 (6 Small Low-Protein meals), PRO-2 (2 Large High-Protein meals) and PRO-6 (6 Small High-Protein meals). Subjects wore a continuous glucose monitor (CGM) and venous blood samples were obtained at baseline and at regular intervals for 8.5 h to monitor postprandial changes in glucose, insulin, triglycerides and high sensitivity C-reactive protein (hsCRP). Blood pressure was measured at regular intervals pre- and post- meal consumption. Urine was collected to measure excretion of creatinine and F2-isoprostanes and its metabolites over the 8.5 h postprandial period.

RESULTS

The high-protein meals, irrespective of meal frequency were beneficial for glycaemic health since glucose incremental area under the curve (iAUC) for PRO-2 (185 ± 166 mmol.min.L(-1)) and PRO-6 (214 ± 188 mmol.min.L(-1)) were 66 and 60 % lower respectively (both p < 0.05), compared with CON-2 (536 ± 290 mmol.min.L(-1)). The iAUC for insulin was the lowest for PRO-6 (13.7 ± 7.1 U.min.L(-1)) as compared with CON-2 (28.4 ± 15.6 U.min.L(-)1), p < 0.001. There were no significant differences in postprandial responses in other measurements between the dietary treatments.

CONCLUSIONS

The consumption of composite meals with higher protein content, irrespective of meal frequency appears to be beneficial for postprandial glycemic and insulinemic responses in young, healthy Chinese males. Implications of this study may be useful in the Asian context where the consumption of high glycemic index, carbohydrate meals is prevalent.

TRIAL REGISTRATION

NCT02529228 .

Metabolic characteristics of keto-adapted ultra-endurance runners

BACKGROUND

Many successful ultra-endurance athletes have switched from a high-carbohydrate to a low-carbohydrate diet, but they have not previously been studied to determine the extent of metabolic adaptations.

METHODS

Twenty elite ultra-marathoners and ironman distance triathletes performed a maximal graded exercise test and a 180 min submaximal run at 64% VO2max on a treadmill to determine metabolic responses. One group habitually consumed a traditional high-carbohydrate (HC: n=10, %carbohydrate:protein:fat=59:14:25) diet, and the other a low-carbohydrate (LC; n=10, 10:19:70) diet for an average of 20 months (range 9 to 36 months).

RESULTS

Peak fat oxidation was 2.3-fold higher in the LC group (1.54±0.18 vs 0.67±0.14 g/min; P=0.000) and it occurred at a higher percentage of VO2max (70.3±6.3 vs 54.9±7.8%; P=0.000). Mean fat oxidation during submaximal exercise was 59% higher in the LC group (1.21±0.02 vs 0.76±0.11 g/min; P=0.000) corresponding to a greater relative contribution of fat (88±2 vs 56±8%; P=0.000). Despite these marked differences in fuel use between LC and HC athletes, there were no significant differences in resting muscle glycogen and the level of depletion after 180 min of running (-64% from pre-exercise) and 120 min of recovery (-36% from pre-exercise).

CONCLUSION

Compared to highly trained ultra-endurance athletes consuming an HC diet, long-term keto-adaptation results in extraordinarily high rates of fat oxidation, whereas muscle glycogen utilization and repletion patterns during and after a 3 hour run are similar.

The relation of saturated fatty acids with low-grade inflammation and cardiovascular disease

The mantra that dietary (saturated) fat must be minimized to reduce cardiovascular disease (CVD) risk has dominated nutritional guidelines for decades. Parallel to decreasing intakes of fat and saturated fatty acids (SFA), there have been increases in carbohydrate and sugar intakes, overweight, obesity and type 2 diabetes mellitus. The "lipid hypothesis" coined the concept that fat, especially SFA, raises blood low-density lipoprotein-cholesterol and thereby CVD risk. In view of current controversies regarding their adequate intakes and effects, this review aims to summarize research regarding this heterogenic group of fatty acids and the mechanisms relating them to (chronic) systemic low-grade inflammation, insulin resistance, metabolic syndrome and notably CVD. The intimate relationship between inflammation and metabolism, including glucose, fat and cholesterol metabolism, revealed that the dyslipidemia in Western societies, notably increased triglycerides, "small dense" low-density lipoprotein and "dysfunctional" high-density lipoprotein, is influenced by many unfavorable lifestyle factors. Dietary SFA is only one of these, not necessarily the most important, in healthy, insulin-sensitive people. The environment provides us not only with many other proinflammatory stimuli than SFA but also with many antiinflammatory counterparts. Resolution of the conflict between our self-designed environment and ancient genome may rather rely on returning to the proinflammatory/antiinflammatory balance of the Paleolithic era in consonance with the 21st century culture. Accordingly, dietary guidelines might reconsider recommendations for SFA replacement and investigate diet in a broader context, together with nondietary lifestyle factors. This should be a clear priority, opposed to the reductionist approach of studying the effects of single nutrients, such as SFA.

Impact of Nutrition on Cerebral Circulation and Cognition in the Metabolic Syndrome

The increasing prevalence of Metabolic Syndrome (MetS), defined as the clustering of abdominal obesity, dyslipidemia, hypertension, and hyperglycemia, appears to be driving the global epidemics cardiovascular disease (CVD) and type 2 diabetes mellitus (T2DM). Nutrition has a major impact on MetS and plays an important role in the prevention, development, and treatment of its features. Structural and functional alterations in the vasculature, associated with MetS, might form the link between MetS and the increased risk of developing CVD and T2DM. Not only does the peripheral vasculature seem to be affected, but the syndrome has a profound impact on the cerebral circulation and thence brain structure as well. Furthermore, strong associations are shown with stroke, cognitive impairment, and dementia. In this review the impact of nutrition on the individual components of MetS, the effects of MetS on peripheral and cerebral vasculature, and its consequences for brain structure and function will be discussed.

A Moderate Low-Carbohydrate Low-Calorie Diet Improves Lipid Profile, Insulin Sensitivity and Adiponectin Expression in Rats

Calorie restriction (CR) via manipulating dietary carbohydrates has attracted increasing interest in the prevention and treatment of metabolic syndrome. There is little consensus about the extent of carbohydrate restriction to elicit optimal results in controlling metabolic parameters. Our study will identify a better carbohydrate-restricted diet using rat models. Rats were fed with one of the following diets for 12 weeks: Control diet, 80% energy (34% carbohydrate-reduced) and 60% energy (68% carbohydrate-reduced) of the control diet. Changes in metabolic parameters and expressions of adiponectin and peroxisome proliferator activator receptor γ (PPARγ) were identified. Compared to the control diet, 68% carbohydrate-reduced diet led to a decrease in serum triglyceride and increases inlow density lipoprotein-cholesterol (LDL-C), high density lipoprotein-cholesterol (HDL-C) and total cholesterol; a 34% carbohydrate-reduced diet resulted in a decrease in triglycerides and an increase in HDL-cholesterol, no changes however, were shown in LDL-cholesterol and total cholesterol; reductions in HOMA-IR were observed in both CR groups. Gene expressions of adiponectin and PPARγ in adipose tissues were found proportionally elevated with an increased degree of energy restriction. Our study for the first time ever identified that a moderate-carbohydrate restricted diet is not only effective in raising gene expressions of adiponectin and PPARγ which potentially lead to better metabolic conditions but is better at improving lipid profiles than a low-carbohydrate diet in rats.

Association of decrease in carbohydrate intake with reduction in abdominal fat during 3-month moderate low-carbohydrate diet among non-obese Japanese patients with type 2 diabetes

OBJECTIVE

The effectiveness of a moderate low-carbohydrate diet (M-LCD) has been demonstrated in terms of glycemic control, body weight and serum lipid profiles. We investigated the effect of a 3-month M-LCD on visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT), and examined an association between decrease in carbohydrate intake and reduction in abdominal fat among patients with Type 2 diabetes mellitus (T2DM).

METHODS

Seventy-six patients (45 men and 31 women; mean age ± SD: 59.5 ± 11.1 years) with T2DM were instructed to follow an M-LCD for 3 months. We assessed abdominal fat distribution using computed tomography and macronutrient intakes from 3-day dietary records at baseline and after 3 months.

RESULTS

The patients complied well with the M-LCD - %carbohydrate: %fat: %protein at baseline and after 3 months were 51:27:15 and 41:33:18 in men and 54:27:16 and 42:37:19 in women, respectively. VAT and SAT significantly decreased during the 3 months (P for time < 0.001 for both). Decrease in carbohydrate intake (g/day) and %carbohydrate were correlated with decrease (%) in VAT. The correlations were significant in men (Spearman correlation coefficient r = 0.469 for carbohydrate intake (g) and r = 0.402 for %carbohydrate) but not in women (r = 0.269 and 0.278, respectively). The correlations in men remained significant in multiple regression analysis adjusted for age and changes in energy intake.

CONCLUSIONS

In men, decrease in carbohydrate intake was significantly correlated with VAT loss during a 3-month M-LCD, independently of reduction in energy intake.

Insulin, carbohydrate restriction, metabolic syndrome and cancer

We propose that dietary carbohydrate restriction, particularly ketogenic diets, may provide benefit as a therapeutic or preventive strategy in cancer, alone or as an adjunct to pharmacology. The argument derives from several points of evidence: There is a close association between cancer and both diabetes and obesity. Extensive evidence shows that low carbohydrate diets are the most effective dietary treatment of Type 2 diabetes and dietary adjunct in Type 1. Such diets also target all the markers of metabolic syndrome. Finally, de facto reduction in carbohydrate likely contributes to total dietary restriction, which is effective in the prevention and treatment of cancer. The idea is consistent with recent interest in treating cancer with drugs that target diabetes. To move forward, we must understand obesity and diabetes as response to a hyperglycemic state rather than simply a cause of downstream effects.

Can we say what diet is best for health?

Diet is established among the most important influences on health in modern societies. Injudicious diet figures among the leading causes of premature death and chronic disease. Optimal eating is associated with increased life expectancy, dramatic reduction in lifetime risk of all chronic disease, and amelioration of gene expression. In this context, claims abound for the competitive merits of various diets relative to one another. Whereas such claims, particularly when attached to commercial interests, emphasize distinctions, the fundamentals of virtually all eating patterns associated with meaningful evidence of health benefit overlap substantially. There have been no rigorous, long-term studies comparing contenders for best diet laurels using methodology that precludes bias and confounding, and for many reasons such studies are unlikely. In the absence of such direct comparisons, claims for the established superiority of any one specific diet over others are exaggerated. The weight of evidence strongly supports a theme of healthful eating while allowing for variations on that theme. A diet of minimally processed foods close to nature, predominantly plants, is decisively associated with health promotion and disease prevention and is consistent with the salient components of seemingly distinct dietary approaches. Efforts to improve public health through diet are forestalled not for want of knowledge about the optimal feeding of Homo sapiens but for distractions associated with exaggerated claims, and our failure to convert what we reliably know into what we routinely do. Knowledge in this case is not, as of yet, power; would that it were so.

Cholesterol-induced inflammation and macrophage accumulation in adipose tissue is reduced by a low carbohydrate diet in guinea pigs

BACKGROUND/OBJECTIVES

The main objective of this study was to evaluate the effects of a high cholesterol (HC) dietary challenge on cholesterol tissue accumulation, inflammation, adipocyte differentiation, and macrophage infiltration in guinea pigs. A second objective was to assess whether macronutrient manipulation would reverse these metabolic alterations.

MATERIALS/METHODS

Male Hartley guinea pigs (10/group) were assigned to either low cholesterol (LC) (0.04g/100g) or high cholesterol (HC) (0.25g/100g) diets for six weeks. For the second experiment, 20 guinea pigs were fed the HC diet for six weeks and then assigned to either a low carbohydrate (CHO) diet (L-CHO) (10% energy from CHO) or a high CHO diet (H-CHO) (54% CHO) for an additional six weeks.

RESULTS

Higher concentrations of total (P < 0.005) and free (P < 0.05) cholesterol were observed in both adipose tissue and aortas of guinea pigs fed the HC compared to those in the LC group. In addition, higher concentrations of pro-inflammatory cytokines in the adipose tissue (P < 0.005) and lower concentrations of anti-inflammatory interleukin (IL)-10 were observed in the HC group (P < 0.05) compared to the LC group. Of particular interest, adipocytes in the HC group were smaller in size (P < 0.05) and showed increased macrophage infiltration compared to the LC group. When compared to the H-CHO group, lower concentrations of cholesterol in both adipose and aortas as well as lower concentrations of inflammatory cytokines in adipose tissue were observed in the L-CHO group (P < 0.05). In addition, guinea pigs fed the L-CHO exhibited larger adipose cells and lower macrophage infiltration compared to the H-CHO group.

CONCLUSIONS

The results of this study strongly suggest that HC induces metabolic dysregulation associated with inflammation in adipose tissue and that L-CHO is more effective than H-CHO in attenuating these detrimental effects.

Three-graded stratification of carbohydrate restriction by level of baseline hemoglobin A1c for type 2 diabetes patients with a moderate low-carbohydrate diet

Background

A moderate low-carbohydrate diet has been receiving attention in the dietary management of type 2 diabetes (T2DM). A fundamental issue has still to be addressed; how much carbohydrate delta-reduction (Δcarbohydrate) from baseline would be necessary to achieve a certain decrease in hemoglobin A1c (HbA1c) levels.

Objective

We investigated the effects of three-graded stratification of carbohydrate restriction by patient baseline HbA1c levels on glycemic control and effects of Δcarbohydrate on decreases in HbA1c levels (ΔHbA1c) in each group.

Research design and methods

We treated 122 outpatients with T2DM by three-graded carbohydrate restriction according to baseline HbA1c levels (≤ 7.4% for Group 1, 7.5%-8.9% for Group 2 and ≥ 9.0% for Group 3) and assessed their HbA1c levels, doses of anti-diabetic drugs and macronutrient intakes over 6 months.

Results

At baseline, the mean HbA1c level and carbohydrate intake were 6.9 ± 0.4% and 252 ± 59 g/day for Group 1 (n = 55), 8.1 ± 0.4% and 282 ± 85 g/day for Group 2 (n = 41) and 10.6 ± 1.4% and 309 ± 88 g/day for Group 3 (n = 26). Following three-graded carbohydrate restriction for 6 months significantly decreased mean carbohydrate intake (g/day) and HbA1c levels for all patients, from 274 ± 78 to 168 ± 52 g and from 8.1 ± 1.6 to 7.1 ± 0.9% (n = 122, P < 0.001 for both) and anti-diabetic drugs could be tapered. ΔHbA1c and Δcarbohydrate were -0.4 ± 0.4% and -74 ± 69 g/day for Group 1, -0.6 ± 0.9% and -117 ± 78 g/day for Group 2 and -3.1 ± 1.4% and -156 ± 74 g/day for Group 3. Linear regression analysis showed that the greater the carbohydrate intake, the greater the HbA1c levels at baseline (P = 0.001). Also, the greater the reduction in carbohydrate intake (g/day), the greater the decrease in HbA1c levels (P < 0.001), but ΔHbA1c was not significantly influenced by changes in other macronutrient intakes (g/day).

Conclusions

Three-graded stratification of carbohydrate restriction according to baseline HbA1c levels may provide T2DM patients with optimal objectives for carbohydrate restriction and prevent restriction from being unnecessarily strict.

Race and gender disparities in nutrient intake are not related to metabolic syndrome in 20- to 59-year-old US adults

BACKGROUND

The goal of this study was to examine the relationship between macronutrient and micronutrient intake and metabolic syndrome within race and gender cohorts of young US adults.

METHODS

The 2007-2010 National Health and Nutrition Examination Survey (NHANES) data for adults (n=2440) aged 20-59 were analyzed. Two 24-hr dietary recalls were used to measure intake of total calories, macronutrients, and 20 vitamins and minerals. Metabolic syndrome and its components were defined by the National Heart, Lung and Blood Institute criteria. Differences in statistical tests were noted when significant at P<0.05.

RESULTS

Prevalence of metabolic syndrome among 20- to 59-year-old adults was 30.4% [95% confidence interval 27.6-33.2]. Among cohorts, metabolic syndrome was highest in black women and white men, and lowest in black men and white women. Regression analysis indicated that no macronutrients were associated with greater risk of metabolic syndrome. For relative macronutrient intake, men with metabolic syndrome consumed more polyunsaturated fats, whereas women with metabolic syndrome consumed more total, saturated and monounsaturated fats and less fiber and starch than women without metabolic syndrome. Among races, white men and women consumed greater absolute quantities of all macronutrients except carbohydrates and sugar. Micronutrient intake was greatest for white men and women; women without metabolic syndrome had greater micronutrient adequacy than women with metabolic syndrome.

CONCLUSION

Nutrient intake varied between race/gender cohorts; however, there were few clinically significant differences in nutrient intake between those with and without metabolic syndrome. Diet may be marginally related to diagnosis of metabolic syndrome.

Moderate replacement of carbohydrates by dietary fats affects features of metabolic syndrome: a randomized crossover clinical trial

OBJECTIVE

Earlier studies on the management of metabolic syndrome (MetS) have mostly focused on very low carbohydrate diets, whereas long-term adherence to such diets is difficult for apparently healthy people. The aim of this study was to examine the effects of moderate replacement of carbohydrates by dietary fats on insulin resistance and features of MetS among women.

METHODS

This randomized crossover clinical trial was performed with 30 overweight or obese (body mass index [BMI] > 25 kg/m(2)) women with MetS. After a 2-wk run-in period, participants were randomly assigned to consume either a calorie-restricted high-carbohydrate (HC) diet (60%-65% of energy from carbohydrates and 20%-25% from fats) or a calorie-restricted moderately restricted carbohydrate (MRC) diet (43%-47% of total calories as carbohydrate and 36%-40% as dietary fats) for 6 wk. Protein contents of both diets were 15% to 17% of total energy. A 2-wk washout period was applied following which participants were crossed over to the alternate treatment arm for an additional 6 wk. Anthropometric, blood pressure, and biochemical measurements were performed before and after each phase of intervention.

RESULTS

Mean age and BMI of study participants was 42.4 y and 33 kg/m(2), respectively. A trend toward greater reduction in waist (-3.9 versus -2.6 cm; P = 0.07) and hip circumferences (-2.7 versus -1.5 cm; P = 0.07) as well as serum triglyceride (TG) levels (-31.3 versus 0.13 mg/dL; P = 0.07) was observed after consumption of an MRC diet compared with an HC diet. The TG to high-density lipoprotein cholesterol (HDL-C) ratio had a tendency to improve with the MRC diet rather than the HC diet (-0.9 versus -0.1; P = 0.06). Consumption of the MRC diet resulted in a greater reduction of systolic blood pressure (-8.93 versus -2.97 mm Hg; P = 0.06) and diastolic blood pressure (-12.7 versus -1.77 mm Hg; P = 0.001) compared with the HC diet. The prevalence of MetS was significantly decreased following the consumption of the MRC diet (P = 0.03). The two diets were not significantly different in terms of their effect on fasting plasma glucose, serum HDL-C, low-density lipoprotein cholesterol, and total cholesterol, insulin levels, and Homeostasis Model Assessment-Insulin Resistance.

CONCLUSION

Moderate replacement of carbohydrates by dietary fats was not associated with statistically different changes in fasting plasma glucose, insulin, or atherogenic dyslipidemia among individuals with the metabolic syndrome; however, it resulted in decreased diastolic blood pressure and lower prevalence of the metabolic syndrome.

Dietary carbohydrate restriction as the first approach in diabetes management: critical review and evidence base

The inability of current recommendations to control the epidemic of diabetes, the specific failure of the prevailing low-fat diets to improve obesity, cardiovascular risk, or general health and the persistent reports of some serious side effects of commonly prescribed diabetic medications, in combination with the continued success of low-carbohydrate diets in the treatment of diabetes and metabolic syndrome without significant side effects, point to the need for a reappraisal of dietary guidelines. The benefits of carbohydrate restriction in diabetes are immediate and well documented. Concerns about the efficacy and safety are long term and conjectural rather than data driven. Dietary carbohydrate restriction reliably reduces high blood glucose, does not require weight loss (although is still best for weight loss), and leads to the reduction or elimination of medication. It has never shown side effects comparable with those seen in many drugs. Here we present 12 points of evidence supporting the use of low-carbohydrate diets as the first approach to treating type 2 diabetes and as the most effective adjunct to pharmacology in type 1. They represent the best-documented, least controversial results. The insistence on long-term randomized controlled trials as the only kind of data that will be accepted is without precedent in science. The seriousness of diabetes requires that we evaluate all of the evidence that is available. The 12 points are sufficiently compelling that we feel that the burden of proof rests with those who are opposed.

Exercise and dietary-mediated reductions in postprandial lipemia

Postprandial hyperlipemia produces long-term derangements in lipid/lipoprotein metabolism, vascular endothelial dysfunction, hypercoagulability, and sympathetic hyperactivity which are strongly linked to atherogenesis. The purpose of this review is to (1) provide a qualitative analysis of the available literature examining the dysregulation of postprandial lipid metabolism in the presence of obesity, (2) inspect the role of adiposity distribution and sex on postprandial lipid metabolism, and (3) examine the role of energy deficit (exercise- and/or energy restriction-mediated), isoenergetic low-carbohydrate diets, and omega-3 (n-3) fatty acid supplementation on postprandial lipid metabolism. We conclude from the literature that central adiposity primarily accounts for sex-related differences in postprandial lipemia and that aerobic exercise attenuates this response in obese or lean men and women to a similar extent through potentially unique mechanisms. In contrast, energy restriction produces only mild reductions in postprandial lipemia suggesting that exercise may be superior to energy restriction alone as a strategy for lowering postprandial lipemia. However, isoenergetic very low-carbohydrate diets and n-3 fatty acid supplementation reduce postprandial lipemia indicating that macronutrient manipulations reduce postprandial lipemia in the absence of energy restriction. Therefore, interactions between exercise/energy restriction and alterations in macronutrient content remain top priorities for the field to identify optimal behavioral treatments to reduce postprandial lipemia.

Plasma phospholipid saturated fatty acids and heart failure risk in the Physicians' Health Study

BACKGROUND & AIMS

Previous studies have suggested that some plasma phospholipid saturated fatty acids (SFA) are associated with an increased risk of coronary heart disease and hypertension, major risk factors for heart failure (HF). However, little is known about the association between SFA and HF. This study examines associations of individual plasma phospholipid SFA with HF risk in US male physicians.

METHODS

The current ancillary study used a prospective nested matched case-control design to select 788 cases of incident HF and 788 controls. Plasma phospholipid SFAs were measured using gas chromatography. HF was self-reported on follow-up questionnaires and validated by review of medical records in a subsample. We used conditional logistic regression to estimate relative risks.

RESULTS

Mean age was 58.7 ± 8.0 years. One standard deviation higher plasma phospholipid 16:0 was associated with an odds ratio (95% CI) of 1.20 (1.04, 1.38) controlling for established HF risk factors and other SFAs (p = 0.042). However, this association was not significant after Bonferroni correction (p > 0.008). We did not observe associations between other SFAs (14:0, 15:0, 18:0, 20:0, or 22:0) and HF risk (all p for trend > 0.05).

CONCLUSIONS

Our data suggested no association between plasma phospholipid SFAs and HF in US male physicians.

Dietary carbohydrate dictates development of Type 2 diabetes in the Nile rat

Amount and type of dietary carbohydrate (CHO), as well as the CHO:fat ratio, are thought to be critical for both the rate of development and severity of Type 2 diabetes mellitus. Thus, these nutritional considerations were examined in the previously described "spontaneous" model of diabetes and metabolic syndrome, the Nile rat. Weanling male Nile rats (n=92) were fed semipurified diets, modifying glycemic index and load by changing the amount of fiber or altering the CHO:fat ratio. Random and fasting blood glucose and body weight were assessed, and diabetes was characterized in terms of blood glucose, relevant plasma and liver parameters, food and water intake and terminal organ weights. Nile rats fed with hiCHO became more hyperglycemic than rats fed with modCHO (P<.05), while loCHO and hiCHO+hiFiber rats remained essentially normoglycemic. Liver lipid and glycogen accumulation was associated with severe hyperlipemia in diabetic rats, analogous to metabolic syndrome in humans. Advanced diabetes was linked to liver and kidney damage and elevated blood urea nitrogen with weight loss. Dispersing dietary CHO by fiber or replacing it by moderate fat (reducing the glycemic index and load) delayed the onset of diabetes but did not prevent signs of insulin resistance. A very low content of dietary CHO (high fat) seemed to prevent even these early indicators of insulin resistance. Thus, the Nile rat represents a novel CHO-sensitive model for study of Type 2 diabetes that reliably follows the course of disease in humans.

Dietary carbohydrate restriction improves insulin sensitivity, blood pressure, microvascular function, and cellular adhesion markers in individuals taking statins

Statins positively impact plasma low-density lipoprotein cholesterol, inflammation and vascular endothelial function (VEF). Carbohydrate restricted diets (CRD) improve atherogenic dyslipidemia, and similar to statins, have been shown to favorably affect markers of inflammation and VEF. No studies have examined whether a CRD provides additional benefit beyond that achieved by habitual statin use. We hypothesized that a CRD (<50 g carbohydrate/d) for 6 weeks would improve lipid profiles and insulin sensitivity, reduce blood pressure, decrease cellular adhesion and inflammatory biomarkers, and augment VEF (flow-mediated dilation and forearm blood flow) in statin users. Participants (n = 21; 59.3 ± 9.3 y, 29.5 ± 3.0 kg/m(2)) decreased total caloric intake by approximately 415 kcal at 6 weeks (P < .001). Daily nutrient intakes at baseline (46/36/17% carb/fat/pro) and averaged across the intervention (11/58/28% carb/fat/pro) demonstrated dietary compliance, with carbohydrate intake at baseline nearly 5-fold greater than during the intervention (P < .001). Compared to baseline, both systolic and diastolic blood pressure decreased after 3 and 6 weeks (P < .01). Peak forearm blood flow, but not flow-mediated dilation, increased at week 6 compared to baseline and week 3 (P ≤ .03). Serum triglyceride, insulin, soluble E-Selectin and intracellular adhesion molecule-1 decreased (P < .01) from baseline at week 3, and this effect was maintained at week 6. In conclusion, these findings demonstrate that individuals undergoing statin therapy experience additional improvements in metabolic and vascular health from a 6 weeks CRD as evidenced by increased insulin sensitivity and resistance vessel endothelial function, and decreased blood pressure, triglycerides, and adhesion molecules.

Dietary strategies to reduce metabolic syndrome

Metabolic syndrome (MetS) is a cluster of metabolic abnormalities characterized by central obesity, dyslipidemias, hypertension, high fasting glucose, chronic low-grade inflammation and oxidative stress. This condition has become an increasing problem in our society where about 34 % of adults are diagnosed with MetS. In parallel with the adult situation, a significant number of children present lipid abnormalities and insulin resistance, which can be used as markers of MetS in the pediatric population. Changes in lifestyle including healthy dietary regimens and increased physical activity should be the first lines of therapy to decrease MetS. In this article, we present the most recent information on successful dietary modifications that can reduce the parameters associated with MetS. Successful dietary strategies include energy restriction and weight loss, manipulation of dietary macronutrients--either through restriction of carbohydrates, fat, or enrichment in beneficial fatty acids, incorporation of functional foods and bioactive nutrients, and adherence to dietary and lifestyle patterns such the Mediterranean diet and diet/exercise regimens. Together, the recent findings presented in this review serve as evidence to support the therapeutic treatment of MetS through diet.

Associations of erythrocyte fatty acids in the de novo lipogenesis pathway with risk of metabolic syndrome in a cohort study of middle-aged and older Chinese

BACKGROUND

Experimental studies suggest that elevated de novo lipogenesis (DNL) might be involved in the pathogenesis of metabolic disorders. Few prospective studies have been conducted, especially among populations with a high carbohydrate intake, to determine whether DNL fatty acids are associated with the risk of the metabolic syndrome (MetS).

OBJECTIVE

We aimed to investigate associations of erythrocyte fatty acids in the DNL pathway-including myristic acid (14:0), palmitic acid (16:0), palmitoleic acid (16:1n-7), hexadecenoic acid (16:1n-9), stearic acid (18:0), vaccenic acid (18:1n-7), and oleic acid (18:1n-9)-with the risk of MetS in a Chinese population with an average carbohydrate intake of >60% of energy.

DESIGN

A total of 1176 free-living Chinese men and women aged 50-70 y from Beijing and Shanghai were included in our analysis, giving rise to 412 incident MetS cases during 6 y of follow-up. Erythrocyte fatty acids and metabolic traits were measured in these participants.

RESULTS

Erythrocyte fatty acids in the DNL pathway were correlated with a high ratio of carbohydrate-to-fat intake, less favorable lipid profiles, and elevated liver enzymes at baseline. In comparison with the lowest quartile, RRs (95% CIs) of MetS in the highest quartile were 1.30 (1.04, 1.62; P-trend = 0.007) for 16:1n-7, 1.48 (1.17, 1.86; P-trend < 0.001) for 16:1n-9, 1.26 (1.01, 1.56; P-trend = 0.06) for 18:1n-7, and 1.51 (1.19, 1.92; P-trend < 0.001) for 18:1n-9 after multivariate adjustment for lifestyle factors and body mass index. Moreover, 16:0 and 16:1n-7 were associated with an elevated risk of diabetes.

CONCLUSION

Our findings suggest that fatty acids in the DNL pathway are independently associated with an elevated risk of metabolic disorders.

Egg intake improves carotenoid status by increasing plasma HDL cholesterol in adults with metabolic syndrome

Metabolic syndrome (MetS) is associated with reductions in plasma lutein and zeaxanthin, along with altered composition of their lipoprotein transporters which may affect disease risk. Egg yolk intake has been demonstrated to increase plasma lutein and zeaxanthin in other populations. The objective of this study was to investigate the effects of whole egg feeding on plasma and lipoprotein carotenoids in participants with MetS. Participants consumed 3 whole eggs per day (EGG, n = 20) or the equivalent amount of yolk-free egg substitute (SUB, n = 17), as part of a carbohydrate-restricted diet (CRD) for 12 weeks. Post-intervention, the EGG group had significant increases in plasma lutein (+21%), zeaxanthin (+48%), and β-carotene (+24%), while the SUB group had increases in plasma β-carotene (+55%) only. Significant enrichment of isolated HDL and LDL fractions in lutein (+20% HDL, +9% LDL) and zeaxanthin (+57% HDL, +46% LDL) was observed in the EGG group after 12 weeks. Increases in the proportion of plasma carotenoids carried by HDL was seen for lutein (P < 0.01), zeaxanthin (P < 0.01), β-cryptoxanthin (P < 0.05), and lycopene (P < 0.05) for all participants after the 12 week intervention. Daily intake of 3 whole eggs, as part of a CRD, increased both plasma and lipoprotein lutein and zeaxanthin. Egg yolk may represent an important food source to improve plasma carotenoid status in a population at high risk for cardiovascular disease and type 2 diabetes.

Fructose in perspective

Whether dietary fructose (as sucrose or high fructose corn syrup) has unique effects separate from its role as carbohydrate, or, in fact, whether it can be considered inherently harmful, even a toxin, has assumed prominence in nutrition. Much of the popular and scientific media have already decided against fructose and calls for regulation and taxation come from many quarters. There are conflicting data, however. Outcomes attributed to fructose — obesity, high triglycerides and other features of metabolic syndrome — are not found in every experimental test and may be more reliably caused by increased total carbohydrate. In this review, we try to put fructose in perspective by looking at the basic metabolic reactions. We conclude that fructose is best understood as part of carbohydrate metabolism. The pathways of fructose and glucose metabolism converge at the level of the triose-phosphates and, therefore, any downstream effects also occur with glucose. In addition, a substantial part of ingested fructose is turned to glucose. Regulation of fructose metabolism per se, is at the level of substrate control — the lower K_m of fructokinase compared to glucokinase will affect the population of triose-phosphates. Generally deleterious effects of administering fructose alone suggest that fructose metabolism is normally controlled in part by glucose. Because the mechanisms of fructose effects are largely those of a carbohydrate, one has to ask what the proper control should be for experiments that compare fructose to glucose. In fact, there is a large literature showing benefits in replacing total carbohydrate with other nutrients, usually fat, and such experiments sensibly constitute the proper control for comparisons of the two sugars. In terms of public health, a rush to judgement analogous to the fat-cholesterol-heart story, is likely to have unpredictable outcome and unintended consequences. Popular opinion cannot be ignored in this problem and comparing fructose to ethanol, for example, is without biochemical correlates. Also, nothing in the biochemistry suggests that sugar is a toxin. Dietary carbohydrate restriction remains the best strategy for obesity, diabetes and metabolic syndrome. The specific contribution of the removal of fructose or sucrose to this effect remains unknown.

Effects of a low-carbohydrate diet on weight loss and cardiometabolic profile in Chinese women: a randomised controlled feeding trial

Little is known about the potential adherence to and the effectiveness of a low-carbohydrate (LC) diet on weight loss and cardiometabolic risk factors in Chinese adults with a habitually high carbohydrate intake. In the present controlled feeding trial, fifty overweight or obese women (age 47·9 (sem 0·9) years; BMI 26·7 (sem 0·3) kg/m²) were randomly assigned to a LC non-energy-restricted diet (initial carbohydrate intake 20 g/d, with a 10 g increase weekly) or an energy-restricted (ER) diet (carbohydrate intake 156-205 g/d, ER to 5021 or 6276 kJ/d, 35% average energy reduction) for 12 weeks. Over the intervention period, the two diets had comparable compliance (96%) and self-reported acceptability. At week 12, carbohydrate intake in the LC and ER groups contributed to 36·1 and 51·1% of total energy, respectively (P < 0·001). Although both diets showed similarly decreased mean body weight (LC - 5·27 (95% CI - 6·08, - 4·46) kg; ER - 5·09 (95% CI - 5·50, - 4·67) kg, P = 0·67) and percentage of fat mass measured by dual-energy X-ray absorptiometry (LC - 1·19 (95% CI - 1·88, - 0·50)%; ER - 1·56 (95% CI - 2·20, - 0·92)%, P = 0·42), participants in the LC group had greater reductions in the ratio of total cholesterol:HDL-cholesterol (P= 0·03) and also in the ratio of TAG:HDL-cholesterol (P = 0·01) than those in the ER group. The present 12-week diet trial suggested that both a LC non-energy-restricted diet and an ER diet were acceptable to Chinese women and both diets were equally effective in reducing weight and fat mass. Moreover, the LC diet showed beneficial effects on blood lipid profiles.

Whole egg consumption improves lipoprotein profiles and insulin sensitivity to a greater extent than yolk-free egg substitute in individuals with metabolic syndrome

OBJECTIVE

We investigated if daily egg feeding, along with carbohydrate restriction, would alter lipoprotein metabolism and influence atherogenic lipoprotein profiles and insulin resistance in men and women with metabolic syndrome (MetS).

METHODS

In a randomized, single-blind, parallel design, participants consumed either 3 whole eggs/day (EGG, n=20) or the equivalent amount of yolk-free egg substitute (SUB, n=17), as part of a moderately carbohydrate-restricted diet (25%-30% energy) for 12 weeks. Plasma lipids, apolipoproteins (apos), oxidized LDL (oxLDL), cholesteryl ester transfer protein (CETP) and lecithin-cholesterol acyltransferase (LCAT) activities were assessed at baseline and week 12. Lipoprotein particle concentrations and sizes were measured by nuclear magnetic resonance spectroscopy.

RESULTS

Atherogenic dyslipidemia improved for all individuals as evidenced by reductions in plasma triglycerides, apoC-III, apoE, oxLDL, VLDL particle diameter, large VDL, total IDL, small LDL, and medium LDL particles (P<0.05). Furthermore, there were increases in HDL-cholesterol, large LDL and large HDL particles (P<0.05) for all individuals. However, there were greater increases in HDL-cholesterol and large HDL particles, and reductions in total VLDL and medium VLDL particles for those consuming EGG compared to SUB (P<0.05). Plasma insulin and insulin resistance (HOMA-IR) were reduced, while LCAT activity, and both HDL and LDL diameters increased over time in the EGG group only (P<0.05).

CONCLUSIONS

Incorporating daily whole egg intake into a moderately carbohydrate-restricted diet provides further improvements in the atherogenic lipoprotein profile and in insulin resistance in individuals with MetS.

Tackling overweight and obesity: does the public health message match the science?

BACKGROUND

Despite the increasing understanding of the mechanisms relating to weight loss and maintenance, there are currently no validated public health interventions that are able to achieve sustained long-term weight loss or to stem the increasing prevalence of obesity in the population. We aimed to examine the models of energy balance underpinning current research about weight-loss intervention from the field of public health, and to determine whether they are consistent with the model provided by basic science. EMBASE was searched for papers published in 2011 on weight-loss interventions. We extracted details of the population, nature of the intervention, and key findings for 27 articles.

DISCUSSION

Most public health interventions identified were based on a simple model of energy balance, and thus attempted to reduce caloric consumption and/or increase physical activity in order to create a negative energy balance. There appeared to be little consideration of homeostatic feedback mechanisms and their effect on weight-loss success. It seems that there has been a lack of translation between recent advances in understanding of the basic science behind weight loss, and the concepts underpinning the increasingly urgent efforts to reduce excess weight in the population.

SUMMARY

Public health weight-loss interventions seem to be based on an outdated understanding of the science. Their continued failure to achieve any meaningful, long-term results reflects the need to develop intervention science that is integrated with knowledge from basic science. Instead of asking why people persist in eating too much and exercising too little, the key questions of obesity research should address those factors (environmental, behavioral or otherwise) that lead to dysregulation of the homeostatic mechanism of energy regulation. There is a need for a multidisciplinary approach in the design of future weight-loss interventions in order to improve long-term weight-loss success.

Pro-atherogenic postprandial profile: meal-induced changes of lipoprotein sub-fractions and inflammation markers in obese boys

BACKGROUND AND AIMS

Obesity is a pro-atherogenic condition and postprandial lipoprotein profile and circulating cytokines changes may contribute to promote the process. The aim of this study is to investigate postprandial metabolic response, lipoprotein oxidation and circulating cytokine levels, after the ingestion of two different meals with different fat/carbohydrate ratio.

METHODS AND RESULTS

Ten prepubertal obese boys consumed two meals with the same energy and protein content but with a different carbohydrate to fat ratio: 1) moderate fat (MF): 61% carbohydrate, 27% fat; 2) high fat (HF): 37% carbohydrate, 52% fat. The AUC of glucose and insulin were significantly (p < 0.05) lower after the HF meal. HF meal was followed by a significant decrease in the cholesterol carried in the HDL fractions, while cholesterol in the small, dense LDL and in the VLDL particles increased, as compared to baseline (p < 0.05 for all). No differences were found in the cholesterol distribution after the MF meal. Moreover, HDL-C concentration was lower (p < 0.05) at 300 min after HF vs. MF meal. Oxidized LDL (ox-LDL) concentration increased after the HF meal but not after the MF meal [9.3(2.2) vs 1.8(2.2)% from baseline, P < 0.02)]. A positive association (r > 0.3, P < 0.05) was observed between the densest LDL particles and the ox-LDL plasma levels. A reduction of IL-6 was found at 120 min after the MF [-23.3(5.5) vs -8.4(3.8)% from baseline, P < 0.05)] compared with the HF meal.

CONCLUSION

A simple change of ≈25% of energy load from fat to carbohydrate in a meal significantly improves postprandial pro-atherogenic factors in obese boys.

Grape polyphenols reduce blood pressure and increase flow-mediated vasodilation in men with metabolic syndrome

We evaluated the effects of grape polyphenols in individuals classified with metabolic syndrome (MetS). Men (n = 24) aged 30-70 y were randomly assigned to consume either a freeze-dried grape polyphenol powder (GRAPE) or a placebo for 30 d in a double-blind, crossover design, separated by a 3-wk washout period. Participants were asked to maintain their usual diet and physical activity during the study and abstain from consuming polyphenol-rich foods. MetS criteria including blood pressure (BP) and markers of vascular endothelial function including brachial artery flow-mediated vasodilation (FMD), plasma total nitrite + nitrate (NOx) to estimate NO production, plasma soluble intercellular adhesion molecule-1 (sICAM-1), and soluble vascular cell adhesion molecule-1 (sVCAM-1) were measured at the end of each dietary period. Systolic BP (P < 0.0025) and plasma sICAM-1 concentrations (P < 0.025) were lower, whereas the FMD response was higher (P < 0.0001), during the GRAPE compared with the placebo period. In addition, changes in sVCAM-1 concentrations between periods were positively correlated with changes in systolic BP (r = 0.45; P < 0.05). Although NOx concentrations did not differ between periods, changes in systolic BP were negatively correlated with changes in NOx concentrations (r = -0.44; P < 0.05), indicating the vasodilating properties of NO. Other MetS variables did not differ between the GRAPE and placebo periods. These results suggest that GRAPE polyphenols may potentiate vasorelaxation and reduce BP and circulating cell adhesion molecules, resulting in improvements in vascular function.

Response of C57Bl/6 mice to a carbohydrate-free diet

High fat feeding in rodents generally leads to obesity and insulin resistance whereas in humans this is only seen if dietary carbohydrate is also high, the result of the anabolic effect of poor regulation of glucose and insulin. A previous study of C57Bl/6 mice (Kennedy AR, et al.: Am J Physiol Endocrinol Metab (2007) 262 E1724-1739) appeared to show the kind of beneficial effects of calorie restriction that is seen in humans but that diet was unusually low in protein (5%). In the current study, we tested a zero-carbohydrate diet that had a higher protein content (20%). Mice on the zero-carbohydrate diet, despite similar caloric intake, consistently gained more weight than animals consuming standard chow, attaining a dramatic difference by week 16 (46.1 ± 1.38 g vs. 30.4 ± 1.00 g for the chow group). Consistent with the obese phenotype, experimental mice had fatty livers and hearts as well as large fat deposits in the abdomino-pelvic cavity, and showed impaired glucose clearance after intraperitoneal injection. In sum, the response of mice to a carbohydrate-free diet was greater weight gain and metabolic disruptions in distinction to the response in humans where low carbohydrate diets cause greater weight loss than isocaloric controls. The results suggest that rodent models of obesity may be most valuable in the understanding of how metabolic mechanisms can work in ways different from the effect in humans.

Differential effects of high-carbohydrate and high-fat diet composition on metabolic control and insulin resistance in normal rats

The macronutrient component of diets is critical for metabolic control and insulin action. The aim of this study was to compare the effects of high fat diets (HFDs) vs. high carbohydrate diets (HCDs) on metabolic control and insulin resistance in Wistar rats. Thirty animals divided into five groups (n = 6) were fed: (1) Control diet (CD); (2) High-saturated fat diet (HSFD); (3) High-unsaturated fat diet (HUFD); (4) High-digestible starch diet, (HDSD); and (5) High-resistant starch diet (HRSD) during eight weeks. HFDs and HCDs reduced weight gain in comparison with CD, however no statistical significance was reached. Calorie intake was similar in both HFDs and CD, but rats receiving HCDs showed higher calorie consumption than other groups, (p < 0.01). HRSD showed the lowest levels of serum and hepatic lipids. The HUFD induced the lowest fasting glycemia levels and HOMA-IR values. The HDSD group exhibited the highest insulin resistance and hepatic cholesterol content. In conclusion, HUFD exhibited the most beneficial effects on glycemic control meanwhile HRSD induced the highest reduction on lipid content and did not modify insulin sensitivity. In both groups, HFDs and HCDs, the diet constituents were more important factors than caloric intake for metabolic disturbance and insulin resistance.

Hypertriglyceridemia and residual dyslipidemia in statin-treated, patients with diabetes at the highest risk for cardiovascular disease and achieving very-low low-density lipoprotein-cholesterol levels

BACKGROUND

As the result of the high prevalence of comorbidities and conventional risk factors among patients with type 2 diabetes (T2DM), most patients belong to the highest cardiovascular disease risk category, and have a target low-density lipoprotein cholesterol (LDL-C) of <70 mg/dL. Because substantial residual risk persists at LDL-C <70 mg/dL, a more comprehensive control of non-LDL-C and particles was recommended in the joint 2008 American Diabetes Association/American College of Cardiology Consensus.

OBJECTIVE

To ascertain, in statin-treated T2DM patients belonging to this greatest-risk group, with on-statin LDL-C <70 mg/dL, (1) the proportion of patients meeting all three critical levels (LDL-C <70 mg/dL, non-high-density lipoprotein cholesterol [HDL-C] <100 mg/dL, apoB <80 mg/dL) and (2) the variables associated with target attainment versus nonattainment.

PATIENTS AND METHODS

Among 675 unselected patients with T2DM, 367 were both at very high cardiometabolic risk and taking statins; 118 of these patient had LDL-C levels <70 mg/dL. Patients meeting all three criteria (LDL-C, non-HDL-C, and apoB; n = 79; all three at goal group) were compared with those only reaching LDL-C (n = 49; only LDL-C at goal group).

RESULTS

LDL-C was 54 (12) for the all three at goal group versus 57 (10) mg/dL for the only LDL-C at goal group (NS). The two groups were similar regarding age, gender, diabetes duration, body mass index, waist circumference, blood pressure, renal function and micro-/macroangiopathy prevalence. A statin plus fibrate was given to 16% of patients in the all three at goal group and 32% in the only LDL-C at goal group. The two groups did not differ in baseline (prestatin) LDL-C, HDL-C, and non-HDL-C, except for pre-/post-lipid-lowering drug(s) triglycerides (TG): 177 (95)/118 (56) for all three at goal versus 279 (134)/ 241 (103) mg/dL for only LDL-C at goal (P = .0230 and P = .0001). The only LDL-C at goal group had lower HDL-C (vs. all three at goal): 41 (12) vs. 47 (14) mg/dL (P = .0237), with atherogenic dyslipidemia [hypo-HDL-C + hyper-TG] prevalence of 35% in the all three at goal versus 56% in the only LDL-C at goal group (P < .0001). log(TG)/HDL-C was 0.049 (0.021) for all three at goal versus 0.063 (0.021) for only LDL-C at goal (P < .0001). The LDL-C/apoB ratio was 0.92 (0.24) for all three at goal vs. 0.67 (0.18) for only LDL-C at goal (P < .0001), suggestive of smaller/denser LDL.

CONCLUSION

The presence of atherogenic dyslipidemia was associated with a failure to meet all three critical modifiable targets for hypercholesterolemia, such a nonachievement being found in a large proportion (one-third) of very-high risk T2DM patients with very-low on-statin LDL-C. Attainment of all three targets will require (1) titration/permutation of statins, (2) lifestyle (re)inforcement; and/or (3) statin-fibrate bitherapy.

Apolipoprotein A-I, apolipoprotein B, high-sensitivity C-reactive protein and severity of coronary artery disease in Tunisian population

BACKGROUND

The relationship between Apolipoprotein A-I, Apolipoprotein B, C-reactive protein and the severity coronary artery disease in Tunisian CAD patients has not been examined. We investigated the association between serum ApoA-I, ApoB, hs-CRP and the severity of coronary artery disease.

METHODS

This study was carried out on 180 patients who underwent angiography and 129 healthy controls. ApoA-I and ApoB as well as the serum total cholesterol, HDL, triglyceride, LDL and hs-CRP levels were measured. The ApoB/ApoA-I ratio was calculated.

RESULTS

We showed a decreased level of ApoA-I and an increased level of ApoB, ApoB/ApoA-I ratio and hs-CRP in CAD patients compared to the control group (P<.001). In addition, we showed a significant increase of ApoB, ApoB/ApoA-I ratio and hs-CRP in CAD patients presenting 0 to 3 vessels stenosis (P<.001). Multivariate analysis showed that ApoB (P<.001), and hs-CRP (P<.001) were independent predictors of the severity of CAD.

CONCLUSION

In this study, ApoB and hs-CRP levels were markedly associated with the severity of CAD in Tunisian patients. We suggested that synergistic effects between dyslipidemia and inflammation led to increase the risk of the severity of CAD.

A Mediterranean-style, low-glycemic-load diet decreases atherogenic lipoproteins and reduces lipoprotein (a) and oxidized low-density lipoprotein in women with metabolic syndrome

The objective was to assess the impact of a Mediterranean-style, low-glycemic-load diet (control group, n = 41) and the same diet plus a medical food (MF) containing phytosterols, soy protein, and extracts from hops and Acacia (MF group, n = 42) on lipoprotein atherogenicity in women with metabolic syndrome. Plasma lipids, apolipoproteins (apos), lipoprotein subfractions and particle size, low-density lipoprotein (LDL) oxidation, and lipoprotein (a) were measured at baseline, week 8, and week 12 of the intervention. Three-day dietary records were collected at the same time points to assess compliance. Compared with baseline, women decreased energy intake from carbohydrate (P < .001) and fat (P < .001), whereas they increased energy intake from protein (P < .001). A significant increase in energy from monounsaturated fatty acids was also observed as well as increases in eicosapentaenoic acid and docosahexaenoic acid, whereas trans-fatty acid intake was reduced (P < .00001). The atherogenic lipoproteins, large very low-density lipoprotein (P < .0001) and small LDL (P < .0001), were reduced, whereas the ratio of large high-density lipoprotein to smaller high-density lipoprotein particles was increased (P < .0001). Apolipoprotein B was reduced for all women (P < .0001), with a greater reduction in the MF group (P < .025). Oxidized LDL (P < .05) and lipoprotein (a) (P < .001) were reduced in both groups at the end of the intervention. Consumption of a Mediterranean-style diet reduces the risk for cardiovascular disease by decreasing atherogenic lipoproteins, oxidized LDL, and apo B. Inclusion of an MF may have an additional effect in reducing apo B.

Nutrition and acne: therapeutic potential of ketogenic diets

The influence of nutrition on skin health is a growing research area but the findings of various studies on the effect of diet on the development of acne have often been contradictory. The general opinion among researchers has oscillated between two different, opposing positions: that diet either is or is not a key factor for acne development. This review examines the evidence supporting an influence of various dietary components on the development of acne particularly focusing on the role played by carbohydrates. The physiological and biochemical effects of the ketogenic diet are examined from this perspective and mechanisms will be proposed via which this type of diet could have a role in the treatment of acne.

Carbohydrates for Physical Activity

Intake of carbohydrates above the dietary guidelines to support performance of physical activity is common but may be unnecessary and counterproductive. Sports nutrition guidelines have not been designed to incorporate characteristics that may make high carbohydrate consumption a source of metabolic stress that may increase oxidative stress, inflammation, and lipogenesis. This metabolic stress is linked to the physiology underlying the development of insulin resistance, type 2 diabetes mellitus, and cardiovascular diseases. This review describes research-based evidence to aid in bridging the gap between dietary guidelines for overall health and those to support physical activity. Characteristics that increase the likelihood of metabolic stress resulting from carbohydrate intake include overweight and obesity, central/visceral adiposity, older age, sedentary lifestyle, and caloric state. Carbohydrate-based foods that provide the most health benefits are whole grains, beans and legumes, fruits, and vegetables. Carbohydrate-based foods that most readily elicit metabolic stress are those with added sugars and refined grains or that have a high glycemic index. A checklist that incorporates both the number of these characteristics and prevailing guidelines for nutrition and physical activity is presented. This may be useful in determining whether additional carbohydrates are needed to support the physical activity level of the individual.

Effects of dietary macronutrient distribution on vascular integrity in obesity and metabolic syndrome

Metabolic syndrome is a condition characterized by a clustering of risk factors for cardiovascular disease. Emerging data suggest vascular integrity is disrupted in metabolic syndrome. Vascular integrity may be determined using several measurements, including pulse wave velocity, augmentation index, and flow-mediated dilation. Arterial stiffness has become an important clinical indicator of cardiovascular disease risk. Several circulating inflammatory peptides also impact vascular integrity. The present review examines the efficacy of nutritional interventions aimed at improving vascular integrity and reducing levels of associated inflammatory peptides in individuals with metabolic syndrome, with a specific focus on the effect of dietary macronutrient redistribution on these factors.

Reducing vascular events risk in patients with dyslipidaemia: an update for clinicians

Reducing the risk of vascular events in patients with dyslipidaemia requires cardiovascular disease risk stratification and lifestyle/pharmacological intervention on modifiable risk factors. Reduction of low-density lipoprotein cholesterol (LDL-C) with statins is highly effective in reducing cardiovascular disease in patients with and without diabetes, but leaves unaddressed a sizeable residual vascular risk (RvR), which is rarely quantified in routine clinical practice. Such RvR may relate to lack of strict target attainment for all atherogenic variables [LDL-C, non-high-density lipoprotein cholesterol (HDL-C) and/or apolipoprotein B(100)]. Another substantial lipid-related and modifiable RvR component is related to atherogenic dyslipidaemia, especially as global rates of obesity, type 2 diabetes and metabolic syndrome are increasing. Atherogenic dyslipidaemia is associated with insulin-stimulated very-low-density lipoprotein overproduction and reduced reverse cholesterol transport. The hallmark of atherogenic dyslipidaemia is the coexistence of low HDL-C and elevated triglycerides. Therapeutic lifestyle changes and combination lipid-lowering therapy with drugs targeting atherogenic dyslipidaemia (such as fibrates or innovative drugs targeting atherogenic dyslipidaemia and/or apolipoprotein B(100) metabolism) on top of background statins, have a potential to reduce RvR in high-risk groups, as shown in the Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial, in which combination therapy with simvastatin plus fenofibrate decreased macrovascular risk in patients with diabetes and atherogenic dyslipidaemia, and retinopathy risk irrespective of baseline lipids.

Waist circumference is positively correlated with markers of inflammation and negatively with adiponectin in women with metabolic syndrome

The purpose of this study was to correlate biomarkers of metabolic syndrome (MetS), with markers of inflammation and macronutrient intake in 89 women (25-72 years) with MetS. We hypothesized that waist circumference (WC) would have the stronger correlations with inflammatory parameters and would correlate with carbohydrate intake. Values for WC (108.7 ± 11.1 cm) and plasma triglycerides (202.7 ± 52.1 mg/dL) were elevated, whereas plasma glucose levels varied from 66 to 179 mg/dL, with 42% of women having insulin resistance. Plasma levels of interleukin 6 (0.2-15.9 mg/L), tumor necrosis factor α (1.47-12.3 mg/L), and high-sensitivity C-reactive protein (0.06-3.08 mg/dL) varied widely, with most women being above values considered normal. Subjects had high intake of total sugar (92.3 ± 56.4 g/d), high glycemic index (59.8 ± 6.5), and glycemic load (127.2 ± 56.1), whereas dietary fiber (17.1 ± 9.1 g/d) was below recommended intake. Waist circumference was positively correlated with insulin (r = 0.275, P < .01) and with the inflammatory markers interleukin 6 (r = 0.307, P < .01) and tumor necrosis factor α (r = 0.228, P < .05) and negatively correlated with plasma adiponectin (r = -0.309, P < .0001). In addition, WC was positively correlated with total carbohydrate, added sugar, and glycemic load (P < .05) but not with fat or protein. These results are consistent with central obesity being a key marker of the inflammatory state, and they also suggest that carbohydrates, particularly those that are digested rapidly, contribute to increased risk of central obesity and development of MetS.