Saturated Fat and Cardiometabolic Risk Factors,Coronary Heart Disease,Stroke, and Diabetes: a Fresh Look at the Evidence

Dietary and policy recommendations frequently focus on reducing saturated fatty acid consumption for improving cardiometabolic health, based largely on ecologic and animal studies. Recent advances in nutritional science now allow assessment of critical questions about health effects of saturated fatty acids (SFA). We reviewed the evidence from randomized controlled trials (RCTs) of lipid and non-lipid risk factors, prospective cohort studies of disease endpoints, and RCTs of disease endpoints for cardiometabolic effects of SFA consumption in humans, including whether effects vary depending on specific SFA chain-length; on the replacement nutrient; or on disease outcomes evaluated. Compared with carbohydrate, the TC:HDL-C ratio is nonsignificantly affected by consumption of myristic or palmitic acid, is nonsignificantly decreased by stearic acid, and is significantly decreased by lauric acid. However, insufficient evidence exists for different chain-length-specific effects on other risk pathways or, more importantly, disease endpoints. Based on consistent evidence from human studies, replacing SFA with polyunsaturated fat modestly lowers coronary heart disease risk, with ~10% risk reduction for a 5% energy substitution; whereas replacing SFA with carbohydrate has no benefit and replacing SFA with monounsaturated fat has uncertain effects. Evidence for the effects of SFA consumption on vascular function, insulin resistance, diabetes, and stroke is mixed, with many studies showing no clear effects, highlighting a need for further investigation of these endpoints. Public health emphasis on reducing SFA consumption without considering the replacement nutrient or, more importantly, the many other food-based risk factors for cardiometabolic disease is unlikely to produce substantial intended benefits.     

Recent Experimental Studies of Maternal Obesity,Diabetes during Pregnancy and the Developmental Origins of Cardiovascular Disease

Globally, cardiovascular disease remains the leading cause of death. Most concerning is the rise in cardiovascular risk factors including obesity, diabetes and hypertension among youth, which increases the likelihood of the development of earlier and more severe cardiovascular disease. While lifestyle factors are involved in these trends, an increasing body of evidence implicates environmental exposures in early life on health outcomes in adulthood. Maternal obesity and diabetes during pregnancy, which have increased dramatically in recent years, also have profound effects on fetal growth and development. Mounting evidence is emerging that maternal obesity and diabetes during pregnancy have lifelong effects on cardiovascular risk factors and heart disease development. However, the mechanisms responsible for these observations are unknown. In this review, we summarize the findings of recent experimental studies, showing that maternal obesity and diabetes during pregnancy affect energy metabolism and heart disease development in the offspring, with a focus on the mechanisms involved. We also evaluate early proof-of-concept studies for interventions that could mitigate maternal obesity and gestational diabetes-induced cardiovascular disease risk in the offspring.     

Estimation of the exposure of the French population to the BSE agent: comparison of the 1980-95 consumption of beef products containing mechanically recovered meat in France and the UK,by birth cohort and gender

Assuming that human exposure to BSE was through beef mechanically recovered meat (MRM) consumed as burgers and other meat products, we estimated the French consumption of different food items containing beef MRM, and compared these consumptions for French and British populations. To estimate consumption of meat products containing bovine MRM, we used dietary data from national individual and household food surveys conducted between 1980 and 1995. After reconciliation of consumption data between the available surveys and calendar year adjustments, we simulated consumption of one-thousandth of the French population. Consumption was estimated by birth cohort and gender, and for the periods 1980-89 and 1990-95 separately. Data showed that burgers (including manufactured minced meat) represented around 75-80% of the individual consumption of meat products containing MRM, and that consumption of burgers increased by 40% over the 1980-95 period. In all age groups, consumption was higher in males than in females. In both genders, the 1940-69 birth cohort had the highest mean consumption of burgers and other beef products containing MRM. Similar findings have been reported for the UK population. Estimated consumption of bovine MRM per calendar year increased markedly over the study period, concomitantly with an increase of bovine carcasses imported from the UK. Comparison of the 1980-1995 pattern of bovine MRM consumption in the UK and France indicated thatthis consumption peaked later in France than in the UK. This difference might result in different temporal pattern of vCJD incidence.     

In depth analysis of risk factors for coeliac disease amongst children under 18 years Old in the Gaza strip. A cross sectional study

Fish consumption and intake of omega-3 fatty acids from fish are associated with a lower risk of cardiovascular disease. However, a prospective study from northern Sweden showed that high consumption of fish is associated with an increased risk of stroke in men, but not in women. The current study aimed to determine if fish consumption is differently related to lifestyle in men compared with women in northern Sweden. Lifestyle information on 32,782 men and 34,866 women (aged 30–60 years) was collected between 1992 and 2006 within the Västerbotten Intervention Programme (a health intervention in northern Sweden). Spearman correlations coefficients (Rs) were calculated between self-reported consumption of fish and other food items. Lifestyle variables were compared between fish consumption categories. Fish consumption was positively associated with other foods considered healthy (e.g., root vegetables, lettuce/cabbage/spinach/broccoli, chicken, and berries; Rs = 0.21-0.30), as well as with other healthy lifestyle factors (e.g., exercise and not smoking) and a higher educational level, in both men and women. The only gender difference found, concerned the association between fish consumption and alcohol consumption. Men who were high consumers of fish had a higher intake of all types of alcohol compared with low to moderate fish consumers. For women, this was true only for wine. Except for alcohol, the association between fish consumption and healthy lifestyle did not differ between men and women in northern Sweden. It is important to adjust for other lifestyle variables and socioeconomic variables in studies concerning the effect of fish consumption on disease outcome.     

Causal assessment of dietary acid load and bone disease: a systematic review & meta-analysis applying Hill's epidemiologic criteria for causality

Background

Modern diets have been suggested to increase systemic acid load and net acid excretion. In response, alkaline diets and products are marketed to avoid or counteract this acid, help the body regulate its pH to prevent and cure disease. The objective of this systematic review was to evaluate causal relationships between dietary acid load and osteoporosis using Hill's criteria.

Methods

Systematic review and meta-analysis. We systematically searched published literature for randomized intervention trials, prospective cohort studies, and meta-analyses of the acid-ash or acid-base diet hypothesis with bone-related outcomes, in which the diet acid load was altered, or an alkaline diet or alkaline salts were provided, to healthy human adults. Cellular mechanism studies were also systematically examined.

Results

Fifty-five of 238 studies met the inclusion criteria: 22 randomized interventions, 2 meta-analyses, and 11 prospective observational studies of bone health outcomes including: urine calcium excretion, calcium balance or retention, changes of bone mineral density, or fractures, among healthy adults in which acid and/or alkaline intakes were manipulated or observed through foods or supplements; and 19 in vitro cell studies which examined the hypothesized mechanism. Urine calcium excretion rates were consistent with osteoporosis development; however calcium balance studies did not demonstrate loss of whole body calcium with higher net acid excretion. Several weaknesses regarding the acid-ash hypothesis were uncovered: No intervention studies provided direct evidence of osteoporosis progression (fragility fractures, or bone strength as measured using biopsy). The supporting prospective cohort studies were not controlled regarding important osteoporosis risk factors including: weight loss during follow-up, family history of osteoporosis, baseline bone mineral density, and estrogen status. No study revealed a biologic mechanism functioning at physiological pH. Finally, randomized studies did not provide evidence for an adverse role of phosphate, milk, and grain foods in osteoporosis.

Conclusions

A causal association between dietary acid load and osteoporotic bone disease is not supported by evidence and there is no evidence that an alkaline diet is protective of bone health.     

Obesity in Mexican school age children is associated with out of-home food consumption: in the journey from home to school

The objective of our study was to evaluate the association between consumption of food during the journey from home to school and back, with overweight and obesity, in a nationwide representative sample of school children. We assessed consumption outside the home in 9537 children, with information on availability and consumption of selected groups of food and beverages. Height, weight, total energy consumption, and sociodemographic variables were also obtained. We developed logistic regression models, and tested interactions with sociodemographic variables. The results of our study show that the prevalence of overweight and obesity was positively associated with dairy consumption in girls (OR:1.70; p = 0.01), as well as fried snacks consumption in school children living in Mexico City (OR: 1.68; p = 0.06). Consumption of fruits and vegetables in medium and high socioeconomic levels was negatively associated with the prevalence of overweight and obesity (OR: 0.54; p = 0.01 and 0.59; p = 0.07, respectively). We concluded that children during their stay away from home have a high availability of energy dense foods, which can influence their consumption and contribute to the development of overweight and obesity, so it is important to investigate this association in prospective studies.     

MAFLD and CKD: An Updated Narrative Review

Accumulating evidence now indicates that non-alcoholic fatty liver disease (NAFLD), which is the most common chronic liver disease observed in clinical practice worldwide, is independently associated with an increased risk of incident chronic kidney disease (CKD). Given that NAFLD is linked to insulin resistance, obesity and type 2 diabetes mellitus, an international panel of experts have recently proposed a name change from NAFLD to metabolic associated fatty liver disease (MAFLD). Since the diagnostic criteria for NAFLD and MAFLD are different, observational studies assessing the potential concordance (or even superiority) of MAFLD, compared with NAFLD, in detecting patients at increased risk of hepatic and extra-hepatic complications (including CKD) are required. Hence, in the last two years, some observational studies have investigated the potential relationship between MAFLD and CKD. The result is that, at present, evidence regarding the concordance or even superiority of MAFLD, compared with NAFLD, in detecting patients at higher risk of CKD is still preliminary, although some data indicate that MAFLD identifies patients with CKD as accurately as NAFLD. In this narrative review, we will discuss: (a) the epidemiological evidence assessing the association between NAFLD and risk of incident CKD, (b) the epidemiological data investigating the association between MAFLD and risk of CKD and (c) the biological mechanisms underlying the association between NAFLD/MAFLD and CKD.     

Olive oil consumption and reduced incidence of hypertension: The SUN study

Olive oil, a major component of the Mediterranean diet, has been associated in some small clinical trials and cross-sectional studies with a reduction in blood pressure. The objective of this study was to assess the association of olive oil consumption with the incidence of hypertension in an epidemiologic cohort, the Seguimiento Universidad de Navarra (SUN) study. The SUN Project is a prospective cohort study whose members are all university graduates. The recruitment and follow-up of participants is made using mailed questionnaires. Diet was assessed using a semiquantitative food frequency questionnaire previously validated in Spain, with 136 items. Outcomes of interest were newly diagnosed cases of hypertension, as reported by participants in the follow-up questionnaires. Logistic regression models were fit to assess the risk of hypertension associated with olive oil consumption. For the present analysis, we have taken in consideration the first 6,863 participants, with at least 2 yr of follow-up. After a median follow-up time of 28.5 mon, the cumulative incidence of hypereension was 4.7% in men and 1.7% in women. A lower risk of hypertension was observed among participants with a higher olive oil consumption at baseline, but the results were not statistically significant (P=0.13 for the linear trend test in the multivariate model). However, among men, the adjusted odds ratios (OR) (95% confidence intervals) of hypertension for the second to fifth quintiles of olive oil consumption, compared with the first quintile, were 0.55 (0.28–1.10), 0.75 (0.39–1.43), 0.32 (0.15–0.70), and 0.46 (0.23–0.94), respectively (P=0.02 for linear trend). No association was found between olive oil consumption and the risk of hypertension among women. In conclusion, in a Mediterranean population, we found olive oil consumption to be associated with a reduced risk of hypertension only among men. The lack of association observed among women might be attributed to the overall lower incidence of hypertension found among females and the resulting lower statistical power.     

Egg: concepts, analyses and controversies in the human health

Cholesterol rich-foods consumption has been related as a causing factor for heart ischemic disease. Because the high cholesterol content of the yolk, the egg consumption has been decreased in spite of it, egg is a complete food, rich in many nutrients, and economically accessible. The cholesterol content in egg yolk has also important properties for the human organism. The present work had the objective to review the scientific literature about egg's cholesterol, describing the possible consequences on the human health and wellbeing, its effect when they are enriched, and the chemical composition in relation to its lipidic profile. Information for this review was collected through national and international inquiries. According to this information, most of the studies on egg consumption are not related to the risk of cardiopathies in healthy people. Also, in people with diabetes mellitus, there is scarce evidence to drawn any conclusion about egg consumption and cardiopathies. Omega-3 egg enrichment presumably possesses a protective effect against cancer, despite its cholesterol content remains unaltered. Many of the Food Chemical Composition Tables contain different values on egg's fat composition, so it should be continuously update to reduce these discrepancies. Also, more studies on omega-3 enriched eggs are necessary for deeper conclusions on their cardio-protective effect.     

The role of consumption of alpha-linolenic, eicosapentaenoic and docosahexaenoic acids in human metabolic syndrome and type 2 diabetes--a mini-review

The human metabolic syndrome and its frequent sequela, type 2 diabetes are epidemic around the world. Alpha-linolenic acid (ALA, 18:3 n-3), eicosapentaenoic acid (EPA, 20:5 n-3) and docosahexaenoic acid (DHA, 22:6 n-3) consumption ameliorates some of these epidemics' features thus leading one to question if consumption of EPA and DHA, and their metabolic precursor ALA reduce the conversion of metabolic syndrome to type 2 diabetes and reduce the major cause of death in the metabolic syndrome and type 2 diabetes-myocardial infarction. Contributing to myocardial infarction are metabolic syndrome's features of dyslipidemia (including elevated total cholesterol and LDL-c), oxidation, inflammation, hypertension, glucose intolerance, overweight and obesity. Inflammation, glucose and lipid levels are variously influenced by disturbances in various adipocytokines which are in turn positively impacted by n-3 polyunsaturated fatty acid consumption. Type 2 diabetes has all these features though elevated total cholesterol and LDL-c are rarer. It is concluded that EPA and DHA consumption significantly benefits metabolic syndrome and type 2 diabetes primarily in terms of dyslipidemia (particularly hypertriglyceridemia) and platelet aggregation with their impact on blood pressure, glucose control, inflammation and oxidation being less established. There is some evidence that EPA and/or DHA consumption, but no published evidence that ALA reduces conversion of metabolic syndrome to type 2 diabetes and reduces death rates due to metabolic syndrome and type 2 diabetes. ALA's only published significance appears to be platelet aggregation reduction in type 2 diabetes.     

Using multiple household food inventories to measure food availability in the home over 30 days: a pilot study

Background  

The consumption of foods, especially by children, may be determined by the types of foods that are available in the home. Because most studies use a single point of data collection to determine the types of foods in the home, which can miss the change in availability when resources are not available, the primary objective of this study was to determine the extent to which the weekly availability of household food items changed over one month by 1) developing the methodology for the direct observation of the presence and amount of food items in the home; 2) conducting five in-home household food inventories over a thirty-day period in a small convenience sample; and 3) determining the frequency that food items were present in the participating households.     

Fats for the food industry: Implications for cholesterol-lowering

The special needs of the food industry may not always coincide with what is healthiest for consumers. People always demand optimal taste, flavor and texture; they expect shelf-stability, convenience and novelty. The edible oils and fat industry has been particularly vulnerable in this regard but has tried, often very successfully, to modify its products to take into account the customer's preferences and their health. The following review illustrates some potential strategies in the retail and commercial sectors, especially in baking, frying and food service areas. Given the large increase in the consumption of convenient, small portion meals, the fat content and composition of such meals and products will critically influence further outcomes in areas related to cardiovascular disease, cancer, obesity and diabetes.     

Bacteria of Lactobacillus casei group: characterization, viability as probiotic in food products and their importance for human health

Lactobacillus casei is a group of phenotypically and genetically heterogeneous lactic acid bacteria, able to colonize various natural and man-made environments. Strains of the Lactobacillus casei group have been widely studied with respect to their health-promoting properties. Several beneficial functions for the human organism have been attributed to regular consumption of food products containing these strains. Bacteria of the Lactobacillus casei group are of great interest for the food industry to improve food quality. A number of studies have been conducted in order to evaluate the viability of strains of Lactobacillus casei group as probiotic in dairy products, desserts, among others food products. Despite its importance for the food industry, the taxonomy of the Lactobacillus casei group is still unclear. This review discusses important studies related to characterization of strains of Lactobacillus casei group, the application of these bacteria as probiotic in different food products and the main beneficial effects attributed to regular consumption of products containing such microorganisms.     

The Distribution of Fatty Acid Biomarkers of Dairy Intake across Serum Lipid Fractions: The Prospective Metabolism and Islet Cell Evaluation (PROMISE) Cohort

Circulating fatty acids (FA) derived largely from dairy consumption have most commonly been measured in total human serum or phospholipid (PL) fractions, and have been used as validated biomarkers of dairy intake in a growing number of epidemiological studies. Nevertheless, measurement and characterization of a wider spectrum of FA biomarkers of dairy across the four major serum lipid fractions is lacking. This study aimed to (1) quantify FA biomarkers of dairy in PL, triacylglycerol (TAG), cholesteryl ester (CE), and unesterified fatty acid (FFA) serum lipid fractions; and (2) identify potential demographic and metabolic factors that may modify the proportions of these FA across serum fractions. Baseline data from 444 adults in the PROMISE cohort were analyzed. FA biomarkers, 15:0, t16:1n-7, 18:2-c9,t11, and t18:1n-7 were quantified from serum. Dairy intake was estimated using the validated Canadian Diet History Questionnaire. Our results show that t18:1n-7 was the most abundant FA biomarker in all fractions except CE, where 18:2-c9,t11 was the most abundant. Positive correlations within fractions, and across FA in the PL, CE, and FFA fractions were found, however, TAG FA were negatively correlated with the other fractions. PL and CE FA were positively associated with dairy intake, and negatively associated with markers of dysmetabolism while, in contrast, these markers were predictors of higher TAG dairy FA. This study is the first to demonstrate distinct proportions of dairy FA in different serum lipid fractions. PL and CE FA marked dairy intake in this cohort, while TAG FA appeared to be markers of dysmetabolism.     

The Endocannabinoid System and Physical Activity—A Robust Duo in the Novel Therapeutic Approach against Metabolic Disorders

Rapidly increasing worldwide prevalence of obesity and related pathologies encompassing coronary heart disease, hypertension, metabolic syndrome, or type 2 diabetes constitute serious threats to global health and are associated with a significantly elevated risk of premature death. Considering the enormous burden of these pathologies, novel therapeutic and preventive patterns are indispensable. Dysregulation of one of the most complex biological systems in the human body namely, the endocannabinoid system (ECS) may result in metabolic imbalance and development of insulin resistance, type 2 diabetes, or non-alcoholic fatty liver disease. Furthermore, many studies showed that physical exercises, depending on their type, intensity, and frequency, exert various alterations within the ECS. Emerging evidence suggests that targeting the ECS via physical activity may produce robust beneficial effects on the course of metabolic pathologies. However, the data showing a direct correlation between the ECS and physical activity in the aspect of metabolic health are very scarce. Therefore, the aim of this review was to provide the most up-to-date state of knowledge about the interplay between the ECS activity and physical exercises in the novel therapeutic and preventive approach toward metabolic pathologies. We believe that this paper, at least in part, will fulfill the existing gap in knowledge and encourage researchers to further explore this very complex yet interesting link between the ECS, its action in physical activity, and subsequent positive outcomes for metabolic health.     

How good is the evidence for the lipid hypothesis?

The evidence for the lipid hypothesis is weak. After 20 years of follow‐up, the Nurses Health Study, a prospective cohort study, was no longer able to demonstrate an association between intakes of saturated fat and risk of developing coronary heart disease. Randomised controlled trials with statins have shown that lowering LDL‐cholesterol levels by 23% can reduce the risk of developing cardiovascular disease but reducing saturated fat can only reduce cholesterol levels by 10%. This issue can only be resolved by carrying out randomised controlled dietary trials with CVD endpoints. Although there are scientific difficulties standing in the way of such trials, it is the opinion of this author that these can be overcome. Whether there is the political will to fund them is another matter although some of the money currently spent on prospective cohort studies would be far better spent on randomised controlled trials.     

Review of analytical methods for prospective cohort studies using time to event data: single studies and implications for meta-analysis

Prospective cohort studies are extremely important in epidemiological research as they give direct information on the sequence of events, which can be used to demonstrate causality. They also have the advantage that many diseases can be studied simultaneously. However, they are usually very time consuming and expensive to run. In addition, practitioners of evidence-based medicine prefer to make decisions based on several studies rather than a single study, hence the need for meta-analysis. The use of meta-analyses in order to synthesize the evidence from randomized controlled trials is extremely popular in medicine and is also being utilized increasingly in epidemiology. The statistical methodology for meta-analyses of epidemiological studies is a long way behind in terms of the advances made in the methodology for randomized controlled trials. Numerous methodological issues, particularly in respect to dealing with biases inherent in these types of studies, have made the results of meta-analyses of epidemiological studies that use summary data open to criticism. This review mainly concentrates on analytical methods for prospective cohort studies that have survival outcomes. In addition, the implications for meta-analysis assuming that the analyst has access to individual participant data are also discussed. The approaches are described with respect to underlying theory and assumptions. It is hoped that this review will promote the use of these approaches in meta-analyses conducted in epidemiology as well as providing some directions for future research.     

Granulocytes and Cells of Granulocyte Origin—The Relevant Players in Colorectal Cancer

Colorectal cancer (CRC) is one of the most common malignancy and cause of cancer death worldwide, and it still remains a therapeutic challenge for western medicine. There is strong evidence that, in addition to genetic predispositions, environmental factors have also a substantial impact in CRC development. The risk of CRC is attributed, among others to dietary habits, alcohol consumption, whereas physical activity, food containing dietary fiber, dairy products, and calcium supplements have a protective effect. Despite progress in the available therapies, surgery remains a basic treatment option for CRC. Implementation of additional methods of treatment such as chemo- and/or targeted immunotherapy, improved survival rates, however, the results are still far from satisfactory. One of the reasons may be the lack of deeper understanding of the interactions between the tumor and different types of cells, including tumor infiltrating granulocytes. While the role of neutrophils is quite well explored in many cancers, role of eosinophils and basophils is often underestimated. As part of this review, we focused on the function of different granulocyte subsets in CRC, emphasizing the beneficial role of eosinophils and basophils, as well as dichotomic mode of neutrophils action. In addition, we addressed the current knowledge on cells of granulocyte origin, specifically granulocytic myeloid derived suppressor cells (Gr-MDSCs) and their role in development and progression of CRC.     

Sedentary lifestyle and risk of obesity and type 2 diabetes

Obesity and type 2 diabetes have reached epidemic proportions in the United States. It is well-established that increasing physical activity plays an important role in reducing rick of obesity and diabetes. Few studies, however, have examined the association between sedentary behaviors such as prolonged television (TV) watching and obesity and diabetes. Using data from a large prospective cohort study, the Health Professionals’ Follow-up Study, we have demonstrated that increasing TV watching is strongly associated with obesity and weight gain, independent of diet and exercise. Also, prolonged TV watching is associated with a significantly increased risk of type 2 diabetes. Men who watched TV more than 40 h per week had a nearly threefold increase in the risk of type 2 diabetes compared with those who spent less than 1 h per week watching TV. The increased risk was not entirely explained by the decreased physical activity and unhealthy eating patterns associated with TV watching. Thus, public health campaigns to reduce the risk of obesity and type 2 diabetes should promote not only increasing exercise levels but also decreasing sedentary behaviors, especially prolonged TV watching.     

Evaluation of the diet of women attended by the Chilean Public Health System

The purpose of this study was to assess the diet quality of women from the Chilean Public Health System, through the Healthy Eating Index (HEI). It was studied a stratified sample of 258 women. The mean HEI score was 69.06 +/- 10.44, classifying the food with "needs improvement", less than 70 percent of compliance of specific recommendations. Variables with lower score were vegetables and simple sugars. The HEI showed no differences between social strata, while the findings showed differences between some components. Adolescent achieved the goals of consumption of cereals, vegetables and meat. Less educated women consumed more cereals and dairy products. The poorest women had better score of Sodium and rural women in dairy and sodium. No association was found between nutritional status and HEI. The protective factor for the food quality was the number of health controls during pregnancy. The findings showed that high proportion of women needs changes in her food habits. The HEI can be used for population studies and is effective to assess the effectiveness of policies and health promotion programs. It can help focalize to educational programs to specific goals.