Carbohydrate quality changes and concurrent changes in cardiovascular risk factors: a longitudinal analysis in the PREDIMED-Plus randomized trial.
The American journal of clinical nutrition. 2020;(2):291-306
BACKGROUND Overall quality of dietary carbohydrate intake rather than total carbohydrate intake may determine the risk of cardiovascular disease (CVD). OBJECTIVE We examined 6- and 12-mo changes in carbohydrate quality index (CQI) and concurrent changes in several CVD risk factors in a multicenter, randomized, primary-prevention trial (PREDIMED-Plus) based on an intensive weight-loss lifestyle intervention program. METHODS Prospective analysis of 5373 overweight/obese Spanish adults (aged 55-75 y) with metabolic syndrome (MetS). Dietary intake information obtained from a validated 143-item semiquantitative food-frequency questionnaire was used to calculate 6- and 12-mo changes in CQI (categorized in quintiles), based on 4 criteria (total dietary fiber intake, glycemic index, whole grain/total grain ratio, and solid carbohydrate/total carbohydrate ratio). The outcomes were changes in intermediate markers of CVD. RESULTS During the 12-mo follow-up, the majority of participants improved their CQI by increasing their consumption of fruits, vegetables, legumes, fish, and nuts and decreasing their consumption of refined cereals, added sugars, and sugar-sweetened beverages. After 6 mo, body weight, waist circumference (WC), systolic and diastolic blood pressure (BP), fasting blood glucose, glycated hemoglobin (HbA1c), triglyceride levels, triglycerides and glucose (TyG) index, and TyG-WC decreased across successive quintiles of improvement in the CQI. After 12 mo, improvements were additionally observed for HDL cholesterol and for the ratio of total to HDL cholesterol. Favorable improvements (expressed in common units of SD and 95% CI) for quintile 5 compared with quintile 1 of CQI change were observed for most risk factors, including TyG-WC (SD -0.20; 95% CI -0.26, -0.15), HbA1c (SD -0.16; 95% CI -0.23, -0.10), weight (SD -0.12; 95% CI -0.14, -0.09), systolic BP (SD -0.11; 95% CI -0.19, -0.02) and diastolic BP (SD -0.11; 95% CI -0.19, -0.04). CONCLUSIONS Improvements in CQI were strongly associated with concurrent favorable CVD risk factor changes maintained over time in overweight/obese adults with MetS. This trial was registered as ISRCTN 89898870.
Effects of Mediterranean Diet and Physical Activity on Pulmonary Function: A Cross-Sectional Analysis in the ILERVAS Project.
Plain language summary
The Mediterranean diet is characterised by an abundant consumption of extra-virgin olive oil, fruits, vegetables, nuts, and legumes, a moderate consumption of fish and seafood, poultry, fermented dairy products, and red wine with meals, and low intakes of sweetened beverages, red meat and ready meals. The aim of the study was to evaluate the association between adherence to a Mediterranean diet and physical activity on pulmonary function in a large middle-aged population at low-to-moderate cardiovascular risk. The study is an ongoing study that between 2015 and 2017 enrolled a total of 3020 subjects – women aged between 50 to 70 years and men aged between 45 to 65 years – with the presence of at least one cardiovascular risk factor. Results indicate that a low adherence to the Mediterranean diet was linked with impaired breathing patterns and higher prevalence of abnormal lung function when compared to participants with a higher adherence to this dietary pattern. Additionally, vigorous physical activity was accompanied by better results in lung function than that observed in inactive subjects. The study provides initial clinical evidence about the independent and deleterious effect of both low adherence to the Mediterranean diet and low physical activity practice on lung function in participants without known pulmonary disease.
undefined: A few studies showed that both adherence to Mediterranean diet (MedDiet) and physical activity practice have a positive impact on pulmonary function in subjects with lung disease. These associations are not well studied in subjects free from lung disease. In a cross-sectional study conducted in 3020 middle-aged subjects free of lung disease, adherence to the MedDiet using the Mediterranean Diet Adherence Screener, and physical activity practice using the International Physical Activity Questionnaire short form were recorded. Respiratory function was assessed using forced spirometry and the results were evaluated according to the Global initiative for Chronic Obstructive Lung Disease. Logistic regression models were used to analyze the associations between adherence to the MedDiet and physical activity practice with the presence of ventilatory defects. Participants with a high adherence to MedDiet, in comparison to those with low adherence, had both higher forced vital capacity (FVC; 100 (87⁻109) vs. 94 (82⁻105) % of predicted, = 0.003) and forced expired volume in the first second (FEV1; 100 (89⁻112) vs. 93 (80⁻107) % of predicted, < 0.001). According to their degree of physical activity, those subjects with a high adherence also had both higher FVC (100 (88⁻107) vs. 94 (83⁻105) % of predicted, = 0.027) and FEV1 (100 (89⁻110) vs. 95 (84⁻108) % of predicted, = 0.047) in comparison with those with low adherence. The multivariable logistic regression models showed a significant and independent association between both low adherence to MedDiet and low physical activity practice, and the presence of altered pulmonary patterns, with differences between men and women. However, no joint effect between adherence to MedDiet and physical activity practice on respiratory function values was observed. Low adherence to MedDiet and low physical activity practice were independently associated with pulmonary impairment. Therefore, the lung mechanics seem to benefit from heart-healthy lifestyle behaviors.
Dietary Glycemic Index and Load and the Risk of Type 2 Diabetes: Assessment of Causal Relations.
Plain language summary
It is generally accepted that certain diet and lifestyle choices contribute to a person’s risk of developing type 2 diabetes (T2D). In this meta-analysis, researchers set out to review previous studies and assess whether there is any evidence that the amount and type of carbohydrate (measured by Glycaemic Index (GI) and Glycaemic Load (GL)) in a person’s diet has a direct influence on their risk of developing T2D. The authors concluded with a high level of confidence that eating high GI and GL foods can lead to a higher risk of developing T2D. They suggest that nutrition advice that favours low GI and GL foods could produce significant cost savings for public healthcare.
While dietary factors are important modifiable risk factors for type 2 diabetes (T2D), the causal role of carbohydrate quality in nutrition remains controversial. Dietary glycemic index (GI) and glycemic load (GL) have been examined in relation to the risk of T2D in multiple prospective cohort studies. Previous meta-analyses indicate significant relations but consideration of causality has been minimal. Here, the results of our recent meta-analyses of prospective cohort studies of 4 to 26-y follow-up are interpreted in the context of the nine Bradford-Hill criteria for causality, that is: (1) Strength of Association, (2) Consistency, (3) Specificity, (4) Temporality, (5) Biological Gradient, (6) Plausibility, (7) Experimental evidence, (8) Analogy, and (9) Coherence. These criteria necessitated referral to a body of literature wider than prospective cohort studies alone, especially in criteria 6 to 9. In this analysis, all nine of the Hill's criteria were met for GI and GL indicating that we can be confident of a role for GI and GL as causal factors contributing to incident T2D. In addition, neither dietary fiber nor cereal fiber nor wholegrain were found to be reliable or effective surrogate measures of GI or GL. Finally, our cost-benefit analysis suggests food and nutrition advice favors lower GI or GL and would produce significant potential cost savings in national healthcare budgets. The high confidence in causal associations for incident T2D is sufficient to consider inclusion of GI and GL in food and nutrient-based recommendations.
Effect of Nut Consumption on Erectile and Sexual Function in Healthy Males: A Secondary Outcome Analysis of the FERTINUTS Randomized Controlled Trial.
Lifestyle risk factors for erectile and sexual function include smoking, excessive alcohol consumption, lack of physical activity, psychological stress, and adherence to unhealthy diets. In the present study, we evaluated the effects of mixed nuts supplementation on erectile and sexual function. Eighty-three healthy male aged 18-35 with erectile function assessment were included in this FERTINUTS study sub-analysis; a 14-week randomized, controlled, parallel feeding trial. Participants were allocated to (1) the usual Western-style diet enriched with 60 g/day of a mixture of nuts (nut group; n = 43), or (2) the usual Western-style diet avoiding nuts (control group; n = 40). At baseline and the end of the intervention, participants answered 15 questions contained in the validated International Index of Erectile Function (IIEF), and peripheral levels of nitric oxide (NO) and E-selectin were measured, as surrogated markers of erectile endothelial function. Anthropometrical characteristics, and seminogram and blood biochemical parameters did not differ between intervention groups at baseline. Compared to the control group, a significant increase in the orgasmic function (p-value = 0.037) and sexual desire (p-value = 0.040) was observed during the nut intervention. No significant differences in changes between groups were shown in peripheral concentrations of NO and E-selectin. Including nuts in a regular diet significantly improved auto-reported orgasmic function and sexual desire.
Effect of a Lifestyle Intervention Program With Energy-Restricted Mediterranean Diet and Exercise on Weight Loss and Cardiovascular Risk Factors: One-Year Results of the PREDIMED-Plus Trial.
Diabetes care. 2019;(5):777-788
OBJECTIVE The long-term impact of intentional weight loss on cardiovascular events remains unknown. We describe 12-month changes in body weight and cardiovascular risk factors in PREvención con DIeta MEDiterránea (PREDIMED)-Plus, a trial designed to evaluate the long-term effectiveness of an intensive weight loss lifestyle intervention on primary cardiovascular prevention. RESEARCH DESIGN AND METHODS Overweight/obese adults with metabolic syndrome aged 55-75 years (n = 626) were randomized to an intensive weight loss lifestyle intervention based on an energy-restricted Mediterranean diet, physical activity promotion, and behavioral support (IG) or a control group (CG). The primary and secondary outcomes were changes in weight and cardiovascular risk markers, respectively. RESULTS Diet and physical activity changes were in the expected direction, with significant improvements in IG versus CG. After 12 months, IG participants lost an average of 3.2 kg vs. 0.7 kg in the CG (P < 0.001), a mean difference of -2.5 kg (95% CI -3.1 to -1.9). Weight loss ≥5% occurred in 33.7% of IG participants compared with 11.9% in the CG (P < 0.001). Compared with the CG, cardiovascular risk factors, including waist circumference, fasting glucose, triglycerides, and HDL cholesterol, significantly improved in IG participants (P < 0.002). Reductions in insulin resistance, HbA1c, and circulating levels of leptin, interleukin-18, and MCP-1 were greater in IG than CG participants (P < 0.05). IG participants with prediabetes/diabetes significantly improved glycemic control and insulin sensitivity, along with triglycerides and HDL cholesterol levels compared with their CG counterparts. CONCLUSIONS PREDIMED-Plus intensive lifestyle intervention for 12 months was effective in decreasing adiposity and improving cardiovascular risk factors in overweight/obese older adults with metabolic syndrome, as well as in individuals with or at risk for diabetes.
Effect of a high-fat Mediterranean diet on bodyweight and waist circumference: a prespecified secondary outcomes analysis of the PREDIMED randomised controlled trial.
The lancet. Diabetes & endocrinology. 2019;(5):e6-e17
BACKGROUND Because of the high density of fat, high-fat diets are perceived as likely to lead to increased bodyweight, hence health-care providers are reluctant to recommend them to overweight or obese individuals. We assessed the long-term effects of ad libitum, high-fat, high-vegetable-fat Mediterranean diets on bodyweight and waist circumference in older people at risk of cardiovascular disease, most of whom were overweight or obese. METHODS PREDIMED was a 5 year parallel-group, multicentre, randomised, controlled clinical trial done in primary care centres affiliated to 11 hospitals in Spain. 7447 asymptomatic men (aged 55-80 years) and women (aged 60-80 years) who had type 2 diabetes or three or more cardiovascular risk factors were randomly assigned (1:1:1) with a computer-generated number sequence to one of three interventions: Mediterranean diet supplemented with extra-virgin olive oil (n=2543); Mediterranean diet supplemented with nuts (n=2454); or a control diet (advice to reduce dietary fat; n=2450). Energy restriction was not advised, nor was physical activity promoted. In 2016, we reported the 5 year changes in bodyweight and waist circumference, but because of a subsequently identified protocol deviation (including enrolment of household members without randomisation, assignment to a study group without randomisation of some participants at one of 11 study sites, and apparent inconsistent use of randomisation tables at another site; 866 [11·6%] participants were affected in total), we have withdrawn our previously published report and now report revised effect estimates based on reanalyses that do not rely exclusively on the assumption that all the participants were randomly assigned. In this analysis of the trial, we measured bodyweight and waist circumference at baseline and yearly for 5 years in the intention-to-treat population. The PREDIMED trial is registered with ISRCTN.com, number ISRCTN35739639. FINDINGS After a median 4·8 years (IQR 2·8-5·8) of follow-up, participants in all three groups had marginally reduced bodyweight and increased waist circumference. After multivariable adjustment, including adjustment for propensity scores and use of robust variance estimators, the difference in 5 year changes in bodyweight in the Mediterranean diet with olive oil group was -0·410 kg (95% CI -0·830 to 0·010; p=0·056) and in the nut group was -0·016 kg (-0·453 to 0·421; p=0·942), compared with the control group. The adjusted difference in 5 year changes in waist circumference was -0·466 cm (-1·109 to 0·176; p=0·154) in the Mediterranean diet with olive oil group and -0·923 cm (-1·604 to -0·241; p=0·008) in the nut group, compared with the control group. INTERPRETATION A long-term intervention with an unrestricted-calorie, high-vegetable-fat Mediterranean diet was associated with no significant difference in bodyweight and some evidence of less gain in central adiposity compared with a control diet. These results lend support to advice not restricting intake of healthy fats for bodyweight maintenance. FUNDING Spanish Government, CIBERobn, Instituto de Salud Carlos III, Hojiblanca, Patrimonio Comunal Olivarero, California Walnut Commission, Borges SA, and Morella Nuts.
Is reduction in appetite beneficial for body weight management in the context of overweight and obesity? Yes, according to the SATIN (Satiety Innovation) study.
Journal of nutritional science. 2019;:e39
New dietary-based concepts are needed for treatment and effective prevention of overweight and obesity. The primary objective was to investigate if reduction in appetite is associated with improved weight loss maintenance. This cohort study was nested within the European Commission project Satiety Innovation (SATIN). Participants achieving ≥8% weight loss during an initial 8-week low-energy formula diet were included in a 12-week randomised double-blind parallel weight loss maintenance intervention. The intervention included food products designed to reduce appetite or matching controls along with instructions to follow national dietary guidelines. Appetite was assessed by ad libitum energy intake and self-reported appetite evaluations using visual analogue scales during standardised appetite probe days. These were evaluated at the first day of the maintenance period compared with baseline (acute effects after a single exposure of intervention products) and post-maintenance compared with baseline (sustained effects after repeated exposures of intervention products) regardless of randomisation. A total of 181 participants (forty-seven men and 134 women) completed the study. Sustained reduction in 24-h energy intake was associated with improved weight loss maintenance (R 0·37; P = 0·001), whereas the association was not found acutely (P = 0·91). Suppression in self-reported appetite was associated with improved weight loss maintenance both acutely (R -0·32; P = 0·033) and sustained (R -0·33; P = 0·042). Reduction in appetite seems to be associated with improved body weight management, making appetite-reducing food products an interesting strategy for dietary-based concepts.
Multiple approaches to associations of physical activity and adherence to the Mediterranean diet with all-cause mortality in older adults: the PREvención con DIeta MEDiterránea study.
European journal of nutrition. 2019;(4):1569-1578
PURPOSE Although evidence indicates that both physical activity and adherence to the Mediterranean diet (MedDiet) reduce the risk of all-cause mortality, a little is known about optimal intensities of physical activity and their combined effect with MedDiet in older adults. We assessed the separate and combined associations of leisure-time physical activity (LTPA) and MedDiet adherence with all-cause mortality. METHODS We prospectively studied 7356 older adults (67 ± 6.2 years) at high vascular risk from the PREvención con DIeta MEDiterránea study. At baseline and yearly thereafter, adherence to the MedDiet and LTPA were measured using validated questionnaires. RESULTS After 6.8 years of follow-up, we documented 498 deaths. Adherence to the MedDiet and total, light, and moderate-to-vigorous LTPA were inversely associated with all-cause mortality (p < 0.01 for all) in multiple adjusted Cox regression models. The adjusted hazard of all-cause mortality was 73% lower (hazard ratio 0.27, 95% confidence interval 0.19-0.38, p < 0.001) for the combined category of highest adherence to the MedDiet (3rd tertile) and highest total LTPA (3rd tertile) compared to lowest adherence to the MedDiet (1st tertile) and lowest total LTPA (1st tertile). Reductions in mortality risk did not meaningfully differ between total, light intensity, and moderate-to-vigorous LTPA. CONCLUSIONS We found that higher levels of LTPA, regardless of intensity (total, light and moderate-to-vigorous), and greater adherence to the MedDiet were associated separately and jointly with lower all-cause mortality. The finding that light LTPA was inversely associated with mortality is relevant because this level of intensity is a feasible option for older adults.
Prevention of Type 2 Diabetes by Lifestyle Changes: A Systematic Review and Meta-Analysis.
Plain language summary
With Type 2 Diabetes growing globally this paper analyses whether T2D is preventable with lifestyle measures including diet. Seven RCTs were included for review with a total of 4090 participants, and 2466 incidents of T2D, and were chosen on the basis that the lifestyle interventions included both physical exercise and diet (typically Mediterranean Diet). They found that diet and lifestyle intervention reduced the risk of T2D by 47%. Sustained risk reduction was also found in follow-up studies up to 10 years later with participants maintaining improved blood glucose control. Lifestyle interventions may also reduce risk factors for cardiovascular disease. Weight reduction was considered a cornerstone of preventing T2D and adherence to lifestyle changes a key element in long term prevention. Dietary foods reviewed include processed meats, white rice and sugars which correlated highly with T2D whilst leafy greens, berries, wholegrains, legumes, dietary fibre and yoghurt correlate with a lower risk of T2D. Dietary patterns of skipping breakfast and snacking correlate higher with T2D. Different criteria for evaluating physical activity estimate that it reduces risk factors by 50%. In conclusion there is high evidence that lifestyle factors which optimise diet, increase physical activity and promote weight reduction are preventative factors for T2D and can be sustained long term.
Prevention of type 2 diabetes (T2D) is a great challenge worldwide. The aim of this evidence synthesis was to summarize the available evidence in order to update the European Association for the Study of Diabetes (EASD) clinical practice guidelines for nutrition therapy. We conducted a systematic review and, where appropriate, meta-analyses of randomized controlled trials (RCTs) carried out in people with impaired glucose tolerance (IGT) (six studies) or dysmetabolism (one study) to answer the following questions: What is the evidence that T2D is preventable by lifestyle changes? What is the optimal diet (with a particular focus on diet quality) for prevention, and does the prevention of T2D result in a lower risk of late complications of T2D? The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach was applied to assess the certainty of the trial evidence. Altogether seven RCTs (N = 4090) fulfilled the eligibility criteria and were included in the meta-analysis. The diagnosis of incident diabetes was based on an oral glucose tolerance test (OGTT). The overall risk reduction of T2D by the lifestyle interventions was 0.53 (95% CI 0.41; 0.67). Most of the trials aimed to reduce weight, increase physical activity, and apply a diet relatively low in saturated fat and high in fiber. The PREDIMED trial that did not meet eligibility criteria for inclusion in the meta-analysis was used in the final assessment of diet quality. We conclude that T2D is preventable by changing lifestyle and the risk reduction is sustained for many years after the active intervention (high certainty of evidence). Healthy dietary changes based on the current recommendations and the Mediterranean dietary pattern can be recommended for the long-term prevention of diabetes. There is limited or insufficient data to show that prevention of T2D by lifestyle changes results in a lower risk of cardiovascular and microvascular complications.
Total and Subtypes of Dietary Fat Intake and Its Association with Components of the Metabolic Syndrome in a Mediterranean Population at High Cardiovascular Risk.
Plain language summary
Obesity, Metabolic Syndrome (MetS) and Cardiovascular Disease (CVD) are becoming a global epidemic and the role of dietary fats is still unclear. The PREDIMED trial is a large study of 6560 Mediterranean men and women, aged 55–75 years old, with overweight/obesity and MetS in which they have tracked all types of dietary fat consumed over a 6-year period to assess the risk factors for CVD. Quality of fat is thought to play an important role in MetS. This study used food questionnaires to measure intake of the following fats: total fat, monounsaturated fatty acids: MUFA, polyunsaturated fatty acids: PUFA, saturated fatty acids: SFA, trans-fatty acids: trans-FA, linoleic acid, a-linolenic acid, and w-3 FA). They were able to divide the participants into groups ranging from highest to lowest fat intake and assess the types of foods and fats being consumed. They found that the group with the highest fat intakes ate less carbohydrates, protein and fibre and had a higher risk of hyperglycaemia (high blood glucose levels). The total fats consumed in this group also included high levels of harmful trans-fatty acids so the researchers concluded that the risk is influenced by the combination of nutrients of the food consumed. They also found that participants who consumed high levels of linoleic acid had significantly higher healthy HDL cholesterol levels and those who consumed high levels of saturated fatty acids and omega 3 had significantly less risk of high triglycerides (another cholesterol marker). Overall they recommend further studies into types of dietary fat to help reduce MetS in the population.
undefined: The effect of dietary fat intake on the metabolic syndrome (MetS) and in turn on cardiovascular disease (CVD) remains unclear in individuals at high CVD risk. To assess the association between fat intake and MetS components in an adult Mediterranean population at high CVD risk. Baseline assessment of nutritional adequacy in participants ( = 6560, men and women, 55-75 years old, with overweight/obesity and MetS) in the PREvención con DIeta MEDiterránea (PREDIMED)-Plus randomized trial. Assessment of fat intake (total fat, monounsatured fatty acids: MUFA, polyunsaturated fatty acids: PUFA, saturated fatty acids: SFA, trans-fatty acids: trans-FA, linoleic acid, α-linolenic acid, and ω-3 FA) using a validated food frequency questionnaire, and diet quality using 17-item Mediterranean dietary questionnaire and fat quality index (FQI). Participants in the highest quintile of total dietary fat intake showed lower intake of energy, carbohydrates, protein and fiber, but higher intake of PUFA, MUFA, SFA, TFA, LA, ALA and ω-3 FA. Differences in MetS components were found according to fat intake. Odds (5th vs. 1st quintile): hyperglycemia: 1.3-1.6 times higher for total fat, MUFA, SFA and ω-3 FA intake; low high-density lipoprotein cholesterol (HDL-c): 1.2 higher for LA; hypertriglyceridemia: 0.7 lower for SFA and ω-3 FA intake. Dietary fats played different role on MetS components of high CVD risk patients. Dietary fat intake was associated with higher risk of hyperglycemia.