Simple sugar intake and cancer incidence, cancer mortality and all-cause mortality: A cohort study from the PREDIMED trial

OBJECTIVE

To examine associations between intake of simple sugars and cancer incidence, cancer mortality, and total mortality in a prospective cohort study based on the PREDIMED trial conducted from 2003 to 2010.

METHODS

Participants were older individuals at high cardiovascular risk. Exposures were total sugar, glucose and fructose from solid or liquid sources, and fructose from fruit and 100% fruit juice. Cancer incidence was the primary outcome; cancer mortality and all-cause mortality were secondary outcomes. Multivariable-adjusted, time-dependent Cox proportional hazard models were used.

RESULTS

Of 7447 individuals enrolled, 7056 (94.7%) were included (57.6% women, aged 67.0 ± 6.2 years). 534 incident cancers with 152 cancer deaths and 409 all-cause deaths were recorded after a median follow-up of 6 years. Intake of simple sugars in solid form was unrelated to outcomes. Higher cancer incidence was found per 5 g/day increase in intake of liquid sugars, with multivariable-adjusted HR of 1.08 (95% CI, 1.03-1.13) for total liquid sugar, 1.19 (95% CI, 1.07-1.31) for liquid glucose, 1.14 (95% CI, 1.05-1.23) for liquid fructose, and 1.39 (95% CI, 1.10-1.74) for fructose from fruit juice. Cancer and all-cause mortality increased to a similar extent with intake of all sugars in liquid form. In categorical models, cancer risk was dose-related for all liquid sugars.

CONCLUSIONS

Simple sugar intake in drinks and fruit juice was associated with an increased risk of overall cancer incidence and mortality and all-cause mortality. This suggests that sugary beverages are a modifiable risk factor for cancer and all-cause mortality.

Adherence to an Energy-restricted Mediterranean Diet Score and Prevalence of Cardiovascular Risk Factors in the PREDIMED-Plus: A Cross-sectional Study

INTRODUCTION AND OBJECTIVES

The cardiovascular benefits of the Mediterranean diet have usually been assessed under assumptions of ad libitum total energy intake (ie, no energy restriction). In the recently launched PREDIMED-Plus, we conducted exploratory analyses to study the baseline associations between adherence to an energy-restricted Mediterranean diet (MedDiet) and the prevalence of cardiovascular risk factors (CVRF).

METHODS

Cross-sectional assessment of all PREDIMED-Plus participants (6874 older adults with overweight/obesity and metabolic syndrome) at baseline. The participants were assessed by their usual primary care physicians to ascertain the prevalence of 4 CVRF (hypertension, obesity, diabetes, and dyslipidemia). A 17-point PREDIMED-Plus score was used to measure adherence to the MedDiet. Multivariable models were fitted to estimate differences in means and prevalence ratios for individual and clustered CVRF.

RESULTS

Better adherence to a MedDiet pattern was significantly associated with lower average triglyceride levels, body mass index, and waist circumference. Compared with low adherence (≤ 7 points in the 17-point score), better adherence to the MedDiet (11-17 points) showed inverse associations with hypertension (prevalence ratio=0.97; 95%CI, 0.94-1.00) and obesity (prevalence ratio=0.96; 95%CI, 0.92-1.00), but positive associations with diabetes (prevalence ratio=1.19; 95%CI, 1.07-1.32). Compared with the lowest third of adherence, women in the upper third showed a significantly lower prevalence of the clustering of 3 or more CVRF (prevalence ratio=0.91; 95%CI, 0.83-0.98).

CONCLUSIONS

Among participants at high cardiovascular risk, better adherence to a MedDiet showed significant inverse associations with CVRF among women, and improved lipid profiles and adiposity measures. This trial was registered in 2014 at the International Standard Randomized Controlled Trial Registry (ISRCTN89898870).

Predictors of short- and long-term adherence with a Mediterranean-type diet intervention: the PREDIMED randomized trial

Background

Dietary intervention success requires strong participant adherence, but very few studies have examined factors related to both short-term and long-term adherence. A better understanding of predictors of adherence is necessary to improve the design and execution of dietary intervention trials. This study was designed to identify participant characteristics at baseline and study features that predict short-term and long-term adherence with interventions promoting the Mediterranean-type diet (MedDiet) in the PREvención con DIeta MEDiterránea (PREDIMED) randomized trial.

Methods

Analyses included men and women living in Spain aged 55–80 at high risk for cardiovascular disease. Participants were randomized to the MedDiet supplemented with either complementary extra-virgin olive oil (EVOO) or tree nuts. The control group and participants with insufficient information on adherence were excluded. PREDIMED began in 2003 and ended in 2010. Investigators assessed covariates at baseline and dietary information was updated yearly throughout follow-up. Adherence was measured with a validated 14-point Mediterranean-type diet adherence score. Logistic regression was used to examine associations between baseline characteristics and adherence at one and four years of follow-up.

Results

Participants were randomized to the MedDiet supplemented with EVOO (n = 2,543; 1,962 after exclusions) or tree nuts (n = 2,454; 2,236 after exclusions). A higher number of cardiovascular risk factors, larger waist circumference, lower physical activity levels, lower total energy intake, poorer baseline adherence to the 14-point adherence score, and allocation to MedDiet + EVOO each independently predicted poorer adherence. Participants from PREDIMED recruiting centers with a higher total workload (measured as total number of persons-years of follow-up) achieved better adherence. No adverse events or side effects were reported.

Conclusions

To maximize dietary adherence in dietary interventions, additional efforts to promote adherence should be used for participants with lower baseline adherence to the intended diet and poorer health status. The design of multicenter nutrition trials should prioritize few large centers with more participants in each, rather than many small centers.

Trial registration

This study was registered at controlled-trials.com (http://www.controlled-trials. com/ISRCTN35739639). International Standard Randomized Controlled Trial Number (ISRCTN): 35739639. Registration date: 5 October 2005.

Trial design: parallel randomized trial.

Electronic supplementary material

The online version of this article (doi:10.1186/s12966-016-0394-6) contains supplementary material, which is available to authorized users.

Nutritional adequacy according to carbohydrates and fat quality

PURPOSE

To investigate the association between carbohydrate quality, fat quality or adherence to the Mediterranean diet and intake adequacy of 19 micronutrients in the PREDIMED (PREvención con DIeta MEDiterránea) trial, a multicenter, randomized, controlled, parallel group and primary prevention trial conducted in Spain.

METHODS

We assessed baseline dietary intake of 6,542 elderly subjects at high cardiovascular risk through a validated food frequency questionnaire (FFQ) and a validated 14-item Mediterranean diet (Med-diet) score. We used a multidimensional carbohydrate quality index (CQI) using four criteria and a fat quality index (FQI) according to the ratio (MUFA + PUFA)/(SFA + TFA). The probability of intake adequacy was calculated comparing the intakes to DRI, and also using the probabilistic approach. Absolute and adjusted probability of having inadequate intake for either ≥6 DRI or ≥8 DRI were estimated to assess nutritional adequacy according to quintiles of each index.

RESULTS

The lowest prevalence of inadequate micronutrient intake (≥8 DRI) was found in the highest quintile of CQI or Med-diet score, and in the lowest quintile of FQI (adjusted fold risk: 1.4, 3.4 and 10.2 respectively in comparison with the lowest quintile). P for trend <0.001 in three multivariable models. A higher CQI or Med-Diet score and a lower FQI were significantly associated with a lower fold risk of unmet EAR values.

CONCLUSIONS

A multidimensional assessment of CQI can be a useful tool to evaluate the quality of carbohydrates. This score and a 14-item Med-diet score were positively related to overall micronutrient adequacy in elderly participants.

[Eating habits and attitudes towards change in Spanish university students and workers]

INTRODUCTION

Universities and workplaces are important targets for the promotion of the nutritional interventions in adult population.

OBJECTIVES

The aim of this study was to assess the dietary habits and attitudes towards change in workers and university students from different academic fields.

METHODS

The study data came from a cross-sectional study of a Spanish University population of 1,429 participants. We analyzed the dietary habits and the attitudes toward dietary change.

RESULTS

The mean age of workers and students was 37 and 23 years, respectively. Both groups reported eating four meals per day. Among students, the consumption of vegetables, wine, fish and nuts was less frequent whereas carbonated beverages, commercial bakery, fast food and red meat was higher. On the other hand, overall dietary pattern of science students was healthier than other students. Although no significant differences were found between students and workers in attitudes towards change, 32% of employees and 39% of students said they were seriously considering changing them.

CONCLUSIONS

The dietary pattern was healthier among workers than among students, particularly those participants that studied social sciences degrees. They constituted the most vulnerable segment of the university population from a nutritional point of view. About a third of workers and students considered changing their habits.

Empirically-derived food patterns and the risk of total mortality and cardiovascular events in the PREDIMED study

BACKGROUND & AIMS

There is little evidence on post hoc-derived dietary patterns (DP) and all-cause mortality in Southern-European populations. Furthermore, the potential effect modification of a DP by a nutritional intervention has not been sufficiently assessed. We assessed the association between a posteriori defined baseline major DP and total mortality or cardiovascular events within each of the three arms of a large primary prevention trial (PREDIMED) where participants were randomized to two active interventions with Mediterranean-type diets or to a control group (allocated to a low-fat diet).

DESIGN

We followed-up 7216 participants for a median of 4.3 years. A validated 137-item food-frequency questionnaire was administered. Baseline DP were ascertained through factor analysis based on 34 predefined groups. Cox regression models were used to estimate multivariable-adjusted hazard ratios (HR) for cardiovascular disease (CVD) or mortality across quartiles of DP within each of the three arms of the trial.

RESULTS

We identified two major baseline DP: the first DP was rich in red and processed meats, alcohol, refined grains and whole dairy products and was labeled Western dietary pattern (WDP). The second DP corresponded to a "Mediterranean-type" dietary pattern (MDP). During follow-up, 328 participants died. After controlling for potential confounders, higher baseline adherence to the MDP was associated with lower risk of CVD (adjusted HR for fourth vs. first quartile: 0.52; 95% CI (Confidence Interval): 0.36, 0.74; p-trend <0.001) and all-cause mortality (adjusted HR: 0.53; 95% CI: 0.38, 0.75; p-trend <0.001), regardless of the allocated arm of the trial. An increasing mortality rate was found across increasing quartiles of the WDP in the control group (allocated to a low-fat diet), though the linear trend was not statistically significant (p = 0.098).

CONCLUSIONS

Higher adherence to an empirically-derived MDP at baseline was associated with a reduced risk of CVD and mortality in the PREDIMED trial regardless of the allocated arm. The WDP was not associated with higher risk of mortality or cardiovascular events.

A provegetarian food pattern and reduction in total mortality in the Prevención con Dieta Mediterránea (PREDIMED) study

BACKGROUND

Vegetarian diets have been associated with reduced mortality. Because a pure vegetarian diet might not easily be embraced by many individuals, consuming preferentially plant-derived foods would be a more easily understood message. A provegetarian food pattern (FP) emphasizing preference for plant-derived foods might reduce all-cause mortality.

OBJECTIVE

The objective was to identify the association between an a priori-defined provegetarian FP and all-cause mortality.

DESIGN

We followed 7216 participants (57% women; mean age: 67 y) at high cardiovascular risk for a median of 4.8 y. A validated 137-item semiquantitative food-frequency questionnaire was administered at baseline and yearly thereafter. Fruit, vegetables, nuts, cereals, legumes, olive oil, and potatoes were positively weighted. Added animal fats, eggs, fish, dairy products, and meats or meat products were negatively weighted. Energy-adjusted quintiles were used to assign points to build the provegetarian FP (range: 12-60 points). Deaths were confirmed by review of medical records and the National Death Index.

RESULTS

There were 323 deaths during the follow-up period (76 from cardiovascular causes, 130 from cancer, 117 for noncancer, noncardiovascular causes). Higher baseline conformity with the provegetarian FP was associated with lower mortality (multivariable-adjusted HR for ≥ 40 compared with <30 points: 0.59; 95% CI: 0.40, 0.88). Similar results were found with the use of updated information on diet (RR: 0.59; 95% CI: 0.39, 0.89).

CONCLUSIONS

Among omnivorous subjects at high cardiovascular risk, better conformity with an FP that emphasized plant-derived foods was associated with a reduced risk of all-cause mortality. This trial was registered at www.controlled-trials.com as ISRCTN35739639.