Association between diet quality and all-cause mortality in a large Dutch cohort.

Food-based dietary guidelines are helpful for governments and health agencies to encourage healthy eating at the population level. In order to assess adherence to such guidelines, index scores have been developed, the version in the Netherlands being the Dutch Healthy Diet-index (2015) (DHD2015-index), which reflect adherence to the 2015 Dutch dietary guidelines. Because a higher diet quality, i.e. a higher adherence to the dietary guidelines, is associated with better health outcomes, a higher DHD2015-index score would also mean better outcomes on measures of health, such as all-cause mortality. The present study aimed to elucidate this by investigating the association between DHD2015-index score and mortality in the Dutch population using data from 97 999 participants in the Lifelines cohort study. For the analyses, Cox Proportional Hazards regression was used, whilst accounting for age, sex, physiological measurements, exercise, and biochemical and lifestyle variables. There was a strong negative association between DHD2015-index score and mortality. Hazard ratios for DHD2015-index scores below 60 were approximately 1.2x larger than the mean. Every 10 unit increase in DHD2015-index scores between 60 and 90 led to a 0.1 reduction in hazard ratio, and every 10 unit increase between 90 and the highest DHD2015-index scores led to a reduction in hazard ratios of 0.05. The hazard ratio for the lowest quartile of DHD2015-index scores was 1.14 (95% CI = 1.04-1.26), whereas that for the highest quartile was 0.88 (95% CI = 0.84-0.92). Our results show a clear inverse relationship between DHD2015-index score and all-cause mortality.

The impact of running on gastrointestinal symptoms in patients with irritable bowel syndrome.

INTRODUCTION: Physical activity has been suggested to alleviate gastrointestinal (GI) symptoms in patients with irritable bowel syndrome (IBS); however, evidence is scarce. Running has become increasingly popular and may be beneficial for patients with IBS. To obtain more insight in the potential application of running as therapy, we aimed to explore the impact of running and its intensity on GI symptoms in patients with IBS. METHODS: Data from a large observational study in runners were used for this nested case-control study, which included 153 runners with IBS and 153 controls. All participants had completed a questionnaire on personal characteristics, running characteristics and GI symptoms. Regarding GI symptoms, the severity of nine symptoms was asked, both at rest and during and/or shortly (up to 3 h) after running. Each symptom could be scored on a scale from 0 (not bothersome) to 100 (very bothersome), resulting in a maximum total score of 900 points. KEY RESULTS: The prevalence and total severity score of GI symptoms were higher in runners with IBS than in controls, both at rest and during running. Among runners with IBS, the median (25th-75th percentile) total severity score during/after running was significantly lower than at rest (118 [50-200] vs. 150 [90-217]), while in controls no significant difference between running and rest was observed. Analyses stratified for running intensity revealed that the beneficial effect in runners with IBS was present when their most intensive training session was moderately intensive or intensive but not very intensive. CONCLUSIONS & INFERENCES: Running, particularly on moderate intensity, could have a beneficial effect on GI symptoms in patients with IBS.

Assessment of the Dutch Healthy Diet index 2015 in the Lifelines cohort study at baseline.

BACKGROUND: Dietary indices are useful measures to investigate associations between dietary intake and disease development. The Dutch Healthy Diet index 2015 (DHD2015-index), a measure of diet quality, assesses adherence to the 2015 Dutch dietary guidelines. We assessed the DHD2015-index in the Lifelines cohort study, and compared calculations from basic and detailed dietary intake data. This article replaces the retracted article that was published on 16 May 2022 [1]. METHODS: Dietary intake was assessed with a specially developed Food Frequency Questionnaire (FFQ) called Flower-FFQ, which consists of one main questionnaire (heart-FFQ), which asks for intakes of major food groups, and three complementary questionnaires (petal-FFQs), which ask for detailed information on food types within major food groups of the heart-FFQ. The DHD2015-index was assessed using data from the total Flower-FFQ (for 56,982 participants), and using data from the heart-FFQ only (for 129,030 participants). Agreement between the two indices was assessed with correlation and cross-classification. RESULTS: The median (25th-75th percentile) DHD2015-index score was 75 (65-85) for men and 81 (70-91) for women based on the Flower-FFQ, and 68 (58-77) for men and 73 (63-82) for women based on the heart-FFQ. The Kendall's tau-b correlation coefficient between the two scores was 0.67 for men and 0.66 for women. Cross-classification into quartiles of the DHD2015-index showed that 59-60% of participants were classified in the same quartile, 36-37% in the adjacent, and 4% in the non-adjacent. CONCLUSION: Dietary data from the Flower-FFQ provide the most optimal information to assess the DHD2015-index. However, the DHD2015-index from the heart-FFQ showed good agreement with the index from the Flower-FFQ of ranking participants according to diet quality, and can be used when the DHD2015 index from the Flower-FFQ is not available.

Efficacy and utility of a tool for both measurement of vitamin B6, B12, D, folate and iron status and assessment of diet quality in athletes.

NutriProfiel® is a tool to measure micronutrient status and to assess diet quality. It consists of measurement of micronutrient status in blood and a short food frequency questionnaire (FFQ) ('Eetscore-FFQ'). Based on the results, individuals receive a dietary advice. In this study, we evaluated the application of NutriProfiel in athletes ('NutriProfiel-Sport') by assessing the coverage of nutrient intake of the Eetscore-FFQ (part 1) and by evaluating athlete's dietary behaviour after using NutriProfiel-Sport and their satisfaction with this tool (part 2). For part 1, data of 419 athletes were used. We evaluated the coverage of nutrient intake of the Eetscore-FFQ using first and second MOMents (MOM1 and MOM2) sum scores of food items in the questionnaire. Forty-eight athletes were involved in part 2. They gave blood samples for micronutrient status measurement and were asked to complete the Eetscore-FFQ at baseline and after 3 months, as well as a questionnaire on their satisfaction with NutriProfiel-Sport. Results showed that for most nutrients, MOM1 and MOM2 scores were above 80 %, meaning that nutrient intake was sufficiently covered by the Eetscore-FFQ. No difference in diet quality was observed between baseline and after 3 months. Nevertheless, a majority of athletes reported the NutriProfiel-Sport results and advice as useful. On a scale from 0 to 10, NutriProfiel-Sport was graded with a mean (±sd) score of 7⋅6 (±0⋅8). In conclusion, NutriProfiel-Sport is a potential valuable and appreciated tool for athletes and the Eetscore-FFQ as part of this tool sufficiently covers nutrient intake in athletes.

Exercise-related abdominal complaints in a large cohort of runners: a survey with a particular focus on nutrition.

Objectives: Abdominal complaints (AC) during exercise are a common problem in runners. Nutrition is known to play a role in exercise-related AC, but information on the role of habitual dietary intake is limited. We assessed the prevalence of AC in a large cohort of runners, and investigated its association with potential risk factors, with a particular focus on nutritional factors in the habitual diet. Methods: A total of 1993 runners completed two online questionnaires: a general questionnaire on, among others, running habits and exercise-related AC and a Food Frequency Questionnaire. Runners with and without either upper AC (UAC) or lower AC (LAC) were compared regarding personal characteristics, running characteristics and habitual dietary intake. Results: 1139 runners (57%) reported AC during and/or up to 3 hours after running: 302 runners (15%) reported UAC, 1115 (56%) LAC and 278 (14%) both. In about one-third of runners with AC, these complaints negatively affected their running. Exercise-related AC were positively associated with female gender, younger age and more intense running. Most associations with nutritional factors were observed only for LAC in men, with a higher intake of energy, all macronutrients and grain products in men with LAC. In both men and women, a higher intake of tea and unhealthy choices were associated with AC. Conclusion: Exercise-related AC were quite prevalent, and in about one-third of the cases, AC impacted their running. Being female, having a younger age and running at higher intensity were positively associated with AC. Some aspects of the habitual diet were associated with AC. Most notable were positive associations for intake of fat, tea and unhealthy choices.

Factors associated with lower limb tendinopathy in a large cohort of runners: a survey with a particular focus on nutrition.

Objectives: Lower limb tendinopathy (LLT) is highly prevalent in runners. Treatment can be challenging, and knowledge of risk factors may be valuable to develop preventive or treatment interventions for LLT. The aims of this study were (1) to assess the prevalence of three common LLTs (Achilles tendinopathy (AT), patellar tendinopathy and plantar fasciopathy) in a large cohort of Dutch and Belgian runners and (2) to investigate its association with potential risk factors, with a particular focus on nutritional factors in the habitual diet. Methods: A total of 1993 runners were included in the study. They completed two online questionnaires: a general questionnaire on running habits and injuries and a Food Frequency Questionnaire. Runners with and without LLT were compared regarding personal characteristics, running characteristics and nutritional factors. Results: The point prevalence for the three LLTs was 6%; 33% of the runners reported LLT in the past and 35% had either a current or past LLT. AT was the most prevalent type of LLT, and prevalence rates for all types of LLT were higher in men than women. Positive associations with LLT were observed for age and running years (men and women), running level and running distance (men). No associations between LLT and nutritional factors were observed. Conclusion: One-third of this population of runners had ever experienced an LLT. These tendinopathies were associated with gender, age and running load, but not with nutritional factors.

Effect of a low carbohydrate, high fat diet versus a high carbohydrate diet on exercise efficiency and economy in recreational male athletes.

BACKGROUND: Exercise efficiency and economy are key determinants of endurance exercise performance. In this cross-over intervention trial, we investigated the effect of adherence to a low carbohydrate, high fat (LCHF) diet versus a high carbohydrate (HC) diet on gross efficiency (GE) and (OC) during exercise, both after 2 days and after 14 days of adherence. METHODS: Fourteen recreational male athletes followed a two-week LCHF diet (<10 energy % carbohydrate) and a two-week HC diet (>50 energy % carbohydrate), in random order, with a wash-out period of three weeks in between. After 2 and 14 days on each diet, the athletes performed a 90-minutes submaximal exercise session on a bicycle ergometer. Indirect calorimetry measurements were done after 60 minutes of exercise to calculate GE and OC. RESULTS: GE was significantly lower on the LCHF diet compared to the HC diet, after 2 days (17.6±1.9 vs. 18.8±1.2%, P=0.011, for the LCHF and HC diet respectively), not after 14 days. OC was significantly higher on the LCHF diet compared to the HC diet, after 2 days (1191±138 vs. 1087±72 mL O2/kCal, P=0.003, for the LCHF and HC diet respectively), and showed a strong tendency to remain higher after 14 days, P=0.018. CONCLUSIONS: Although LCHF diets are popular strategies to increase fat oxidation during exercise, adherence to a LCHF diet was associated with a lower exercise efficiency and economy compared to a HC diet.

Pitfalls in interpreting red blood cell parameters in elite high-altitude and sea-level athletes: A unique case series.

Standard routine hematological measurements are commonly used to investigate differences in blood parameters between high-altitude athletes (HAA) and sea-level athletes (SLA), and to monitor the effect of high-altitude training. In this way, red blood cell (RBC) parameters are usually expressed as relative parameters (concentration) rather than absolute parameters (total amount). In this unique case series of elite HAA and SLA, we describe how different ways of parameter expression can affect the interpretation of blood tests. In a group of 42 elite athletes, relative and absolute RBC parameters were compared between HAA and SLA. Absolute parameters were calculated by multiplying relative values with formula-based estimated blood volume (BV-e). Additionally, in two individual athletes, one HAA and one SLA, absolute parameters were also calculated with blood volume (BV) obtained by measurement with a dilution method (BV-m). In men, HAA had a significantly higher hemoglobin (Hb) concentration (+7.8%; p = 0.001) and total Hb mass per kg body weight (BW) (+12.0%; p = 0.002). When not corrected for BW, HAA had a lower, non-significant, total Hb mass (-7.8%; p = 0.055). In women, no significant differences between HLA and SLA were observed. The two individual athletes showed that, based on BV-m, in the HAA, total Hb mass and total Hb mass per kg BW were respectively 14.1% and 31.0% higher than in the SLA, whereas based on BV-e, in the HAA, total Hb mass was 20.8% lower and total Hb mass per kg BW was only 2.4% higher. Similar inconsistencies were observed for total RBC count. Thus, different ways of parameter expression, and different methods of BV assessment for the calculation of absolute parameter values, influence the interpretation of blood tests in athletes, which may lead to misinterpretation and incorrect conclusions.

Dietary Intake in the Lifelines Cohort Study: Baseline Results from the Flower Food Frequency Questionnaire among 59,982 Participants.

The role of nutrition in health and disease is well established. However, more research on this topic is needed to fill gaps in our current knowledge. The Lifelines cohort study, a large Dutch prospective cohort study, was established as a resource for international researchers, aiming to obtain insight into the aetiology of healthy ageing. The study started with 167,729 participants, covering three generations, aiming to follow them for thirty years. This article describes the habitual dietary intake, assessed using the Flower Food Frequency Questionnaire (FFQ), among Lifelines cohort study participants at baseline, stratified by sex and different categories of age, socioeconomic status (SES) and body mass index (BMI). A total of 59,982 adults (23,703 men and 36,279 women), who completed the Flower FFQ and reported plausible habitual dietary intake, were included in the analyses. Median daily energy intake was higher in men (2368 kcal) than in women (1848 kcal), as well as macronutrient intake. Energy and macronutrient intake decreased with increasing age and BMI categories; no differences were observed between SES categories. Intake of most micronutrients was higher in men than in women. Differences were observed between age categories, but not between SES and BMI categories. Food groups were consumed in different amounts by men and women; differences between age, SES and BMI categories were observed as well. The Lifelines cohort study provides extensive dietary intake data, which are generalisable to the general Dutch population. As such, highly valuable dietary intake data are available to study associations between dietary intake and the development of chronic diseases and healthy aging.