An updated systematic review and meta-analysis on adherence to mediterranean diet and risk of cancer.
European journal of nutrition. 2021;60(3):1561-1586
Plain language summary
The development of cancer is associated with a number of risk factors, including smoking, obesity, sedentary lifestyles, alcohol consumption, infections, pollution, and dietary imbalances. Based on previous research, optimal consumption of fruits, vegetables, and whole grains, along with reduced consumption of red and processed meat, reduces cancer risk. According to this systematic review and meta-analysis, adherence to the Mediterranean diet is associated with lower cancer mortality and site-specific cancer development. A Mediterranean diet includes fruits, vegetables, nuts, legumes, fish, whole grains, extra virgin olive oil, and low amounts of red meat, processed meat, egg, and dairy, along with moderate amounts of red wine. According to this systematic review and meta-analysis, adherence to the Mediterranean diet reduces the risk of cancer mortality and the risk of developing cancers specific to the site, such as colorectal cancer, bladder cancer, gastric cancer, and lung cancer. Among the components of the Mediterranean diet, fruits, vegetables, and whole grains have been shown to reduce cancer risk. Bioactive substances found in Mediterranean diet components require additional robust studies to evaluate their benefits. A healthcare professional can use the results of this study to make clinical decisions and recommend therapeutic interventions to cancer patients.
PURPOSE The aim of current systematic review was to update the body of evidence on associations between adherence to the Mediterranean diet (MedDiet) and risk of cancer mortality, site-specific cancer in the general population; all-cause, and cancer mortality as well as cancer reoccurrence among cancer survivors. METHODS A literature search for randomized controlled trials (RCTs), case-control and cohort studies published up to April 2020 was performed using PubMed and Scopus. Study-specific risk estimates for the highest versus lowest adherence to the MedDiet category were pooled using random-effects meta-analyses. Certainty of evidence from cohort studies and RCTs was evaluated using the NutriGrade scoring system. RESULTS The updated search revealed 44 studies not identified in the previous review. Altogether, 117 studies including 3,202,496 participants were enclosed for meta-analysis. The highest adherence to MedDiet was inversely associated with cancer mortality (RRcohort: 0.87, 95% CI 0.82, 0.92; N = 18 studies), all-cause mortality among cancer survivors (RRcohort: 0.75, 95% CI 0.66, 0.86; N = 8), breast (RRobservational: 0.94, 95% CI 0.90, 0.97; N = 23), colorectal (RRobservational: 0.83, 95% CI 0.76, 0.90; N = 17), head and neck (RRobservational: 0.56, 95% CI 0.44, 0.72; N = 9), respiratory (RRcohort: 0.84, 95% CI 0.76, 0.94; N = 5), gastric (RRobservational: 0.70, 95% CI 0.61, 0.80; N = 7), bladder (RRobservational: 0.87, 95% CI 0.76, 0.98; N = 4), and liver cancer (RRobservational: 0.64, 95% CI 0.54, 0.75; N = 4). Adhering to MedDiet did not modify risk of blood, esophageal, pancreatic and prostate cancer risk. CONCLUSION In conclusion, our results suggest that highest adherence to the MedDiet was related to lower risk of cancer mortality in the general population, and all-cause mortality among cancer survivors as well as colorectal, head and neck, respiratory, gastric, liver and bladder cancer risks. Moderate certainty of evidence from cohort studies suggest an inverse association for cancer mortality and colorectal cancer, but most of the comparisons were rated as low or very low certainty of evidence.
Effect of dietary nitrate on human muscle power: a systematic review and individual participant data meta-analysis.
Journal of the International Society of Sports Nutrition. 2021;18(1):66
Plain language summary
Previous reviews have concluded that dietary nitrate (NO3−) improves maximal neuromuscular power in humans, but these were based on a limited number of studies. This is the first systematic review and meta-analysis evaluating the effects of dietary NO3− supplementation on muscular power in humans. The study also aims to quantify the size of this beneficial effect. 19 studies with a total of 268 participants were included. Most of these used concentrated beetroot juice as the source of NO3− given as an acute dose (short term high level). A positive effect of dietary NO3− on muscle power was observed in all 19 studies. Analyses were done on sub groups - age, sex and the amount of muscle mass engaged in the activity. Dietary NO3− intake significantly increases maximal muscle power in humans. The magnitude of this effect has practical and clinical importance; not just for athletes but also for patient groups. This effect is independent of subject age, sex, or the amount of muscle mass engaged in the activity but may be greater with acute vs. repeated dosing. Further research is needed to determine factors such as the optimal supplementation regimen and target population.
Conflicts of interest:
A: Meta-analyses, position-stands, randomized-controlled trials (RCTs)
B: Systematic reviews including RCTs of limited number
C: Non-randomized trials, observational studies, narrative reviews
D: Case-reports, evidence-based clinical findings
E: Opinion piece, other
- In 2007, researchers uncovered the ingestion of dietary nitrates reduced the oxygen cost of submaximal exercise, and since, over 100 studies have examined the effects of nitrates on endurance performance.
- With regards to the impact of nitrates on maximal force output, only trivial results had been previously found.
- This review study found that while nitrates do not impact force development, they do demonstrate primary effect on the speed of muscle contraction (i.e. muscular power is the product of force x speed).
- The reviews primary finding was that nitrate intake can significantly enhance muscular power, regardless of subject age or sex.
Clinical practice applications:
- These new findings highlight the ability of dietary nitrates to improve neuromuscular power production is highly relevant for team sport athletes, due to the explosive nature of these sports with constant accelerations and decelerations during training and competition.
- In the general population, falls and fractures amongst older adults significantly reduces quality of life and costs the healthcare system hundreds of millions of pounds to treat.
- Improved contractile properties of muscle, most notably speed of contraction, may offer protection to older adults as well as the benefit of additional nitric oxide (NO) to support vascular health as well.
- The typical intake of dietary nitrates in the general population is about 31-185mg/day in Europe and 40-100mg/day in North America. Most studies use doses between 300-600mg of dietary nitrates. Increasing dietary or supplemental intake is key to achieving the neuromuscular effect.
Considerations for future research:
- The results of the present meta-analysis clearly demonstrate that dietary nitrates increases muscle power in humans, but the mechanism responsible for this effect is still unclear.
- There are notable differences between rodent and human metabolism of dietary nitrates, therefore the biochemical mechanism by which nitrate intake improves human muscle power requires additional study.
BACKGROUND Previous narrative reviews have concluded that dietary nitrate (NO3-) improves maximal neuromuscular power in humans. This conclusion, however, was based on a limited number of studies, and no attempt has been made to quantify the exact magnitude of this beneficial effect. Such information would help ensure adequate statistical power in future studies and could help place the effects of dietary NO3- on various aspects of exercise performance (i.e., endurance vs. strength vs. power) in better context. We therefore undertook a systematic review and individual participant data meta-analysis to quantify the effects of NO3- supplementation on human muscle power. METHODS The literature was searched using a strategy developed by a health sciences librarian. Data sources included Medline Ovid, Embase, SPORTDiscus, Scopus, Clinicaltrials.gov , and Google Scholar. Studies were included if they used a randomized, double-blind, placebo-controlled, crossover experimental design to measure the effects of dietary NO3- on maximal power during exercise in the non-fatigued state and the within-subject correlation could be determined from data in the published manuscript or obtained from the authors. RESULTS Nineteen studies of a total of 268 participants (218 men, 50 women) met the criteria for inclusion. The overall effect size (ES; Hedge's g) calculated using a fixed effects model was 0.42 (95% confidence interval (CI) 0.29, 0.56; p = 6.310 × 10- 11). There was limited heterogeneity between studies (i.e., I2 = 22.79%, H2 = 1.30, p = 0.3460). The ES estimated using a random effects model was therefore similar (i.e., 0.45, 95% CI 0.30, 0.61; p = 1.064 × 10- 9). Sub-group analyses revealed no significant differences due to subject age, sex, or test modality (i.e., small vs. large muscle mass exercise). However, the ES in studies using an acute dose (i.e., 0.54, 95% CI 0.37, 0.71; p = 6.774 × 10- 12) was greater (p = 0.0211) than in studies using a multiple dose regimen (i.e., 0.22, 95% CI 0.01, 0.43; p = 0.003630). CONCLUSIONS Acute or chronic dietary NO3- intake significantly increases maximal muscle power in humans. The magnitude of this effect-on average, ~ 5%-is likely to be of considerable practical and clinical importance.
The benefits and risks of beetroot juice consumption: a systematic review.
Critical reviews in food science and nutrition. 2021;61(5):788-804
Plain language summary
This review examined the health benefits and risks associated with beetroot juice (BRJ) from 86 studies. The nitrate contained in high amounts in BRJ increases nitric oxide (NO) levels in the body. NO has vasodilatory effects and thus reduces blood pressure and helps oxygen- and nutrient delivery to organs and muscles. Hence there has been an interest in BRJ for sports performance improvement and the prevention and treatment of cardiovascular disease. The review collected evidence of the effect of BRJ on the cardiovascular system and sports performance according to gender, trained and untrained individuals. Whilst the authors also briefly mention other health benefits of BRJ. From wider research, it is known that excess nitrate can form carcinogenic N-nitroso compounds (NOCs) in the body. Yet little is known whether this could also be a potential risk with BRJ consumption since vegetable consumption and many plant compounds generally appear to reduce the risk of cancers and can block the formation of NOCs. Hence the authors concluded that more research is needed to ensure that currently suggested dosages for BRJ do not aid NOCs production. In summary, BRJ has a beneficial effect on nitric oxide levels, oxygen consumption, blood flow, platelet aggregation, heart rate, cardiac output, blood pressure, improves sports performance and endurance and could be valuable for the management of cardiovascular disease. Yet high levels of consumption may not come without risks and more studies are needed to assess safety.
Beetroot juice (BRJ) has become increasingly popular amongst athletes aiming to improve sport performances. BRJ contains high concentrations of nitrate, which can be converted into nitric oxide (NO) after consumption. NO has various functions in the human body, including a vasodilatory effect, which reduces blood pressure and increases oxygen- and nutrient delivery to various organs. These effects indicate that BRJ may have relevant applications in prevention and treatment of cardiovascular disease. Furthermore, the consumption of BRJ also has an impact on oxygen delivery to skeletal muscles, muscle efficiency, tolerance and endurance and may thus have a positive impact on sports performances. Aside from the beneficial aspects of BRJ consumption, there may also be potential health risks. Drinking BRJ may easily increase nitrate intake above the acceptable daily intake, which is known to stimulate the endogenous formation of N-nitroso compounds (NOC's), a class of compounds that is known to be carcinogenic and that may also induce several other adverse effects. Compared to studies on the beneficial effects, the amount of data and literature on the negative effects of BRJ is rather limited, and should be increased in order to perform a balanced risk assessment.
Effect of a Parent-Focused eHealth Intervention on Children's Fruit, Vegetable, and Discretionary Food Intake (Food4toddlers): Randomized Controlled Trial.
Journal of medical Internet research. 2021;23(2):e18311
Plain language summary
Diet in childhood tends to reflect that in adolescence and adulthood and so healthy eating habits established during this time may prevent increased weight, non-communicable diseases and even cancer. Healthy diet promotion to parents may be able to ensure that a healthy food environment is established, which will then continue throughout life. This randomised controlled trial of 404 parents aimed to determine the effect of parent-focused healthy food promotion via the internet for 12 months. The results showed that after 6 months that frequency of vegetable intake increased but this was not seen at 12 months. No differences were seen in the frequency of intake of sweet foods at either time point. It was concluded that intervention through a web-based healthy diet programme increased vegetable intake in the short-term, however in the long-term a personalised intervention or reminders may be needed. This study could be used by healthcare professionals to understand the importance of establishing a healthy diet from a young age and that parental support may be required to do this.
BACKGROUND In Western countries, children's diets are often low in fruits and vegetables and high in discretionary foods. Diet in early life tends to track through childhood and youth and even into adulthood. Interventions should, therefore, be delivered in periods when habitual traits are established, as in toddlerhood when children adapt to their family's diet. OBJECTIVE In this study, we assessed the effect of the Food4toddlers eHealth intervention, which aimed to enhance toddlers' diets by shaping their food and eating environment. METHODS The Food4toddlers randomized controlled trial was conducted in Norway in 2017-2018. Parent-child dyads were recruited through social media. In total, 298 parents completed an online questionnaire at baseline (mean child age 10.9 months, SD 1.2). Postintervention questionnaires were completed immediately after the intervention (ie, follow-up 1; mean child age 17.8 months, SD 1.3) and 6 months after the intervention (ie, follow-up 2; mean child age 24.2 months, SD 1.9). The intervention was guided by social cognitive theory, which targets the linked relationship between the person, the behavior, and the environment. The intervention group (148/298, 49.7%) got access to the Food4toddlers website for 6 months from baseline. The website included information on diet and on how to create a healthy food and eating environment as well as activities, recipes, and collaboration opportunities. To assess intervention effects on child diet from baseline to follow-up 1 and from baseline to follow-up 2, we used generalized estimating equations and a time × group interaction term. Between-group differences in changes over time for frequency and variety of fruits and vegetables and frequency of discretionary foods were assessed. RESULTS At follow-up 1, a significant time × group interaction was observed for the frequency of vegetable intake (P=.02). The difference between groups in the change from baseline to follow-up 1 was 0.46 vegetable items per day (95% CI 0.06-0.86) in favor of the intervention group. No other significant between-group differences in dietary changes from baseline to follow-up 1 or follow-up 2 were observed. However, there is a clear time trend showing that the intake of discretionary foods increases by time from less than 1 item per week at baseline to more than 4 items per week at 2 years of age (P<.001), regardless of group. CONCLUSIONS A positive intervention effect was observed for the frequency of vegetable intake at follow-up 1 but not at follow-up 2. No other between-group effects on diet were observed. eHealth interventions of longer duration, including reminders after the main content of the intervention has been delivered, may be needed to obtain long-terms effects, along with tailoring in a digital or a personal form. TRIAL REGISTRATION International Standard Randomized Controlled Trial Number (ISRCTN) 92980420; https://doi.org/10.1186/ISRCTN92980420.
Role of mitochondria, oxidative stress and the response to antioxidants in myalgic encephalomyelitis/chronic fatigue syndrome: A possible approach to SARS-CoV-2 'long-haulers'?
Chronic diseases and translational medicine. 2021;7(1):14-26
Plain language summary
Cases of chronic fatigue have been reported following recovery from Covid-19, in what is termed ‘Long Covid’, with symptoms likened to that of sufferers from chronic fatigue syndrome (CFS) and myalgic encephalomyelitis (ME). How CFS/ME develop and treatments may help to further understand Covid-19. This review study of 111 studies aimed to identify where urgent research is required to help understand the potential of chronic fatigue therapies in Covid-19. The study first reviewed disrupted cellular energy production in ME/CFS and increased presence of damaging oxidants. Current therapies for improving cellular energy production in CFS/ME were then reviewed and Ritalin, ubiquinone and mitoquinol mesylate were heavily featured. Antioxidant therapies in CFS/ME were reviewed and observations would suggest that trials in patients with long covid are needed. It was concluded that research in cellular energy production in CFS/ME has been increasing, however remains contradictory due to a lack of a definitive diagnosis, differing disease severity and the huge differences between patients who suffer from CFS/ME. Further research is required in ME/CFS and Covid-19. This study could be used by health care professionals to understand the importance of monitoring symptoms of fatigue post Covid-19 infection and the possible use of ME/CFS treatments.
A significant number of SARS-CoV-2 (COVID-19) pandemic patients have developed chronic symptoms lasting weeks or months which are very similar to those described for myalgic encephalomyelitis/chronic fatigue syndrome. This study reviews the current literature and understanding of the role that mitochondria, oxidative stress and antioxidants may play in the understanding of the pathophysiology and treatment of chronic fatigue. It describes what is known about the dysfunctional pathways which can develop in mitochondria and their relationship to chronic fatigue. It also reviews what is known about oxidative stress and how this can be related to the pathophysiology of fatigue, as well as examining the potential for specific therapy directed at mitochondria for the treatment of chronic fatigue in the form of antioxidants. This study identifies areas which require urgent, further research in order to fully elucidate the clinical and therapeutic potential of these approaches.
Western Dietary Pattern Antioxidant Intakes and Oxidative Stress: Importance During the SARS-CoV-2/COVID-19 Pandemic.
Advances in nutrition (Bethesda, Md.). 2021;12(3):670-681
Plain language summary
The Atlantic diet (AD), Mediterranean diet (MD) and diets which follow the American dietary guidelines (AmD) all supply enough nutrients for the body to stay healthy. However, during periods of viral pandemics, such as the Covid-19 pandemic, these diets may be inadequate for optimal resistance to infection. Furthermore, nutrient requirements may alter with age, stress, and health. This review paper aimed to discuss the three different diets and their suitability depending on age and physical and mental state. Supplementation during a pandemic was also discussed. When the body contracts viruses such as Covid-19, reactive oxygen species can accumulate resulting in oxidative stress which can damage the cells. Nutrients in the diet, which act as antioxidants may be of benefit, in this instance, however traditional balanced diets such as the AD, MD and AmD may be inadequate. In tandem with a balanced diet, supplementation may improve health. Zinc, vitamin A, selenium, vitamin D, vitamin C, and iron have been shown in research to improve the body’s response to viruses. It was concluded that the Covid-19 pandemic has caused severe infections, which can result in oxidative stress, increasing vulnerability to viral infections. Supplementing certain nutrients may be of benefit especially in vulnerable individuals. This study could be used by healthcare professionals to understand that a balanced diet is essential during viral pandemics, and it may be necessary to consider supplementation for high-risk individuals.
The importance of balanced dietary habits, which include appropriate amounts of antioxidants to maintain the immune system, has become increasingly relevant during the current SARS-CoV-2/COVID-19 pandemic, because viral infections are characterized by high oxidative stress. Furthermore, the measures taken by governments to control the pandemic have led to increased anxiety, stress, and depression, which affect physical and mental health, all of which are influenced by nutritional status, diet, and lifestyle. The Mediterranean diet (MD), Atlantic diet (AD), and the Dietary Guidelines for Americans all provide the essential vitamins, minerals, and phenolic compounds needed to activate enzymatic and nonenzymatic antioxidant responses. However, viral pandemics such as the current COVID-19 crisis entail high oxidative damage caused by both the infection and the resultant social stresses within populations, which increases the probability and severity of infection. Balanced dietary patterns such as the MD and the AD are characterized by the consumption of fruit, vegetables, legumes, olive oil, and whole grains with low intakes of processed foods and red meat. For a healthy lifestyle in young adults, the MD in particular provides the required amount of antioxidants per day for vitamins D (0.3-3.8 μg), E (17.0 mg), C (137.2-269.8 mg), A (1273.3 μg), B-12 (1.5-2.0 μg), and folate (455.1-561.3 μg), the minerals Se (120.0 μg), Zn (11.0 mg), Fe (15.0-18.8 mg), and Mn (5.2-12.5 mg), and polyphenols (1171.00 mg) needed to maintain an active immune response. However, all of these diets are deficient in the recommended amount of vitamin D (20 μg/d). Therefore, vulnerable populations such as elders and obese individuals could benefit from antioxidant supplementation to improve their antioxidant response. Although evidence remains scarce, there is some indication that a healthy diet, along with supplemental antioxidant intake, is beneficial to COVID-19 patients.
Plant-Based Foods and Their Bioactive Compounds on Fatty Liver Disease: Effects, Mechanisms, and Clinical Application.
Oxidative medicine and cellular longevity. 2021;2021:6621644
Plain language summary
Fatty liver disease is the accumulation of fats and inflammation associated with poor dietary patterns. Plant-based foods have been recommended to manage this disease and this review aimed to highlight the most recent data on the mechanisms for this. Beyond their obvious capabilities of being low in fat, plant-based foods may contain naturally occurring compounds that can help alleviate fatty liver disease through improved inflammation, improved gut microbiota and cellular changes. In support of this, clinical benefits on fatty liver outcomes have been reported in the research. There may be safety issues with isolating certain natural compounds from plant-based foods, which requires more research, however plant-based foods is a promising therapy for fatty liver disease.
Fatty liver disease (FLD), including nonalcoholic fatty liver disease (NAFLD) and alcoholic fatty liver disease (AFLD), is a serious chronic metabolic disease that affects a wide range of people. Lipid accumulation accompanied by oxidative stress and inflammation in the liver is the most important pathogenesis of FLD. The plant-based, high-fiber, and low-fat diet has been recommended to manage FLD for a long time. This review discusses the current state of the art into the effects, mechanisms, and clinical application of plant-based foods in NAFLD and AFLD, with highlighting related molecular mechanisms. Epidemiological evidence revealed that the consumption of several plant-based foods was beneficial to alleviating FLD. Further experimental studies found out that fruits, spices, teas, coffee, and other plants, as well as their bioactive compounds, such as resveratrol, anthocyanin, curcumin, and tea polyphenols, could alleviate FLD by ameliorating hepatic steatosis, oxidative stress, inflammation, gut dysbiosis, and apoptosis, as well as regulating autophagy and ethanol metabolism. More importantly, clinical trials confirmed the beneficial effects of plant-based foods on patients with fatty liver. However, several issues need to be further studied especially the safety and effective doses of plant-based foods and their bioactive compounds. Overall, certain plant-based foods are promising natural sources of bioactive compounds to prevent and alleviate fatty liver disease.
Prospective association between organic food consumption and the risk of type 2 diabetes: findings from the NutriNet-Santé cohort study.
The international journal of behavioral nutrition and physical activity. 2020;17(1):136
Plain language summary
The prevalence of type 2 diabetes (T2D) has significantly increased over recent decades, concomitantly to the obesity epidemic. Among the emergent risk factors, exposure to environmental contaminants including pesticides is of major concern. In fact, a recent European Food Safety Authority report indicated that 44% of conventional crop-based food contained at least one quantifiable pesticide residue, vs 6.5% in organic-labelled foods (OF). The aims of this study were (a) to investigate the prospective association between OF consumption and the risk of T2D, and (b) to estimate the mediation effect by the potential healthiness of a plant-based diet. This study is prospective cohort study based on the data from the web-based NutriNet-Santé study with an analysis sample of 33,256 participants. Results indicate an inverse association between organic plant-based food consumption and T2D risk especially in women. The association persisted after accounting for potential confounding effects of various factors, including lifestyles, dietary patterns and adiposity. Authors conclude that further studies are needed to replicate these findings for confirmation purposes and to elucidate underlying mechanisms.
BACKGROUND Organic food (OF) consumption has substantially increased in high income countries, mostly driven by environmental concerns and health beliefs. Lower exposure to synthetic pesticides has been systematically documented among consumers of organic products compared to non-consumers. While experimental studies suggest that pesticides currently used in food production may be associated with type 2 diabetes (T2D), no well-conducted prospective studies have investigated the potential association between consumption of organic products and the risk of T2D, controlling for potential confounding factors. The objective of this prospective study was to estimate the association between OF consumption and the risk of T2D. METHODS A total of 33,256 participants (76% women, mean (SD) age: 53 years (14)) of the French NutriNet-Santé prospective cohort study who completed the organic food frequency questionnaire were included (2014-2019). The proportion of OF in the diet (as weight without drinking water) was computed. The associations between the proportion of OF in the diet (as 5% increment and as quintiles) and the risk of T2D were estimated using multivariable Hazard Ratio (HR) and 95% confidence interval (95% CI) derived from proportional hazards models adjusted for confounders (sociodemographic, anthropometric, lifestyle, medical and nutritional factors). RESULTS During follow-up (mean = 4.05 y, SD = 1.03 y, 134,990 person-years), 293 incident cases of T2D were identified. After adjustment for confounders including lifestyle (physical activity, smoking status, alcohol consumption) and nutritional quality of the diet assessed by the adherence to the French food-based dietary guidelines, OF consumption was associated with a lower risk of T2D. Participants with the highest quintile of OF consumption, compared with those with the lowest quintile, had 35% lower risk of T2D (95% CI = 0.43-0.97). Each increment of 5% in the proportion of OF in the diet was associated with 3% lower risk of T2D (HR 0.97, 95% CI = 0.95-0.99). CONCLUSIONS In this large prospective cohort study, OF consumption was inversely associated with the risk of T2D. Further experimental and prospective studies should be conducted to confirm these observations. CLINICAL TRIAL REGISTRY The study was registered at ClinicalTrials.gov ( NCT03335644 ).
Respiratory and Allergic Effects in Children Exposed to Pesticides-A Systematic Review.
International journal of environmental research and public health. 2020;17(8)
Plain language summary
Agricultural pesticides are harmful chemicals used to protect plants from pests and diseases. There has been previous research showing a link between pesticide usage and respiratory symptoms, asthma, allergies, and lung function irregularities in children. To evaluate the relationship between pesticide usage and allergic and respiratory effects in children, 21 studies were included in this systematic review. This systematic review reports an association between multiple sources of pesticide exposure during fetal and early development and respiratory symptoms and allergies among children. Compared to high-income countries, children in the middle- and low-income countries were exposed to multiple pesticide sources. As current scientific evidence is sparse, more research is needed to determine the causal relationship between pesticides and respiratory and allergic symptoms in children. Robust research in low- and middle-income countries is necessary. Healthcare professionals can use the results of this study to understand the harmful effects of pesticide exposure in children and to take clinical decisions to reduce the exposure and its effects.
Pesticide exposure may affect children's respiratory and allergic health, although results from epidemiological studies have not reached consensus. This review aims to analyze the scientific evidence on respiratory and allergic effects of exposure to agricultural pesticides in children aged up to 12 years old. The databases PubMed, Web of Science, Scielo, and Lilacs were screened to select articles published in English, Spanish, or Portuguese, and 21 articles were included in this review. Most investigations were conducted in North America (mostly in the United States), while no studies conducted in Latin America or Africa were found, despite their intensive use of pesticides. Children are exposed to pesticides through multiple pathways from the prenatal period throughout later developmental stages and may experience several respiratory effects. Most studies (79%) found positive associations with pesticide exposure and children's respiratory and allergic effects such as asthma, wheezing, coughs, acute respiratory infections, hay fever, rhinitis, eczema, chronic phlegm, and lung function impairments. Contrastingly, 21% of the studies found no associations between pesticide exposure and children's respiratory health. The vast differences among the characteristics of the studies hamper any comparison of the results. Exposure to pesticides may have several impacts on childhood respiratory health. More studies must be conducted, especially in low- and middle-income countries, preferably with comparable research protocols adapted to local realities. Efforts should be made to develop comprehensive risk mitigation strategies and behavioral interventions to reduce children's exposure to pesticides used in agriculture and respiratory health effects, and to ensure healthy childhood growth.
Estimation of Primary Prevention of Gout in Men Through Modification of Obesity and Other Key Lifestyle Factors.
JAMA network open. 2020;3(11):e2027421
Plain language summary
Gout is prevalent in most Western countries. Modifying the contributary factors such as obesity and alcohol intake could prevent gout, however the impact this could have on prevention is unknown. This cohort study of 44,654 men, aimed to estimate the proportion of gout cases that could be prevented through the modification of risk factors. The results showed that the most important risk factor for gout was body mass index (BMI) and modifying other risk factors did not prevent gout. 77% of gout cases could be prevented if all men had been of normal weight, had no alcohol intake, if they adhered to a diet known as the Dietary Approaches to Stop Hypertension (DASH) diet and if they didn't take drugs to increase urine output. It was concluded that weight loss in men determines their ability to prevent gout, regardless of whether they have modified other contributory factors. This study could be used by healthcare professionals to understand that unless weight loss is achieved in individuals who are overweight and have gout, then other interventions may have minimal impact. Recommending the DASH diet to achieve weight loss, may be more successful in the long-term management of gout.
Importance: The population impact of modifying obesity and other key risk factors for hyperuricemia has been estimated in cross-sectional studies; however, the proportion of incident gout cases (a clinical end point) that could be prevented by modifying such factors has not been evaluated. Objective: To estimate the proportion of incident gout cases that could be avoided through simultaneous modification of obesity and other key risk factors. Design, Setting, and Participants: The Health Professionals Follow-up Study is a US prospective cohort study of 51 529 male health professionals enrolled in 1986 and followed up through questionnaires every 2 years through 2012. Self-reported gout cases were confirmed through June 2015. Clean and complete data used for this analysis were available in June 2016, with statistical analyses performed from July 2016 to July 2019. Exposures: From data collected in the validated questionnaires, men were categorized to low-risk groups according to combinations of the following 4 factors: normal body mass index (BMI [calculated as weight in kilograms divided by height in meters squared]; <25), no alcohol intake, adherence to Dietary Approaches to Stop Hypertension (DASH)-style diet (highest quintile of DASH diet score), and no diuretic use. Main Outcomes and Measures: Population attributable risks (PARs) for incident gout meeting the preliminary American College of Rheumatology survey criteria, overall and stratified by BMI. Results: We analyzed 44 654 men (mean [SD] age, 54.0 [9.8] years) with no history of gout at baseline. During 26 years of follow-up, 1741 (3.9%) developed incident gout. Among all participants, PAR for the 4 risk factors combined (BMI, diet, alcohol use, and diuretic use) was 77% (95% CI, 56%-88%). Among men with normal weight (BMI <25.0) and overweight (BMI 25.0-29.9), we estimated that more than half of incident gout cases (69% [95% CI, 42%-83%] and 59% [95% CI, 30%-75%], respectively) may have been prevented by the combination of DASH-style diet, no alcohol intake, and no diuretic use. However, among men with obesity (BMI ≥30), PAR was substantially lower and not significant (5% [95% CI, 0%-47%]). Conclusions and Relevance: The findings of this cohort study suggest that addressing excess adiposity and other key modifiable factors has the potential to prevent the majority of incident gout cases among men. Men with obesity may not benefit from other modifications unless weight loss is addressed.