Understanding the role of vegetarian diet, adiposity and grip strength in cancer risk

Cancer is a leading cause of death with rising incidence every year. Lifestyle factors play crucial roles in the risk of this disease. However, more evidence is needed to understand the association between diet, adiposity and physical activity with different cancer site, because most of the evidence still being inconclusive. Therefore, this thesis aims to determine the associations of type of diet, adiposity, grip strength with cancer risk. The thesis includes four research papers that were conducted in order to achieve its general aim. These studies were conducted utilising data from the UK Biobank. Across these manuscripts, the associations between the different exposures (diet, adiposity and grip strength) and cancer outcomes were studied. The cancer risks of four types of diet (meat eaters, poultry eaters, pescatarians, and vegetarians) were investigated in the first paper. The study found that vegetarians had a lower risk of all cancer than meat eaters. The study also found that vegetarians had a lower risk of 7 out of the 19 cancer sites studied, including stomach, bladder, and blood cancers. Pescatarians also had a lower risk of colorectal cancer than meat-eaters. The meta-analysis, which included 15 studies with 1,180,523 participants, supported the findings of the UK Biobank study, with vegetarians having a lower risk of all cancer and fish-eaters having a lower risk of gastric cancer than to meat-eaters. The second study found that higher levels of all six adiposity-related markers were associated with a higher risk of developing and dying from cancer. BMI, waist circumference, hip circumference, and waist-to-hip ratio were positively associated with the incidence and mortality from several cancer types, including liver, lung, and pancreas cancers. The third study identified that both general obesity (defined as BMI ≥30 kg/m²) and central obesity (defined as waist circumference >90 cm for men and >84 cm for women) were independently associated with a higher risk of developing and dying from cancer. The combined presence of general and central obesity was associated with a higher risk of developing and dying from several colorectal, liver, and pancreatic cancers. Finally, the fourth study found that both absolute and relative grip strength were inversely associated with the risk of cancer. The association between grip strength and cancer risk was consistent across different cancer types and subgroups of participants. In conclusion, these four papers provide important insights into the roles of lifestyle factors on cancer risk and highlight the importance of maintaining a healthy diet, maintaining muscle strength, and maintaining a healthy body weight for cancer prevention. All of the studies included in the thesis were observational. Therefore, they cannot establish that a particular diet, adiposity, or grip strength caused cancer. However, they are in line with the current research on cancer prevention

Does insulin-like growth factor moderate the association between height and risk of cancer at 24 sites?

Background: Whether the association of height with cancers differs by insulin-like growth factors has not been fully elucidated. Therefore, this study aimed to investigate the sex-specific associations between height and 24 site-specific cancers and to assess whether the association differed by IGF-1. Methods: In total, 414,923 participants from the UK Biobank prospective cohort study were included. The association of height (per 5-cm increment) with incidence and mortality from 24 cancer sites was investigated by using Cox proportional hazard models. Results: The median follow-up was 6.0 years. In men, height was positively associated with incidence risk of all-cause cancer and at five sites (lung, lymphatic, leukaemia, non-Hodgkin lymphoma and melanoma). In women, it was associated with breast, melanoma, lymphatic, non-Hodgkin lymphoma and all-cause cancer. The association was stronger in women than men for all-cause cancer incidence. The strength of the association did not differ by IGF-1 concentration. Conclusions: Adult height was associated with risk of several cancer sites. However, some of these associations were sex-specific. There was no strong evidence to support IGF-1 moderating the association between height and cancer

Changes over 15 years in the contribution of adiposity and smoking to deaths in England and Scotland

Background: For many years smoking has been the major threat to public health in developed countries. However, smoking prevalence has declined over a period when adiposity has increased. The aim of this study was to determine whether adiposity now accounts for more deaths than smoking in the general population as a whole or sub-groups of it. Methods: This is a comparative risk assessment study using Health Surveys for England and Scottish Health Surveys from 2003 to 2017. Annual prevalence of overweight, obesity, current and former smoking were obtained and combined using population-based weights. Sex-specific risk ratios for all-cause mortality were obtained from the most recently published meta-analyses. Population attributable fractions across yeas were then estimated. Findings: Overall, deaths attributable to current/former smoking declined from 23.1% (95% CI 20.6–25.8%) in 2003 to 19.4% (95% CI 17.3–21.6%) in 2017, whilst those attributable to adiposity (overweight or obesity) increased from 17.9% (95% CI 17.3–18.4%) in 2003 to 23.1% (95% CI 22.3–23.8%) in 2017 with cross-over occurring in 2013. Cross-over occurred earlier in men (2011) than women (2014). It occurred in 2006 for those aged over 65 years of age and in 2012 for those aged 45–64 years. Below 45 years, smoking remained the larger contributor to mortality. Interpretation: Adiposity now accounts for more deaths in England and Scotland than smoking among people in middle- and old-age. National strategies to address adiposity should be a public health priority

Dietary Patterns and Dietary Recommendations Achievement From Latin American College Students During the COVID-19 Pandemic Lockdown

This study aimed to compare the diet quality of different dietary patterns among college students from Latin American countries, including vegetarians, vegans, and omnivores during the COVID-19 pandemic. A cross-sectional, observational, multicenter study was conducted including a non- probabilistic sample of university students from 10 countries. University students were invited to participate in the study through social network platforms. Participants were self-reported to have followed a specific dietary pattern; either the Prudent diet, Western diet, Ovo-dairy-vegetarian diet, Fish-vegetarian diet, Strict vegetarian diet (vegan) or other. The last three patterns (vegetarians and vegans) were grouped as following a plant-based diet. A self-assessment survey was used to evaluate healthy eating habits using a questionnaire with values between 1 (do not consume) and 5 (consume) for a total of 9–45 points (higher values represent better eating habits). Unhealthy habits were assessed with nine questions. A total of 4,809 students filled out the questionnaire, and the majority of them were females (73.7%). Murillo et al. College Dietary Patterns During COVID-19 A high percentage have been in lockdown for more than 5 months and were in lockdown when the survey was released. 74.3% were self-reported to follow a prudent diet, while 11.4% reported following a western dietary pattern and 8.8% a plant-based diet. When compliance with healthy and unhealthy dietary habits was analyzed, although all groups had low compliance, the plant-based diet group (56.09 ± 6.11) performed better than the Western diet group (48.03 ± 5.99). The total diet quality score was significantly higher for plant-based diet followers, who also tended to better achieve the recommendations than omnivorous students, especially the ones following a western diet. These results present evidence that young adults such as college-aged students have unhealthy dietary habits. However, the ones who follow a plant-based diet such as vegetarians and vegans exhibit better scores and healthier dietary conducts.UCR::Vicerrectoría de Docencia::Salud::Facultad de Medicina::Escuela de Medicin

Absolute and relative grip strength as predictors of cancer: prospective cohort study of 445 552 participants in UK Biobank

Background: Reduced muscular strength, as measured by absolute grip strength, has been associated with increased risk of some site-specific cancers. The ability of grip strength to predict other diseases may be affected by whether it is expressed in absolute or relative terms, but the evidence for cancer is scarce. This study compared the associations of absolute and relative grip strength with all-cause and 15 site-specific cancers. Methods A prospective cohort study was undertaken using data from the UK Biobank. The exposure variable was grip strength, in absolute form (kilogrammes) and relative to weight, body mass index (BMI), height. and body fat mass. The outcome was incident cancer, at 15 sites and overall. Cox proportional hazard models were performed to study the associations. Results: This study included 445 552 participants, where 53.8% of the participants were women, with a mean (SD) age of 56.3 (8.11) years. During a median of 8.8 years follow-up period, 48 886 (11.0%) patients were diagnosed with cancer. After adjusting for sociodemographic and lifestyle factors, as well as multiple testing, absolute grip strength was inversely and linearly associated with endometrial [hazard ratio (HR): 0.74, 95% confidence interval (CI): 0.69; 0.79, P value <0.001], gallbladder (HR: 0.81, 95% CI: 0.72; 0.92, P value = 0.001), liver (HR: 0.86, 95% CI: 0.79; 0.93, P value <0.001), kidney (HR: 0.93, 95% CI: 0.88; 0.99), and breast (HR: 0.93, 95% CI: 0.91; 0.96, P value = 0.031), as well as all-cause cancer (HR: 0.97, 95% CI: 0.95; 0.98, P value <0.001). Eight cancer sites were inversely associated with HGS relative to weight and BMI: endometrium, liver, gallbladder, kidney, oesophagus, pancreas, colorectal, breast, and all-cause cancer. Compared with absolute grip strength, grip strength relative to body fat mass had better discriminatory power for head and neck and breast cancer. Grip strength relative to BMI was marginally better than absolute grip strength in predicting stomach cancer. Conclusions: Grip strength was associated with risk of several site-specific cancers and all-cause cancer. Head and neck and breast cancers might be better predicted by relative grip strength

Combined association of general and central obesity with incidence and mortality of cancers in 22 sites

Background Body mass index (BMI) and waist circumference (WC) are measures of general and central obesity, respectively, and both have been shown to be associated with cancer. However, there is insufficient evidence of their combined association with the risk of cancer. Objectives This study aimed to investigate the associations of combinations of BMI and WC with cancer at 22 sites. Methods A total of 386,101 (54.5% women) UK Biobank participants aged from 37 to 73 y were included. The outcomes were incidence of and mortality from cancer at 22 sites. Participants were categorized as normal weight (BMI 18.5–24.9) or overweight (including obese, BMI ≥ 25) and as normal WC or centrally obese (WC ≥ 94 cm for men and ≥80 cm for women). Four mutually exclusive groups were derived: 1) normal weight without central obesity, 2) normal weight with central obesity, 3) overweight without central obesity, and 4) overweight with central obesity. We used Cox proportional hazards models to estimate HRs and 95% CIs. Results The mean follow-up period was 8.8 y. Compared with participants with normal weight and WC, men who were overweight and centrally obese had higher cancer incidence risk at 3 sites [stomach (HR: 1.75; 95% CI: 1.33, 2.32; Padj = 0.002), kidney (HR: 1.45; 95% CI: 1.17, 1.81; Padj = 0.016), and colorectal (HR: 1.31; 95% CI: 1.17, 1.47; Padj < 0.001) cancer]. Similar associations were found at 4 sites in women [endometrial (HR: 2.48; 95% CI: 2.06, 2.98; Padj < 0.001), uterine (HR: 2.23; 95% CI: 1.89, 2.64; Padj < 0.001), kidney (HR: 1.84; 95% CI: 1.37, 2.46; Padj = 0.001), and breast (HR: 1.24; 95% CI: 1.16, 1.32; Padj < 0.001) cancer] and for all-cause cancer (HR: 1.07; 95% CI: 1.03, 1.10; Padj = 0.003). Only endometrial cancer mortality (HR: 3.28; 95% CI: 1.77, 6.07; Padj = 0.004) was significantly associated with being overweight and centrally obese. Conclusions The combination of general and central obesity was associated with a higher risk at several cancer sites and some associations were sex-specific

Dietary patterns and dietary recommendations achievement from Latin American college students during the COVID-19 pandemic lockdown

Abstract: This study aimed to compare the diet quality of different dietary patterns among college students from Latin American countries, including vegetarians, vegans, and omnivores during the COVID-19 pandemic. A cross-sectional, observational, multicenter study was conducted including a non- probabilistic sample of university students from 10 countries. University students were invited to participate in the study through social network platforms. Participants were self-reported to have followed a specific dietary pattern; either the Prudent diet, Western diet, Ovo-dairy-vegetarian diet, Fish-vegetarian diet, Strict vegetarian diet (vegan) or other. The last three patterns (vegetarians and vegans) were grouped as following a plant-based diet. A self-assessment survey was used to evaluate healthy eating habits using a questionnaire with values between 1 (do not consume) and 5 (consume) for a total of 9–45 points (higher values represent better eating habits). Unhealthy habits were assessed with nine questions. A total of 4,809 students filled out the questionnaire, and the majority of them were females (73.7%). A high percentage have been in lockdown for more than 5 months and were in lockdown when the survey was released. 74.3% were self-reported to follow a prudent diet, while 11.4% reported following a western dietary pattern and 8.8% a plant-based diet. When compliance with healthy and unhealthy dietary habits was analyzed, although all groups had low compliance, the plant-based diet group (56.09 ±6.11) performed better than the Western diet group (48.03 ± 5.99). The total diet quality score was significantly higher for plant-based diet followers, who also tended to better achieve the recommendations than omnivorous students, especially the ones following a western diet. These results present evidence that young adults such as college-aged students have unhealthy dietary habits. However, the ones who follow a plant-based diet such as vegetarians and vegans exhibit better scores and healthier dietary conducts

Body weight in relation to hours of sleep, and physical activity in Latin American university students during the Covid-19 pandemic

Introduction: Short sleep, physical inactivity, and being locked up are risk factors for weight gain. Objective: We evaluated weight gain according to sex, age, hours of sleep and physical activity in university students from 10 Latin American countries during the COVID-19 pandemic. Methods: Cross-sectional and multicenter study (n = 4880). Results: The average age was 22.5 ± 4.4 years. 60.2% were currently locked up. 73.6% were women, 48.2% increased their body weight, 66% reported insufficient sleep hours, and 65.9% were inactive. Women gained more weight than men (73.2%) and younger students gained more weight (85.1%). Those who had insufficient sleep hours gained most weight (67.6%). Inactive participants gained most weight (74.7%). Students who have insufficient sleep are 21% more likely to have changes in body weight compared to students who have optimal sleep. Conclusion: The increase in body weight and its risk factors during confinement should be considered as emerging from public health

Body weight in relation to hours of sleep, and physical activity in latin american university students during the Covid-19 pandemic

Abstract: Introduction: Short sleep, physical inactivity, and being locked up are risk factors for weight gain. Objective: We evaluated weight gain according to sex, age, hours of sleep and physical activity in university students from 10 Latin American countries during the COVID-19 pandemic. Methods: Cross-sectional and multicenter study (n = 4880). Results: The average age was 22.5 ± 4.4 years. 60.2% were currently locked up. 73.6% were women, 48.2% increased their body weight, 66% reported insufficient sleep hours, and 65.9% were inactive. Women gained more weight than men (73.2%) and younger students gained more weight (85.1%). Those who had insufficient sleep hours gained most weight (67.6%). Inactive participants gained most weight (74.7%). Students who have insufficient sleep are 21% more likely to have changes in body weight compared to students who have optimal sleep. Conclusion: The increase in body weight and its risk factors during confinement should be considered as emerging from public health

Healthy Lifestyle Habits in Latin American University Students during COVID-19 Pandemic: A Multi-Center Study

ABSTRACT Background: Deterioration in the health-related quality of life (HRQoL) and healthy eating behavior due to the effect of COVID-19 lockdown has been reported. The aim of this study was to associate eating habits and HRQoL with physical activity behavior in Latin American university students during COVID-19 pandemic. Methods: Measured 4,859 university students with a mean age of 22.4years and they were mostly female (73.7%) from 10 Latin American countries (Argentina, Chile, Colombia, Costa Rica, Ecuador, Guatemala, Mexico, Panama, Paraguay and, Peru). Eating habits were measured using a survey validated with other university students, HRQoL was assessments using the short version of the World Health Organization (WHOQOL-BREF) scale and physical activity behavior with a dicotomous question based on the international recommendations for physical activity. Results: There is a higher complaince for all the international recommendations for healthy foods intake in the physically active group of students (p<0.01), with the exception of alcohol and salt. In addition, physically active students presented a significantly higher HRQoL (p<0.001) in all the dimensions analyzed when compared to physically inactive students. Conclusions: Latin American university students who are physically active are more likely to have a healthier eating behavior and a lower risk of a decreased HRQoL during COVID-19 pandemic.Universidad de Costa Rica//UCR/Costa RicaUCR::Vicerrectoría de Docencia::Salud::Facultad de Medicina::Escuela de Medicin