The Third Expert Report on Diet, Nutrition, Physical Activity, and Cancer: A Global Perspective by the World Cancer Research Fund (WCRF) and the American Institute for Cancer Research (AICR) ...represents the most comprehensive, detailed, and objective analysis of the accumulated research in the discipline. The report provides a framework for public health efforts around the globe by governments and other organizations with the goal of significantly reducing the burden of cancer, enhancing health, and improving quality of life for cancer survivors. Coupled with the WCRF/AICR Continuous Update Panel reports on specific cancers, these efforts also provide guidance to healthcare practitioners engaged in counseling individuals who may benefit from diet and lifestyle changes. Most critically, this report defines priorities for future research efforts that will improve the evidence base of future recommendations both for population-based public health efforts and increasingly for more personalized strategies targeting individuals who are cancer survivors or at risk due to genetic predisposition or carcinogenic exposures.
Numerous studies have examined the association between body mass index and
mortality and often observed that risk of mortality was higher in those with
lower body mass index than those who were ...overweight or even obese (“obesity
paradox”). One potential explanation of the obesity paradox is the limitation of
body mass index as an imperfect measure of adiposity. However, relatively few
studies have examined the association between body composition and mortality due
to practical issues of assessing body composition in large-scale epidemiological
settings. The available epidemiologic studies on this topic were heterogenous
with regard to study design, analyses, results, and interpretations. The
majority of studies using direct body composition measures such as dual-energy
x-ray absorptiometry or computed tomography had relatively small sample size,
short follow-up period and restricted study population. Studies have also used
other approaches to indirectly estimate body composition to examine the
association with mortality in a larger and more representative population.
Overall findings were not consistent but suggested that fat mass and lean body
mass may play an independent role on mortality in the general population.
Various shapes of the associations were observed, but studies generally
suggested that high fat mass was associated with increased risk of mortality
(especially higher range of fat mass) and low lean body mass was associated with
increased risk of mortality (especially lower range of lean body mass). On the
other hand, fat mass and lean body mass tended to show either null or inverse
association with mortality in elderly populations. Given the complex
relationship of two body components as well as with other factors (e.g., age,
smoking, disease, etc.), future studies should be conducted and interpreted
after careful consideration of potential biases. In summary, the available data
suggest independent associations of fat mass and lean body mass on mortality in
the general population.
Impact statement
Current understanding of the association of body composition on mortality in
the general population is limited. This review evaluated the available
epidemiologic studies on body composition and mortality that leveraged
diverse approaches to estimate body composition. Although studies showed
inconsistent results, there was evidence suggesting that high fat mass and
low lean body mass may be independently associated with mortality in the
general population. This review may help partially explain the “obesity
paradox” phenomenon and facilitate further studies to advance the
understanding of the association of body composition on health in the
general and patient populations.
The association between dietary fat and mortality remains inconsistent, and recent results for the association between dietary saturated fat and chronic disease are controversial. To quantitatively ...assess this association, we conducted a meta-analysis of prospective cohort studies.
The PubMed and Web of Science were searched up to February 2020. A random effects model was used.
Nineteen studies including 1,013,273participants and 195,515deaths were identified. Significant inverse associations between all-cause mortality and a 5% energy increment in intakes of total (RR = 0.99; 95% CI:0.98–1.00), monounsaturated (RR = 0.98; 95% CI:0.97–0.99), and polyunsaturated fat (RR = 0.93; 95% CI:0.89–0.97) were found. A 5% increase in energy from polyunsaturated fat was associated with 5% (RR = 0.95; 95% CI:0.91–0.98) and 4% (RR = 0.96; 95% CI:0.94–0.99) lower mortality from CVD and cancer, respectively. A 1% energy increment in dietary trans-fat was associated with 6% higher risk of mortality from all-causes (RR = 1.06; 95% CI:1.01–1.10) and CVD (RR = 1.06; 95% CI:1.02–1.11). We found a non-linear association between dietary saturated fat and all-cause mortality showing a significant increased risk up to 11% of energy from saturated fat intake. The risk of cancer mortality increased by 4% for every 5% increase in energy from saturated fat (RR = 1.04; 95% CI:1.02–1.06).
Diets high in saturated fat were associated with higher mortality from all-causes, CVD, and cancer, whereas diets high in polyunsaturated fat were associated with lower mortality from all-causes, CVD, and cancer. Diets high in trans-fat were associated with higher mortality from all-causes and CVD. Diets high in monounsaturated fat were associated with lower all-cause mortality.
Dramatically increasing trends in consumption of ultra-processed foods have been reported across the globe. Public concern about the health consequences of ultra-processed foods is high. This ...manuscript provides a comprehensive review of trends in global consumption of ultra-processed foods, dietary nutrient profile of ultra-processed foods, demographic, socioeconomic, psychological, and behavioral characteristics of ultra-processed food consumers, current evidence from longitudinal studies at the population level on the association between ultra-processed foods consumption and major health outcomes (including all-cause and cause-specific mortality, cardiovascular disease, overweight and obesity, body composition and fat deposition, diabetes, cancer, and gastrointestinal and other diseases), potential mechanisms linking ultra-processed foods with these outcomes (nutrient displacement, factors that influence adiposity, and processing), and challenges and future research directions. The global trends in consumption of ultra-processed foods, the generally unfavorable nutrient profile of ultra-processed foods, the characteristics of ultra-processed food consumers, the accumulating longitudinal studies associating ultra-processed foods with major health outcomes, and the uncertainties and complexities in putative mechanisms all highlight the need for future high-quality epidemiologic and mechanistic investigations on this topic. It is critical to interpret findings in the light of the totality of evidence.
Widespread prostate‐specific antigen (PSA) screening detects many cancers that would have otherwise gone undiagnosed. To estimate the prevalence of unsuspected prostate cancer, we reviewed 19 studies ...of prostate cancer discovered at autopsy among 6,024 men. Among men aged 70–79, tumor was found in 36% of Caucasians and 51% of African‐Americans. This enormous prevalence, coupled with the high sensitivity of PSA screening, has led to the marked increase in the apparent incidence of prostate cancer. The impact of PSA screening on clinical practice is well‐recognized, but its effect on epidemiologic research is less appreciated. Before screening, a larger proportion of incident prostate cancers had lethal potential and were diagnosed at advanced stage. However, in the PSA era, overall incident prostate cancer mainly is indolent disease, and often reflects the propensity to be screened and biopsied. Studies must therefore focus on cancers with lethal potential, and include long follow‐up to accommodate the lead time induced by screening. Moreover, risk factor patterns differ markedly for potentially lethal and indolent disease, suggesting separate etiologies and distinct disease entities. Studies of total incident or indolent prostate cancer are of limited clinical utility, and the main focus of research should be on prostate cancers of lethal potential.
IMPORTANCE: It is important to document patterns of prescription drug use to inform both clinical practice and research. OBJECTIVE: To evaluate trends in prescription drug use among adults living in ...the United States. DESIGN, SETTING, AND PARTICIPANTS: Temporal trends in prescription drug use were evaluated using nationally representative data from the National Health and Nutrition Examination Survey (NHANES). Participants included 37 959 noninstitutionalized US adults, aged 20 years and older. Seven NHANES cycles were included (1999-2000 to 2011-2012), and the sample size per cycle ranged from 4861 to 6212. EXPOSURES: Calendar year, as represented by continuous NHANES cycle. MAIN OUTCOMES AND MEASURES: Within each NHANES cycle, use of prescription drugs in the prior 30 days was assessed overall and by drug class. Temporal trends across cycles were evaluated. Analyses were weighted to represent the US adult population. RESULTS: Results indicate an increase in overall use of prescription drugs among US adults between 1999-2000 and 2011-2012 with an estimated 51% of US adults reporting use of any prescription drugs in 1999-2000 and an estimated 59% reporting use of any prescription drugs in 2011-2012 (difference, 8% 95% CI, 3.8%-12%; P for trend <.001). The prevalence of polypharmacy (use of ≥5 prescription drugs) increased from an estimated 8.2% in 1999-2000 to 15% in 2011-2012 (difference, 6.6% 95% CI, 4.4%-8.2%; P for trend <.001). These trends remained statistically significant with age adjustment. Among the 18 drug classes used by more than 2.5% of the population at any point over the study period, the prevalence of use increased in 11 drug classes including antihyperlipidemic agents, antidepressants, prescription proton-pump inhibitors, and muscle relaxants. CONCLUSIONS AND RELEVANCE: In this nationally representative survey, significant increases in overall prescription drug use and polypharmacy were observed. These increases persisted after accounting for changes in the age distribution of the population. The prevalence of prescription drug use increased in the majority of, but not all, drug classes.
Recent evidence has suggested that flavonoid and lignan intake may be associated with decreased risk of chronic and degenerative diseases. The aim of this meta-analysis was to assess the association ...between dietary flavonoid and lignan intake and all-cause and cardiovascular disease (CVD) mortality in prospective cohort studies. A systematic search was conducted in electronic databases to identify studies published from January 1996 to December 2015 that satisfied inclusion/exclusion criteria. Risk ratios and 95% confidence intervals were extracted and analyzed using a random-effects model. Nonlinear dose-response analysis was modeled by using restricted cubic splines. The inclusion criteria were met by 22 prospective studies exploring various flavonoid and lignan classes. Compared with lower intake, high consumption of total flavonoids was associated with decreased risk of all-cause mortality (risk ratio = 0.74, 95% confidence intervals: 0.55, 0.99), while a 100-mg/day increment in intake led to a (linear) decreased risk of 6% and 4% of all-cause and CVD mortality, respectively. Among flavonoid classes, significant results were obtained for intakes of flavonols, flavones, flavanones, anthocyanidins, and proanthocyanidins. Only limited evidence was available on flavonoid classes and lignans and all-cause mortality. Findings from this meta-analysis indicated that dietary flavonoids are associated with decreased risk of all-cause and CVD mortality.
Serrated polyps (SPs) and conventional adenomas are precursor lesions for colorectal cancer (CRC), but they are believed to arise via distinct pathways. We characterized risk factor profiles for SPs ...and conventional adenomas in a post hoc analysis of data from 3 large prospective studies.
We collected data from the Nurses’ Health Study, the Nurses’ Health Study 2, and the Health Professionals Follow-up Study on subjects who developed SPs or conventional adenomas. Our analysis comprised 141,143 participants who had undergone lower gastrointestinal endoscopy, provided updated diet and lifestyle data every 2–4 years, and were followed until diagnosis of a first polyp. We assessed 13 risk factors for CRC in patients with SPs or conventional adenomas and examined the associations according to histopathology features.
We documented 7945 SPs, 9212 conventional adenomas, and 2382 synchronous SPs and conventional adenomas during 18–20 years of follow-up. Smoking, body mass index, alcohol intake, family history of CRC, and height were associated with higher risk of SPs and conventional adenomas, whereas higher intake of vitamin D and marine omega-3 fatty acid were associated with lower risk. The associations tended to be stronger for synchronous SPs and conventional adenomas. Smoking, body mass index, and alcohol intake were more strongly associated with SPs than conventional adenomas (P for heterogeneity <.05), whereas physical activity and intake of total folate and calcium were inversely associated with conventional adenomas but not SPs. For SPs and conventional adenomas, the associations tended to be stronger for polyps in the distal colon and rectum, of 10 mm or larger or with advanced histology.
In an analysis of data from 3 large prospective studies, we found that although SPs and conventional adenomas share many risk factors, some factors are more strongly associated with one type of lesion than the other. These findings provide support for the etiologic heterogeneity of colorectal neoplasia.
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AbstractObjectiveTo investigate the association of predicted lean body mass, fat mass, and body mass index (BMI) with all cause and cause specific mortality in men.DesignProspective cohort ...study.SettingHealth professionals in the United StatesParticipants38 006 men (aged 40-75 years) from the Health Professionals Follow-up Study, followed up for death (1987-2012).Main outcome measuresAll cause and cause specific mortality.ResultsUsing validated anthropometric prediction equations previously developed from the National Health and Nutrition Examination Survey, lean body mass and fat mass were estimated for all participants. During a mean of 21.4 years of follow-up, 12 356 deaths were identified. A J shaped association was consistently observed between BMI and all cause mortality. Multivariable adjusted Cox models including predicted fat mass and lean body mass showed a strong positive monotonic association between predicted fat mass and all cause mortality. Compared with those in the lowest fifth of predicted fat mass, men in the highest fifth had a hazard ratio of 1.35 (95% confidence interval 1.26 to 1.46) for mortality from all causes. In contrast, a U shaped association was found between predicted lean body mass and all cause mortality. Compared with those in the lowest fifth of predicted lean body mass, men in the second to fourth fifths had 8-10% lower risk of mortality from all causes. In the restricted cubic spline models, the risk of all cause mortality was relatively flat until 21 kg of predicted fat mass and increased rapidly afterwards, with a hazard ratio of 1.22 (1.18 to 1.26) per standard deviation. For predicted lean body mass, a large reduction of the risk was seen within the lower range until 56 kg, with a hazard ratio of 0.87 (0.82 to 0.92) per standard deviation, which increased thereafter (P for non-linearity <0.001). For cause specific mortality, men in the highest fifth of predicted fat mass had hazard ratios of 1.67 (1.47 to 1.89) for cardiovascular disease, 1.24 (1.09 to 1.43) for cancer, and 1.26 (0.97 to 1.64) for respiratory disease. On the other hand, a U shaped association was found between predicted lean body mass and mortality from cardiovascular disease and cancer. However, a strong inverse association existed between predicted lean body mass and mortality from respiratory disease (P for trend <0.001).ConclusionsThe shape of the association between BMI and mortality was determined by the relation between two body components (lean body mass and fat mass) and mortality. This finding suggests that the “obesity paradox” controversy may be largely explained by low lean body mass, rather than low fat mass, in the lower range of BMI.
Endoscopic screening reduces incidence and mortality of colorectal cancer (CRC) because precursor lesions, such as conventional adenomas or serrated polyps, are removed. Individuals with ...polypectomies are advised to undergo colonoscopy surveillance to prevent CRC. However, guidelines for surveillance intervals after diagnosis of a precursor lesion, particularly for individuals with serrated polyps, vary widely, and lack sufficient supporting evidence. Consequently, some high-risk patients do not receive enough surveillance and lower-risk subjects receive excessive surveillance.
We examined the association between findings from first endoscopy and CRC risk among 122,899 participants who underwent flexible sigmoidoscopy or colonoscopy in the Nurses’ Health Study 1 (1990–2012), Nurses’ Health Study 2 (1989–2013), or the Health Professionals Follow-up Study (1990–2012). Endoscopic findings were categorized as no polyp, conventional adenoma, or serrated polyp (hyperplastic polyp, traditional serrated adenoma, or sessile serrated adenoma, with or without cytological dysplasia). Conventional adenomas were classified as advanced (≥10 mm, high-grade dysplasia, or tubulovillous or villous histology) or nonadvanced, and serrated polyps were assigned to categories of large (≥10 mm) or small (<10 mm). We used a Cox proportional hazards regression model to calculate the hazard ratios (HRs) of CRC incidence, after adjusting for various potential risk factors.
After a median follow-up period of 10 years, we documented 491 incident cases of CRC: 51 occurred in 6161 participants with conventional adenomas, 24 in 5918 participants with serrated polyps, and 427 in 112,107 participants with no polyp. Compared with participants with no polyp detected during initial endoscopy, the multivariable HR for incident CRC in individuals with an advanced adenoma was 4.07 (95% confidence interval CI 2.89–5.72) and the HR for CRC in individuals with a large serrated polyp was 3.35 (95% CI 1.37–8.15). In contrast, there was no significant increase in risk of CRC in patients with nonadvanced adenomas (HR 1.21; 95% CI 0.68–2.16, P = .52) or small serrated polyps (HR 1.25; 95% CI 0.76–2.08; P = .38).
These findings provide support for guidelines that recommend repeat lower endoscopy within 3 years of a diagnosis of advanced adenoma and large serrated polyps. In contrast, patients with nonadvanced adenoma or small serrated polyps may not require more intensive surveillance than patients without polyps.
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