Behavioural interventions delivered through interactive social media for health behaviour change, health outcomes, and health equity in the adult population.

BACKGROUND: Social networking platforms offer a wide reach for public health interventions allowing communication with broad audiences using tools that are generally free and straightforward to use and may be combined with other components, such as public health policies. We define interactive social media as activities, practices, or behaviours among communities of people who have gathered online to interactively share information, knowledge, and opinions. OBJECTIVES: We aimed to assess the effectiveness of interactive social media interventions, in which adults are able to communicate directly with each other, on changing health behaviours, body functions, psychological health, well-being, and adverse effects. Our secondary objective was to assess the effects of these interventions on the health of populations who experience health inequity as defined by PROGRESS-Plus. We assessed whether there is evidence about PROGRESS-Plus populations being included in studies and whether results are analysed across any of these characteristics. SEARCH METHODS: We searched CENTRAL, CINAHL, Embase, MEDLINE (including trial registries) and PsycINFO. We used Google, Web of Science, and relevant web sites to identify additional studies and searched reference lists of included studies. We searched for published and unpublished studies from 2001 until June 1, 2020. We did not limit results by language. SELECTION CRITERIA: We included randomised controlled trials (RCTs), controlled before-and-after (CBAs) and interrupted time series studies (ITSs). We included studies in which the intervention website, app, or social media platform described a goal of changing a health behaviour, or included a behaviour change technique. The social media intervention had to be delivered to adults via a commonly-used social media platform or one that mimicked a commonly-used platform. We included studies comparing an interactive social media intervention alone or as a component of a multi-component intervention with either a non-interactive social media control or an active but less-interactive social media comparator (e.g. a moderated versus an unmoderated discussion group). Our main outcomes were health behaviours (e.g. physical activity), body function outcomes (e.g. blood glucose), psychological health outcomes (e.g. depression), well-being, and adverse events. Our secondary outcomes were process outcomes important for behaviour change and included knowledge, attitudes, intention and motivation, perceived susceptibility, self-efficacy, and social support. DATA COLLECTION AND ANALYSIS: We used a pre-tested data extraction form and collected data independently, in duplicate. Because we aimed to assess broad outcomes, we extracted only one outcome per main and secondary outcome categories prioritised by those that were the primary outcome as reported by the study authors, used in a sample size calculation, and patient-important. MAIN RESULTS: We included 88 studies (871,378 participants), of which 84 were RCTs, three were CBAs and one was an ITS. The majority of the studies were conducted in the USA (54%). In total, 86% were conducted in high-income countries and the remaining 14% in upper middle-income countries. The most commonly used social media platform was Facebook (39%) with few studies utilising other platforms such as WeChat, Twitter, WhatsApp, and Google Hangouts. Many studies (48%) used web-based communities or apps that mimic functions of these well-known social media platforms. We compared studies assessing interactive social media interventions with non-interactive social media interventions, which included paper-based or in-person interventions or no intervention. We only reported the RCT results in our 'Summary of findings' table. We found a range of effects on health behaviours, such as breastfeeding, condom use, diet quality, medication adherence, medical screening and testing, physical activity, tobacco use, and vaccination. For example, these interventions may increase physical activity and medical screening tests but there was little to no effect for other health behaviours, such as improved diet or reduced tobacco use (20,139 participants in 54 RCTs). For body function outcomes, interactive social media interventions may result in small but important positive effects, such as a small but important positive effect on weight loss and a small but important reduction in resting heart rate (4521 participants in 30 RCTs). Interactive social media may improve overall well-being (standardised mean difference (SMD) 0.46, 95% confidence interval (CI) 0.14 to 0.79, moderate effect, low-certainty evidence) demonstrated by an increase of 3.77 points on a general well-being scale (from 1.15 to 6.48 points higher) where scores range from 14 to 70 (3792 participants in 16 studies). We found no difference in effect on psychological outcomes (depression and distress) representing a difference of 0.1 points on a standard scale in which scores range from 0 to 63 points (SMD -0.01, 95% CI -0.14 to 0.12, low-certainty evidence, 2070 participants in 12 RCTs). We also compared studies assessing interactive social media interventions with those with an active but less interactive social media control (11 studies). Four RCTs (1523 participants) that reported on physical activity found an improvement demonstrated by an increase of 28 minutes of moderate-to-vigorous physical activity per week (from 10 to 47 minutes more, SMD 0.35, 95% CI 0.12 to 0.59, small effect, very low-certainty evidence). Two studies found little to no difference in well-being for those in the intervention and control groups (SMD 0.02, 95% CI -0.08 to 0.13, small effect, low-certainty evidence), demonstrated by a mean change of 0.4 points on a scale with a range of 0 to 100. Adverse events related to the social media component of the interventions, such as privacy issues, were not reported in any of our included studies. We were unable to conduct planned subgroup analyses related to health equity as only four studies reported relevant data. AUTHORS' CONCLUSIONS: This review combined data for a variety of outcomes and found that social media interventions that aim to increase physical activity may be effective and social media interventions may improve well-being. While we assessed many other outcomes, there were too few studies to compare or, where there were studies, the evidence was uncertain. None of our included studies reported adverse effects related to the social media component of the intervention. Future studies should assess adverse events related to the interactive social media component and should report on population characteristics to increase our understanding of the potential effect of these interventions on reducing health inequities.

Migration and diabetes in British Columbia and Quebec: prevalence and health service utilization.

OBJECTIVES: This study describes prevalence of diabetes among immigrants and health service utilization among diabetic immigrants in British Columbia (BC) and Quebec (QC). METHODS: Immigrants to BC and QC between 1985 and 1999 were identified. Using age-standardized rate ratios, they were compared with a matched comparison group with respect to their diabetes prevalence and, among those with diabetes, physician service utilization. RESULTS: Immigrant women in both provinces and men in BC had higher rates of diabetes compared to the matched comparison group. Rates varied by region of birth and language ability. Diabetes prevalence rate ratios increased with length of stay in BC. Diabetic immigrants had lower rates of physician visits than diabetic comparisons. This gap decreased commensurate with immigrants' length of stay in BC. Diabetic immigrants who spoke neither official language had similar or higher rates of physician visits compared with immigrants who spoke one or both official languages. CONCLUSIONS: Genetic predisposition, lifestyle changes, acculturation, resettlement stress and differential health care access may explain increased prevalence of diabetes among many immigrants. These results can inform diabetes prevention and management programs tailored to the needs of specific immigrant groups. The gap in health service use between diabetic immigrants and comparisons does not appear to be related to language ability. Further studies are required to identify reasons.

Monitoring gender equity in mental health in a low-, middle-, and high-income country in the Americas.

OBJECTIVE: Gender disparities in mental health highlight the need to include gender equity measures when planning, implementing, and evaluating mental health programs at national, state or provincial, and municipal levels. This study aimed to identify, select, and assess the feasibility of comparing gender-sensitive mental health indicators in a low- (Peru), middle- (Colombia), and high- (Canada) income country. METHODS: The indicators were selected by a multidisciplinary group of experts who used criteria and a framework proposed by the World Health Organization. Data from national, population-based databases from each country were used to measure the indicators. RESULTS: Seven indicators (12-month prevalence of the following: depression, psychological distress, generalized anxiety disorder, suicide attempts, alcohol dependence, mental health service use, and psychological impairment) were feasible for measurement in at least two countries. Only five indicators were comparable between two countries, and only one was comparable among all countries (suicide attempts). The indicators that showed the greatest inequities between men and women were depression, anxiety, suicide attempts, use of mental health services, and alcohol dependence. Female-to-male ratios for prevalence of mental illness ranged from .1 to 2.3, and ratios for service use ranged from 1.3 to 1.9. Significant trends were found when the indicators were considered by age, education, marital status, and income. CONCLUSIONS: Some of these indicators can be used to identify populations most vulnerable to gender inequities in mental health. The results from this study may provide useful information to program planners who aim to implement, improve, and monitor national mental health strategies that reduce gender inequities under different national conditions.

Breast cancer risk associated with residential proximity to industrial plants in Canada.

OBJECTIVE: The relationship between breast cancer risk and residential proximity to paper mills, pulp mills, petroleum refineries, steel mills, thermal power plants, alum smelters, nickel smelters, lead smelters, copper smelters, and zinc smelters was assessed. METHODS: We conducted a population-based case-control study of 2343 cases with breast cancer and 2467 controls using residential proximity at some time between 1960 and 5 years before the completion of questionnaire in Canada. RESULTS: Adjusted odds ratios were statistically significantly increased for residing near steel mills (0.8 to 3.2 km) and thermal power plants (<0.8 km) in premenopausal women, petroleum refinery (0.8 to 3.2 km) and pulp mills (0.8 to 3.2 km) in postmenopausal women, and for 10 or more years of residing near thermal power plants of 0.8 km. CONCLUSIONS: Our preliminary results suggested possible weak associations between breast cancer and proximity to steel mills, pulp mills, petroleum refineries, and thermal power plants.

Leisure-time physical activity and marital status in relation to depression between men and women: A prospective study.

BACKGROUND: Previous studies have identified the preventive effect of leisure-time physical activity (LTPA) on depression. Women and men have different emotional vulnerabilities. The impact of LTPA on depression varies by gender. Little is known about the impact of LTPA on depression for people with different marital status. OBJECTIVES: The objective of this study was to assess the long-term effects of LTPA, changes in LTPA, and marital status on the risk of developing depression for general Canadians. METHODS: Data from the biennial National Population Health Survey (NPHS) cycles conducted between 1994/95 and 2004/05 were analyzed in 2008. After excluding individuals with preexisting depression at baseline, respondents were classified as physically active or inactive and then followed up in subsequent cycles of the NPHS to look at risk of developing depression. Individuals who changed their activity level were also examined. Subgroup analyses by different marital status were performed to identify high-risk populations. RESULTS: In 1994/1995, 17,276 participants were included in the NPHS longitudinal panel. Respondents who were inactive were more likely to be older, female, obese, widowed/separated/divorced, not working, low income, and lacking social support. After controlling for potential confounding factors, it was found that LTPA reduced the risk of developing depression for women. The modest risk reduction observed for men was not statistically significant. Women who were active at baseline and two years of follow-up were significantly less likely to report depression at four years of follow-up compared to women who were inactive at baseline and at two years of follow-up. A 51% greater probability of developing depression was observed after two years for women who changed their LTPA from active to inactive compared to women who remained active. No significant results were found for men. Divorced/separated/widowed women who stopped LTPA had 4.2 times the risk of developing depression after two years compared to those who remained active. The risk of developing depression after stopping activity did not vary according to marital status among men. CONCLUSIONS: LTPA has preventive effects on depression for women. Reduction in LTPA level is associated with subsequent depression for women. Divorced/separated/widowed women are at particularly high risk of developing depression if LTPA is stopped.

Migration and health in Canada: health in the global village.

BACKGROUND: Immigration has been and remains an important force shaping Canadian demography and identity. Health characteristics associated with the movement of large numbers of people have current and future implications for migrants, health practitioners and health systems. We aimed to identify demographics and health status data for migrant populations in Canada. METHODS: We systematically searched Ovid MEDLINE (1996-2009) and other relevant web-based databases to examine immigrant selection processes, demographic statistics, health status from population studies and health service implications associated with migration to Canada. Studies and data were selected based on relevance, use of recent data and quality. RESULTS: Currently, immigration represents two-thirds of Canada's population growth, and immigrants make up more than 20% of the nation's population. Both of these metrics are expected to increase. In general, newly arriving immigrants are healthier than the Canadian population, but over time there is a decline in this healthy immigrant effect. Immigrants and children born to new immigrants represent growing cohorts; in some metropolitan regions of Canada, they represent the majority of the patient population. Access to health services and health conditions of some migrant populations differ from patterns among Canadian-born patients, and these disparities have implications for preventive care and provision of health services. INTERPRETATION: Because the health characteristics of some migrant populations vary according to their origin and experience, improved understanding of the scope and nature of the immigration process will help practitioners who will be increasingly involved in the care of immigrant populations, including prevention, early detection of disease and treatment.

Cancer incidence among Canadian immigrants, 1980-1998: results from a national cohort study.

Canadian immigrants have lower overall cancer risk than the Canadian-born population. Less is known about risks for immigrant subgroups and site-specific cancers. Linked administrative data sets were used to compare cancer incidence between subgroups of immigrants to Canada and the general Canadian population. The study involved 128,962 refugees and 241,010 non-refugees. Standardized incidence ratios (SIRs) were calculated for all-site and site-specific cancers by immigration categories and regions of birth. Relative to the general Canadian population, incidence of all-site cancer was lower among immigrants overall, by sex and refugee status (non-refugee SIRs 0.25: men, 0.24: women; refugee SIRs 0.31: both). Significantly higher SIRs resulted for liver, nasopharyngeal and cervical cancers, including liver cancer among South-East Asian and North-East Asian immigrants, and nasopharyngeal cancer among North-East Asian non-refugees. Hypothesized explanations for variation in cancer incidence include earlier viral infection in the country of origin.

A meta-analysis of randomized control trials of home-based secondary prevention programs for coronary artery disease.

BACKGROUND: A variety of different types of secondary prevention programs for coronary heart disease (CHD) exist. Home-based programs have become more common and may be more accessible or preferable to some patients. This review compared the benefits and costs of home-based programs with usual care and cardiac rehabilitation. METHODS: A meta-analysis following a systematic search of 19 databases, existing reviews, and references was designed. Studies evaluated home-based interventions that addressed more than one main CHD risk factor using a randomized trial with a usual care or cardiac rehabilitation comparison group with data extractable for CHD patients only and reported in English as a full article or thesis. RESULTS: Thirty-nine articles reporting 36 trials were reviewed. Compared with usual care, home-based interventions significantly improved quality of life [weighted mean difference: 0.23; 95% confidence interval (95% CI): 0.02-0.45], systolic blood pressure (weighted mean difference: -4.36 mmHg; 95% CI: -6.50 to -2.22), smoking cessation (difference in proportion: 14%; 95% CI: 0.02-0.26), total cholesterol (standardized mean difference: -0.33; 95% CI: -0.57 to -0.08), and depression (standardized mean difference: -0.33; 95% CI: -0.59 to -0.07). Effect sizes were small to moderate and trials were of low-to-moderate quality. Comparisons with cardiac rehabilitation could not be made because of the small number of trials and high levels of heterogeneity. CONCLUSION: Home-based secondary prevention programs for CHD are an effective and relatively low-cost complement to hospital-based cardiac rehabilitation and should be considered for stable patients less likely to access or adhere to hospital-based services.

Age- and sex-related prevalence of diabetes mellitus among immigrants to Ontario, Canada.

BACKGROUND: The majority of immigrants to Canada originate from the developing world, where the most rapid increase in prevalence of diabetes mellitus is occurring. We undertook a population-based study involving immigrants to Ontario, Canada, to evaluate the distribution of risk for diabetes in this population. METHODS: We used linked administrative health and immigration records to calculate age-specific and age-adjusted prevalence rates among men and women aged 20 years or older in 2005. We compared rates among 1,122,771 immigrants to Ontario by country and region of birth to rates among long-term residents of the province. We used logistic regression to identify and quantify risk factors for diabetes in the immigrant population. RESULTS: After controlling for age, immigration category, level of education, level of income and time since arrival, we found that, as compared with immigrants from western Europe and North America, risk for diabetes was elevated among immigrants from South Asia (odds ratio [OR] for men 4.01, 95% CI 3.82-4.21; OR for women 3.22, 95% CI 3.07-3.37), Latin America and the Caribbean (OR for men 2.18, 95% CI 2.08-2.30; OR for women 2.40, 95% CI: 2.29-2.52), and sub-Saharan Africa (OR for men 2.31, 95% CI 2.17-2.45; OR for women 1.83, 95% CI 1.72-1.95). Increased risk became evident at an early age (35-49 years) and was equally high or higher among women as compared with men. Lower socio-economic status and greater time living in Canada were also associated with increased risk for diabetes. INTERPRETATION: Recent immigrants, particularly women and immigrants of South Asian and African origin, are at high risk for diabetes compared with long-term residents of Ontario. This risk becomes evident at an early age, suggesting that effective programs for prevention of diabetes should be developed and targeted to immigrants in all age groups.

Total fluid and specific beverage intake and risk of renal cell carcinoma in Canada.

BACKGROUND: Intake of total fluids and specific beverages may be associated with the risk of renal cell carcinoma (RCC) through a diluting effect of carcinogens. However, total fluid consumption and RCC risk has not received sufficient examination. In this study, we assessed the roles of total fluid intake and type of beverage intake in the risk of RCC. METHODS: Mailed questionnaires were completed by 1138 newly diagnosed, histologically confirmed RCC cases and 5039 population controls between 1994 and 1997 in 8 Canadian provinces. Data collection included information on socio-economic status, physical activity, smoking habits, alcoholic and non-alcoholic beverage use, diet, residential history and occupational history. Odds ratios (ORs) and 95% confidence intervals (CIs) were derived through unconditional logistic regression. RESULTS: Higher total fluid intake was associated with risk of RCC; the OR for the highest versus the lowest quartile was 1.49 (95% CI 1.20-1.85). Intake of total juices and coffee was also related to the risk of RCC; for the highest versus the lowest quartile, the ORs were 1.53 (95% CI 1.18-1.99) and 1.33 (95% CI 1.07-1.66), respectively. These positive associations were stronger in men, but not in women. Higher coffee intake was more strongly associated with RCC in normal weight subjects. In contrast, total intake of alcohol was inversely associated with the risk of RCC. Intake of tap water (not in coffee or tea), bottled water, tea, soft drinks and milk was not related to RCC. CONCLUSIONS: The risk of RCC for higher intake of total fluids, coffee and juices might involve gender differences.

Socioeconomic status and cardiovascular disease: risks and implications for care.

Socioeconomic status (SES) refers to an individual's social position relative to other members of a society. Low SES is associated with large increases in cardiovascular disease (CVD) risk in men and women. The inverse association between SES and CVD risk in high-income countries is the result of the high prevalence and compounding effects of multiple behavioral and psychosocial risk factors in people of low SES. However, strong and consistent evidence shows that parental SES, childhood and early-life factors, and inequalities in health services also contribute to elevated CVD risk in people of low SES who live in high-income countries. In addition, place of residence can affect CVD risk, although the data on the influence of wealth distribution and work-related factors are inconsistent. Studies on the effects of SES on CVD risk in low-income and middle-income countries is scarce, but evidence is emerging that the increasing wealth of these countries is beginning to lead to replication of the patterns seen in high-income countries. Clinicians should address the association between SES and CVD by incorporating SES into CVD risk calculations and screening tools, reducing behavioral and psychosocial risk factors via effective and equitable primary and secondary prevention, undertaking health equity audits to assess inequalities in care provision and outcomes, and by use of multidisciplinary teams to address risk factors over the life course.

Migration to western industrialised countries and perinatal health: a systematic review.

Influxes of migrant women of childbearing age to receiving countries have made their perinatal health status a key priority for many governments. The international research collaboration Reproductive Outcomes And Migration (ROAM) reviewed published studies to assess whether migrants in western industrialised countries have consistently poorer perinatal health than receiving-country women. A systematic review of literature from Medline, Health Star, Embase and PsychInfo from 1995 to 2008 included studies of migrant women/infants related to pregnancy or birth. Studies were excluded if there was no cross-border movement or comparison group or if the receiving country was not western and industrialised. Studies were assessed for quality, analysed descriptively and meta-analysed when possible. We identified 133 reports (>20,000,000 migrants), only 23 of which could be meta-analysed. Migrants were described primarily by geographic origin; other relevant aspects (e.g., time in country, language fluency) were rarely studied. Migrants' results for preterm birth, low birthweight and health-promoting behaviour were as good or better as those for receiving-country women in >or=50% of all studies. Meta-analyses found that Asian, North African and sub-Saharan African migrants were at greater risk of feto-infant mortality than 'majority' receiving populations, and Asian and sub-Saharan African migrants at greater risk of preterm birth. The migration literature is extensive, but the heterogeneity of the study designs and definitions of migrants limits the conclusions that can be drawn. Research that uses clear, specific migrant definitions, adjusts for relevant risk factors and includes other aspects of migrant experience is needed to confirm and understand these associations.

Dietary vitamin C, E, and carotenoid intake and risk of renal cell carcinoma.

OBJECT: The study examines the association between dietary intake of vitamin C, E, and carotenoids and the risk of renal cell carcinoma (RCC). METHODS: Between 1994 and 1997 in 8 Canadian provinces, mailed questionnaires were completed by 1,138 incident, histologically confirmed cases of RCC and 5,039 population controls, including information on socio-economic status, lifestyle habits and diet. A 69-item food frequency questionnaire provided data on eating habits 2 years before data collection. Odds ratios (OR) and 95% confidence intervals (CI) were computed using unconditional logistic regression. RESULTS: Dietary intake of beta-carotene and lutein/zeaxanthin was inversely associated with the risk of RCC. The ORs for the highest versus the lowest quartile were 0.74 (95% CI, 0.59-0.92) and 0.77 (95% CI, 0.62-0.95), respectively. The significant inverse association with beta-carotene and lutein/zeaxanthin was more pronounced in women, and in overweight or obese subjects. The relation of lutein/zeaxanthin to RCC was stronger in ever smokers. No clear association was observed with vitamin C and E, beta-cryptozanthin, and lycopene. CONCLUSION: The findings provide evidence that a diet rich in beta-carotene and lutein/zeaxanthin may play a role in RCC prevention.

A review of the cost of cardiovascular disease.

In Canada, 74,255 deaths (33% of all deaths) in 2003 were due to cardio-vascular disease (CVD). As one of the most costly diseases, CVD represents a major economic burden on health care systems. The purpose of the present study was to review the literature on the economic costs of CVD in Canada and other developed countries (United States, Europe and Australia) published from 1998 to 2006, with a focus on Canada. Of 1656 screened titles and abstracts, 34 articles were reviewed including six Canadian studies and 17 American studies. While considerable variation was observed among studies, all studies indicated that the costs of treating CVD-related conditions are significant, outlining a convincing case for CVD prevention programs.

Individual, social, environmental, and physical environmental correlates with physical activity among Canadians: a cross-sectional study.

BACKGROUND: The identification of various individual, social and physical environmental factors affecting physical activity (PA) behavior in Canada can help in the development of more tailored intervention strategies for promoting higher PA levels in Canada. This study examined the influences of various individual, social and physical environmental factors on PA participation by gender, age and socioeconomic status, using data from the 2002 nationwide survey of the Physical Activity Monitor. METHODS: In 2002, 5,167 Canadians aged 15-79 years, selected by random-digit dialling from household-based telephone exchanges, completed a telephone survey. The short version of the International Physical Activity Questionnaire was used to collect information on total physical activity. The effects of socio-economical status, self-rated health, self-efficacy, intention, perceived barriers to PA, health benefits of PA, social support, and facility availability on PA level were examined by multiple logistic regression analyses. RESULTS: Self-efficacy and intention were the strongest correlates and had the greatest effect on PA. Family income, self-rated health and perceived barriers were also consistently associated with PA. The effects of the perceived health benefits, education and family income were more salient to older people, whereas the influence of education was more important to women and the influence of perceived barriers was more salient to women and younger people. Facility availability was more strongly associated with PA among people with a university degree than among people with a lower education level. However, social support was not significantly related to PA in any subgroup. CONCLUSION: This study suggests that PA promotion strategies should be tailored to enhance people's confidence to engage in PA, motivate people to be more active, educate people on PA's health benefits and reduce barriers, as well as target different factors for men and women and for differing socio-economic and demographic groups.

Rural-urban disparities in health: how does Canada fare and how does Canada compare with Australia?

OBJECTIVE: To analyse rural-urban and intra-rural disparities in health status in Canada and to compare Canada with Australia with respect to such disparities. DESIGN: Four indicators were used to show rural-urban and intra-rural differences in health status: (i) mortality due to circulatory diseases, (ii) mortality due to cancer, (iii) injury-related mortality; and (iv) all-cause mortality. Rural was disaggregated into finer categories based on degree of remoteness, using the Metropolitan Influence Zone classification in Canada and the Accessibility/Remoteness Index of Australia. Comparisons were made using age-standardised mortality rates and standardised mortality ratios. PARTICIPANTS: Rural and urban populations of Canada and Australia. RESULTS: The study confirmed previous findings that rural Canadians tended to have poorer health status than their urban counterparts. However, when rural was disaggregated into finer categories, different health status patterns emerged. Although the most rural areas tended to have the worst health status, the least rural areas generally enjoyed good health. The Canada-Australia comparisons revealed convergence and divergence. CONCLUSIONS: The similarities between Canada and Australia show that rural-urban disparities in health status are not limited to a particular country. For several causes of death, whereas the mortality risks in Rural 1 areas in Canada are significantly lower than in urban areas, the opposite is true in Australia, suggesting that although there are some common patterns across the two countries in relation to rural-urban health status disparities, nation-specific uniqueness is to be expected.

Energy intake, physical activity, energy balance, and cancer: epidemiologic evidence.

Energy intake, physical activity, and obesity are modifiable lifestyle factors. This chapter reviews and summarizes the epidemiologic evidence on the relation of energy intake, physical activity, and obesity to cancer. High energy intake may increase the risk of cancers of colon-rectum, prostate (especially advanced prostate cancer), and breast. However, because physical activity, body size, and metabolic efficiency are highly related to total energy intake and expenditure, it is difficult to assess the independent effect of energy intake on cancer risk. There are sufficient evidences to support a role of physical activity in preventing cancers of the colon and breast, whereas the association is stronger in men than in women for colon cancer and in postmenopausal than in premenopausal women for breast cancer. The evidence also suggests that physical activity likely reduces the risk of cancers of endometrium, lung, and prostate (to a lesser extent). On the other hand, there is little or no evidence that the risk of rectal cancer is related to physical activity, whereas the results have been inconsistent regarding the association between physical activity and the risks of cancers of pancreas, ovary and kidney. Epidemiologic studies provide sufficient evidence that obesity is a risk factor for both cancer incidence and mortality. The evidence supports strong links of obesity with the risk of cancers of the colon, rectum, breast (in postmenopausal women), endometrium, kidney (renal cell), and adenocarcinoma of the esophagus. Epidemiologic evidence also indicates that obesity is probably related to cancers of the pancreas, liver, and gallbladder, and aggressive prostate cancer, while it seems that obesity is not associated with lung cancer. The role of obesity in other cancer risks is unclear.

Nutrient and fiber intake and risk of renal cell carcinoma.

This study examines the association between nutrient and fiber intake and the risk of renal cell carcinoma (RCC). Between 1994 and 1997 in 8 Canadian provinces, mailed questionnaires were completed by 1,138 incident, histologically confirmed cases of RCC and 5,039 population controls. Measurement included information on socioeconomic status, lifestyle habits, and diet. A 69-item food frequency questionnaire provided data on eating habits 2 yr before data collection. Odds ratios (ORs) and 95% confidence intervals were derived through unconditional logistic regression. Intakes of total fat, saturated fat, monounsaturated fat, trans-fat, and cholesterol were associated with the risk of RCC; the ORs for the highest vs. the lowest quartile were 1.67, 1.53 and 1.46, 1.31, and 1.48, respectively. The positive association was apparently stronger in women, overweight or obese, and never smokers. Sucrose was related to the risk of RCC. High fiber intake was inversely associated with RCC risk. No association was found with intake of total protein and polyunsaturated fat, n-3 and n-6 polyunsaturated fatty acids, and total carbohydrates. The results were consistent across strata of sex, tobacco, and BMI. The findings suggest that a diet low in fats and cholesterol and rich in fiber could favorably affect the risk of RCC.

Supporting knowledge into action: The Canadian Best Practices Initiative for Health Promotion and Chronic Disease Prevention.

Public health practitioners and policy-makers working to address the burden of chronic disease are increasingly seeking to use best practices given the need to make thoughtful program and policy choices with limited resources. While the evidence base in chronic disease prevention is growing through a number of different information sources, there is often a disconnect between the desire to use best practices and their implementation. This is related not only to individual and organizational barriers in terms of time and resources, but also to lack of agreement on what constitutes best practice and what sources of evidence are valid guides for practice. This is compounded by lack of user-friendly and streamlined access to credible best practice evidence and decision making/practice supports. In response to these needs, six years ago Canadian researchers, policy-makers and practitioners came together to begin working on creating a best practice system in Canada for health promotion and chronic disease prevention. This article presents an overview of the development of the Canadian Best Practices Portal and in particular how an evolution in thinking about best practice methodology and evidence will contribute to an enriched knowledge base for health promotion and chronic disease prevention policy, practice and research.