Allergic conditions and brain tumor risk

An inverse association between allergic conditions and glioma risk has been reported previously. In this large population-based case-control study, the authors identified cases diagnosed with glioma or meningioma in Denmark, Norway, Finland, Sweden, and southeast England between 2000 and 2004. Detailed information on self-reported physician-diagnosed allergic conditions was collected from 1,527 glioma cases, 1,210 meningioma cases, and 3,309 randomly selected controls. Logistic regression showed an odds ratio of 0.70 (95% confidence interval: 0.61, 0.80) for glioma associated with a diagnosis of any of asthma, hay fever, eczema, or other type of allergy. The risk estimates for glioma were around 0.65 for each allergic condition (asthma, eczema, hay fever, and food allergy), and the 95% confidence intervals were equally consistent, at around 0.55, 0.80. The reduced risks of glioma related to eczema, hay fever, and allergy overall, but not asthma, were confined to current rather than past conditions. Meningioma risk was not associated with allergic conditions, except for eczema (odds ratio = 0.74, 95% confidence interval: 0.60, 0.91). Our results show a reduced risk for glioma associated primarily with current allergic conditions. If this is etiologic, it has implications for the understanding of how allergic conditions might reduce the tumor risk.     

History of allergic disease and risk of meningioma

Epidemiologic studies have consistently shown inverse associations of allergic disease with risk of glioma, but it is unclear whether this association also applies to meningioma. The authors conducted a pooled analysis of meningioma risk in relation to a history of allergic disease based on data from two population-based, case-control studies with 475 cases and 1,716 controls in the United Kingdom (2001-2004). Meningioma risk was significantly reduced in relation to self-reported, physician-diagnosed allergic disease (odds ratio = 0.76, 95% confidence interval (CI): 0.61, 0.96) but was nonsignificantly reduced for individual conditions: asthma (odds ratio = 0.85, 95% CI: 0.61, 1.18), hay fever (odds ratio = 0.81, 95% CI: 0.62, 1.06), and eczema (odds ratio = 0.72, 95% CI: 0.51, 1.02). Risk reductions were greatest for asthma (odds ratio = 0.43, 95% CI: 0.21, 0.89) and hay fever (odds ratio = 0.50, 95% CI: 0.25, 1.00) with an early age at onset (<10 years) and for eczema (odds ratio = 0.46, 95% CI: 0.21, 1.07) with an onset at ages 10-19 years; they were near unity for onset in adulthood. This study suggests an inverse association between a history of allergies and meningioma risk, but with smaller risk reductions than for glioma. The reasons for this association need clarification, as well as an etiologic explanation. Consideration also needs to be given to confounding or bias.     

Obesity and adult asthma: potential effect modification by gender, but not by hay fever

PURPOSE: First, we sought to estimate the magnitude of the cross-sectional associations between overweight/obesity and asthma stratified by gender and by self-reported hay fever and second we sought to assess both directions of causality in longitudinal analyses. METHODS: We used cross-sectional and longitudinal data from a population-based cohort study (n=5114, ages 40-65 at baseline). After 8.5 years, 4010 adults were followed-up by questionnaires. Self-reported height and weight were used to calculate body mass index categories. Multivariate adjusted prevalence ratios (PRs), relative risks (RRs), and 95% confidence intervals (95% CI) were calculated using Poisson regression. RESULTS: In cross-sectional analyses, adjusted PRs were comparable for overweight women and men but differed between obese women and men (PR 1.93, 95% CI 1.19-3.14 and PR 0.98, 95% CI 0.56-1.72). PRs were similar when stratified by hay fever. Longitudinal analyses suggested that overweight/obesity did not increase asthma risk substantially (RR 1.02, 95% CI 0.50-2.06), but a relation between asthma and subsequent weight gain could not be excluded (RR 1.34, 95% CI 1.01-1.77). CONCLUSIONS: The prevalence of asthma is almost twice as high in obese versus normal weight women, but not in obese men. The association between overweight/obesity and asthma does not vary by hay fever. A causal relationship between asthma and incident weight gain cannot be excluded.     

Allergy and cancer: organ site-specific results from the Adventist Health Study.

The relation between allergy and risk of cancer was evaluated in a cohort study of 34,198 Seventh-day Adventists in California. Information on prevalence of asthma, hay fever, and reactions to chemicals, medications, bee stings, and poison oak (or ivy) was obtained by questionnaire in 1976. The reported allergies must have been serious enough to require treatment by a physician. The cohort was then followed for 6 years (1977-1982). Both stratified analysis and Cox proportional hazards regression analyses were utilized to evaluate the relation of allergy to cancer after taking into account several potentially confounding variables. For all cancer sites combined in males, there was a 33% increased risk associated with reaction to medications. In contrast, among females, reaction to medications was associated with a 21% decrease in risk. Both results were statistically significant. Prostate and breast cancer risk were elevated in persons who reported any type of allergic history, as was risk of lymphatic or hematopoietic cancers and sarcoma. For each of these types of cancer, risk increased with increasing numbers of allergies. However, ovarian cancer risk was decreased in persons with any allergic history and increasing numbers of allergies was associated with decreasing risk of this form of cancer. These results suggest that the association between allergy and cancer is complex and depends on the specific allergy and the specific organ site under consideration.     

Opposing effects of emphysema, hay fever, and select genetic variants on lung cancer risk

The authors compared histories of nonmalignant respiratory diseases (asthma, bronchitis, emphysema, hay fever, and pneumonia) in 1,553 lung cancer patients and 1,375 healthy controls enrolled in a Texas case-control study from 1995 to 2003. They incorporated data on two biologically relevant polymorphic genes, matrix metalloproteinase-1 and myeloperoxidase. Emphysema was associated with a statistically significant increased lung cancer risk (odds ratio (OR) = 2.87, 95% confidence interval (CI): 2.20, 3.76), while hay fever had a significant protective effect (OR = 0.58, 95% CI: 0.48, 0.70). Odds ratios were consistent after exclusion of respiratory disease diagnoses made up to 10 years before interview. There was little association between other respiratory diseases and lung cancer risk. Among carriers of "protective" genotypes, emphysema was associated with a 1.7-fold increased risk (95% CI: 0.84, 3.50), as compared with the substantially higher risk for persons possessing one (OR = 4.98, 95% CI: 2.94, 8.44) or two (OR = 4.23, 95% CI: 1.84, 9.73) "adverse" genotypes. For hay fever, significantly decreased risks were evident with one (OR = 0.32, 95% CI: 0.21, 0.50) or two (OR = 0.35, 95% CI: 0.19, 0.66) protective genotypes as compared with none (OR = 0.69, 95% CI: 0.30, 1.59). The biologic role of respiratory disease in lung cancer is unclear. Further study may yield new insights for identification of susceptible subgroups.     

Allergy,atopy, and cancer: a prospective study of the 1981 Busselton cohort

The associations among certain allergic disorders, atopy upon skin-prick testing, and specific cancers were evaluated in a prospective study. Information regarding history of asthma and hay fever was collected by questionnaire from 3,308 cancer-free participants in the 1981 Busselton Health Survey. A subset of 1,005 participants also underwent skin-prick testing. The cohort was followed for a new diagnosis of cancer or death until the end of 1999. Cox proportional hazards regression analysis was used to estimate adjusted hazard ratios (relative risks) for breast, prostate, colorectal, lung, and hematologic cancers and melanoma. Having a skin reaction to house dust mites nearly tripled the risk of prostate cancer (relative risk = 2.90, 95% confidence interval: 1.26, 6.68). History of asthma and hay fever were associated with a trend toward a reduced risk of colorectal cancer and increased risk of leukemia, but these results were not statistically significant. Hay fever was associated with melanoma risk in men but not in women. No association was found between breast and lung cancers and allergic disorders or atopy.     

Mode of delivery is associated with asthma and allergy occurrences in children

PURPOSE: A growing body of evidence indicates that perinatal factors modulate immune development and thereby may affect childhood asthma risk. In this study, we examined the associations between birth by cesarean section (C-section) and atopic disease occurrence in childhood. METHODS: Subjects were born in California between 1975 and 1987 and were 8 to 17 years old during their enrollment in the Children's Health Study. Our analysis was restricted to 3464 children born at or after 37 weeks of gestation with a birth weight of 2500 g or greater based on birth certificate data. Information about sociodemographic factors, reported physician-diagnosed asthma, and other atopic diseases was obtained by using a self-administered structured questionnaire. Logistic regression models were fitted to compute odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: Children born by C-section were at increased risk for asthma (OR, 1.33; 95% CI, 1.01-1.75), hay fever (OR, 1.57; 95% CI, 1.24-1.99), and allergy (OR, 1.26; 95% CI, 1.03-1.53) compared with those born vaginally. Risk associated with C-section was the same for children regardless of family history of asthma or allergy. CONCLUSION: We conclude that birth by C-section or processes associated with it may increase the risk for atopic disease in childhood.     

History of allergic disease and epilepsy and risk of glioma and meningioma (INTERPHONE study group,Germany)

The aim of the present analysis was to examine the association of a medical history of asthma, hay fever, eczema, or epilepsy with the risk of glioma and meningioma. Data of a German population-based case–control study included 381 meningioma cases, 366 glioma cases, and 1,494 controls. Participants’ histories of asthma, hay fever, eczema, and epilepsy and the respective ages at onset were asked during a personal interview. A small inverse association between allergic condition and both glioma (odds ratio: 0.92; 95% CI: 0.70–1.22) and meningioma (odd ratio: 0.87; 95% CI: 0.66–1.14) was found. For glioma, this inverse association was more pronounced in persons reporting to have asthma compared to other allergic conditions. The positive association between epilepsy and particularly glioma suggests that epilepsy is an early symptom of the disease. As the association was seen also for epilepsies occurring more than a decade before the diagnosis of glioma, this might indicate either an aetiological role of epilepsy, or a relatively long preclinical phase. In conclusion our study confirms previous findings of case control studies but not those from cohort studies. However, possible selection bias in case control studies might not explain the different results in its entirety.     

Family history and the risk of early-onset persistent, early-onset transient, and late-onset asthma

Family history of asthma and allergies strongly influences asthma risk in children, but the association may differ for early-onset persistent, early-onset transient, and late-onset asthma. We analyzed the relation between family history and these types of asthma using cross-sectional data from a school-based study of 5,046 Southern California children. Parental and/or sibling history of asthma and allergy were generally more strongly associated with early-onset persistent asthma compared with early-onset transient or late-onset asthma. For children with two asthmatic parents relative to those with none, the prevalence ratio for early-onset persistent asthma was 12.1 [95% confidence interval (CI) = 7.91-18.7] compared with 7.51 (95% CI = 2.62-21.5) for early-onset transient asthma and 5.38 (95% CI = 3.40-8.50) for late-onset asthma. Maternal smoking in pregnancy was predominantly related to the risk of early-onset persistent asthma in the presence of parental history of allergy and asthma, and the joint effects were more than additive (interaction contrast ratio = 3.10, 95% CI = 1.45-4.75). Our results confirm earlier data that parental history of asthma and allergy is most strongly associated with early-onset persistent asthma and suggest that among genetically predisposed children, an early-life environmental exposure, maternal smoking during pregnancy, favors the development of early-onset asthma that persists into later early childhood.     

Socioeconomic status and mortality in Swedish women: opposing trends for cardiovascular disease and cancer

We examined relations between socioeconomic status and cardiovascular disease, cancer, and diabetes mellitus in a 24-year prospective study of 1,462 Swedish women. Two socioeconomic indicators were used: the husband's occupational category for married women and a composite indicator combining women's educational level with household income for all women. The husband's occupational category was strongly associated with cardiovascular disease and cancer mortality in opposite directions, independent of age and other potential confounders. Women with husbands of lower occupational categories had an increased risk of cardiovascular disease mortality [relative risk (RR) = 1.60; 95% confidence interval (95% CI) = 1.09-2.33] while experiencing lower rates of all-site cancer mortality (RR = 0.69; 95% CI = 0.50-0.96). A similar relation was seen with the composite variable: women with low socioeconomic status had an increased risk of cardiovascular disease (RR = 1.37; 95% CI = 1.01-1.84) but a somewhat lower risk for cancer of all sites (RR = 0.86; 95% CI = 0.66-1.11). Finally, morbidity data (diabetes mellitus, stroke, and breast cancer) yielded results that were consistent with the mortality trends, and breast cancer appeared to account for a major part of the association between total cancer and high socioeconomic status. In summary, higher socioeconomic status was associated with decreased cardiovascular disease mortality and excess cancer mortality, in such a way that only a weak association was seen for all-cause mortality.     

Fertility rates in women with asthma, eczema, and hay fever: a general population-based cohort study

The protective association between having older siblings and the risk of subsequent allergic disease may be due to decreased fertility among women with allergic disease. In this study, the authors compared fertility rates among women with asthma, eczema, or hay fever with those in the general female population. Computerized primary-care data from the United Kingdom were used to conduct a cohort analysis of 491,516 women. General fertility rates and age-specific fertility rates for 1994-2004 were estimated. Using Poisson regression, the authors compared fertility rates among women with asthma, eczema, or hay fever with rates in women without these diagnoses. Fertility rates were 53.0 and 52.3 livebirths per 1,000 person-years in women with and without asthma, respectively. The fertility rate ratio for women with asthma compared with women without asthma was 1.02 (95% confidence interval (CI): 1.00, 1.04) after adjustment for age, smoking, body mass index, and socioeconomic status. Equivalent fertility rate ratios for eczema and hay fever were 1.15 (95% CI: 1.13, 1.17) and 1.08 (95% CI: 1.06, 1.10), respectively. The authors found no evidence that the fertility rates of women with asthma, eczema, or hay fever are lower than those of women in the general population.     

Allergy-related diseases and cancer: an inverse association

This paper presents the results of a retrospective study that examines the association of cancer with a history of asthma, hay fever, hives, and other allergy-related diseases. This study is based on interview data collected from 13,665 cancer cases and 4,079 nonneoplastic controls who were admitted to Roswell Park Memorial Institute from 1957 to 1965. Although there is a general tendency for the age- and cigarette smoking-adjusted odds ratios associated with a history of asthma and hay fever to be less than 1, for both males and females, there is stronger evidence for a decreased risk of cancer associated with a history of hives and other allergy-related diseases. Decreased risks associated with a history of hives and other allergies are seen in males for oral cancer, cancers of the lung, larynx, digestive system, urinary system, and cancers of all sites combined and in females for cancers of the digestive system, reproductive system, in particular, cancer of the cervix, and cancers of all sites combined. None of the few odds ratios over 1 associated with a history of any allergy-related condition are statistically significant (alpha = 0.05). These findings suggest that individuals with allergy-related disorders may be at decreased risk of cancer, although reasons for cautious interpretation of the findings are emphasized. Prospective studies of carefully defined allergic disease cohorts are needed.     

Effect of body mass on the association between estrogen replacement therapy and mortality among elderly US women

In observational studies, estrogen replacement therapy is associated with decreased cardiovascular disease rates and increased breast cancer rates. Recent evidence suggests that the impact of estrogen use on disease outcomes may vary by body mass. In a prospective study of 290,827 postmenopausal US women with no history of cancer or cardiovascular disease at enrollment in 1982, the authors examined the association between postmenopausal estrogen use and all-cause, coronary heart disease, stroke, all-cancer, and breast cancer death rates and whether these associations differed by body mass. After 12 years of follow-up, results from Cox proportional hazards models showed that all-cause death rates were lower among baseline estrogen users than never users (rate ratio (RR) = 0.82, 95% confidence interval (CI): 0.78, 0.87). The lowest relative risk was found for coronary heart disease (RR = 0.66, 95% CI: 0.58, 0.77). The inverse association between estrogen use and coronary heart disease mortality was strongest for thin women (body mass index <22 kg/m2) (RR = 0.49, p for interaction = 0.02). Breast cancer mortality did not increase with estrogen use overall, and no increased risk was observed for thin or heavy women. In this population, the reduction in coronary heart disease mortality among estrogen users was greatest for thinner women. Additional studies are needed to confirm or refute these results.     

Associations between socioeconomic position and asthma: findings from a historical cohort

Understanding the association between asthma and socioeconomic position (SEP) is key to identify preventable exposures to prevent inequalities and lessen overall disease burden. We aim to assess the variation in asthma across SEP groups in a historical cohort before the rise in asthma prevalence. Male students participating in a health survey at Glasgow University from 1948 to 1968 (n?=?11,274) completed medical history of bronchitis, asthma, hay fever, eczema/urticaria, and reported father's occupation. A subsample responded to postal follow-up in adulthood (n?=?4,101) that collected data on respiratory diseases, early life and adult SEP. Lower father's occupational class was associated with higher odds of asthma only (asthma without eczema/urticaria or hay fever) (trend adjusted multinomial odds ratio (aMOR)?=?1.23, 95?% CI 1.03-1.47) but with lower odds of asthma with atopy (asthma with eczema/urticaria or hay fever) (trend aMOR?=?0.66, 95?% CI 0.52-0.83) and atopy alone (trend aMOR?=?0.84, 95?% CI 0.75-0.93). Household amenities (<3), in early life was associated with higher odds of adult-onset asthma (onset?>?30?years) (OR?=?1.48, 95?% CI 1.07-2.05) though this association attenuated after adjusting for age. Adult SEP (household crowding, occupation, income and car ownership) was not associated with adult-onset asthma. Lower father's occupational class in early life was associated with higher odds of asthma alone but lower odds of asthma with atopy in a cohort that preceded the 1960s rise in asthma prevalence. Different environmental exposures and/or disease awareness may explain this opposed socioeconomic patterning, but it is important to highlight that such patterning was already present before rises in the prevalence of asthma and atopy.     

Plasma carotene and alpha-tocopherol in relation to 10-y all-cause and cause-specific mortality in European elderly: the Survey in Europe on Nutrition and the Elderly, a Concerted Action (SENECA)

BACKGROUND: Only a few observational studies have related plasma carotene and alpha-tocopherol to mortality in elderly subjects. OBJECTIVE: The objective was to study the association of plasma carotene (alpha-and beta-carotene) and alpha-tocopherol with all-cause and cause-specific mortality in elderly subjects who participated in a European prospective study. DESIGN: Plasma concentrations of carotene and alpha-tocopherol were measured in 1168 elderly men and women. After a follow-up period of 10 y, 388 persons had died. The association between plasma antioxidants and mortality was analyzed by using Cox proportional hazard models. To put our results in context, we performed a meta-analysis of 5 studies on plasma antioxidants and all-cause mortality in elderly populations. RESULTS: Plasma carotene concentrations were associated with a lower mortality risk [adjusted rate ratio (RR) for an increment of 0.39 micromol/L: 0.79; 95% CI: 0.70, 0.89]. This lower mortality risk was observed for both cancer (RR: 0.59; 95% CI: 0.44, 0.79) and cardiovascular disease (RR: 0.83; 95% CI: 0.70, 1.00). The lower risk of cardiovascular death was confined to those with a body mass index (in kg/m2) <25 (RR: 0.67; 95% CI: 0.49, 0.94). Plasma concentrations of alpha-tocopherol were not associated with all-cause or cause-specific mortality. The results for both plasma antioxidants and all-cause mortality were confirmed by the meta-analysis. CONCLUSIONS: This prospective study suggests that high plasma concentrations of carotene are associated both with lower mortality from all causes and with cancer in the elderly. For cardiovascular mortality, the inverse association was confined to elderly with body mass indexes <25.     

Education, lifestyle factors and mortality from cardiovascular disease and cancer. A 25-year follow-up of Swedish 50-year-old men.

BACKGROUND: There is a well-established inverse relation between education and mortality from cardiovascular disease and cancer. The reasons for this are still in part unclear. We aimed to investigate whether differences in traditional vascular risk factors, adult height, physical activity, and biomarkers of fatty acid and antioxidant intake, could explain this association. METHODS: In all, 2301 50-year-old men in Uppsala, Sweden (82% of the background population) were examined with regard to educational level, blood pressure, blood glucose, body mass index, serum lipids, smoking, body height, physical activity, serum beta carotene, alpha tocopherol, selenium, and serum fatty acids in cholesterol esters. Cause-specific mortality was registered 25 years later. RESULTS: Low education was associated with a higher rate of mortality from cardiovascular disease (crude relative risk [RR] = 1.67, 95% CI : 1.17-2.39), and from cancer (crude RR = 1.94, 95% CI : 1.21-3.10), compared to high educational attainment. Men with high education had an overall more beneficial risk factor profile concerning traditional cardiovascular risk factors, physical activity, and biomarkers of dietary intake of antioxidants and fat. After adjustment for all examined risk factors, the inverse gradient between education and cardiovascular mortality disappeared (RR in low education = 1.01. 95% CI : 0.67-1.52). Controlling for smoking, physical activity and dietary biomarkers explained less than half of the excess cancer mortality in the lower educational groups. Smoking (adjusted RR = 1.89, 95% CI : 1.37-2.61), and high proportions of palmitoleic acid in serum cholesterol esters (adjusted RR per 1 SD = 1.39, 95% CI : 1.07-1.82) predicted cancer mortality, independently of all other factors. There were no independent relations between serum antioxidants and mortality. CONCLUSIONS: These data indicate that modifiable lifestyle factors mediate the inverse gradient between education and death from cerebro- and cardiovascular disease. Smoking, physical activity and dietary factors explained half of the excess cancer mortality in lower educated groups. Further studies are needed to explore the proposed association between palmitoleic acid, a marker of high intake of animal and dairy fat, and cancer.     

Eosinophilia and positive skin tests predict cardiovascular mortality in a general population sample followed for 30 years.

The authors investigated whether two objective allergy markers, peripheral blood eosinophilia and skin tests for common aeroallergens, were associated with cardiovascular death. Of 5,382 subjects in the Vlagtwedde-Vlaardingen Study (the Netherlands) with data on allergy markers in 1965-1972, 507 subjects died from cardiovascular disease during 30 years of follow-up. Subjects with eosinophilia had an increased risk of cardiovascular death (relative risk (RR) = 1.7; 95% confidence interval (CI): 1.4, 2.2), including ischemic heart disease death (RR = 1.6; 95% CI: 1.2, 2.2) and cerebrovascular death (RR = 2.3; 95% CI: 1.4, 3.8), independent of major risk factors. This association was limited to subjects with a percentage of the predicted forced expiratory volume in 1 second (FEV1 % predicted) of <100%. Positive skin tests were associated with a significantly reduced cardiovascular mortality in subjects with normal lung function and weight who did not smoke (RR = 0.15; 95% CI: 0.05, 0.46). Conversely, when subjects with positive skin tests had a body mass index of > or =25 kg/m2, had an FEV1 % predicted of <80%, or smoked, they had an increased risk for cardiovascular mortality. These results were not restricted to asthmatics. Our data suggest a possible link between eosinophilia and positive skin tests and cardiovascular mortality, especially in combination with other risk factors associated with its mortality.     

The association between hay fever and stroke in a cohort of middle aged and elderly adults.

BACKGROUND: Asthma has been linked to stroke, but it is unknown if hay fever is related to stroke. This study was designed to investigate if there is an association between a reported history of hay fever and stroke during a 4.4-year study period. METHODS: Analysis was performed of the Atherosclerosis Risk in Communities study, a cohort of middle aged and elderly adults. We examined the association of a reported history of hay fever to the development of stroke. RESULTS: There were 9272 participants meeting our criteria, of which 125 had strokes. Of those with a history of hay fever, 2.2% had a stroke. Of those without a history of hay fever, 1.25% had a stroke. Participants with a history of hay fever had an unadjusted hazard ratio of 1.72 (95% CI, 1.08-2.27) for stroke versus participants without hay fever. Risk of stroke remained significant (hazard ratio, 1.87 [95% CI, 1.17-2.99]) after controlling for age, sex, race, smoking status, body mass index, diabetes, hypertension, alcohol use, and hyperlipidemia. CONCLUSION: A history of hay fever seems to be a risk factor for stroke, and this association may be an area for future research and intervention.     

Poultry and Fish Consumption in Relation to Total Cancer Mortality: A Meta-Analysis of Prospective Studies

Observational studies on the association between fish and poultry intake and the risk of total cancer mortality have been reported with mixed results. Thus, we aimed to assess this association by conducting a meta-analysis of prospective studies. We performed a literature search on PubMed database through February 1, 2017 to identify relative prospective studies. A random-effects model was used to calculate the summary estimates. We identified fourteen prospective studies involving 2,378,204 participants and 96,712 cancer mortality events. Comparing the highest category of consumption with lowest category, pooled relative risk (RR) of total cancer mortality was 0.99 (95% confidence interval [CI], 0.94–1.05) for fish (10 studies) and 0.96 (95% CI, 0.93–1.00) for poultry (8 studies), respectively. However, we failed to identify any dose–response association based on a limited number of eligible studies, with a pooled RR of 0.98 (95% CI, 0.92–1.05) and 0.97 (95% CI, 0.88–1.07) for each 100 g per day increment in fish and poultry consumption, respectively. In summary, this meta-analysis indicates that consumption of either fish or poultry is not substantially associated with lower risk of total cancer mortality. The observed weak inverse association for high poultry consumption needs to be verified in additional large prospective studies.     

The associations between childhood asthma and atopy, and parental asthma, hay fever and smoking

Summary. The aim of this analysis was to examine the degree to which a life time prevalence of asthma in a 7-year-old child is statistically associated with atopic conditions of the child, and with parental asthma, hay fever and smoking. In 1968, 8585 children who were born in 1961 and who were attending school in Tasmania were surveyed. This comprised 99% of the eligible population. The prevalence of a history of asthma in the 7-year-olds was 16.2% (males 19.0%, females 13.2%). Multiple logistic regression analysis showed that a history of asthma in a 7-year-old was associated with the child being male (odds ratio [OR] 1.56; 99% confidence interval 1.30–1.86), having a history of hay fever (3.86; 3.12–4.78), eczema (2.04; 1.63–2.55), hives (1.34; 1.09–1.65) or allergy to foods or medicines (1.70; 1.26–2.30), the child's mother or father having a history of asthma (2.63; 2.08–3.31 or 2.52; 1.99–3.19, respectively), and the mother being a smoker (1.26; 1.05–1.51). Parental hay fever and paternal smoking were not independently associated with childhood asthma. The strength of association between childhood asthma and parental asthma was independent of the sex of either the parent or the child, and of atopic conditions in the child. In the 133 children for whom both parents were asthmatic, 65 (49%) had a history of asthma. These findings, based on a population survey, are consistent, not only with a childhood history of asthma being strongly associated with atopy, but also with the existence of strong unmeasured determinants common to family members, the effects of which are not mediated via atopy. The risk for asthma being independent of both the sex of the child and of the parent, is consistent with a genetic aetiology for susceptibility to asthma.