Julie Aarestrup

Flaxseed dietary fibers lower cholesterol and increase fecal fat excretion, but magnitude of effect depend on food type

BackgroundDietary fibers have been proposed to play a role in cardiovascular risk as well as body weight management. Flaxseeds are a good source of dietary fibers, and a large proportion of these are water-soluble viscous fibers.MethodHere, we examine the effect of flaxseed dietary fibers in different food matrices on blood lipids and fecal excretion of fat and energy in a double-blind randomized crossover study with 17 subjects. Three different 7-d diets were tested: a low-fiber control diet (Control), a diet with flaxseed fiber drink (3/day) (Flax drink), and a diet with flaxseed fiber bread (3/day) (Flax bread). Total fat and energy excretion was measured in feces, blood samples were collected before and after each period, and appetite sensation registered 3 times daily before main meals.ResultsCompared to control, Flax drink lowered fasting total-cholesterol and LDL-cholesterol by 12 and 15%, respectively, (p < 0.01), whereas Flax bread only produced a reduction of 7 and 9%, respectively (p < 0.05). Fecal fat and energy excretion increased by 50 and 23% with Flax drink consumption compared to control (p < 0.05), but only fecal fat excretion was increased with Flax bread compared to control (p < 0.05).ConclusionBoth Flax drink and Flax bread resulted in decreased plasma total and LDL-cholesterol and increased fat excretion, but the food matrix and/or processing may be of importance. Viscous flaxseed dietary fibers may be a useful tool for lowering blood cholesterol and potentially play a role in energy balance.Trial RegistrationClinicalTrials.gov: NCT00953004

Tracking of body mass index from 7 to 69 years of age

Background:Heavy children have an increased risk of being overweight young adults. Whether this risk remains in late adulthood is not well-understood. We investigated body mass index (BMI; kg m−2) tracking from childhood to late adulthood.Methods:From the Copenhagen School Health Records Register, 72 959 men and 25 252 women born between 1930 and 1989 with BMI values at 7 and/or 13 years and as adults were included. Using a meta-regression approach, age- and sex-specific partial correlation analyses and logistic regressions were performed.Results:Correlations between BMI at 7 years and young adult ages (18–19 years) were r=0.55 for men and r=0.55 for women. At late ages (60–69 years) these were r=0.28 for men and r=0.26 for women. The correlations did not differ by birth years. Compared with normal-weight 7-year-olds, overweight children had a higher odds of overweight at 18–19 years; odds ratio (OR)=14.02 (95% confidence interval (CI): 12.14–16.19) for men and 10.46 (95% CI: 4.82–22.70) for women. At ages 60–69 years ORs were 5.46 (95% CI: 0.95–31.36) for men and 1.61 (95% CI: 0.83–3.15) for women. Correlations and ORs were stronger at age 13 years than age 7 years as expected, but the overall patterns were similar.Conclusions:BMI tracking was weaker at late adult ages than at young adult ages. Although BMI tracks across the life course, childhood BMI is relatively poor at identifying later adult overweight or obesity at ages when chronic diseases generally emerge.

Childhood height and birth weight in relation to future prostate cancer risk: a cohort study based on the Copenhagen School Health Records Register

Background: Adult height has been positively associated with prostate cancer risk. However, the exposure window of importance is currently unknown and assessments of height during earlier growth periods are scarce. In addition, the association between birth weight and prostate cancer remains undetermined. We assessed these relationships in a cohort of the Copenhagen School Health Records Register (CSHRR). Methods: The CSHRR comprises 372,636 school children. For boys born between the 1930s and 1969, birth weight and annual childhood heights—measured between ages 7 and 13 years—were analyzed in relation to prostate cancer risk. Cox proportional hazards regression models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CI). Results: There were 125,211 males for analysis, 2,987 of who were subsequently diagnosed with prostate cancer during 2.57 million person-years of follow-up. Height z-score was significantly associated with prostate cancer risk at all ages (HRs, 1.13 to 1.14). Height at age 13 years was more important than height change (P = 0.024) and height at age 7 years (P = 0.024), when estimates from mutually adjusted models were compared. Adjustment of birth weight did not alter the estimates. Birth weight was not associated with prostate cancer risk. Conclusions: The association between childhood height and prostate cancer risk was driven by height at age 13 years. Impact: Our findings implicate late childhood, adolescence, and adulthood growth periods as containing the exposure window(s) of interest that underlies the association between height and prostate cancer. The causal factor may not be singular given the complexity of both human growth and carcinogenesis. Cancer Epidemiol Biomarkers Prev; 22(12); 2232–40. ©2013 AACR.

Whole Grain, Dietary Fiber, and Incidence of Endometrial Cancer in a Danish Cohort Study

Whole grains and dietary fiber might be inversely associated with endometrial cancer risk through their effects on sex hormone metabolism and body fat. We investigated whether a higher intake of whole grains and dietary fiber was associated with a lower incidence of endometrial cancer in the Diet, Cancer and Health cohort of 29,875 women aged 50–64 years at enrollment in 1993–1997. Information on diet and lifestyle was derived from self-administered questionnaires. The incidence rate ratios and 95% confidence intervals were estimated based on a Cox proportional hazards model. Of the 24,418 women included as cohort members, 217 had a diagnosis of endometrial cancer. No clear associations were found between intake of whole grains or dietary fiber and the incidence of endometrial cancer.

Childhood body mass index and the risk of prostate cancer in adult men

Background:Prostate cancer aetiology is poorly understood. It may have origins early in life; previously we found a positive association with childhood height. The effects of early life body mass index (BMI; kg m−2) on prostate cancer remain equivocal. We investigated if childhood BMI, independently and adjusted for height, is positively associated with adult prostate cancer.Methods:Subjects were a cohort of 125 208 boys formed from the Copenhagen School Health Records Register, born 1930–1969 with height and weight measurements at 7–13 years. Cases were identified through linkage to the Danish Cancer Registry. Cox proportional hazards regressions were performed.Results:Overall, 3355 men were diagnosed with prostate cancer. Body mass index during childhood was positively associated with adult prostate cancer. The hazard ratio of prostate cancer was 1.06 (95% confidence interval (CI): 1.01–1.10) per BMI z-score at age 7, and 1.05 (95% CI: 1.01–1.10) per BMI z-score at age 13. Estimates were similar and significant at all other ages. However, adjustment for childhood height attenuated the associations at all but the youngest ages as most estimates became nonsignificant.Conclusions:These results suggest that at most childhood ages, BMI does not confer an additional risk for prostate cancer beyond that of height.

Childhood height increases the risk of prostate cancer mortality

BACKGROUND Adult body size is positively associated with aggressive and fatal prostate cancers. It is unknown whether these associations originate in early life. Therefore, we investigated if childhood height, body mass index (BMI; kg/m(2)) and growth are associated with prostate cancer-specific mortality and survival. METHODS Subjects were 125,208 men from the Copenhagen School Health Records Register, born 1930-1969 with height and weight measurements at ages 7-13years. Linkage to the Danish Cancer Registry and the Register of Causes of Death enabled identification of incident and fatal prostate cancers. Cox proportional hazards regressions were performed. RESULTS 630 men had prostate cancer recorded as the underlying cause of death. Childhood height at age 13years was positively associated with prostate cancer-specific mortality (hazard ratio [HR]per z-score=1.2, 95% confidence interval [CI]: 1.1-1.3). Associations were significant at all other childhood ages. Growth analyses showed that height at age 13years had a stronger association with prostate cancer-specific mortality than height at age 7, suggesting the association at age 7 is largely mediated through later childhood height. The tallest boys at age 13years had a significantly worse survival, but only when restricted to a diagnosis at <60years of age (HRz-score of 1=1.7, 95% CI: 1.3-2.4). These associations were significant at all other childhood ages. Childhood BMI was not associated with prostate cancer mortality or survival. CONCLUSION Childhood height was positively associated with the hard end-point of prostate cancer-specific mortality, which strengthens prior epidemiologic observations of a positive association with prostate cancer incidence.

Childhood body mass index and height and risk of histologic subtypes of endometrial cancer

Background:Endometrial cancer risk factors include adult obesity and taller stature, but the influence of size earlier in life is incompletely understood. We examined whether childhood body mass index (BMI; kg m−2) and height were associated with histologic subtypes of endometrial cancer.Methods:From the Copenhagen School Health Records Register, 155 505 girls born 1930–1989 with measured weights and heights from 7 to 13 years were linked to health registers. BMI and height were transformed to age-specific z-scores. Hazard ratios (HRs) and 95% confidence intervals were estimated by Cox regressions.Results:A total of 1020 endometrial cancers were recorded. BMI was non-linearly associated with all endometrial cancers, oestrogen-dependent cancers and the subtype of endometrioid adenocarcinomas; associations were statistically significant and positive above a z-score=0 and non-significant below zero. Compared with a 7-year-old girl with a BMI z-score=0, an equally tall girl who was 3.6 kg heavier (BMI z-score=1.5) had a hazard ratio=1.53 (95% confidence interval: 1.29–1.82) for endometrioid adenocarcinoma. BMI was not associated with non-oestrogen-dependent cancers, except at the oldest childhood ages. Height at all ages was statistically significant and positively associated with all endometrial cancers, except non-oestrogen-dependent cancers. At 7 years, per ~5.2 cm (1 z-score), the risk of endometrioid adenocarcinoma was 1.18 (95% confidence interval: 1.09–1.28). Among non-users of unopposed oestrogens, associations between BMI and endometrioid adenocarcinoma strengthened, but no effects on height associations were observed.Conclusions:Endometrial carcinogenesis is linked to early-life body size, suggesting that childhood BMI and height may be useful indicators for the risk of later development of endometrial cancer and might aid in the early prevention of obesity-related endometrial cancers.

Plasma enterolactone and incidence of endometrial cancer in a case-cohort study of Danish women.

The phyto-oestrogen enterolactone has been hypothesised to protect against hormone-dependent cancers, probably through its antioestrogenic potential. We investigated whether a higher level of plasma enterolactone was associated with a lower incidence of endometrial cancer in a case-cohort study in the ‘Diet, Cancer and Health’ cohort. The cohort study included 29 875 women aged 50–64 years enrolled between 1993 and 1997. Information on diet and lifestyle was provided by self-administrated questionnaires and blood was drawn from each participant. Time-resolved fluoroimmunoassay was used for biochemical determination of plasma enterolactone. A total of 173 cases and 149 randomly selected cohort members were included. We estimated incidence rate ratio (IRR) and 95% CI by a Cox proportional hazards model. A 20 nmol/l higher plasma concentration of enterolactone was associated with a non-significant lower risk of endometrial cancer (IRR 0.93, 95% CI 0.84, 1.04). When excluding women with low enterolactone concentrations (quartile 1) due to potential recent antibiotic use, the association became slightly stronger, but remained non-significant (IRR 0.90, 95% CI 0.79, 1.02). Menopausal status, hormone replacement therapy or BMI did not modify the association. In conclusion, we found some support for a possible inverse association between plasma enterolactone concentration and endometrial cancer incidence.

Childhood body mass index growth trajectories and endometrial cancer risk

Previously, we found that excess weight already in childhood has positive associations with endometrial cancer; however, associations with changes in body mass index (BMI) during childhood are not well understood. Therefore, we examined whether growth in childhood BMI is associated with endometrial cancer and its sub‐types. A cohort of 155,505 girls from the Copenhagen School Health Records Register with measured weights and heights at the ages of 6–14 years and born 1930–1989 formed the analytical population. BMI was transformed to age‐specific z scores. Using linear spline multilevel models, each girls BMI growth trajectory was estimated as the deviance from the average trajectory for three different growth periods (6.25–7.99, 8.0–10.99, 11.0–14.0 years). Via a link to health registers, 1,020 endometrial cancer cases were identified, and Cox regressions were performed. A greater gain in BMI during childhood was positively associated with endometrial cancer but no differences between the different growth periods were detected in models adjusted for baseline BMI. The hazard ratios for the associations with overall growth during childhood per 0.1 z score increase were 1.15 (95% confidence interval [CI]: 1.07–1.24) for all endometrial cancers, 1.12 (95% CI: 1.04–1.21) for estrogen‐dependent cancers, 1.16 (95% CI: 1.06–1.26) for endometrioid adenocarcinomas and 1.46 (95% CI: 1.16–1.84) for non‐estrogen‐dependent cancers. Growth in BMI in early life is positively linked to later endometrial cancer risk. We did not identify any sensitive childhood growth period, which suggests that excess gain in BMI during the entire childhood period should be avoided.

Ethnic Inequalities in Overweight and Obesity Prevalence among Copenhagen Schoolchildren from 2002 to 2007.

Background: The stabilization in levels of childhood overweight has masked increasing gaps among different ethnic and socioeconomic groups in several countries. Objective: To examine if levels and trends in childhood overweight and obesity differed by ethnicity and socioeconomic areas in Copenhagen schoolchildren. Methods: From measured heights and weights of 32,951 children 5-8 and 14-16 years of age, the prevalence of overweight (including obesity) and obesity were estimated using International Obesity Task Force criteria. Differences in prevalence levels and trends across six school years by ethnicity and socioeconomic areas were examined using logistic regression. Results: The prevalence of overweight significantly decreased from 2002 to 2007 among the youngest Western girls and boys, showed no significant changes among the oldest non-Western girls and increased among the oldest non-Western boys. In all years, the youngest non-Western children had significantly higher levels of overweight than Western children. Although the prevalence of overweight tended to be higher in low socioeconomic areas as compared with high socioeconomic areas, few differences were statistically significant. Consistent trends in overweight across the years by socioeconomic area were not observed. Conclusion: Ethnic and social inequalities exist in childhood overweight among Copenhagen schoolchildren; thus appropriate interventions targeting high-risk groups are needed