Speed of eating and 3-year BMI change: a nationwide prospective study of mid-age women.

OBJECTIVE: To conduct the first nationwide population survey to examine the associations between changes in speed of eating and weight gain over 3 years. The study also explored whether faster eating at baseline was related to healthy-weight women becoming overweight after 3 years. DESIGN: Longitudinal. At baseline, participants were randomly selected from a nationally representative sampling frame to participate in a prospective study. Women completed self-administered baseline questionnaires on demographic and health measures. Self-reported speed of eating, smoking status, physical activity, menopause status, and height and weight were collected at baseline and again 3 years later. SETTING: Nationwide study, New Zealand. SUBJECTS: Women (n 1601) aged 40-50 years were recruited at baseline from New Zealand electoral rolls. RESULTS: There was no evidence of associations between 3-year BMI adjusting for baseline BMI and either baseline speed of eating (slower and faster; P=0.524) or change in speed of eating (consistently faster eating, consistently slower eating, slower eating at baseline but not at 3 years, faster eating at baseline but not at 3 years; P=0.845). Of the 488 women with healthy BMI (18.5 to <25.0 kg/m2) at baseline, seventy-seven (15.8%) became overweight (BMI≥25.0 kg/m2) after 3 years. Compared with those who were slower eaters at baseline, faster eating at baseline did not increase the risk of becoming overweight 3 years later (P=0.958) nor did change in speed of eating (P=0.236). CONCLUSIONS: Results suggest that once women have reached mid-life, faster eating does not predict further weight gain.

Eating in response to hunger and satiety signals is related to BMI in a nationwide sample of 1601 mid-age New Zealand women.

OBJECTIVE: To examine the association between eating in response to hunger and satiety signals (intuitive eating) and BMI. A second objective was to determine whether the hypothesized higher BMI in less intuitive eaters could be explained by the intake of specific foods, speed of eating or binge eating. DESIGN: Cross-sectional survey. Participants were randomly selected from a nationally representative sampling frame. Eating in response to hunger and satiety signals (termed 'intuitive eating'), self-reported height and weight, frequency of binge eating, speed of eating and usual intakes of fruits, vegetables and selected high-fat and/or high-sugar foods were measured. SETTING: Nationwide study, New Zealand. SUBJECTS: Women (n 2500) aged 40-50 years randomly selected from New Zealand electoral rolls, including Maori rolls (66 % response rate; n 1601). RESULTS: Intuitive Eating Scale (IES) scores were significantly associated with BMI in an inverse direction, after adjusting for potential confounding variables. When controlling for confounding variables, as well as potential mediators, the inverse association between intuitive eating (potential range of IES score: 21-105) and BMI was only slightly attenuated and remained statistically significant (5.1 % decrease in BMI for every 10-unit increase in intuitive eating; 95 % CI 4.2, 6.1 %; P < 0.001). The relationship between intuitive eating and BMI was partially mediated by frequency of binge eating. CONCLUSIONS: Eating in response to hunger and satiety signals is strongly associated with lower BMI in mid-age women. The direction of causality needs to be investigated in longitudinal studies and randomized controlled trials.

Validation of brief instruments to measure adult fruit and vegetable consumption.

Four brief food frequency questionnaires were developed and validated to measure an adult's usual daily intake of fruit or vegetable servings over the past month. Fifty males and 50 females, aged 25-52 years, completed two fruit instruments, two vegetable instruments, and a dietary history (the reference method). Individual agreement and group mean estimation were assessed. The 5-item fruit instrument and the 15-item vegetable instrument performed best. At an individual level, the 5-item fruit instrument had 64% sensitivity and 88% specificity for assessing goal attainment (≥ 2 fruit servings/day), while the 15-item vegetable instrument had 67% sensitivity and 82% specificity for measuring goal attainment (≥ 3 vegetable servings/day). At a group level, the 15-item vegetable instrument closely estimated mean intake (ratio of geometric means=0.94), while the 5-item fruit instrument overestimated mean intake by 32%. Nevertheless, when it was used to rank participants, reference method fruit servings increased across the quartiles of intake. These two instruments can be used to assess goal attainment. This vegetable instrument can also be used to estimate group mean intakes, while the fruit instrument can be used to rank participants. Used appropriately, these instruments can be used for screening, monitoring, and evaluation purposes in New Zealand public health and clinical settings.

A Research Agenda to Examine the Efficacy and Relevance of the Transtheoretical Model for Physical Activity Behavior.

Regular physical activity (PA) decreases the risk of several chronic diseases including some cancers, type II diabetes, obesity, and cardiovascular disease; however, the majority of US adults are not meeting the recommended levels to experience these benefits. To address this public health concern, the underlying mechanisms for behavior change need to be understood, translated and disseminated into appropriately tailored interventions. The Transtheoretical Model (TTM) provides a framework for both the conceptualization and measurement of behavior change, as well as facilitating promotion strategies that are individualized and easily adapted. The purpose of this manuscript is to present the constructs of the TTM as they relate to PA behavior change. We begin with a brief synopsis of recent examinations of the TTM constructs and their application. Subsequent to its introduction, we specifically present the TTM within the PA context and discuss its application and usefulness to researchers and practitioners. Criticisms of the TTM are also noted and presented as opportunities for future research to enhance the valid application of the TTM. We offer general study design recommendations to appropriately test the hypothesized relationships within the model. With further examinations using appropriate study design and statistical analyses, we believe the TTM has the potential to advance the public health impact of future PA promotion interventions.

Investigating fruit and vegetable consumption using the transtheoretical model.

PURPOSE: Test the applicability of the transtheoretical model (TTM) to adult fruit/vegetable consumption. DESIGN: Cross-sectional random-digit dial survey. SETTING: Hawaii. SUBJECTS: 700 (62.6% female; age [mean +/- SD], 47 +/- 17.1 years; education [mean +/- SD], 14.6 +/- 2.8 years; 35.0% white, 31.1% Asian, 22.1% native Hawaiian/Pacific Islander, 11.8% other). MEASURES: Stages, processes, self-efficacy, decisional balance, and self-reported fruit/vegetable consumption. ANALYSIS: Confirmatory factor analysis tested the factor structure. Analyses of variance were used to explore stage differences in constructs. RESULTS: Stage distribution was precontemplation (33%), contemplation (4%), preparation (37%), action (3%), and maintenance (23%). A 10-factor process model with two higher-order correlated factors (experiential and behavioral) provided the best data fit (chi2 = 1446.12; df = 366; p < .0001; comparative fit index [CFI] = .89; standardized root mean square residual [SRMR] = .05). The self-efficacy structure fit the data well (chi 2 = 81.86; df = 9; p < .0001; CFI = .94; SRMR = .04), as did the decisional balance structure (chi2 = 37.42; df = 19; p = .007; CFI = .99; SRMR = .02). Processes, self-efficacy, decisional balance, and fruit/vegetable consumption behavior differed significantly by stage, with medium effect sizes for most variables. CONCLUSION: The variables revealed adequate fit to the theorized measurement models. TTM predictions regarding stage differences in self-efficacy, pros and cons, and fruit/vegetable consumption were confirmed; however, most experiential and behavioral processes increased in the early stages and then leveled off.

Non-dieting group interventions for overweight and obese women: what predicts non-completion and does completion improve outcomes?

OBJECTIVE: To determine factors which predict non-completion of group non-dieting interventions for overweight women, and to investigate whether completion improves outcomes. DESIGN: First, baseline predictors of non-completion were identified; then changes at 10 weeks and 12 months were compared between completers and non-completers of 10-week non-dieting interventions. SETTING: General community. SUBJECTS: Participants were 119 women (aged 25-65 years, BMI > or = 28 kg/m2) with at least one cardiovascular risk factor. Participants who attended at least eight of the ten sessions were classified as completers, and non-completers were those who attended fewer than eight sessions. Measures included BMI, blood pressure, psychological distress, lifestyle behaviours and eating self-efficacy. RESULTS: Logistic regression analyses indicated that women were less likely to be non-completers at non-dieting group programmes if, at baseline, they were more highly educated or had healthier nutrition behaviours (controlling for education). Only healthier nutrition behaviour was negatively associated with non-completion in the final model. Twelve months after the intervention, completers showed significantly greater improvements in body weight (mean change -0.53 kg), systolic and diastolic blood pressure (-6.3 and -4.1 mmHg, respectively), stress management behaviour score (+0.5) and psychotic symptoms score (-0.1) than non-completers (all P < 0.05). CONCLUSIONS: Highly educated women already engaging in some healthier lifestyle choices were less likely to be non-completers in non-dieting group programmes. Since important treatment outcomes vary according to attendance, future trials of non-dieting interventions should report the effects of completion on outcomes.

Validated scales to assess adult decisional balance to eat more fruits and vegetables.

A scale to measure adult decisional balance to eat more fruits and vegetables was developed and confirmed, and its psychometric properties were assessed. Two simple random samples of adults ages 25-60 years were selected from a nationally representative sampling frame. The development survey had a 72% response rate (n = 231). The confirmation survey had a 67.4% response rate (n = 2132). In both surveys, a self-administered questionnaire assessed demographics, fruit and vegetable intakes, stages of change, and decisional balance. Principal components analysis with varimax rotation and confirmatory factor analysis were performed. The decisional balance scale had three reliable subscales: "health pros," "non-health pros," and "cons." Model fit was adequate for a "pros" and "cons" hierarchical structure. For both fruits and vegetables, health pros increased significantly between precontemplation and contemplation stages, surpassing the cons. Non-health pros increased significantly between precontemplation and contemplation fruit stages, surpassing the cons in preparation stage. Between precontemplation and action stages, health pros increased (mean effect size = 0.90 [fruit] and 0.80 [vegetables]) and cons decreased (mean effect size = 0.27 [fruit] and 0.35 [vegetables]). Heterogeneity in this sample may have diluted these effect sizes. This decisional balance scale is valid and reliable.

Validated scales to assess adult self-efficacy to eat fruits and vegetables.

PURPOSE: An audience-centered approach was used to develop valid and reliable scales to measure adult self-efficacy to eat fruit and vegetables. DESIGN: Cross-sectional survey of a national population. SETTING: New Zealand. SUBJECTS: A sample of 350 adults ages 25 to 60 years was randomly selected from a nationally representative sampling frame. Overall, 231 questionnaires were returned, producing a 72% response rate. The mean age of subjects was 42.7years; 58% were female; 80% were of European descent; 11% were indigenous Maori. MEASURES: The 76-item, self-administered questionnaire collected data on demographics, fruit and vegetable intakes, stages of change, decisional balance, and self-efficacy (24 items). ANALYSIS: Principal components analysis with oblimin rotation was performed. RESULTS: Principal components analysis yielded three distinct and reliable scales for self-efficacy to eat "vegetables," "fruit," and "fruit and vegetables" (Cronbach alpha = .80, .85, and .73, respectively). These scales were correlated, but only the "vegetable" scale was positively correlated with the "fruit and vegetable" scale (Kendall tau r = 0.30, -0.26 [fruit, "fruit and vegetables"], -0.38 [fruit, vegetable]). As predicted, self-efficacy was associated with intake (r = 0.30 [fruit], 0.34 [vegetables]). CONCLUSION: Assuming the factor structure is confirmed in independent samples, these brief psychometrically sound scales may be used to assess adult self-efficacy to eat fruit and to eat vegetables (separately) but not self-efficacy to eat "fruit and vegetables."

Weight-Focused Physical Activity Is Associated with Poorer Eating Motivation Quality and Lower Intuitive Eating in Women.

BACKGROUND: Evidence suggests that physical activity may be related to improved eating regulation, helping people self-regulate their eating in a healthier way. Yet the positive associations between physical activity and eating-related behaviors appear to depend on the goals pursued by individuals when they engage in physical activity. OBJECTIVE: This study investigated differences in eating motivations (informed by Self-Determination Theory) and intuitive eating between women who did physical activity to lose weight (PA-Wt) vs for non-weight goals (PA-NWt), and explores whether eating motivations mediate associations between weight-focused physical activity and intuitive eating. DESIGN/PARTICIPANTS: A sample of 1,435 physically active women (40 to 50 years) participated in a nationally representative survey conducted in 2009 in New Zealand. Women were asked whether they did physical activity predominantly to lose weight and were dichotomized into PA-Wt and PA-NWt groups. MAIN OUTCOME MEASURES: Questions assessing eating in response to hunger and satiety cues (intuitive eating) and eating-related motivations were completed by participants. STATISTICAL ANALYSES: Analyses of covariance, t tests, correlations, and mediation analyses were conducted to test the study hypotheses. RESULTS: PA-Wt participants reported lower levels of intuitive eating than did PA-NWt (0.26

Evaluation of a "nondieting" stress reduction program for overweight women: a randomized trial.

PURPOSE: Determine if a "nondieting" intervention focused on intensive training in eliciting the relaxation response enhances health outcomes compared with nondieting interventions without such training. DESIGN: Randomized trial with follow-up at 10 weeks, 4 months, and 12 months. SETTING: General community. SUBJECTS: Total of 225 overweight and obese women with at least one other cardiovascular risk factor. INTERVENTIONS: Three 10-week nondieting interventions: a group program (P1) focused on intensive training in techniques for eliciting the relaxation response (n = 60), a group program (P2) focused on healthy eating and physical activity (n = 61), and a self-guided, mail-delivered version of P2 (P3; n = 101). MEASURES: The Revised Symptom Checklist measured psychological distress, the Medical Symptoms Checklist measured the experience of medical symptoms, and the Health-Promoting Lifestyle Profile measured a range of lifestyle behaviors. Self-efficacy for low-fat eating intuitive eating, and body mass index were also assessed. ANALYSIS: An intention-to-treat analysis was used. RESULTS: At 12 months, P1 produced statistically greater improvements in stress management behaviors and medical symptom discomfort and was the only program to significantly improve self-efficacy for low-fat eating. In P1, the effect sizes for reductions in depression (0.75) and interpersonal sensitivity (0.85) were large. At 12 months, mean weight was unchanged. CONCLUSION: Inclusion of intensive relaxation response training in a nondieting program for overweight women enhanced stress management and medical symptoms outcomes but not weight outcomes.

Teaching Intuitive Eating and Acceptance and Commitment Therapy Skills Via a Web-Based Intervention: A Pilot Single-Arm Intervention Study.

BACKGROUND: Middle-aged women are at risk of weight gain and associated comorbidities. Deliberate restriction of food intake (dieting) produces short-term weight loss but is largely unsuccessful for long-term weight management. Two promising approaches for the prevention of weight gain are intuitive eating (ie, eating in accordance with hunger and satiety signals) and the development of greater psychological flexibility (ie, the aim of acceptance and commitment therapy [ACT]). OBJECTIVES: This pilot study investigated the usage, acceptability, and feasibility of "Mind, Body, Food," a Web-based weight gain prevention intervention prototype that teaches intuitive eating and psychological flexibility skills. METHODS: Participants were 40 overweight women (mean age 44.8 [standard deviation, SD, 3.06] years, mean body mass index [BMI] 32.9 [SD 6.01] kg/m2, mean Intuitive Eating Scale [IES-1] total score 53.4 [SD 7.46], classified as below average) who were recruited from the general population in Dunedin, New Zealand. Module completion and study site metrics were assessed using Google Analytics. Use of an online self-monitoring tool was determined by entries saved to a secure online database. Intervention acceptability was assessed postintervention. BMI, intuitive eating, binge eating, psychological flexibility, and general mental and physical health were assessed pre- and postintervention and 3-months postintervention. RESULTS: Of the 40 women enrolled in the study, 12 (30%) completed all 12 modules (median 7.5 [interquartile range, IQR, 2-12] modules) and 4 (10%) used the self-monitoring tool for all 14 weeks of the intervention period (median 3 [IQR 1-9] weeks). Among 26 women who completed postintervention assessments, most women rated "Mind, Body, Food" as useful (20/26, 77%), easy to use (17/25, 68%) and liked the intervention (22/25, 88%). From pre- to postintervention, there were statistically significant within-group increases in intuitive eating (IES-2 total score P<.001; all IES-2 subscale scores: P ≤.01), psychological flexibility (P=.01), and general mental health (P<.001) as well as significant decreases in binge eating (P=.01). At the 3-month follow-up, IES-2 improvements were maintained, and there were further improvements in binge eating (P<.001) and general mental health (P=.03), and a marginal yet nonsignificant tendency for further improvement in psychological flexibility (P=.06). There were no significant within-group changes in BMI from pre- to postintervention and postintervention to 3-month follow-up (P=.46 and P=.93, respectively). CONCLUSIONS: The "Mind, Body, Food" prototype Web-based intervention is appealing to middle-aged women and may be a useful tool to help women learn intuitive eating and ACT skills, reduce binge eating, and maintain weight over 3 months. Further work to improve the user experience and engagement is required before testing the online intervention in a randomized controlled trial.

Many apples a day keep the blues away--daily experiences of negative and positive affect and food consumption in young adults.

OBJECTIVES: Prior research has focused on the association between negative affect and eating behaviour, often utilizing laboratory or cross-sectional study designs. These studies have inherent limitations, and the association between positive affect and eating behaviour remains relatively unexplored. Therefore, the objective of this study was to investigate the bidirectional relationships between daily negative and positive affective experiences and food consumption in a naturalistic setting among healthy young adults. DESIGN: Daily diary study across 21 days (microlongitudinal, correlational design). METHODS: A total of 281 young adults with a mean age of 19.9 (± 1.2) years completed an Internet-based daily diary for 21 consecutive days. Each day they reported their negative and positive affect, and their consumption of five specific foods. Hierarchical linear modelling was used to test same-day associations between daily affect and food consumption, and next-day (lagged) associations to determine directionality. Moderating effects of BMI and gender were also examined in exploratory analyses. RESULTS: Analyses of same-day within-person associations revealed that on days when young adults experienced greater positive affect, they reported eating more servings of fruit (p = .002) and vegetables (p < .001). Results of lagged analysis showed that fruits and vegetables predicted improvements in positive affect the next day, suggesting that healthy foods were driving affective experiences and not vice versa. Meaningful changes in positive affect were observed with the daily consumption of approximately 7-8 servings of fruit or vegetables. CONCLUSIONS: Eating fruit and vegetables may promote emotional well-being among healthy young adults.

Does the transtheoretical model of behavior change provide a useful basis for interventions to promote fruit and vegetable consumption?

PURPOSE: To determine whether Transtheoretical Model (TTM) constructs differ between individuals making successful versus unsuccessful stage transitions for consumption of five or more servings of fruit and vegetables each day and thus provide a useful basis for designing health promotion interventions. DESIGN: Longitudinal, observational study. A randomly selected, multiethnic cohort of adults assessed at 6-month intervals over 2 years. SETTING: General community, Hawaii. SUBJECTS: There were 700 participants (62.6% female; mean = 47 ± 17.1 years; 31.1% Asian, 22.1% Native Hawaiian/Pacific Islander, 35.0% Caucasian; 25.1% participation rate). MEASURES: Stage of readiness, experiential and behavioral processes of change, pros, cons, self-efficacy, and self-reported fruit and vegetable consumption. ANALYSIS: The study used t-tests to determine which TTM variable scores differed consistently between those making "successful" versus "unsuccessful " stage transitions from precontemplation, preparation, and maintenance. Sample sizes for contemplation and action prohibited similar analyses. RESULTS: Compared to those remaining in precontemplation, individuals successfully progressing from precontemplation showed significantly greater use of behavioral processes (collectively and self-liberation) and consciousness raising (p < .001). However, only self-liberation demonstrated significant differences consistently over time. CONCLUSION: This longitudinal investigation reveals that TTM behavioral processes, particularly self-liberation, predict successful transition out of precontemplation for adult fruit and vegetable consumption, suggesting that public health messages tailored according to these TTM variables may be effective for this group. However, for adults prepared to adopt or maintain fruit and vegetable consumption, tailoring based on variables from other theories is needed.

A nationwide survey of weight control practices among middle-aged New Zealand women.

AIM: To examine the prevalence of weight control practices in a nationwide representative sample of 40-50 year old New Zealand women. METHODS: In May 2009, a cross-sectional mail survey was conducted among 2500 women randomly selected from nationwide electoral rolls who were each mailed a self-administered questionnaire about their weight control practices, demographics and anthropometry. RESULTS: After excluding ineligible recipients, a 66% participation rate was achieved (n=1601). Thirty-nine percent of the sample (n=630) reported trying to control their weight, and among those who were not, 69% (n=674) were attempting to prevent weight gain. The weight control practices most commonly used were cutting down on meal/snack size (42%) and cutting down on fats/sugars (45%). Smoking, exercising in a driven or compulsive way, and fasting were used at least once a week as weight control strategies by 14%, 22% and 5% of women, respectively. Other potentially health-damaging practices (i.e. laxatives, diuretics, diet pills, vomiting) were employed by 1-4% of women. CONCLUSIONS: Most women reported weight control practices that were consistent with public health messages, however the use of smoking and exercising in a driven or compulsive way are of particular concern.

Agreement between measured and self-reported height, weight and BMI in predominantly European middle-aged New Zealanders: findings from a nationwide 1989 survey.

AIM: To examine the agreement between self-reported and measured height, weight and BMI in 40-50 year old New Zealand men and women. METHOD: Self-reported and measured height, weight and derived BMI were examined using data from 345 40-50 year old participants in the 1989/1990 Life In New Zealand Survey. Factors associated with biased reporting were assessed using regression models. RESULTS: Height was overestimated by men (1.08 cm, 95%CI 0.58, 1.59 p<0.001) and women (0.61 cm, 95%CI 0.35, 0.87, p<0.001), contributing to a small but statistically significant underestimation of BMI (men 0.31 kg/m2, 95%CI 0.14, 0.48, p<0.001; women 0.26 kg/m2 95%CI 0.11, 0.41, p<0.001). Weight was not statistically significantly misestimated by either sex. Bias in self-reported BMI did not differ by age, sex, ethnicity, SES or measured BMI category (all p-values <0.231). Agreement between BMI categories based on self-reported and measured data was very good (kappa: men 0.80, women 0.93). CONCLUSION: Self-reported height and weight from New Zealand 40-50 year olds in 1989 produced BMI estimates valid for use in epidemiological studies, especially when used as a continuous variable. Our analyses need to be replicated using data from a current and representative New Zealand sample.

Food outlet accessibility and fruit and vegetable consumption.

PURPOSE: To examine if spatial access to healthy and unhealthy outlets comprising the local food environment was associated with fruit and vegetable consumption. DESIGN: Cross-sectional. SETTING: Population-based sample residing in Hawaii. Subjects . Three hundred and eighty-four adults (36% Asian-American, 33% non-Hispanic white, 31% other/mixed race). MEASURES: A spatial model of the local food environment was constructed using radial buffers extending from participants' place of residence. Fruit and vegetable intake was estimated using the National Cancer Institute Fruit and Vegetable All-Day Screener. ANALYSIS: Mean intakes of fruits and vegetables were compared for spatial access to total, healthy, and unhealthy food outlets at distances of .5 to 3.5 km. Multiple linear regression was used to estimate differences in fruit and vegetable intake for residing further from a food outlet or for residing in an area with a greater number of food outlets. RESULTS: Residing in an area with a greater density of total or healthy food outlets was associated with a higher mean intake of fruits and vegetables (p < .05) at .5 km. No differences in mean intakes were detected for distances beyond .5 km or for regression models. CONCLUSION: Findings suggest that greater spatial accessibility to food outlets comprising the local food environment in Hawaii may not be meaningfully associated with fruit and vegetable consumption; however, associations were detected for the smallest spatial scale examined, warranting further investigation.

Vitamin B12 and folate status of older New Zealand women.

The primary aim of this study was to assess the biochemical vitamin B12 and folate status of a representative group of elderly women (70-80 y) living in Dunedin, New Zealand. A second aim was to determine the prevalence of hyperhomocysteinaemia and to explore the determinants of homocysteine (hcy) concentration in this population. A cross-sectional study was carried out between June and August of 2000. Two hundred and fifty women were randomly selected from the 1998 electoral roll. Fasting blood samples were analysed for folate, vitamin B12, total hcy, creatinine, and haematological parameters. Of the women selected, 87 did not respond, 37 were not traceable, 23 were not eligible or had died, and 103 agreed to participate. The overall response rate was 46%. Based on a cut-off of 150 pmol/L for serum B12, 13% of participants would be classified as having sub-optimal vitamin B12 status. Of the women, 3 and 5%, respectively, had low serum (< 6.6 nmol/L) and erythrocyte folate (< 317 nmol/L) concentrations. No participant had megaloblastic anaemia. The prevalence of hyperhomocysteinaemia (> 15 mumol/L) in this population was 18%. Hyperhomocysteinaemia in this group may be partly explained by renal insufficiency because there was a significant association between serum creatinine and plasma hcy (P < 0.001). Blood folate levels but not serum B12 were significantly inversely associated with hcy. In conclusion, there was a moderately high prevalence of hyperhomocysteinaemia and suboptimal plasma vitamin B12 concentrations but not low blood folate concentrations in this elderly female population.