Terryl J. Hartman

A simultaneous evaluation of 10 commonly used physical activity questionnaires.

Ten commonly used physical activity questionnaires were evaluated for reliability and validity in 78 men and women aged 20-59, with varying physical activity habits. One month reliability was found to be high for all questionnaires except those pertaining only to the last week or month. Longer term test-retest reliability tended to be lower. Validity was studied in relation to treadmill exercise performance, vital capacity, body fatness, the average of 14 4-wk physical activity histories and the average of 14 2-d accelerometer readings. No questionnaire measure was correlated with the accelerometer reading, and correlations with vital capacity were generally low. Only the Minnesota Leisure Time Physical Activity Questionnaire household chores measure was correlated with habitual performance of household chores. Most questionnaires, even very simple ones, were related to performance of heavy intensity physical activity and treadmill performance; these same questionnaires tended to be related to percent body fat. Fewer questionnaires related to performance of light or moderate activity. Occupational activity was unrelated to any of the validation measures. It is concluded that there are multiple, nonoverlapping dimensions of physical activity, reflected in multiple nonoverlapping validation realms. More important than the length or attention to detail of a questionnaire seems to be the logic of its questions. Important areas of physical activity that should be addressed in future questionnaires include sleep, light, moderate and heavy intensity leisure activities, household chores, and occupational activity. Recent versus habitual activity should also be considered.

Oxidative stress and antioxidants: exposure and impact on female fertility

BACKGROUND Reproductive failure is a significant public health concern. Although relatively little is known about factors affecting fertility and early pregnancy loss, a growing body of literature suggests that environmental and lifestyle factors play an important role. There is sufficient evidence to hypothesize that diet, particularly its constituent antioxidants, and oxidative stress (OS) may influence the timing and maintenance of a viable pregnancy. We hypothesize that conditions leading to OS in the female affect time-to-pregnancy and early pregnancy loss. METHODS We review the epidemiology of female infertility related to antioxidant defenses and oxidation and examine potential sources of OS from the ovarian germ cell through the stages of human pregnancy and pregnancy complications related to infertility. Articles were identified through a search of the PubMed database. RESULTS Female OS is a likely mediator of conception and threshold levels for OS exist, dependent on anatomic location and stage of preconception. CONCLUSIONS Prospective pregnancy studies with dietary assessment and collection of biological samples prior to conception with endpoints of time-to-pregnancy and early pregnancy loss are needed.

Examining Breast Cancer Growth and Lifestyle Risk Factors: Early Life, Childhood, and Adolescence

The perinatal period, childhood, and adolescence are important intervals for breast cancer risk development. Endogenous estrogen exposure is thought to be highest in utero, and exposure to estrogens throughout life plays an important role in increasing breast cancer risk. Some evidence suggests that breast tissue is not fully differentiated until after the first full-term pregnancy; thus, breast tissue might be more susceptible to carcinogenic influences during early life and adolescence. Birth characteristics of the daughter, including gestational age, birth weight, and birth length are associated with maternal hormone levels during the index pregnancy, and birth size has been related to daughters timing of puberty and adult breast cancer incidence. Furthermore, early life and adolescence are critical times for maturation of the hypothalamic pituitary ovarian axis, which regulates production of ovarian hormones including estrogen and progesterone. Childhood height, growth, diet, and body mass index (BMI) have also been associated with breast cancer risk later in life. Of the examined characteristics, we conclude that the available evidence is suggestive of a positive relationship of breast cancer risk with birth weight, birth length, and adolescent height, and an inverse relationship with gestational age and childhood BMI, although several inconsistencies exist in the literature. The best evidence for a relationship of adolescent diet and adult breast cancer risk is indirect, and the relationship of diet, weight status, and weight gain in childhood deserves further attention. The interaction of birth characteristics with established risk factors over the life course, such as age at menarche, in addition to gene-environment interactions, require more research. Further study is also needed to clarify the biologic mechanisms influencing the observed associations.

Dietary Energy Density Is Associated with Body Weight Status and Vegetable Intake in U.S. Children

The objective was to determine the relationship between dietary energy density (ED; kcal/g) and measured weight status in children. The present study used data from a nationally representative sample of 2442 children between 2 and 8 y old who participated in the 2001-2004 NHANES. Survey measures included 24-h dietary recall data, measurement of MyPyramid servings of various food groups, and anthropometry. The relationship among dietary ED, body weight status as calculated using the 2000 CDC growth charts, and food intake was evaluated using quartiles of ED. Additionally, other dietary characteristics associated with ED among children are described. Specific survey procedures were used in the analysis to account for sample weights, unequal selection probability, and the clustered design of the NHANES sample. In this sample, dietary ED was positively associated with body weight status in U.S. children aged 2-8 y. Obese children had a higher dietary ED than lean children (2.08 ± 0.03 vs. 1.93 ± 0.05; P = 0.02). Diets high in ED were also found to be associated with greater intakes of energy and added sugars, more energy from fat; and significantly lower intake of fruits and vegetables. Interventions that lower dietary ED by means of increasing fruit and vegetable intake and decreasing fat consumption may be an effective strategy for reducing childhood obesity.

Development and evaluation of a method for calculating the Healthy Eating Index-2005 using the Nutrition Data System for Research

OBJECTIVE To develop and evaluate a method for calculating the Healthy Eating Index-2005 (HEI-2005) with the widely used Nutrition Data System for Research (NDSR) based on the method developed for use with the US Department of Agricultures (USDA) Food and Nutrient Dietary Data System (FNDDS) and MyPyramid Equivalents Database (MPED). DESIGN Cross-sectional. SETTING Non-institutionalized, community-dwelling adults aged 70 years and above. SUBJECTS Two hundred and seventy-one adults participating in the Geisinger Rural Aging Study (GRAS) and 620 age- and race-matched adults from the National Health and Nutrition Examination Survey 2001-2002 (NHANES) were included in the analysis. The HEI-2005 scores were generated using NDSR in GRAS and compared to scores generated using FNDDS and MPED in NHANES. RESULTS Similar total HEI-2005 scores (mean 62·0 (se 0·75) in GRAS v. 57·4 (se 0·55) in NHANES) were estimated, and the individual components most strongly correlated with total score in both samples were compared. Cronbachs coefficient α values of HEI-2005 were 0·52 in GRAS and 0·43 in NHANES. CONCLUSIONS Since NDSR is commonly used for educational purposes, in clinical settings and in nutrition research, it is important to develop methodology for assessing diet quality through the use of HEI-2005 with this dietary analysis software application and its accompanying food and nutrient database. Results from the present study show that HEI-2005 scores can be generated with NDSR using the method described in the present study and the detailed USDA Center for Nutrition Policy and Promotion technical report as guidance.

Dietary Patterns and Colorectal Adenoma and Cancer Risk: A Review of the Epidemiological Evidence

A number of studies exploring associations between individual dietary components and colorectal adenoma or cancer risk have yielded conflicting results. The study of food-based dietary patterns in relation to chronic disease risk represents an alternative approach to the evaluation of single dietary exposures in epidemiological investigations. Results from prospective cohort and population-based case-control studies examining associations between dietary patterns and colorectal cancer or adenoma risk were evaluated and described in this review. Despite notable differences in population characteristics, study design, and methods used for characterizing dietary patterns across the different studies, two general dietary patterns were found to modestly predict colorectal adenoma and cancer risk. A healthier pattern consisting of greater intakes of fruits and vegetables, and lower intakes of red and processed meat, appeared protective against colorectal adenoma and cancer incidence. Findings also suggest that a less healthy pattern characterized by higher intakes of red and processed meat, as well as potatoes and refined carbohydrates, may increase risk. Continued research efforts are needed to evaluate the cumulative and interactive effects of numerous dietary exposures on colorectal cancer risk.

All-Cause Mortality Risk of Metabolically Healthy Obese Individuals in NHANES III

Mortality risk across metabolic health-by-BMI categories in NHANES-III was examined. Metabolic health was defined as: (1) homeostasis model assessment-insulin resistance (HOMA-IR) <2.5; (2) ≤2 Adult Treatment Panel (ATP) III metabolic syndrome criteria; (3) combined definition using ≤1 of the following: HOMA-IR ≥1.95 (or diabetes medications), triglycerides ≥1.7 mmol/L, HDL-C <1.04 mmol/L (males) or <1.30 mmol/L (females), LDL-C ≥2.6 mmol/L, and total cholesterol ≥5.2 mmol/L (or cholesterol-lowering medications). Hazard ratios (HR) for all-cause mortality were estimated with Cox regression models. Nonpregnant women and men were included (n = 4373, mean ± SD, age 37.1 ± 10.9 years, BMI 27.3 ± 5.8 kg/m2, 49.4% female). Only 40 of 1160 obese individuals were identified as MHO by all definitions. MHO groups had superior levels of clinical risk factors compared to unhealthy individuals but inferior levels compared to healthy lean groups. There was increased risk of all-cause mortality in metabolically unhealthy obese participants regardless of definition (HOMA-IR HR 2.07 (CI 1.3–3.4), P < 0.01; ATP-III HR 1.98 (CI 1.4–2.9), P < 0.001; combined definition HR 2.19 (CI 1.3–3.8), P < 0.01). MHO participants were not significantly different from healthy lean individuals by any definition. While MHO individuals are not at significantly increased risk of all-cause mortality, their clinical risk profile is worse than that of metabolically healthy lean individuals.

The effect of walnut intake on factors related to prostate and vascular health in older men

BackgroundTocopherols may protect against prostate cancer and cardiovascular disease (CVD).MethodsWe assessed the effect of walnuts, which are rich in tocopherols, on markers of prostate and vascular health in men at risk for prostate cancer. We conducted an 8-week walnut supplement study to examine effects of walnuts on serum tocopherols and prostate specific antigen (PSA). Subjects (n = 21) consumed (in random order) their usual diet +/- a walnut supplement (75 g/d) that was isocalorically incorporated in their habitual diets. Prior to the supplement study, 5 fasted subjects participated in an acute timecourse experiment and had blood taken at baseline and 1, 2, 4, and 8 h after consuming walnuts (75 g).ResultsDuring the timecourse experiment, triglycerides peaked at 4 h, and gamma-tocopherol (γ-T) increased from 4 to 8 h. Triglyceride – normalized γ-T was two-fold higher (P = 0.01) after 8 versus 4 h. In the supplement study, change from baseline was +0.83 ± 0.52 μmol/L for γ-T, -2.65 ± 1.30 μmol/L for alpha-tocopherol (α-T) and -3.49 ± 1.99 for the tocopherol ratio (α-T: γ-T). A linear mixed model showed that, although PSA did not change, the ratio of free PSA:total PSA increased and approached significance (P = 0.07). The α-T: γ-T ratio decreased significantly (P = 0.01), partly reflecting an increase in serum γ-T, which approached significance (P = 0.08).ConclusionThe significant decrease in the α-T: γ-T ratio with an increase in serum γ-T and a trend towards an increase in the ratio of free PSA:total PSA following the 8-week supplement study suggest that walnuts may improve biomarkers of prostate and vascular status.

Consumption of a Legume-Enriched, Low-Glycemic Index Diet Is Associated with Biomarkers of Insulin Resistance and Inflammation among Men at Risk for Colorectal Cancer

The Legume Inflammation Feeding Experiment is, to our knowledge, the first randomized crossover feeding trial testing the effects of a legume-enriched, low-glycemic index (GI) diet among men characterized for colorectal adenomas and insulin resistance (IR) status. This study was designed to test the effects of a legume-enriched diet compared with a healthy American (HA) diet under weight-stable conditions. The primary objective was to assess effects on C-reactive protein (CRP) and C-peptide levels. The secondary objective was to assess changes by IR status or history of adenomas. A total of 64 men who completed a colonoscopy within the previous 2 y consumed 2 diets in random order each for 4 wk separated by a washout period. The diets were a legume-enriched (250 g/d), low-GI (GI 38) diet and a high-GI (GI 69) HA diet. We measured fasting glucose, insulin, C-peptide, CRP, and soluble tumor necrosis factor-alpha receptors I and II (sTNFRI/II) at the beginning and end of the diet periods. Participants who consumed both the legume and HA diets had favorably improved CRP (-20.2 and -18.3%) and sTNFRI (-3.7 and -4.4%) concentrations, respectively. The sTNFRII concentrations declined marginally during the legume diet period (-3.8%; P = 0.060) and significantly during the HA diet period (-5.1%; P < 0.001). Fasting glucose increased significantly during both the legume (+1.8%) and HA (-2.2%) diet periods. Only the changes in glucose differed between the diet periods. Serum C-peptide and plasma insulin levels did not change in participants consuming either diet. Healthful dietary changes can improve biomarkers of IR and inflammation.

Diet Index-Based and Empirically Derived Dietary Patterns Are Associated with Colorectal Cancer Risk

Previous studies have derived patterns by measuring compliance with preestablished dietary guidance or empirical methods, such as principal components analysis (PCA). Our objective was to examine colorectal cancer risk associated with patterns identified by both methods. The study included 431 incident colorectal cancer cases (225 men, 206 women) and 726 healthy controls (330 men, 396 women) participating in a population-based, case-control study. PCA identified sex-specific dietary patterns and the Healthy Eating Index-2005 (HEI-05) assessed adherence to the 2005 Dietary Guidelines for Americans. A fruits and vegetables pattern and a meat, potatoes, and refined grains pattern were identified among men and women; a third pattern (alcohol and sweetened beverages) was identified in men. The fruits and vegetables pattern was inversely associated with risk among men [odds ratio (OR) = 0.38, 95% CI = 0.21-0.69 for the highest compared with the lowest quartile] and women (OR = 0.35, 95% CI = 0.19-0.65). The meat, potatoes, and refined grains pattern was positively associated with risk in women (OR = 2.20, 95% CI = 1.08-4.50) and there was a suggestion of a positive association among men (OR = 1.56, 95% CI = 0.84-2.90; P-trend = 0.070). Men and women with greater HEI-05 scores had a significantly reduced risk of colorectal cancer (OR = 0.56, 95% CI = 0.31-0.99; OR = 0.44, 95% CI = 0.24-0.77, respectively). Following the Dietary Guidelines or a dietary pattern lower in meat, potatoes, high fat, and refined foods and higher in fruits and vegetables may reduce colorectal cancer risk.