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M L McCullough

Publications and source records attributed to M L McCullough.

At least 19 recordsLinked to original sources
PubMed2006

Alcohol intake and ovarian cancer risk: a pooled analysis of 10 cohort studies.

Alcohol has been hypothesized to promote ovarian carcinogenesis by its potential to increase circulating levels of estrogen and other hormones; through its oxidation byproduct, acetaldehyde, which may act as a cocarcinogen; and by depletion of folate and other nutrients. Case-control and cohort studies have reported conflicting results relating alcohol intake to ovarian cancer risk. We conducted a pooled analysis of the primary data from ten prospective cohort studies. The analysis included 529 638 women among whom 2001 incident epithelial ovarian cases were documented. After study-specific relative risks (RR) and 95% confidence intervals (CI) were calculated by Cox proportional hazards models, and then were pooled using a random effects model; no associations were observed for intakes of total alcohol (pooled multivariate RR=1.12, 95% CI 0.86-1.44 comparing > or =30 to 0 g day(-1) of alcohol) or alcohol from wine, beer or spirits and ovarian cancer risk. The association with alcohol consumption was not modified by oral contraceptive use, hormone replacement therapy, parity, menopausal status, folate intake, body mass index, or smoking. Associations for endometrioid, mucinous, and serous ovarian cancer were similar to the overall findings. This pooled analysis does not support an association between moderate alcohol intake and ovarian cancer risk.

Adult↗
PubMed2005

Prospective study of occupation and amyotrophic lateral sclerosis mortality.

Occupational exposures are suspected of contributing to the risk of amyotrophic lateral sclerosis (ALS), but results of epidemiologic studies have been inconsistent. The authors prospectively assessed the relation between occupation and ALS mortality among more than 1 million participants in the Cancer Prevention Study II of the American Cancer Society. Follow-up from 1989 through 2002 identified 507 ALS deaths among men and 430 among women. Adjusted rate ratios were calculated by using Mantel-Haenszel weights and Cox proportional hazards. Among men, elevated ALS mortality was found for programmers (rate ratio = 4.55, 95% confidence interval: 1.46, 14.2; p = 0.009) and laboratory technicians (rate ratio = 1.96, 95% confidence interval: 1.04, 3.66; p = 0.04). Occupations previously associated with increased risk of ALS for which no increased risk was found included farmers, electricians, and welders, although the numbers of electricians (eight ALS deaths) and welders (two ALS deaths) were small. Among women, only machine assemblers had significantly increased ALS mortality (rate ratio = 2.81, 95% confidence interval: 1.05, 7.53; p = 0.04). Results, which suggest that male programmers and laboratory technicians and female machine assemblers may be at increased risk of death from ALS, should be interpreted cautiously, however, because they are based on small numbers.

Amyotrophic Lateral Sclerosis↗
PubMed2005

Prospective study of military service and mortality from ALS.

BACKGROUND: Two recent studies suggest that the risk of ALS is increased among Gulf War veterans. It is not known whether military service outside of the Gulf War is associated with increased risk of ALS. METHODS: The authors prospectively assessed the relation between service in the military and ALS mortality among participants in the Cancer Prevention Study II cohort of the American Cancer Society, a cohort that includes over 500,000 men from the 50 states, Washington, DC, and Puerto Rico. Participant follow-up was conducted from 1989 through 1998 for ALS mortality. There were a total of 280 deaths from ALS among 126,414 men who did not serve in the military and 281,874 who did. Adjusted relative risks (RRs) were calculated using Mantel-Haenszel weights and Cox proportional hazards. RESULTS: Men who served in the military had an increased death rate from ALS (RR = 1.53; 95% CI: 1.12 to 2.09; p = 0.007) compared with those who did not serve. The increase in ALS mortality was observed among men who served in the Army or National Guard (RR = 1.54), Navy (RR = 1.87), Air Force (RR = 1.54), and Coast Guard (RR = 2.24); no increase in risk was found in men who served in the Marine Corps, although there were only 13,670 men in this group. The risk of ALS among men who served was elevated in every 5-year birth cohort from 1915 through 1939. CONCLUSIONS: Military personnel have an increased risk of ALS. This increase appeared to be largely independent of the branch of service and the time period served.

Amyotrophic Lateral Sclerosis↗
PubMed2004

Prospective study of cigarette smoking and amyotrophic lateral sclerosis.

Cigarette smoking has been proposed as a risk factor for amyotrophic lateral sclerosis (ALS), but because of the low incidence of ALS this association has been examined only with case-control methods. The authors prospectively assessed the relation between cigarette smoking and ALS mortality among participants in the Cancer Prevention Study II cohort of the American Cancer Society, a cohort of over 1 million people enrolled in 1982 who completed a lifestyle questionnaire including a detailed smoking history at baseline. Causes of deaths were ascertained through death certificates; ALS was not identified separately until 1989. From January 1, 1989, through 1998, 291 women and 330 men died from ALS. The relative risk of ALS among current smokers compared with never smokers was 1.67 (95% confidence interval: 1.24, 2.24; p = 0.002) in women and 0.69 (95% confidence interval: 0.49, 0.99; p = 0.04) in men. The difference in the relative risk estimates between the sexes was statistically significant (p < 0.0003). This large prospective study provides limited evidence that current cigarette smoking may be associated with increased death rates from ALS in women but not in men.

Adult↗
PubMed2001

Multivitamin use and colon cancer mortality in the Cancer Prevention Study II cohort (United States).

OBJECTIVE: Multivitamins contain several nutrients, including folic acid, which are hypothesized to reduce colon cancer risk. Previous epidemiologic studies have suggested that effects of multivitamins containing substantial amounts of folic acid (introduced in 1973) may not be evident until 15 or more years since first use. METHODS: We examined the association between daily multivitamin use and colon cancer mortality among 806,397 US men and women in the Cancer Prevention Study II cohort who completed a questionnaire at enrollment in 1982 and were followed for mortality through 1998. RESULTS: After multivariate adjustment, multivitamin use at enrollment showed little association with colon cancer mortality. After 15 years since first use of a multivitamin potentially containing folic acid, we observed slightly decreased risk of colon cancer mortality (rate ratio (RR) = 0.89, 95% confidence interval (CI) 0.80-0.99). Consistent with previous reports, this association was stronger among participants consuming two or more alcoholic drinks per day (RR = 0.71, 95% CI 0.56-0.91). CONCLUSION: Our results are consistent with a modest reduction in colon cancer mortality associated with use of folic acid-containing multivitamins among moderate to heavy alcohol users.

Adult↗
PubMed2001

Vitamin C and vitamin E supplement use and colorectal cancer mortality in a large American Cancer Society cohort.

Some recent epidemiological studies have suggested that use of vitamin C or vitamin E supplements, both of which are important antioxidants, may substantially reduce the risk of colon or colorectal cancer. We examined the association between colorectal cancer mortality and use of individual vitamin C and E supplements in the American Cancer Society's Cancer Prevention Study II cohort. We used proportional hazards modeling to estimate rate ratios among 711,891 men and women in the United States who completed a self-administered questionnaire at study enrollment in 1982, had no history of cancer, and were followed for mortality through 1996. During the 14 years of follow-up, 4404 deaths from colorectal cancer occurred. After adjustment for multiple colorectal cancer risk factors, regular use of vitamin C or E supplements, even long-term use, was not associated with colorectal cancer mortality. The combined-sex rate ratios were 0.89 [95% confidence interval (CI), 0.73-1.09] for 10 or more years of vitamin C use and 1.08 (95% CI, 0.85-1.38) for 10 or more years of vitamin E use. In subgroup analyses, use of vitamin C supplements for 10 or more years was associated with decreased risk of colorectal cancer mortality before age 65 years (rate ratio = 0.48; 95% CI, 0.28-0.81) and decreased risk of rectal cancer mortality at any age (rate ratio = 0.40; 95% CI, 0.20-0.80). Our results do not support a substantial effect of vitamin C or E supplement use on overall colorectal cancer mortality.

Adult↗
PubMed2001

A prospective study of diet and stomach cancer mortality in United States men and women.

Frequent consumption of fruits, vegetables, and whole grains has been associated with a reduced risk of stomach cancer in the majority of case-control studies of these factors: however, prospective studies have been less consistent. We examined the association between selected major food groups (citrus fruits, vegetables, whole grains, and processed meats) and risk of fatal stomach cancer in the Cancer Prevention Study (CPS) II cohort of 1.2 million United States men and women. During 14 years of follow-up, we documented 439 stomach cancer deaths in women and 910 in men after exclusion of individuals with prevalent cancers, inadequate diet information, and recent weight loss at baseline in 1982. After controlling for other risk factors, none of the food groups examined were associated with risk of stomach cancer except for an unexpected increased risk with vegetable consumption in women [relative risk (RR) = 1.25; 95% confidence interval (CI), 0.99-1.58; highest versus lowest tertile, P = 0.06 for trend]. A high overall plant food intake (a sum of vegetables, citrus fruit, and whole grains) was associated with reduced risk in men (RR = 0.79; 95% CI, 0.67-0.93; highest versus lowest tertile, P = 0.003 for trend), but not in women (RR = 1.18; 95% CI, 0.93-1.50; P = 0.16 for trend). Of individual foods examined, liver consumption greater than twice/week was associated with an increased risk of fatal stomach cancer in women (RR = 1.96; 95% CI, 1.09-3.53) and men (RR = 1.63; 95% CI, 1.02-2.62) compared with nonconsumers. This study supports a modest role for plant foods in reducing the risk of fatal stomach cancer in men, but not in women.

Adult↗
PubMed2000

Adherence to the Dietary Guidelines for Americans and risk of major chronic disease in women.

BACKGROUND: Little is known about the overall health effects of adherence to the Dietary Guidelines for Americans. The healthy eating index (HEI), developed at the US Department of Agriculture, measures how well Americans' diets conform to these guidelines. OBJECTIVE: We tested whether the HEI (scores range from 0 to 100; 100 is best) calculated from food-frequency questionnaires (HEI-f) would predict risk of major chronic disease in women. DESIGN: A total of 67272 US female nurses who were free of major disease completed detailed questionnaires on diet and chronic disease risk factors in 1984 and repeatedly over 12 y. Major chronic disease was defined as fatal or nonfatal cardiovascular disease (myocardial infarction or stroke, n = 1365), fatal or nonfatal cancer (n = 5216), or other nontraumatic deaths (n = 496), whichever came first. We also examined cardiovascular disease and cancer as separate outcomes. RESULTS: After adjustment for smoking and other risk factors, the HEI-f score was not associated with risk of overall major chronic disease in women [relative risk (RR) = 0.97; 95% CI: 0.89, 1.06 comparing the highest with the lowest quintile of HEI-f score]. Being in the highest HEI-f quintile was associated with a 14% reduction in cardiovascular disease risk (RR = 0.86; 95% CI: 0.72, 1. 03) and was not associated with lower cancer risk (RR = 1.02; 95% CI: 0.93, 1.12). CONCLUSION: These data suggest that adherence to the 1995 Dietary Guidelines for Americans, as measured by the HEI-f, will have limited benefit in preventing major chronic disease in women.

Adult↗
PubMed2000

Adherence to the Dietary Guidelines for Americans and risk of major chronic disease in men.

BACKGROUND: The Dietary Guidelines for Americans and the food guide pyramid aim to reduce the risk of major chronic disease in the United States, but data supporting their overall effectiveness are sparse. The healthy eating index (HEI) measures the concordance of dietary patterns with these guidelines. OBJECTIVE: We tested whether a high HEI score (range: 0-100; 100 is best) calculated from a validated food-frequency questionnaire (HEI-f) could predict lower risk of major chronic disease in men. DESIGN: A cohort of US male health professionals without major disease completed detailed questionnaires on food intake and other risk factors for heart disease and cancer in 1986 and repeatedly during the 8-y follow-up. Major chronic disease outcome was defined as incident major cardiovascular disease (stroke or myocardial infarction, n = 1092), cancer (n = 1661), or other non-trauma-related deaths (n = 366). RESULTS: The HEI-f was weakly inversely associated with risk of major chronic disease [comparing highest with lowest quintile of the HEI-f, relative risk (RR) = 0.89; 95% CI: 0.79, 1.00; P: < 0.001 for trend]. The HEI-f was associated with moderately lower risk of cardiovascular disease (RR = 0.72; 95% CI: 0.60, 0.88; P: < 0.001) but was not associated with lower cancer risk. CONCLUSIONS: The HEI-f was only weakly associated with risk of major chronic disease, suggesting that improvements to the HEI may be warranted. Further research on the HEI could have implications for refinements to the Dietary Guidelines for Americans and the food guide pyramid.

Alcohol Drinking↗
PubMed1999

Descriptive characteristics of the dietary patterns used in the Dietary Approaches to Stop Hypertension Trial. DASH Collaborative Research Group.

The Dietary Approaches to Stop Hypertension trial was a randomized, multicenter, controlled feeding study to compare the effect on blood pressure of 3 dietary patterns: control, fruits and vegetables, and combination diets. The patterns differed in selected nutrients hypothesized to alter blood pressure. This article examines the food-group structure and nutrient composition of the study diets and reports participant nutrient consumption during intervention. Participants consumed the control dietary pattern during a 3-week run-in period. They were then randomized either to continue on the control diet or to change to the fruits and vegetables or the combination diet for 8 weeks. Sodium intake and body weight were constant during the entire feeding period. Analysis of variance models compared the nutrient content of the 3 diets. Targeting a few nutrients thought to influence blood pressure resulted in diets that were profoundly different in their food-group and nutrient composition. The control and fruits and vegetables diets contained more oils, table fats, salad dressings, and red meats and were higher in saturated fat, total fat, and cholesterol than was the combination diet. The fruits and vegetables and combination diets contained relatively more servings of fruits, juices, vegetables, and nuts/seeds, and were higher in magnesium, potassium, and fiber than was the control diet. Both the fruits and vegetables and combination diets were low in sweets and sugar-containing drinks. The combination diet contained a greater variety of fruits, and its high calcium content was obtained by increasing low-fat dairy products. In addition, the distinct food grouping pattern across the 3 diets resulted in substantial differences in the levels of vitamins A, C, E, folate, B-6, and zinc.

Adult↗
PubMed1999

Pre-enrollment diets of Dietary Approaches to Stop Hypertension trial participants. DASH Collaborative Research Group.

A large body of evidence suggests that several nutrients are related to blood pressure. Less is known about the eating patterns of special populations, such as those at risk for hypertension, or how demographic factors affect the diets of these populations. This article characterizes the usual diets of participants before they enrolled in the Dietary Approaches to Stop Hypertension (DASH) trial. During screening for DASH, 380 participants completed the National Cancer Institute food frequency questionnaire. Nutrient and food group intake, the Keys score (a measure of a diet's atherogenicity), and the Diet Quality Index were estimated from the food frequency questionnaire. The effects of age, sex, race, baseline weight, and education on these dietary factors were assessed among DASH participants and compared with similar data from the Third National Health and Nutrition Examination Survey and other published reports. Among DASH participants, African-Americans reported lower intakes of dairy products (P < .001), calcium (P < .001), and magnesium (P < .05) than did whites. Older women reported greater intakes of calcium, magnesium, and potassium (all P < .05) and less fat (P < .05) than did younger women. Older men consumed fewer servings of fruits (P < .03), less vitamin C (P < .05), and had a higher Keys score (P < .05) than did younger men. Heavier (body mass index > or = 25) participants reported lower intakes of protein and potassium, but higher fat and energy intakes (all P < .05). Taken together, these data show that younger, overweight African-American women have the least healthful diets, because they consume more atherogenic foods and fewer of the nutrients related to decreased blood pressure. Overall Diet Quality Index scores did not differ between African-American and white participants. Despite differences in dietary assessment methods between the population samples of DASH and the Third National Health and Nutrition Examination Survey, within each population sample patterns of micronutrient intake were similar between African-American and white participants.

Adult↗
PubMed1999

The Linear Index Model for establishing nutrient goals in the Dietary Approaches to Stop Hypertension trial. DASH Collaborative Research Group.

Establishing target levels of nutrients in feeding studies presents a challenge to dietitians. Although researchers studying energy-containing nutrients, such as protein and fat, commonly establish target levels according to body weight or as a percentage of energy, it is less clear how to establish levels of micronutrients. Typically, a constant target level is used regardless of energy requirements. Alternatively, nutrients could be provided at a fixed level per 1,000 kcal. Such an approach, however, could result in absolute levels of nutrient intakes that are difficult to achieve through foods alone, particularly for persons with high energy requirements. This report describes the Linear Index Model, a new approach for establishing target levels of selected micronutrients in the Dietary Approaches to Stop Hypertension trial. This model indexes micronutrient levels to energy levels to achieve a linear range of targeted intake in proportion to the energy intake. The Linear Index Model has several benefits: it takes advantage of indexing nutrients according to energy requirements, thus providing levels of nutrient intakes that can be readily achieved by foods; it is based on population consumption data, thus providing a realistic range of intakes for the experimental conditions; and it ensures distinct contrasts in experimental conditions. The Linear Index Model is a feasible and practical approach for establishing target levels of nutrients in feeding studies.

Blood Pressure↗
PubMed1999

Comparison of 4 nutrient databases with chemical composition data from the Dietary Approaches to Stop Hypertension trial. DASH Collaborative Research Group.

Accuracy of computerized nutrient databases is an important consideration in selecting a nutrient analysis system. We project compared the nutrient content of daily menus calculated from 4 microcomputer programs to chemical analysis of menus analyzed for the Dietary Approaches to Stop Hypertension (DASH) trial. Thirty-six menus were entered at 2 independent DASH sites using the ESHA Food Processor, Minnesota Nutrition Data System, Moore's Extended Nutrient Database, and Nutritionist IV databases. Food prepared according to these menus was chemically analyzed at the Food Analysis Laboratory Control Center at Virginia Polytechnic Institute and State University, Department of Biochemistry, Blacksburg. Estimates for 13 nutrients were compared: energy, total fat, saturated fat, monounsaturated fat, polyunsaturated fat, carbohydrate, protein, cholesterol, calcium, potassium, magnesium, iron, and sodium. The overall intraclass correlation between the 2 sites' data entry was 0.998; thus, values were averaged for analyses. Databases varied significantly in their mean deviations from chemical analyses values for saturated, monounsaturated, and polyunsaturated fatty acids, potassium, magnesium, and iron (P < .05); however, these differences were small (< 10%). Absolute deviations, which estimate the combined effect of bias and precision, were significantly different among databases for energy, saturated fatty acids, and polyunsaturated acids. Absolute differences from the laboratory values varied by < 15%, except for iron. All 4 databases were comparable in accuracy and precision and performed well. Criteria for database selection depends not only on overall database accuracy, especially for nutrients of interest, but also on the ease of use of the program, relevant features of the associated software; and cost.

Blood Pressure↗
PubMed1999

Dietary adherence in the Dietary Approaches to Stop Hypertension trial. DASH Collaborative Research Group.

Participants in controlled feeding studies must consume all study foods and abstain from all other foods. In outpatient studies in which adherence may be compromised by free-living conditions, promoting, documenting, and monitoring dietary adherence are necessary. In the Dietary Approaches to Stop Hypertension (DASH) trial, a thorough participant screening process, an orientation session, and a run-in feeding period before randomization aided in the selection of participants who would most likely adhere to the demands of the study protocol. Throughout the feeding period, various educational and motivational techniques were used to encourage DASH participants to adhere to the dietary protocol. Both objective and subjective methods documented excellent participant adherence. Daily monitoring of individual adherence was based on meal attendance, body weight measurements, and daily diaries. Urinary sodium, potassium, phosphorus, and urea nitrogen values and an anonymous poststudy survey were used to evaluate adherence at the end of the study. Most DASH participants adhered to the feeding regimen by consuming only study foods and no other foods. When adherence lapsed, participants generally cited the lack of menu variety as a reason. Successful participant adherence to the constraints of an outpatient controlled feeding study is possible with carefully selected participants and a variety of adherence-promoting strategies incorporated into the study protocol.

Blood Pressure↗
PubMed1998

Spinal motor patterns in the turtle.

Rhythmic alternation between ipsilateral hip flexors and extensors occurs during the normal pattern of fictive rostral scratching in response to unilateral midbody stimulation in D3-end turtles (complete spinal transection posterior to the forelimb enlargement). Unilateral midbody stimulation evokes rhythmic bursts of ipsilateral hip flexor activity with no hip extensor activity in D3-end turtles with D6-D7 contralateral hemisection (transverse hemisection anterior to the hindlimb enlargement). Bilateral midbody stimulation in these turtles evokes reconstruction of rhythmic alternation between intact side hip flexors and extensors. These normal motor patterns in response to two-site stimulation are reconstructed because one-site stimulation in this preparation activates only hip flexor rhythms (J. Neurosci. 18: 467). Hip flexor rhythms can therefore occur without hip extensor activation. This supports the concept that reciprocal inhibition between flexor and extensor interneurons is not required for flexor motor rhythm generation. Reciprocal inhibition, when present, also contributes to rhythmicity (J. Neurophysiol. 78: 3479; see also Currie and Gonsalves, this volume). Both mechanisms for rhythmicity are included in the Grillner unit burst generator model: hip flexor unit burst generators may be rhythmogenic in the absence of hip extensor activity and reciprocal inhibition contributes to rhythmogenesis. Contralateral midbody stimulation assisted in the activation of ipsilateral hip extensor rhythmicity during reconstructed rostral scratching. This result provides additional support for the hypothesis that a bilateral shared core of hip interneuronal circuitry plays a critical role in the generation of the normal pattern of fictive rostral scratching (J. Neurosci. 15: 4343).

Animals↗
PubMed1998

Reconstruction of flexor/extensor alternation during fictive rostral scratching by two-site stimulation in the spinal turtle with a transverse spinal hemisection.

Analyses of fictive scratching motor patterns in the spinal turtle with transverse hemisection provided support for the concept of bilateral shared spinal cord circuitry among neurons responsible for generating left- and right-side rostral, pocket, and caudal fictive scratching. Rhythmic bursts of hip flexor activity, the hip extensor deletion variation of fictive rostral scratching, were elicited by ipsilateral stimulation in the rostral scratch receptive field of a spinal turtle [transection at the segmental border between the second (D2) and third (D3) postcervical spinal segments] with a contralateral transverse hemisection one segment anterior to the hindlimb enlargement (at the D6-D7 segmental border). In addition, other sites were stimulated in this preparation: (1) contralateral sites in a rostral, pocket, or caudal scratch receptive field or (2) ipsilateral sites in a caudal scratch receptive field. A reconstructed fictive rostral scratch motor pattern of rhythmic alternation between hip flexor and hip extensor activation was produced by simultaneous stimulation of one site in the ipsilateral rostral scratch receptive field and another site in one of the other scratch receptive fields. This reconstructed rostral scratch motor pattern resembled the normal rostral scratch motor pattern produced by one-site rostral scratch stimulation of a spinal turtle (D2-D3 transection) with no additional transections. The observation of a reconstructed rostral scratch motor pattern produced by two-site stimulation in the spinal turtle with transverse hemisection supports the concept that hip extensor circuitry activated by stimulation of other scratch receptive fields is shared with circuitry activated by ipsilateral rostral scratch receptive field stimulation.

Animals↗
PubMed1998

The recovered memories debate: how reliable is the scholarship?

The disputed issues that comprise the recovered memories controversy are so important that they deserve the most careful and intellectually honest scholarship that the academic and professional community can muster. Drawing partly on illustrative material from the recent Health Care Analysis paper by Goodyear-Smith et al. and associated commentaries, it is argued that the controversy is not being well served. The rules of scholarship are too often broken, with the result that the products are often superficial, containing what should have been readily avoided factual errors, and are sometimes even misleading.

Adult↗