Edington, Jacqueline D., Geekie, Moira, Carter, Robin, Benfield, Lisa, Ball, Madeleine, and Mann, Jim
American Journal of Clinical Nutrition. July 1989, Vol. 50 Issue 1, p58, 5 p.
Health aspects, Physiological aspects, Research, Control, Hyperlipoproteinemia -- Health aspects, Cholesterol -- Physiological aspects, Low cholesterol diet -- Research, Blood cholesterol -- Control, and Low-cholesterol diet -- Research
Both cholesterol and saturated fat in the diet have been linked to increased risk of coronary artery disease. Dietary cholesterol and saturated fat appear to contribute to heart disease by raising blood cholesterol. The elevated circulating cholesterol may adhere to the inner walls of the coronary arteries, slowing or blocking blood flow. While dietary cholesterol is only found in animal foods such as meat, eggs and dairy products, saturated fat may be found in animal or vegetable foods. Persons who wish to reduce their risk of heart disease are usually advised to make several changes in their diet: reduce cholesterol, reduce saturated fat, and increase fiber. The 58 participants followed a low-saturated-fat, high-fiber diet throughout the 12 weeks. To this background diet were added nine eggs per week for the first four weeks, zero eggs for the second four weeks and nine eggs per week for the last four weeks. Eggs were used as a source of cholesterol. The participants' blood cholesterol levels did not change significantly when the number of eggs was changed from nine to zero and back to nine. The subjects showed no consistent evidence of 'hyperresponse', defined as a greater than average increase in blood cholesterol in response to a given increase in dietary cholesterol. It is concluded that once a person is eating a low-saturated-fat, high-fiber diet, reducing dietary cholesterol to below 400 mg per day provides little additional benefit in terms of lowering blood cholesterol. A cholesterol intake of 400 mg per day is considered moderate and was provided in the diet containing nine eggs per week. When subjects added zero eggs to the background diet they consumed 90 mg cholesterol per day.
Vallacher, Robin R., Wegner, Daniel M., McMahan, Susan C., Cotter, Jacqueline, and Larsen, Kathleen A.
Social Cognition; Fall 1992, Vol. 10 Issue: 3 p335-355, 21p
This study tested the performance optimality hypothesis of action identification theory in the context of self-presentation. Optimal performance is said to occur when a personally easy action is identified in relatively high level terms (i.e., the action's goals and likely effects) or a personally difficult action is identified in relatively low level terms (i.e., the action's mechanical details). To test this idea with respect to self-presentation, subjects were asked to describe themselves to either a difficult-to-impress or an easy-to-impress stranger in advance of a get-acquainted conversation with him or her. Subjects were induced to think about the self-description task in either high level terms (e.g., demonstrating their personality) or low level terms (e.g., smiling when appropriate). Support for the optimality hypothesis was obtained in subjects' self-reports of their self-presentation effectiveness and in observers' evaluations of subjects. Discussion centered on the manifestation of self-presentation nonoptimality in the early stages of relationship formation.
Horn-Ross, Pamela L., Whittemore, Alice S., Harris, Robin, and Itnyre, Jacqueline
Epidemiology; November 1992, Vol. 3 Issue: 6 p490-495, 6p
Nonepithelial ovarian cancers are rare, and little is known about their etiology. Of particular interest are the effects of oral contraceptive use and pregnancy, both of which are associated with large decreases in risk for epithelial ovarian cancer. We examined the risk factors for nonepithelial ovarian tumors by combining data from four case-control studies conducted in the United States. We compared personal characteristics of 38 germ cell cases and 45 stromal cases, respectively, with 1,142 and 2,617 general population controls. All subjects were over age 18 years. For germ cell tumors, there was a weak negative association with parity but no consistent pattern of decreasing risk with increasing parity. In contrast, relative to nulligravid women, gravid nulliparous women were at increased risk of developing a germ cell cancer odds ratio (OR) 4.8, 95 confidence interval (CI) 1.2-18.61. The use of oral contraceptives was also associated with elevated risk (OR 2.0,95 CI 0.77- 5.1); however, no clear trends in risk were observed. For stromal tumors, oral contraceptive use was associated with decreased risk (OR 0.37, 95 CI 0.16-0.83), whereas pregnancy was associated with a small elevation in risk. A trend of increasing risk with increasing age at first term pregnancy was observed, with an odds ratio of 3.6 (95 CI 1.0-12.5) for a first birth after age 29 years. Risk factors for nonepithelial ovarian cancers do not appear to parallel each other or those for epithelial ovarian cancer. (Epidemiology 1992;3490-495)
Whittemore, Alice S., Harris, Robin, Itnyre, Jacqueline, Halpern, Jerry, and Group, the Collaborative Ovarian Cancer
American Journal of Epidemiology; November 1992, Vol. 136 Issue: 10 p1175-1175, 1p
Data from 12 US case-control studies of ovarian cancer, conducted during the period 1956–1986 and representing some 3, 000 cases and 10,000 controls, were pooled and reanalyzed. Separate analyses were conducted for four subgroups of the pooled data: invasive epithelial ovarian cancers in white women; epithelial ovarian cancers of low malignant potential in white women, epithelial ovarian cancers in black women, and nonepithelial ovarian cancers. This paper gives a brief description of the participating studies and describes the methods used in the collaborative analysis. Am J Epidemiol1992; 136: 1175–83
Whittmore, Alice S., Harris, Robin, Itnyre, Jacqueline, and Group, the Collaborative Ovarian Cancer
American Journal of Epidemiology; November 1992, Vol. 136 Issue: 10 p1184-1184, 1p
Data collected from 2,197 white ovarian cancer patients and 8,893 white controls in 12 US case-control studies conducted in the period 1956–1986 were used to evaluate the relation of invasive epithelial ovarian cancer to reproductive and menstrual characteristics, exogenous estrogen use, and prior pelvic surgeries. Clear trends of decreasing risk were evident with increasing number of pregnancies (regardless of outcome) and increasing duration of breast feeding and oral contraceptive use. Ovarian dysfunction leading to both infertility and malignancy is an unlikely explanation for these trends for several reasons: 1) The trends were evident even among the highly parous; 2) risk among nulliparous women did not vary by marital status or gravidity; and 3) risk among ever-married women showed little relation to length of longest pregnancy attempt or history of clinically diagnosed infertility. Risk was increased among women who had used fertility drugs and among women with long total duration of premenopausal sexual activity without birth control; these associations were particularly strong among the nulligravid. No consistent trends in risk were seen with age at menarche, age at menopause, or duration of estrogen replacement therapy. A history of tubal ligation or of hystereclomy with ovarian conservation was associated with reduced ovarian cancer risk. These observations suggest that pregnancy, breast feeding, and oral contraceptive use induce biological changes that protect against ovarian malignancy, that, at most, a small fraction of the excess ovarian cancer risk among nulliparous women is due to infertility, and that any increased risk associated with infertility may be due to the use of fertility drugs. Am J Epidemiol 1992; 136: 1184–1203
Harris, Robin, Whittemore, Alice S., Itnyre, Jacqueline, and Group, the Collaborative Ovarian Cancer
American Journal of Epidemiology; November 1992, Vol. 136 Issue: 10 p1204-1204, 1p
Epithelial ovarian neoplasms of low malignant potential, also called borderline ovarian tumors, have various features of malignancy, but they do not invade the ovarian stroma. Women with these tumors usually are younger when diagnosed and have better prognoses than do women with invasive tumors. There have been few epidemiologic studies of borderline tumors, and it is unclear whether there are etiologic differences between the two types of tumor behavior. Combined data from nine case-control studies, conducted from 1974 to 1986 and representing 327 white women with tumors of low malignant potential and 4, 144 white controls, were used to evaluate the relation between these tumors and personal characteristics related to invasive ovarian cancer. The risk profile for tumors of low malignant potential was found to be similar to that for invasive tumors, with two exceptions: Compared with that of invasive tumors, risk of borderline tumors was less clearly reduced among women who had used oral contraceptives and more clearly elevated among women with a history of Infertility. Am J Epidemiol 1992; 136: 1204–11
Whittemore, Alice S., Harris, Robin, ltnyre, Jacqueline, and Group, the Collaborative Ovarian Cancer
American Journal of Epidemiology; November 1992, Vol. 136 Issue: 10 p1212-1212, 1p
Two hypotheses have been proposed to explain the reduced risk of epithelial ovarian cancer associated with pregnancy and oral contraceptive use. The first states that some sequelae of ovulation increase the likelihood of malignancy and that pregnancies and oral contraceptives protect by suppressing ovulation. The second hypothesis states that circulating levels of pituitary gonadotropins increase the risk of malignancy and that pregnancies and oral contraceptives protect by suppressing secretion of these hormones. The authors evaluate the two hypotheses in light of combined data from 12 United States case-oxitrol studies of epithelial ovarian cancer in white women conducted from 1956 to 1986. While a number of observations support both hypotheses, there are exceptions. Differential risk reduction associated with pregnancy and oral contraceptive use (pregnancy being the more effective in young women and the less effective in older women) conflicts with the first “ovulation” hypothesis, while reduced risk associated with breast feeding and absence of altered risk associated with estrogen replacement therapy conflicts with the second “gonadotropin” hypothesis. Several findings would not have been predicted by either hypothesis, e.g., only weak trends relate cancer risk to age at menarche, and, among older women, no clear trends relate risk to age at menopause. Odds ratio attenuation due to errors in reporting personal characteristics may be responsible for some of these inconsistencies. Multidisciplinary research is needed to clarify the etkrfogic roles of ovulation and gonadotropin stimulation, both of which may enhance carcinogenesis in the ovarian epithelium. Am J Epidemiol 1992: 136: 1212–20