Specific Types Of Fat Research Articles

Effects of Rich-in-Fat Diets and Highly Selective COX-2 Inhibitors on 7,12-Dimethylbenz-(A)-Anthracene-Induced Tumor Growth

The effects of diet, of non-steroidal anti-inflammatory drugs, or of their combination on carcinogenesis continue to be a case for controversy. Diets that are high in fat have been linked to increased risk of various tumors. At the same time there is substantial, but not conclusive, evidence that the risk of breast and colon cancer correlates with total fat intake rather than a specific type of fat. On the other hand, non-steroidal anti-inflammatory drugs (NSAIDs) have been studied extensively because they appear to delay or inhibit the development of malignant and pre-malignant lesions. 7,12-Dimethylbenz-(a)-anthracene (DMBA) has been used for a long time to induce carcinogenesis in a number of rat animal models. The present study attempts to identify the effects on DMBA-induced tumor growth (a) of diets rich in fat and (b) of the highly selective COX-2 inhibitor Celecoxib, which has been claimed to offer substantial protection against carcinogenesis.

Fat

Fat

Hungry for life

Hungry for life

Dietary Fat and Risk of Postmenopausal Breast Cancer in a 20-year Follow-up

Dietary fat in midlife has not been associated with breast cancer risk in most studies, but few have followed women beyond one decade. The authors examined the relation of dietary fat, assessed by repeated questionnaires, to incidence of postmenopausal breast cancer in a cohort of 80,375 US women (3,537 new cases) prospectively followed for 20 years between 1980 and 2000. The multivariable relative risk for an increment of 5% of energy from total dietary fat intake was 0.98 (95% confidence interval: 0.95, 1.00). Additionally, specific types of fat were not associated with an increased risk of breast cancer. Furthermore, secondary analyses indicated no differences in breast cancer risk by estrogen receptor or progesterone receptor status. However, stratification by waist circumference indicated a significant decrease in breast cancer risk for participants with a waist circumference of 35 inches (88.9 cm) or greater (p-trend = 0.04). None of the latency intervals investigated were associated with an increased risk of breast cancer. In addition, fat intake before menopause was not related to risk of postmenopausal breast cancer. These results suggest a reduction in breast cancer risk for women with insulin resistance syndrome who consume high-fat diets and no association between specific sources of fat during midlife and risk of postmenopausal breast cancer.

The Uncoupling Protein 1 Gene (UCP1) Is Disrupted in the Pig Lineage: A Genetic Explanation for Poor Thermoregulation in Piglets

Piglets appear to lack brown adipose tissue, a specific type of fat that is essential for nonshivering thermogenesis in mammals, and they rely on shivering as the main mechanism for thermoregulation. Here we provide a genetic explanation for the poor thermoregulation in pigs as we demonstrate that the gene for uncoupling protein 1 (UCP1) was disrupted in the pig lineage. UCP1 is exclusively expressed in brown adipose tissue and plays a crucial role for thermogenesis by uncoupling oxidative phosphorylation. We used long-range PCR and genome walking to determine the complete genome sequence of pig UCP1. An alignment with human UCP1 revealed that exons 3 to 5 were eliminated by a deletion in the pig sequence. The presence of this deletion was confirmed in all tested domestic pigs, as well as in European wild boars, Bornean bearded pigs, wart hogs, and red river hogs. Three additional disrupting mutations were detected in the remaining exons. Furthermore, the rate of nonsynonymous substitutions was clearly elevated in the pig sequence compared with the corresponding sequences in humans, cattle, and mice, and we used this increased rate to estimate that UCP1 was disrupted about 20 million years ago.

Facts on fats

Cardiovascular disease and age-related macular degeneration (AMD) may share common risk factors in their causal pathways. Decades of research from the cardiovascular sciences on fats have led investigators to focus on specific types of fats rather than total fat as a whole. They have established that saturated and trans-unsaturated fats (trans fats) are damaging to cardiovascular health while polyunsaturated fats, particularly the marine omega 3 fatty acids appear protective. This has led to a number of studies investigating the associations of fat and AMD. Though the causal relationship between fats and AMD remain unproven, some studies suggest that an association may be present. To be able to understand and interpret the study results and their implications, an understanding of the fats in the diet is important. This review aims to give an overview of fatty acids, particularly the trans-unsaturated fatty acids, and the relevant food groups.

Dietary Fat Intake and Risk of Coronary Heart Disease in Women: 20 Years of Follow-up of the Nurses' Health Study

The authors examined the associations of dietary fat and specific types of fat with risk of coronary heart disease (CHD) among 78,778 US women initially free of cardiovascular disease and diabetes in 1980. They documented 1,766 incident CHD cases (including 1,241 nonfatal myocardial infarctions and 525 CHD deaths) during 20 years of follow-up. Polyunsaturated fat intake was inversely associated with CHD risk (multivariate relative risk (RR) for the highest vs. the lowest quintile = 0.75, 95% confidence interval (CI): 0.60, 0.92; p(trend) = 0.004), whereas trans-fat intake was associated with an elevated risk of CHD (RR = 1.33, 95% CI: 1.07, 1.66; p(trend) = 0.01). The associations between intakes of polyunsaturated fat and trans-fat with CHD risk were most evident among women younger than age 65 years (for polyunsaturated fat, RR = 0.66, 95% CI: 0.50, 0.85; p(trend) = 0.002 and for trans-fat, RR = 1.50, 95% CI: 1.13, 2.00; p(trend) = 0.01). The inverse association between polyunsaturated fat intake and CHD risk was strongest among women whose body mass index was >or=25 kg/m(2). Findings continue to support an inverse relation between polyunsaturated fat intake and CHD risk, particularly among younger or overweight women. In addition, trans-fat intake was associated with increased risk of CHD, particularly for younger women.

The role of nutrition in the prevention of breast cancer.

Nutrition has been widely studied as a leading environmental factor in the prevention of breast cancer (BC). Despite the challenges in relating consumption of specific nutrients to BC risk, particularly in the context of a total diet, many investigators have contributed valuable information. Dietary fat has received the most attention and also created the most uncertainty. Specific types of fat, particularly monounsaturated fat and the ratio of omega-3 to omega-6 fatty acids, demonstrate more potential to influence BC risk. A wide variety of other dietary factors have been studied in relation to BC including total energy, dietary fiber, alcohol, micronutrients, phytochemicals, specific foods, and food constituents. Results of epidemiological studies relating consumption of these dietary factors to BC have increased the knowledge base that provides rationale for various nutritional strategies to contribute to BC prevention.

Is There Something Fishy About Bipolar Disorder

Lower rates of cardiovascular disease have been associated with greater dietary intake of specific types of fats, and it has been suggested that lower

Dietary fat intake and risk of stroke in male US healthcare professionals: 14 year prospective cohort study

Objective To examine the association between intake of total fat, specific types of fat, and cholesterol and risk of stroke in men.Design and setting Health professional follow up study with...

Interpreting Epidemiologic Research: Lessons From Studies of Childhood Cancer

In recent years, the public has shown concern about trends in incidence rates, the occurrence of clusters, and the role of certain environmental exposures in the cause of childhood cancers. A front-page news story in the New York Times 1 stimulated a dramatic upswing of public anxiety about these issues. Hearings by the US Senate Environment and Public Works Committee on a cluster of 11 childhood acute lymphoblastic leukemia (ALL) cases (since increased to 13) among the 8200 residents of a town in Nevada over a 3-year period led to a featured article in USA Today 2 describing legislation under consideration to enhance the federal government’s role in responding to apparent cancer outbreaks in US communities. Compared with 1.22 million cancers (excluding non-melanoma skin cancers) diagnosed annually among adults in the United States (corresponding to an average annual incidence rate for all cancers of 398 per 100 000 person-years),3 there are only ∼8700 diagnosed per year among children younger than 15 years and 12 400 among children and adolescents younger than 20 years (corresponding to average annual incidence rates of 13.4 per 100 000 and 14.9 per 100 000 person-years, respectively).4 Carcinomas predominate among adults, and the major pediatric tumors are nonepithelial. The most common pediatric neoplasms are the leukemias (representing 30.2% of all cancers diagnosed in children younger than 15 years), brain and central nervous system cancers (21.7%), and lymphomas (10.9%); these 3 categories (together constituting 63%) and the remaining 37% of pediatric malignancies are characterized by substantial histologic and biological diversity.5–7 Instead of the anatomic site-based categories used for adult malignancies, a more appropriate classification system developed for pediatric neoplasms8 was recently updated and designated as the International Classification of Childhood Cancer.9 This article includes 3 components. The first section focuses …

Prospective study of dietary fat and the risk of age-related macular degeneration

The relation between intakes of total fat and specific types of fat and age-related macular degeneration (AMD) remains unclear. Our objective was to examine prospectively the association between fat intake and AMD. We conducted a prospective follow-up study of participants in the Nurses' Health Study and the Health Professionals Follow-up Study. At baseline (1984 for women and 1986 for men), the study included 42743 women and 29746 men aged > or = 50 y with no diagnosis of AMD who were followed until 1996. Fat intake was assessed with a food-frequency questionnaire. We accrued 567 patients with AMD with a visual loss of 20/30 or worse. The pooled multivariate relative risk (RR) for the highest compared with the lowest quintile of total fat intake was 1.54 (95% CI: 1.17, 2.01; P for trend = 0.008). Linolenic acid was positively associated with risk of AMD (top versus bottom quintile of RR: 1.49; 95% CI: 1.15, 1.94; P for trend = 0.0009). Docosahexaenoic acid had a modest inverse relation with AMD (top versus bottom quintile of RR: 0.70; 95% CI: 0.52, 0.93; P for trend = 0.05), and >4 servings of fish/wk was associated with a 35% lower risk of AMD compared with < or = 3 servings/mo (RR: 0.65; 95% CI: 0.46, 0.91; P for trend = 0.009). Total fat intake was positively associated with risk of AMD, which may have been due to intakes of individual fatty acids, such as linolenic acid, rather than to total fat intakes per se. A high intake of fish may reduce the risk of AMD.

Lipids in health and disease: quantity, quality, and more

Lipids in health and disease: quantity, quality, and more

Dietary protein and risk of ischemic heart disease in women

Ingestion of animal protein raises serum cholesterol in some experimental models but not in others, and ecologic studies have suggested a positive association between animal protein intake and risk of ischemic heart disease. Prospective data on the relation of protein intake to risk of ischemic heart disease are sparse. The objective was to examine the relation between protein intake and risk of ischemic heart disease. The study was a prospective cohort study. We examined the association between dietary protein intake and incidence of ischemic heart disease in a cohort of 80082 women aged 34-59 y and without a previous diagnosis of ischemic heart disease, stroke, cancer, hypercholesterolemia, or diabetes in 1980. Intakes of protein and other nutrients were assessed with validated dietary questionnaires. We documented 939 major instances of ischemic heart disease during 14 y of follow-up. After age, smoking, total energy intake, percentages of energy from specific types of fat, and other ischemic heart disease risk factors were controlled for, high protein intakes were associated with a low risk of ischemic heart disease; when extreme quintiles of total protein intake were compared, the relative risk was 0.74 (95% CI: 0.59, 0.94). Both animal and vegetable proteins contributed to the lower risk. This inverse association was similar in women with low- or high-fat diets. Our data do not support the hypothesis that a high protein intake increases the risk of ischemic heart disease. In contrast, our findings suggest that replacing carbohydrates with protein may be associated with a lower risk of ischemic heart disease. Because a high dietary protein intake is often accompanied by increases in saturated fat and cholesterol intakes, application of these findings to public dietary advice should be cautious.

Dietary fat, olive oil intake and breast cancer risk.

As part of a population-based case-control study on diet and breast cancer in Spain, the role of dietary fat and vegetable oils in breast cancer etiology was examined. A validated, semi-quantitative food-frequency questionnaire was completed by 762 women, 18-75 years of age, with histologically confirmed, newly diagnosed breast cancer, and 988 randomly selected female controls. For each food item and nutrient, the study subjects were divided into quartiles according to intake levels, with the lowest quartile serving as the reference category. Adjustment for total energy intake and other potential confounders was made using multiple logistic regression for all women as well as separately for pre- and post-menopausal women. Neither total fat intake nor specific types of fat were significantly associated with breast cancer in pre- or post-menopausal women. However, higher consumption of olive oil (rich in monounsaturated fat) was significantly related to a lower risk of breast cancer [for highest vs. lowest quartile of consumption, odds ratio (OR) = 0.66; 95% CI, 0.46-0.97] with a significant dose-response trend. While these findings do not support a relation between total fat intake and breast cancer risk, they do provide evidence for an inverse association between olive oil (and suggest one between monounsaturated fat) and risk of breast cancer.