Doing Qualitative Research

Effects of dietary fatty acids and carbohydrates on the ratio of serum total to HDL cholesterol and on serum lipids and apolipoproteins: a meta-analysis of 60 controlled trials

Background: Experimental models and observational studies suggest that vitamin E supplementation may prevent cardiovascular disease and cancer. However, several trials of high-dosage vitamin E supplementation showed non–statistically significant increases in total mortality. Purpose: To perform a meta-analysis of the dose–response relationship between vitamin E supplementation and total mortality by using data from randomized, controlled trials. Patients: 135 967 participants in 19 clinical trials. Of these trials, 9 tested vitamin E alone and 10 tested vitamin E combined with other vitamins or minerals. The dosages of vitamin E ranged from 16.5 to 2000 IU/d (median, 400 IU/d). Data Sources: PubMed search from 1966 through August 2004, complemented by a search of the Cochrane Clinical Trials Database and review of citations of published reviews and metaanalyses. No language restrictions were applied. Data Extraction: 3 investigators independently abstracted study reports. The investigators of the original publications were contacted if required information was not available. Data Synthesis: 9 of 11 trials testing high-dosage vitamin E (>400 IU/d) showed increased risk (risk difference > 0) for allcause mortality in comparisons of vitamin E versus control. The pooled all-cause mortality risk difference in high-dosage vitamin E trials was 39 per 10 000 persons (95% CI, 3 to 74 per 10 000 persons; P 0.035). For low-dosage vitamin E trials, the risk difference was 16 per 10 000 persons (CI, 41 to 10 per 10 000 persons; P > 0.2). A dose–response analysis showed a statistically significant relationship between vitamin E dosage and all-cause mortality, with increased risk of dosages greater than 150 IU/d. Limitations: High-dosage (>400 IU/d) trials were often small and were performed in patients with chronic diseases. The generalizability of the findings to healthy adults is uncertain. Precise estimation of the threshold at which risk increases is difficult. Conclusion: High-dosage (>400 IU/d) vitamin E supplements may increase all-cause mortality and should be avoided.

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Meta-Analysis: High-Dosage Vitamin E Supplementation May Increase All-Cause Mortality

The intake of trans fat has been associated with coronary heart disease, sudden death from cardiac causes, and diabetes. This article reviews the evidence for physiological and cellular effects of trans fatty acids, unsaturated fatty acids with at least one double bond in the trans configuration. The authors consider the feasibility and potential implications of reducing or eliminating the consumption of trans fatty acids from partially hydrogenated vegetable oils in the United States.

/pdf/trans-fatty-acids-and-cardiovascular-disease-4sc886xs8j.pdf

Trans Fatty Acids and Cardiovascular Disease

Background There are limited data from randomized trials regarding whether volume-based, low-dose computed tomographic (CT) screening can reduce lung-cancer mortality among male former and...

https://www.nejm.org/doi/pdf/10.1056/NEJMoa1911793?articleTools=true

Reduced Lung-Cancer Mortality with Volume CT Screening in a Randomized Trial

Effects of partially hydrogenated fish oil, partially hydrogenated soybean oil, and butter on serum lipoproteins and Lp[a] in men.

Background: Dietary calcium and antioxidants have been suggested as protective agents against colorectal cancer. This has been supported by animal experimental studies, case control and cohort studies. Materials and Methods: In a prospective intervention study of colorectal adenomas, and intermediary stage in colorectal carcinogenesis, 116 polyp-bearing patients received a placebo-controlled daily mixture of β-carotene 15 mg, vitamin C 150 mg, vitamin E 75 mg, selenium 101 µg, and calcium (1.6 g daily) as carbonate for a period of 3 years with annual colonoscopic follow-up to test if the mixture was able to reduce polyp growth or recurrence. All polyps of Results: 87–91% of the patients attended the annual endoscopic follow-up investigations, and 19% of the patients dropped out of the medical intervention. The rest consumed 85% of the total amount of tablets over the 3 years. The fecal calcium concentration was 2.3–2.7 times higher in patients taking active medication compared to the placebo group. Diet registration showed that, when adding the intake of antioxidants and calcium from diet and intervention, there was a significant difference between the intake of these substances in the active and the placebo group. No difference was detected in the growth of adenomas between the active and the placebo group from year to year and for the total study period. Moreover, there was no effect on polyps of Conclusion: The study did not find an overall effect on polyp growth. Our data, however, may support a protective role of calcium and antioxidants on new adenoma formation.

Growth and Recurrence of Colorectal Polyps: A Double-Blind 3-Year Intervention with Calcium and Antioxidants

We have compared the effects of partially hydrogenated fish oil (PHFO-diet), partially hydrogenated soy- bean oil (PHSO-diet), and butterfat (butter-diet) on serum lipids and lipoprotein(a) in 31 young men. The three test marga- rines, which contributed 78% of total fat in the diets, were produced from 70% of butterfat, PHSO, or PHFO, each with 30% of soybean oil. Fat provided about 35% of energy, and trans fatty acids 0.9%, 8.5%, and 8.0% of energy in the butter-, the PHSO-, and the PHFO-diet, respectively. Dietary cholesterol was balanced by the addition of dried egg powder to the PHSO-

fish oil, partially hydrogenated soybean oil, and butter on serum lipoproteins and Lp(a) in men

Objectives: To study the association between content in adipose tissue of very long-chain n-3 fatty acids, trans fatty acids, linoleic acid and α-linolenic acid and risk of a first myocardial infarction. Design and subjects: A case-control design among 100 patients and 98 population controls both men and postmenopausal women, age 45–75 y. Adipose tissue fatty acids were determined by gas–liquid chromatography. Intake data were obtained through interview using a validated food frequency questionnaire. Results: Dietary intake and adipose tissue content of the fatty acids studied correlated significantly. Adipose tissue contents of eicosapentaenoic acid (20:5n-3), docosapentaenoic acid (22:5n-3) and docosahexaenoic acid (22:6n-3) were significantly lower while those of trans fatty acids, linoleic and α-linolenic acid were significantly higher in patients than in controls. Age and sex adjusted odds ratios (OR) were significantly reduced with increasing quintiles of very long-chain n-3 fatty acids, thus the OR in the fifth compared to the first quintile was 0.23 (95% CI 0.08–0.70). After further adjustment for waist-to-hip ratio, smoking, family history of CHD and content of trans fatty acids, the OR in the highest quintile was 0.17 (95% CI 0.04–0.76) and the P for trend 0.016. Age and sex adjusted OR was increased in the fifth compared to the first quintile of trans fatty acids (OR 2.81, 95% CI 1.16–6.84), linoleic acid (OR 2.10, 95% CI 0.87–5.07) and α-linolenic acid (OR 1.96, 95% CI 0.83–4.61), and P for trend was 0.002, 0.005 and 0.020, respectively. The trends remained significant after adjustment for waist-to-hip ratio, smoking, and family history of coronary heart disease. Trans fatty acids, linoleic acid and α-linolenic acid in adipose tissue were strongly correlated, indicating a common source, most likely margarine. When each of these fatty acid species were adjusted for the two others the trends were no longer significant. Conclusion: Intake of very long-chain n-3 fatty acids as reflected in adipose tissue content is inversely associated with risk of myocardial infarction. Trans fatty acids, linoleic and α-linolenic acid were intercorrelated and associated with increased risk. It is suggested that the increased risk may be connected to trans fatty acids or to some other factor associated with margarine consumption. Sponsorship: Throne Holst's Foundation for Nutrition Research, The Norwegian Association of Margarine Producers, DeNoFa Fabriker A/S, Tine Norwegian Dairies. European Journal of Clinical Nutrition 54, 618–625.

Adipose tissue fatty acids and risk of myocardial infarction--a case-control study.

© 2014 The Authors. Journal of Clinical Nursing Published by John Wiley & Sons Ltd

This is an open access article under the terms of the Creative Commons Attribution-NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.

https://www.duo.uio.no/bitstream/handle/10852/42000/Barriereartikkelen_JCN.pdf?sequence=1

Kari Almendingen

Papers

Effects of partially hydrogenated fish oil, partially hydrogenated soybean oil, and butter on serum lipoproteins and Lp[a] in men.

Growth and Recurrence of Colorectal Polyps: A Double-Blind 3-Year Intervention with Calcium and Antioxidants

fish oil, partially hydrogenated soybean oil, and butter on serum lipoproteins and Lp(a) in men

Adipose tissue fatty acids and risk of myocardial infarction--a case-control study.

Barriers to nutritional care for the undernourished hospitalised elderly: perspectives of nurses