Effects of a Combination of Beta Carotene and Vitamin A on Lung Cancer and Cardiovascular Disease

Omenn, Gilbert S.; Goodman, Gary E.; Thornquist, Mark; Balmes, John R.; Cullen, Mark R.; Glass, Andrew G.; Keogh, James P.; Meyskens, Frank L.; Valanis, Barbara; Williams, J. H.; Barnhart, Scott; Hammar, Samuel P.

doi:10.1056/nejm199605023341802

Cited by 3,234 publications

(1,642 citation statements)

References 23 publications

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“…A bene®cial effect of high dietary consumption of fresh fruits and vegetables, the main source of antioxidants, was repeatedly shown in epidemiological studies (Rimm et al, 1996;Key et al, 1996;Ness & Powles, 1997). This explanation would also accommodate the results of the recent clinical trials which failed to show any bene®cial effects of beta-carotene supplementation on the occurrence of CVD (The Alpha-Tocopherol, BetaCarotene Cancer Prevention Study Group, 1994;Hennekens et al, 1996;Omenn et al, 1996).…”

Section: Discussionmentioning

confidence: 89%

Could antioxidants play a role in high rates of coronary heart disease in the Czech Republic?

Bobák

Brunner

et al. 1998

Eur J Clin Nutr

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Objectives: To compare plasma levels of antioxidant vitamins in the Czech population with those in a western European population, and to investigate whether plasma levels of antioxidant vitamins in Czech population are related to risk of MI. Design: The study has two parts: a cross-sectional survey and a population based case-control study. Setting: Adult population in two districts of the Czech Republic, and London based civil servants group as the comparison. Subjects: A random sample of men and women aged 25±64 y resident in two districts were selected for the cross-sectional survey. Subjects in the age group 40±49 y were compared to a sample of British civil servants of the same age enrolled in the Whitehall II Study. Men in the Czech sample served as controls to 52 male cases of ®rst non-fatal myocardial infarction (MI) which occurred in the same population. Plasma samples were obtained from venepuncture during an interview in hospital in the population sample and immediately after hospitalization in the MI cases. Main outcome measures: Plasma levels of b-carotene and a-tocopherol, and the event of MI. Identical protocol and one laboratory was used for all analyses. Results: The mean plasma levels of b-carotene and a-tocopherol in healthy Czech men and women were substantially lower than in a subsample of British civil servants examined in the same laboratory. Smoking was strongly related to b-carotene in both populations but differences between Czechs and Brits were present in both smokers and non-smokers. In the case-control study among Czech men, low levels of the vitamins were strongly related to an increases risk of MI. Age-adjusted odds ratios for concentrations below the median were 3.33 (95% con®dence interval 1.43±8.33) for b-carotene and 1.89 (0.94±3.45) for a-tocopherol; further adjustment for a range of variables reduced these estimates only slightly. Conclusions: Plasma concentrations of antioxidants in the Czech population appeared to be very low, and men with low levels of these substances are at increased risk of MI. This indicates that sub-optimal intake of antioxidants or related dietary factors may have played a role in the high rates of coronary heart disease in this population. Sponsorship: This study was supported by grants from the Wellcome Trust, Czech Ministry of Health and the British Heart Foundation. MB was a Wellcome Trust fellow in clinical epidemiology.

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Section: Discussionmentioning

confidence: 89%

Could antioxidants play a role in high rates of coronary heart disease in the Czech Republic?

Bobák

Brunner

et al. 1998

Eur J Clin Nutr

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“…Plasma levels of the carotenoids including lutein, a-cryptoxanthin, lycopene, a-carotene and b-carotene were all higher in the vegetarian group by about 15% on average, and this is consistent with the greater intake of vegetables and subsequently a higher intake of carotenes in vegetarians. These carotenoids have been found to exhibit anti-carcinogenic and anti-atherogenic properties as reviewed previously (Mayne, 1996;Palace et al, 1999), although it should be noted that randomized intervention trials with relatively high doses of individual carotenoids fed in isolation have shown an increased risk of some chronic diseases (Alpha-Tocopherol, Beta Carotene Cancer Prevention Study Group, 1994;Omenn et al, 1996). Nonetheless, the combined effects of increased levels of various carotenoids could have significant biological effects, as it has been suggested that several phytochemicals in combination may have a better protective effect than their individual parts (Liu, 2003).…”

Section: Discussionmentioning

confidence: 99%

Influence of habitual diet on antioxidant status: a study in a population of vegetarians and omnivores

et al. 2007

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Background: Antioxidant status can be used as a biomarker to assess chronic disease risk and diet can modulate antioxidant defence. Objective: To examine effects of vegetarian diet and variations in the habitual intakes of foods and nutrients on blood antioxidants. Subjects and Setting: Thirty-one vegetarians (including six vegans) and 58 omnivores, non-smokers, in Northern Ireland. Design: A diet history method was used to assess habitual diet. Antioxidant vitamins, carotenoids, uric acid, zinc-and ferricreducing ability of plasma (FRAP) were measured in fasting plasma and activities of glutathione peroxidase (GPX), superoxide dismutase (SOD) and glutathione S-transferase (GST) and level of reduced glutathione (GSH) were measured in erythrocytes. Results: Vegetarians had approximately 15% higher levels of plasma carotenoids compared with omnivores, including lutein (Pp0.05), a-cryptoxanthin Pp0.05), lycopene (NS), a-carotene (NS) and b-carotene (NS). The levels/activities of all other antioxidants measured were similar between vegetarians and omnivores. Total intake of fruits, vegetables and fruit juices was positively associated with plasma levels of several carotenoids and vitamin C. Intake of vegetables was positively associated with plasma lutein, a-cryptoxanthin, a-carotene and b-carotene, whereas intake of fruits was positively associated with plasma b-cryptoxanthin. Intake of tea and wine was positively associated with FRAP value, whereas intake of herbal tea associated positively with plasma vitamin C. Intakes of meat and fish were positively associated with plasma uric acid and FRAP value. Conclusions: The overall antioxidant status was similar between vegetarians and omnivores. Good correlations were found between intakes of carotenoids and their respective status in blood.

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“…In ecological studies and early case-control studies it appeared that β-carotene was a cancer-protective agent. Randomized controlled trials of β-carotene found that the isolated nutrient was either neutral [141] or actually increased risk of lung cancer in smokers [142,143]. Beta-carotene may be a marker for intake of fruits and vegetables, but it does not have a powerful protective effect in isolated pharmacological doses.…”

Section: Reviewmentioning

confidence: 99%

Nutrition and cancer: A review of the evidence for an anti-cancer diet

Donaldson¹

2004

Nutr J

564

344

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It has been estimated that 30–40 percent of all cancers can be prevented by lifestyle and dietary measures alone. Obesity, nutrient sparse foods such as concentrated sugars and refined flour products that contribute to impaired glucose metabolism (which leads to diabetes), low fiber intake, consumption of red meat, and imbalance of omega 3 and omega 6 fats all contribute to excess cancer risk. Intake of flax seed, especially its lignan fraction, and abundant portions of fruits and vegetables will lower cancer risk. Allium and cruciferous vegetables are especially beneficial, with broccoli sprouts being the densest source of sulforophane. Protective elements in a cancer prevention diet include selenium, folic acid, vitamin B-12, vitamin D, chlorophyll, and antioxidants such as the carotenoids (α-carotene, β-carotene, lycopene, lutein, cryptoxanthin). Ascorbic acid has limited benefits orally, but could be very beneficial intravenously. Supplementary use of oral digestive enzymes and probiotics also has merit as anticancer dietary measures. When a diet is compiled according to the guidelines here it is likely that there would be at least a 60–70 percent decrease in breast, colorectal, and prostate cancers, and even a 40–50 percent decrease in lung cancer, along with similar reductions in cancers at other sites. Such a diet would be conducive to preventing cancer and would favor recovery from cancer as well.

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Effects of a Combination of Beta Carotene and Vitamin A on Lung Cancer and Cardiovascular Disease

Cited by 3,234 publications

References 23 publications

Could antioxidants play a role in high rates of coronary heart disease in the Czech Republic?

Could antioxidants play a role in high rates of coronary heart disease in the Czech Republic?

Influence of habitual diet on antioxidant status: a study in a population of vegetarians and omnivores

Nutrition and cancer: A review of the evidence for an anti-cancer diet

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