OBJECTIVES: Higher plasma micronutrient levels have been associated with decreased cancer risks. The objective of this study was to determine the relative effects of reduced fat and/or increased fruit-vegetable (FV) intakes on plasma micronutrient levels. METHODS:Healthy, premenopausal women with a family history of breast cancer (n = 122) were randomized across four diet arms for one year in a 2 x 2 factorial design study: control, low-fat, high fruit-vegetable and combination low-fat/high FV diets. Levels of plasma micronutrients were measured in plasma at 0, 3, 6 and 12 months. RESULTS: The high FV intervention, regardless of fat intake, significantly increased alpha-carotene, beta-carotene and vitamin C levels in plasma. Only the combination high FV, low-fat intervention significantly increased plasma beta-cryptoxanthin and zeaxanthin levels over time. Although alpha-tocopherol was not affected, a potential concern is that the low-fat intervention resulted in significantly decreased both gamma-tocopherol dietary intakes and plasma levels, regardless of whether or not FV intakes were concomitantly increased. CONCLUSIONS:Unlike alpha-tocopherol, gamma-tocopherol plasma levels were decreased by a low fat diet, perhaps because gamma-tocopherol is not generally added to foods nor widely used in vitamin E supplements. The decreased dietary intakes and plasma levels of gamma-tocopherol with a low-fat diet may have implications for health risks since the biological functions of the different tocopherol isomers have been reported to be distinct.
RCT Entities:
OBJECTIVES: Higher plasma micronutrient levels have been associated with decreased cancer risks. The objective of this study was to determine the relative effects of reduced fat and/or increased fruit-vegetable (FV) intakes on plasma micronutrient levels. METHODS: Healthy, premenopausal women with a family history of breast cancer (n = 122) were randomized across four diet arms for one year in a 2 x 2 factorial design study: control, low-fat, high fruit-vegetable and combination low-fat/high FV diets. Levels of plasma micronutrients were measured in plasma at 0, 3, 6 and 12 months. RESULTS: The high FV intervention, regardless of fat intake, significantly increased alpha-carotene, beta-carotene and vitamin C levels in plasma. Only the combination high FV, low-fat intervention significantly increased plasma beta-cryptoxanthin and zeaxanthin levels over time. Although alpha-tocopherol was not affected, a potential concern is that the low-fat intervention resulted in significantly decreased both gamma-tocopherol dietary intakes and plasma levels, regardless of whether or not FV intakes were concomitantly increased. CONCLUSIONS: Unlike alpha-tocopherol, gamma-tocopherol plasma levels were decreased by a low fat diet, perhaps because gamma-tocopherol is not generally added to foods nor widely used in vitamin E supplements. The decreased dietary intakes and plasma levels of gamma-tocopherol with a low-fat diet may have implications for health risks since the biological functions of the different tocopherol isomers have been reported to be distinct.
Authors: Kathryn A Kaiser; Andrew W Brown; Michelle M Bohan Brown; James M Shikany; Richard D Mattes; David B Allison Journal: Am J Clin Nutr Date: 2014-06-25 Impact factor: 7.045
Authors: Zora Djuric; Jennifer S Ellsworth; Anne L Weldon; Jianwei Ren; Caroline R Richardson; Kenneth Resnicow; Lisa A Newman; Daniel F Hayes; Ananda Sen Journal: Open Obes J Date: 2011