The American journal of clinical nutrition
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Randomized Controlled Trial Multicenter Study
Randomized controlled trial of dietary fiber for the prevention of radiation-induced gastrointestinal toxicity during pelvic radiotherapy.
Background: Therapeutic radiotherapy is an important treatment of pelvic cancers. Historically, low-fiber diets have been recommended despite a lack of evidence and potentially beneficial mechanisms of fiber. Objective: This randomized controlled trial compared low-, habitual-, and high-fiber diets for the prevention of gastrointestinal toxicity in patients undergoing pelvic radiotherapy. ⋯ Conclusions: Dietary advice to follow a high-fiber diet during pelvic radiotherapy resulted in reduced gastrointestinal toxicity both acutely and at 1 y compared with habitual-fiber intake. Restrictive, non-evidence-based advice to reduce fiber intake in this setting should be abandoned. This trial was registered at clinicaltrials.gov as NCT 01170299.
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Background: The benefits of the use of folic acid supplements (FASs) during the periconception period to prevent neural tube defects and to ensure normal brain development in offspring are well known. There is concern, however, about the long-term effects of the maternal use of high dosages of FASs that exceed the Tolerable Upper Intake Level (UL) (≥1000 μg/d) on child neurocognitive outcomes. Objective: The objective of the study was to examine the association between the use of high dosages of FASs during pregnancy and child neuropsychological development at ages 4-5 y. ⋯ The use of FAS dosages ≥1000 μg/d in this period was negatively associated with several neuropsychological outcomes scores in children: global verbal (β = -2.49; 95% CI: -4.71, -0.27), verbal memory (β = -3.59; 95% CI: -6.95, -0.23), cognitive function of posterior cortex (β = -2.31; 95% CI: -4.45, -0.18), and cognitive function of left posterior cortex (β = -3.26; 95% CI: -5.51, -1.01). Conclusions: The use of FAS dosages exceeding the UL (≥1000 μg/d) during the periconception period was associated with lower levels of cognitive development in children aged 4-5 y. The use of FAS dosages ≥1000 μg/d during pregnancy should be monitored and prevented as much as possible, unless medically prescribed.