MICRONUCLEI IN LYMPHOCYTES AND EXFOLIATED BUCCAL CELLS OF POSTMENOPAUSAL WOMEN WITH DIETARY-CHANGES IN FOLATE

Folate deficiency is associated with anemia, birth defects, cancer and neuropsychiatric disorders. The purpose of this study was to determin e if a moderate folate deficiency during controlled changes in folate intake would affect chromosomal damage in lymphocytes and buccal cells . A study of nine healthy postmenopausal women volunteers (age 49-63 y ears) was carried out in a metabolic unit (baseline week with folate i ntake of 195 mu g/day, five-week depletion at 56 mu g/day, and gradual repletion including four weeks at 111 mu g/day, 11 days at 286 mu g/d ay and 9 days at 516 mu g/day). Plasma folate, vitamin B-12, and homoc ysteine were measured weekly. Cytogenetic damage was assessed by scori ng micronucleus (MN) frequency in lymphocytes and buccal cells three t imes: (1) ar the beginning of the study, (2) at the end oi depletion, and (3) after repletion. The MN frequency increased in binucleated lym phocytes, as well as in all lymphocytes, after depletion (p = 0.037), and later decreased following repletion (p = 0.028). Both kinetochore- positive and kinetochore-negative MN were increased after depletion (p = 0.015 and 0.028), but after repletion only the change in kinetochor e-positive MN was statistically significant(p = 0.048). The main varia bles affecting MN were: (1) vitamin B-12 level, (2) plasma folate leve l, and (3) baseline frequency of MN. The MN frequency in exfoliated bu ccal cells was decreased after dietary supplementation of 516 mu g/day folate (p = 0.010). Thus, low folate, without clinical symptoms of an emia, results in higher levels of cytogenetic damage in both the blood and oral cavity of postmenopausal women. (C) 1998 Elsevier Science B. V. All rights reserved.