Affiliations: United States Department of Agriculture,
Agricultural Research Service, Grand Forks Human Nutrition Research Center,
Grand Forks, ND 58202-9034
Note: [] Address for correspondence: Forrest H. Nielsen, USDA, ARS, Grand
Forks Human Nutrition Research Center, PO Box 9034, Grand Forks, ND 58202-9034,
USA. Tel.: +1 701 795 8455; Fax: +1 701 795 8220; E-mail:
fnielsen@gfhnrc.ars.usda.gov
Abstract: Female and male rats weighing about 170 g and 200 g, respectively,
were fed diets (∼70 μg boron/kg) in
a factorial arrangement with supplemental boron at 0 (deficient) and 3
(adequate) mg/kg and canola oil or palm oil at 75 g/kg of diet as variables.
After 5 weeks, six females in each treatment were bred. Dams and pups continued
on their respective dietary treatments through gestation, lactation and
post-weaning. Thirteen weeks after weaning, plasma and bones were collected
from 12 male and 12 female offspring in each treatment. Boron supplementation
increased femur strength measured by the breaking variable bending moment;
tibial calcium and phosphorus concentrations; and plasma alkaline phosphatase.
Femur breaking stress was greatest in boron-supplemented rats fed canola oil,
and lowest in boron-deprived females fed canola oil; this group also exhibited
the lowest femur bending moment. Minerals associated with bone organic matrix,
zinc and potassium, were increased by boron supplementation in tibia. Plasma
phospholipids were decreased by boron deprivation in females, but not males.
Plasma cholesterol was decreased in boron-supplemented males by replacing
canola oil with palm oil. The findings suggest that a diet high in omega-3
α-linolenic acid promotes femur strength best when the
dietary boron is adequate.
