Although dairy food intake is low among the Navajo people, hip fracture rat
es are lower than in Caucasians. Genetic differences in bone density have b
een cited as the reasons for low fracture rates among Native Americans and
other segments of the population. However, more detailed examination of min
eral intakes suggests that environmental factors may provide part of the ex
planation for the lower fracture rates. Cultural practices such as the addi
tion of ash to traditional foods and the high mineral content of water may
provide much higher intakes of bone-related minerals than food intake surve
ys have previously reported. As part of a larger study to assess overall in
take of minerals related to bone health and other conditions, water samples
were collected from the Navajo reservation. Duplicates were collected at l
east one week apart from 53 sites including wells, springs, taps, and stora
ge barrels and analyzed by atomic absorption and inductively coupled plasma
spectrometry for a number of minerals. For average intakes of 2 1/day, wat
er could provide up to 212 mg of calcium, 150 mg of magnesium and 8 mg of z
inc. The combined contribution of mineral intakes provided by the addition
of juniper ash to traditional foods, not genetic differences, may partially
explain the lower fracture rates of the Navajo people. Further research in
this area is required to confirm this hypothesis. (C) 2000 Elsevier Scienc
e Ireland Ltd. All rights reserved.