Manganese absorption and retention in rats is affected by the type of dietary fat

There is evidence that manganese (Mn) metabolism may be altered by the form and amount of dietary fat. Also, iron (Fe) absorption is greater with satu rated fats, as compared to polyunsaturated fatty acids (PUFAs). The absorpt ion of Fe and Mn are interrelated in many aspects; therefore, the form of d ietary fat may indirectly alter Mn absorption. The reported studies were co nducted to determine whether saturated fat, as compared to unsaturated fat, affected Mn absorption, retention, and metabolism. In experiment I, adult rats were fed diets containing either 0.7 or 100.4 mug/g Mn with the fat so urce as high-linoleic safflower oil or stearic acid. After 2 wk of equilibr ation, the animals were fed a test meal of Mn-54 followed by whole-body cou nting for 10 d. Manganese absorption was significantly (p < 0.05) lower in the stearic acid group (0.9-4.8%) than in the safflower oil group (20-33.8% ); however, the biological half-life was shorter in the safflower oil group . Retention of 54Mn and total Mn was always significantly (p < 0.05) greate r in the safflower oil group when dietary Mn was low, but it was the same w hen dietary Mn was high. In experiment II, weanling rats were fed 1.3, 39.3 , or 174.6 mug Mn/g and either stearate, high-oleic safflower oil or high-l inoleic safflower oil for 8 wk.