Graduate Program on Toxicological Biochemistry, Center of Natural and Exact Sciences, Federal University of Santa Maria, Santa Maria, RS Brazil.
Hum Exp Toxicol. 2011 Aug;30(8):981-91. doi: 10.1177/0960327110384526. Epub 2010 Sep 27.
Dietary fiber can affect cadmium (Cd) absorption and toxicity, but the effect appears to depend on the type of dietary fiber. The aim of the present study was to compare the effect of dietary sources containing distinct amounts of soluble and insoluble fiber on Cd absorption, accumulation and toxicity in growing rats. The absorption of essential macrominerals (Ca, P and Mg) was also evaluated. Animals received a nutritionally balanced diet with cellulose (cel - control), wheat bran or flaxseed as the fiber source with 0 or 50 mg Cd kg(-1) diet, during 30 days. Cd exposure reduced body weight gain, feed efficiency ratio, epididymal fat relative weight and liver relative weight, and increased plasma alanine aminotransferase activity in all fiber groups. The apparent Cd absorption was similar among Cd-groups, but the flax-Cd group had a higher hepatic and renal Cd concentration. Cd decreased the absorption of Ca and P, and increased Mg absorption in the wheat bran and flaxseed groups, but not in the cel group. Although the different fiber sources investigated had no effect on Cd toxicity, the major soluble fiber source, flaxseed, increased Cd retention. Thus, caution should be taken in the intake of flaxseed by Cd-exposed populations.
膳食纤维可以影响镉（Cd）的吸收和毒性，但这种影响似乎取决于膳食纤维的类型。本研究旨在比较含有不同量可溶性和不溶性纤维的饮食来源对生长大鼠镉吸收、积累和毒性的影响。还评估了必需宏量矿物质（Ca、P 和 Mg）的吸收情况。动物在 30 天内接受含有纤维素（cel-对照）、麦麸或亚麻籽作为纤维来源的营养均衡饮食，并添加 0 或 50mgCd/kg 饮食中的镉。镉暴露降低了体重增长率、饲料效率比、附睾脂肪相对重量和肝脏相对重量，并增加了所有纤维组的血浆丙氨酸氨基转移酶活性。Cd 组的表观 Cd 吸收率相似，但亚麻-Cd 组的肝和肾 Cd 浓度更高。Cd 减少了麦麸和亚麻籽组中 Ca 和 P 的吸收，增加了 Mg 的吸收，但在 cel 组中没有影响。尽管研究中不同的纤维来源对 Cd 毒性没有影响，但主要的可溶性纤维来源亚麻籽增加了 Cd 的保留。因此，Cd 暴露人群在摄入亚麻籽时应谨慎。
