HOMOCYSTEINE DIET STUDY: EFFECTS OF DIFFERENT FOLATE SOURCES

同型半胱氨酸是血液中发现的一种因子，在患有心脏病的成年人中被发现升高，类似于血液胆固醇水平升高。 这种相对危险的心脏病因素已经被发现对膳食维生素叶酸或叶酸有反应。 饮食中叶酸有三种不同的来源。 一种来自典型的多种维生素，另一种来自早餐谷物和其他含有叶酸的食物，第三种来自豆类和绿叶蔬菜，它们具有天然的高叶酸水平。 本研究的目的是确定这三种叶酸来源中哪一种在降低同型半胱氨酸水平中度升高的成人中最有效。60名参与者被随机分配到四组中的一组：复合维生素，强化食品，豆类和绿色食品，或安慰剂组。 六周后，研究人员发现，服用复合维生素的那一组血液中的同型半胱氨酸水平下降最多。 吃强化食品的那一组几乎和吃复合维生素的那一组一样好。 吃豆类和绿色食物的那一组并不比安慰剂组好，两组的变化都可以忽略不计。 在这些来源中发现的叶酸形式的知识可以解释观察到的差异。 在多种维生素和强化食品中，叶酸的形式是最小的，最好吸收的叶酸形式，而在豆类和蔬菜中，叶酸以更大，更复杂的形式存在，并且不容易吸收。 总之，在饮食中增加叶酸的两种安全且容易获得的方法可有效降低升高的同型半胱氨酸水平，但增加豆类和绿色蔬菜的每日摄入量的方法对改善这一特定的心脏病风险因素无效。

Homocysteine is a factor found in blood that has been found to be elevated among adults with heart disease, similar to elevated blood cholesterol levels. This relatively risk factor for heart disease has been found to respond to the dietary vitamin known as either folate or folic acid. There are three different sources of folate in the diet. One is from typical multivitamins, another is from breakfast cereals and others that have been with folate, and a third is from beans and leafy greens, which have naturally high folate levels. The purpose of this study was to determine which of those three sources of folate would be most effective in lowering homocysteine levels in adults with moderately elevated homocysteine. Sixty participants were enrolled and randomly assigned to be in one of four groups: Multivitamin, fortified foods, beans and greens, or a placebo group. After six weeks it was found that blood levels of homocysteine dropped the most for the group taking the multivitamin. The group eating the fortified foods did almost as well as the multivitamin group. The group eating beans and greens did no better than the placebo group, both showed negligible change. Knowledge of the form of folate found in each of these sources might explain the observed differences. In the multivitamins and fortified foods, the form of folate used is the smallest, best absorbed form of folate, whereas in the beans and greens the folate is found in a larger, more complex form, and is not as readily absorbed. In conclusion, two safe and readily available approaches for increasing folate in the diet were effective at lowering elevated homocysteine levels, but the approach of increasing daily consumption of beans and greens was not effective for improving this one particular heart disease risk factor.