Laboratory of Nutrition and Clinical Dietetics, Department of Nutrition and Dietetics, Harokopio University, Athens, Greece.
Nutrition. 2010 Oct;26(10):969-74. doi: 10.1016/j.nut.2009.09.022. Epub 2010 Jan 25.
To explore the influence of folate-fortified foods (ready-to-eat [RTE] breakfast cereals or fruit-juice drinks) on the relation between the methylenetetrahydrofolate reductase (MTHFR 677C>T) polymorphism and plasma total homocysteine (tHcy) concentrations in healthy children.
This was a cross-sectional study by face-to-face interview. A total of 186 sixth-grade students participated from randomly selected primary schools in Volos, Greece. Fasting plasma tHcy, folate, and vitamin B12 were measured. The MTHFR genotypes were determined. Anthropometric data were collected and dietary intake was assessed by two non-consecutive 24-h recalls. Participants were characterized as non-consumers of RTE breakfast cereals or fruit-juice drinks if there was no report of any such food during the 24-h recall interviews; all other children were classified as consumers.
Geometric means for plasma tHcy were higher, whereas plasma folate was lower in non-consumers compared with consumers. The sample was divided by consumption status (yes or no) to explore the significance of each polymorphism depending on consumption status. The association between the genotype and tHcy was restricted to non-consumers (P<0.05). Specifically, only in children who did not consume RTE breakfast cereals or fruit-juice drinks did the TT genotype carriers exhibit higher tHcy concentrations when compared with C-allele carriers (P<0.05). In contrast, in consumers, circulating tHcy was similar regardless of genotype.
These observational findings support a beneficial effect of RTE breakfast cereals and fruit-juice drinks on lowering plasma tHcy and improving folate status in children. Also, consumption of folate-fortified foods modulates the association of the MTHFR 677C>T polymorphism with tHcy, suggesting that habitual consumption of folate-fortified foods is a practical approach in providing consistent protection to those children who may benefit the most, i.e., carriers of the TT genotype.
探究叶酸强化食品（即食早餐麦片或果汁饮料）对亚甲基四氢叶酸还原酶（MTHFR677C>T）多态性与健康儿童血浆总同型半胱氨酸（tHcy）浓度之间关系的影响。
这是一项通过面对面访谈进行的横断面研究。共 186 名来自希腊沃洛斯随机选定小学的六年级学生参与了该研究。测量了空腹血浆 tHcy、叶酸和维生素 B12。确定了 MTHFR 基因型。收集了人体测量数据，并通过两次非连续 24 小时回顾性饮食摄入评估来评估饮食摄入情况。如果在 24 小时回顾性访谈中没有报告任何此类食物，则将参与者归类为非即食早餐麦片或果汁饮料的消费者；所有其他儿童均归类为消费者。
与消费者相比，非消费者的血浆 tHcy 几何均数更高，而血浆叶酸水平更低。根据消费状况（是或否）将样本进行分组，以探究每种多态性在消费状况下的意义。基因型与 tHcy 的关联仅限于非消费者（P<0.05）。具体而言，仅在未食用即食早餐麦片或果汁饮料的儿童中，TT 基因型携带者的 tHcy 浓度明显高于 C 等位基因携带者（P<0.05）。相比之下，在消费者中，无论基因型如何，循环 tHcy 均相似。
这些观察性发现支持即食早餐麦片和果汁饮料对降低儿童血浆 tHcy 和改善叶酸状态的有益作用。此外，叶酸强化食品的消费调节了 MTHFR677C>T 多态性与 tHcy 之间的关联，表明习惯性食用叶酸强化食品是为那些最有可能受益的儿童（即 TT 基因型携带者）提供持续保护的一种实用方法。
