An abundance of vitamin C in the diet may help lower a person's risk of developing type 2 diabetes, new research suggests.
In a study of middle-aged and older men and women, those with the highest blood levels of vitamin C were significantly less likely to develop diabetes over 12 years than those with the lowest levels, researchers found.

Fruits and vegetables are the main source of vitamin C in Western diets, and blood levels of vitamin C are good markers of fruit and vegetable intake, Dr. Nita G. Forouhi, at the Institute of Metabolic Science at Addenbrooke's Hospital, Cambridge, England, and colleagues note.

The current findings "re-endorse the public health message of the beneficial effect of increasing total fruit and vegetable intake," the investigators wrote in Archives of Internal Medicine.

Forouhi's team followed 21,831 healthy men and women who were 40 to 75 years old for the development of type 2 diabetes. At study entry, all participants provided detailed health and lifestyle information, as well as blood samples, which investigators used to determine vitamin C levels.

Over the course of the study, 423 men and 312 women developed type 2 diabetes, an overall rate of 3.2 percent.

According to the investigators, the likelihood of developing diabetes was 62 percent lower in men and women with the highest circulating vitamin C levels, relative to men and women with the lowest vitamin C levels.

Factoring out other characteristics associated with diabetes risk, such as older age, gender, family history, alcohol intake, physical activity, smoking status and body weight did not significantly alter these associations.

These data offer "persuasive evidence of a beneficial effect of vitamin C and fruit and vegetable intake on diabetes risk," Forouhi and colleagues conclude.

新的研究表明，飲食中豐富的維生素 C 可能有助于降低一個人患 2 型糖尿病的風險。

在一項對中年及老年男子和婦女的研究中，研究人員發現，過去 12 年里，那些在血液中具有最高維生素 C 水平的人比那些具有最低水平的人顯著地不太可能患糖尿病。

英格蘭劍橋 Addenbrooke 醫院代謝科學研究所的 Nita G. Forouhi 博士和他的同事們注意到，水果和蔬菜是西方飲食中維生素 C 的主要來源，而血液中維生素 C 的水平正好是水果和蔬菜攝入量的標志。

目前的調查結果“重新支持增加水果和蔬菜的總攝入量對公共健康有有益作用的信息，”在內科醫學文獻中的這份調查寫道。

Forouhi 的團隊對 21,831 個 40 至 75 歲的健康男人和女人患 2 型糖尿病的情況進行了跟蹤。在進入研究的時候，所有的參與者都提供了詳細的健康狀況和生活方式信息，以及由調查者用來確定維生素 C 水平的血液樣本。
 
在研究過程中，423 名男子和 312 名婦女患了 2 型糖尿病，總體比例為百分之 3.2。

據調查者說，具有最高循環維生素 C 水平的男性和女性，相對于具有最低維生素 C 水平的男性和女性，患糖尿病的可能性要低 62％。

理出其它與糖尿病風險相關的特征，如老年人的年齡、性別、家族病史、飲酒、體力活動、吸煙狀況和體重等，都沒有顯著改變這些關聯。

這些數據提供了“有說服力的證據，說明維生素 C 以及水果和蔬菜的攝入，對于防止糖尿病的風險來說，是有有利作用的，” Forouhi 博士和他的同事們總結說。