What’s one of the first things you do when you think you’re coming down with a cold? If you’re like most people, you drink orange juice and pop several chewable vitamin C tablets with hopes that you can ward off sneezing, congestion, and sheer misery.

But now, you can think about vitamin C for more than just cold and flu prevention. Recent published research has shown vitamin C to be a multi-tasker when it comes to disease prevention — including type 2 diabetes.¹ The population-based study measured blood levels of vitamin C in healthy participants over a 4-year time span. It also evaluated participants’ fruit and vegetable intake by way of a food frequency questionnaire.

The most significant finding was that higher blood levels of vitamin C were associated with decreased risk for type 2 diabetes — most likely the result of diet and vitamin C supplementation. The study showed that fruit and vegetable intake alone had a somewhat lesser impact on type 2 diabetes risk. (Note: this finding was limited by unknowns such as the vitamin C content of the fruits and vegetables and estimation of portion sizes noted on the questionnaires.)

Despite that, the authors of this study suggest that eating more vegetables, fruits and supplementing with vitamin C are steps we can all take as preventive measures when it comes to type 2 diabetes risk.

It’s ironic that when such a wonderful finding comes to light, many people have selective hearing or only apply one part of the information. I can just hear a fruit lover thinking, “Oh, I love fruit and this study says it’s good for me. So I am going to eat all I want.”

For these people, I would like to give just one warning. When it comes to diabetes risk, we must keep in mind that glycemic load (total amount of glucose from a food) and glycemic index (the food’s effect on blood sugar) have a profound effect on blood sugar and diabetes risk.

Many studies show that increased intake of high GI and GL foods can increase the risk of developing metabolic syndrome and diabetes. I suspect that if a person put themselves out of glycemic control by eating too much fruit, the benefits of the vitamin C would be quickly undone.

So how can we have our “cake” and eat it too? I advise my patients to simply apply the 3:1 rule — for every three vegetables you eat, eat no more than one serving of fruit as part of your daily intake. And choose lower GI/GL fruits such as apples, cherries, grapefruit, oranges, peaches, pears, plums, etc.

I highly recommend against consuming large amounts of fruit juices, which give you concentrated amounts of sugars but little or no fiber to slow down absorption into the bloodstream. This is supported by another recent study that showed increased fruit drink consumption by African American women was associated with a greater risk for type 2 diabetes, independent of the participants’ body mass index.²

So when it comes to increasing vitamin C in your diet, use common sense: don’t sabotage your healthy low-carb eating habits with large amounts of fruits and fruit juices. Eat more organic vegetables high in vitamin C such as sweet peppers, coriander leaf (cilantro) and tomatoes to name a few, and include fruit at levels that don’t increase your blood sugar.

References

1. Harding A, et al. Arch Intern Med. 2008;168:1493.- 99.
2. Feinglos M and Totten S. Arch Intern Med. 2008;168:1485-1486,1487-1492.

[Ed. Note: Laura B. LaValle, RD, LD is presently the director of dietetics nutrition at LaValle Metabolic Institute (formerly part of Living Longer Institute). She offers personal nutritional counseling at LMI for clients who need help with their diet in relation to illness or disease. Laura also provides educational services in the areas of health promotion, wellness, and disease prevention. To learn more, click here.]