Vitamin C a Major Part of '5 a Day'

Source: Tufts University
July 2, 2001 (Reviewed: December 23, 2002)

New potential for vitamin C

In the late 1700's, British sailors were nicknamed "Limeys" after physicians realized that eating citrus fruits--mainly limes and lemons--would cure and prevent scurvy (a form of vitamin C deficiency) during long voyages. In addition to preventing scurvy, scientists now see a role for vitamin C as a possible protector against chronic diseases like heart disease, osteoporosis, and cancer. A study that took a closer look at the disease-fighting potential of vitamin C was published in a recent issue of Lancet.

Almost 20,000 men and women ages 45-79, with no history of heart disease, stroke, or cancer completed questionnaires about their health and lifestyle. They recorded their food intake over a 7-day period and also reported any use of vitamin, mineral, or herbal supplements. The researchers then drew blood from each volunteer and measured the level of ascorbic acid (vitamin C), which indicates the amount of dietary vitamin C consumed over the past few weeks. The participants were followed for about 4 years and the researchers recorded any deaths from heart disease, stroke, or cancer.

See what C can do

The volunteers with the highest blood levels of vitamin C were about 50% less likely to die from heart disease, stroke, or cancer during the course of the study. This was true for both women and men, but the results were more striking in men.

The volunteers with higher blood levels of vitamin C also had lower blood pressure and body fat and higher levels of HDL ("good") cholesterol, which are factors that might have minimized their risk. But even after the scientists mathematically adjusted for those and other disease risk factors such as age, smoking, and supplement use, volunteers with the highest blood levels of vitamin C showed a marked decrease in deaths from heart disease, stroke, and cancer.

The ability of vitamin C to fight disease may be due to its antioxidant properties, which help protect cells from damage that can cause disease. It may also help prevent the formation of lesions on artery walls that lead to heart disease and stroke.

Good sources of C

This study adds more support to the current public health guideline to eat at least 5 servings of fruits and vegetables a day. Several of those servings should be foods high in vitamin C, including citrus fruits, strawberries, broccoli, cantaloupe, tomatoes, mangoes, and green pepper.

If that sounds like a lot to chew on, begin with just one additional daily fruit or vegetable. Slice strawberries on your cereal or start a meal with salad. Then, add more servings from there. You can make these changes gradually even if you currently follow a "meat and potato" meal pattern, because a potato baked with the skin is a good vitamin C source. And while you're at it, how about raising an ice-cold glass of fresh-squeezed lemonade in honor of the British sailors who were the basis of our knowledge of the life-saving properties of vitamin C?

Source

• Relation between plasma ascorbic acid and mortality in men and women in EPIC-Norfolk prospective study: a prospective population study. KT. Khaw, S. Bingham, A. Welch,  et al., The Lancet, 2001, vol. 357, pp. 657--663

Related Links
How to increase your intake of fruits and vegetables
A healthy diet contains plenty of produce
Tufts University's Nutrition Navigator

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