Vitamin C ‘as effective as exercise’ for supporting vascular health of overweight people

A new study has demonstrated that vitamin C may mimic some of the effects of exercise in overweight and obese individuals.

The small study was conducted on 35 participants and focused on how vitamin C affects constriction of blood vessels.


The protein endothelin-1 (ET-1) has a constricting action on small blood vessels. This activity is increased in overweight and obese individuals, making small blood vessels more prone to constrict and less able to handle blood flow demand, increasing the risk of vascular disease.

For the puposes of this research, the study was conducted on participants who had impaired vascular tone.

Caitlin Dow, PhD, postdoctoral research fellow at the University of Colorado, Boulder, and colleagues followed the sedentary, overweight/obese study participants through a three-month test period. Twenty participants took supplements during that time but did not increase their activity, while 15 subjects took a brisk walk 5 to 7 times a week.

By the end of the test period no one in either group had lost any weight; however, the scientists found that taking 500 mg of vitamin C supplements daily reduced ET-1 related blood vessel constriction as much as walking did.

Exercise and vitamin C intake together was found to return the participants’ vascular tone to normal—a far superior goal—but participants who took vitamin C alone also experienced the same health benefits to a lessor degree.

Why is vascular tone so important?

Poor vascular tone can lead to a downward health spiral. The spiral starts with inflammation, graduates into high blood pressure, and can ultimately lead to a stroke.

All of the study’s participants were found to be at increased risk of developing high blood pressure and suffering heart attacks and strokes, so were prime candidates for the study.

The results of the study, presented at the American Physiological Society’s annual meeting in Atlanta, represent good news for people who cannot physically exercise. But for everyone else, warn the study’s authors, it’s still important to get off the couch and start moving.

“This is not ‘the exercise pill,’” said Dow.

Besides improving vascular tone, regular exercise is critical for health in a number of ways. It also helps lower the so-called “bad” (LDL) cholesterol; improves metabolic function throughout the body; and boosts mood and cognitive function, among other things.

Yet, like regular exercise, taking a vitamin C—the most common supplement taken—may also have broader implications. For instance, it may be able to cut some of the risks linked to weight gain and obesity. And since those with established obesity rarely succeed at losing weight and keeping it off (fewer than 1%), every little bit helps.

“If we can improve different measures of risk for disease without changing weight, it takes a little bit of the pressure off some people,” Dow said. While Vitamin C “certainly isn’t a new cure,” she added, “it’s important to know what other lifestyle changes we can offer people who can’t exercise.”

Though this study only involved a few participants, and is accompanied by the patently-obvious warnings that taking a supplement should not be looked at as a “replacement pill,” it does offer more insight into one of the numerous benefits that vitamin C supplements provide: less inflammation.

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