Oh, the hype! New, eyebrow-raising research is making a big impression in health news this week. According to a study conducted at the University of Colorado, Boulder, overweight and obese adults can receive the same heart-healthy benefits from a daily vitamin C supplement that they would get from routine aerobic exercise.
What the Study Does Say
The emphasis should be on "heart-health benefits," not the concept of an alternative to regular exercise. The small study of 35 obese volunteers looked at the way blood vessels respond to vitamin C versus a workout. The study's press release, titled "Vitamin C: The Exercise Replacement?" explains, "The blood vessels of overweight and obese adults have elevated activity of the small vessel-constricting protein endothelin (ET)-1."
Put simply, "Endothelial function, which is how the blood vessels constrict and relax, is important for a healthy heart. You've got to be able to relax your blood vessels, which is why exercise is so helpful, because it helps them to relax," says Dennis A. Goodman, MD, cardiologist and director of integrative medicine at the Leon H. Charney Division of Cardiology at NYU Langone Medical Center.
"So when you have endothelial dysfunction, it means your blood vessels are not relaxing properly," he adds. "And it has been shown to be one of the early signs of atherosclerosis, which is when there's plaque in the arteries."
So elevated endothelial activity ultimately leads to heart disease. And while regular exercise can lessen this protein's activity, the study authors discovered that a daily dose of vitamin C (500 mg, time-released), which may improve blood vessel function, "reduced ET-1-related vessel constriction as much as walking for exercise did."
So can you substitute a sweaty workout for a simple supplement? Don't toss your sneakers just yet.
What the Study Doesn't Say and Why It Isn't Necessarily New Information
"This [study's press release] title is catchy, it's sexy, but it's extremely misleading," Dr. Goodman says.
He points to another small study that was published in the journal Atherosclerosis back in 2006: "These researchers had 12 healthy, young males and they showed that when you pre-treat with vitamin C, it can block endothelin-1. So there's nothing new in this latest article," Goodman says. "I think the key here is to give credit — another study showing something we already knew: Vitamin C has some antioxidant effect. And with an antioxidant effect, you can reduce your chances of having endothelial dysfunction," and, in turn, heart disease.
As for the idea of ditching exercise for a vitamin?
"The answer is categorically 'no,'" Goodman says. "Exercise has so many other benefits, and to say for one second it's going to replace all of these other benefits — from losing weight, lowering LDL (the bad) cholesterol, raising HDL (the good) cholesterol, increasing endorphins, lowering your chances of diabetes — is an absurd conclusion at this point."
"I'm not bashing the study," he concludes. "It's just a nice way to say, 'We're showing that vitamin C does something good.'"