A new study has found that anti-tuberculosis drugs killed more bacteria in laboratory mice given a vitamin C supplement than those given drugs alone.
If the findings hold up in human studies, the authors say, the result could be that there's a cheap, safe way to reduce the months-long treatment time for one of the world's leading killers. Also, the vitamin supplement could offer a way to cut down on the development of drug-resistant TB, a serious health threat.
Tuberculosis is one of the leading causes of death worldwide. According to the World Health Organization, 1.7 million people died of the disease last year. Of more than 10 million new infections, about 600,000 were resistant to the leading drug.
Front-line drugs attack TB cells as they multiply, but a small proportion of the bacteria survive by going dormant. If therapy stops too soon, these "persisters" start multiplying and the patient relapses, often with strains that are resistant to the drugs.
Current TB treatment takes six months, largely to outlast the persisters. But it's hard for patients to stay on treatment for so long.
Albert Einstein College of Medicine microbiologist William Jacobs and colleagues previously discovered by accident that antioxidants like vitamin C stopped TB bacteria in a test tube from becoming persisters.
"When we first discovered it, it was like, 'Wow! There's just so much we don't know yet. And wouldn't that be really cool if it really works,' " Jacobs said.
The study in the journal Antimicrobial Agents and Chemotherapy said Jacobs and colleagues found that TB-infected mice treated with two standard drugs plus a high dose of vitamin C had roughly tenfold fewer bacteria in their lungs after several weeks than mice treated with drugs alone.
"It's not sterilization yet," he added, "but it's heading in that direction."
But will it work in people?
"The bottom line is that we don't know the answer," Jacobs acknowledged. "But I think what this study suggests is we should really go and [find out]."
Other experts not connected to the study agreed.
Even though there has been very little research on vitamin C and tuberculosis, the nutrient is "a safe compound, it's widely available, it's inexpensive," noted David Alland, associate dean of clinical research at Rutgers New Jersey Medical School. "I think that when we have those kinds of options to look at, we should look at them without having to spend decades trying to figure out exactly how they work."
And if it does work, he added, "you'd get a big bang for your buck."