Feed a Cold, Starve MS
Natural Anti-Fat Hormone Seen as Key to Autoimmune Diseases
In an editorial accompanying the Matarese team's study, Steinman and colleagues suggest that starving an autoimmune disease might protect against immune damage.
"I think that this is one of the remarkable ways our eating habits and metabolism tie into immunology," Steinman tells WebMD. "But these things are really complicated. Diet may be an important factor in MS, but in very different ways than people may expect. There is a tremendous amount to be learned. People with autoimmune diseases have to be cautious and shouldn't just start fasting until more is known."
One problem with fasting, Matarese says, is that mice had to lose a fifth of their body weight before they had significant disease protection. It takes only two days of fasting for a mouse to do this -- but for a human, that would mean two weeks of fasting.
The Italian researchers are looking for ways to block leptin's effects on the body. Steinman thinks a more natural approach -- dietary restriction -- would be safer and more natural. He's joined in that opinion by Harvard endocrinologist Jeffrey S. Flier, chief academic officer at Boston's Beth Israel Deaconess Medical Center. Like Steinman and Matarese, Flier is one of the first researchers to look at the link between leptin and immunity.
"A therapy aimed at blocking leptin would have many consequences other than improving autoimmunity -- it might make people obese," Flier tells WebMD. "Now, it could turn out that partial blocking wouldn't have too bad an effect on obesity, but would have a good effect on autoimmunity. But I wouldn't see it as a slam-dunk thing."
Meanwhile, Matarese is also looking at the other side of the coin. Leptin stimulation of immunity is bad for people with autoimmune diseases -- but it might be a good thing for people whose immune systems need a boost. His lab is now studying this possibility in animals.