Scleroderma: Is Food the Cause?

An acquain­tance of mine has scle­ro­der­ma, and she asked me whether scle­ro­der­ma has any­thing to do with diet. The answer to that ques­tion seems to depend on whom you ask.

Peo­ple who haven’t both­ered to study the sci­en­tif­ic lit­er­a­ture on nutri­tion insist that food has noth­ing to do with scle­ro­der­ma. Such idiots deserve to be swat­ted on the snout with a rolled-up med­ical jour­nal, because they are spread­ing dan­ger­ous non­sense. On the oth­er hand, the sci­en­tists who have ded­i­cat­ed their sci­en­tif­ic careers to study­ing the rela­tion­ship between food and diet say that the autoim­mune dis­eases, includ­ing scle­ro­der­ma, are strong­ly relat­ed to diet.

The rules for avoid­ing autoim­mune dis­ease are sim­ple: don’t eat your rel­a­tives, don’t eat too much fat, and make sure you get plen­ty of vit­a­min D. If you get an autoim­mune dis­ease any­way, get test­ed for celi­ac dis­ease and ask a reg­is­tered dietit­ian to help you plan an exclu­sion diet to see if some­thing you are eat­ing is trig­ger­ing your prob­lem.

Like oth­er autoim­mune dis­eases, scle­ro­der­ma is com­mon in the same pop­u­la­tions that eat a lot of ani­mal-based foods, which means a lot of ani­mal pro­tein and a lot of fat. On the oth­er hand, autoim­mune dis­eases are rare in pop­u­la­tions that eat a low-fat, plant-based diet. Autoim­mune dis­eases are also less com­mon in sun­ny cli­mates, which sug­gests that vit­a­min D (the “sun­shine vit­a­min”) plays a role in pre­vent­ing them. A diet-relat­ed ill­ness called celi­ac dis­ease seems to increase the risk of oth­er autoim­mune dis­eases, prob­a­bly because it caus­es “leaky gut.”

Why do I say “don’t eat your rel­a­tives”? Why does eat­ing ani­mal pro­tein pose such a risk of autoim­mune dis­ease? It all has to do with a sim­ple fact about DNA. The more close­ly relat­ed two species are, the more alike their DNA is, and the more alike their pro­teins are. The more alike two pro­teins are, the more eas­i­ly they can be mis­tak­en for each oth­er by the immune sys­tem.

Let’s imag­ine that you eat some meat and some pota­toes. Ordi­nar­i­ly, the pro­teins from the meat and the pro­teins from the pota­toes would get bro­ken apart into indi­vid­ual amino acids in your diges­tive sys­tem, and from there the indi­vid­ual amino acids get absorbed into your blood­stream. But let’s imag­ine that you have a prob­lem with your intes­tine. It leaks a lit­tle, so some frag­ments of pro­tein from the meat and from the pota­toes make their way into your blood­stream before they are com­plete­ly bro­ken down. The immune sys­tem may mis­take these pro­teins for a for­eign invad­er and make anti­bod­ies against them. Unfor­tu­nate­ly, the pro­teins from the meat look a lot like your body’s own pro­teins, so the anti­bod­ies against them end up attack­ing some of your own tis­sue. The pro­teins from the pota­to have no “fam­i­ly resem­blance” to any­thing in your body, so any anti­bod­ies that you pro­duce against them will prob­a­bly not attack your own body. So don’t eat your rel­a­tives! Eat plants, instead. How­ev­er, you may have to be a lit­tle picky about which plants you eat.

In peo­ple with celi­ac dis­ease, a pro­tein from wheat (or from rye or bar­ley, both of which are close­ly relat­ed to wheat) trig­gers the immune sys­tem to attack the intes­tine. Celi­ac dis­ease can cause a wide range of prob­lems, rang­ing from mal­ab­sorp­tion to “leaky gut.” So you’d expect peo­ple with celi­ac dis­ease to be at par­tic­u­lar­ly high risk for an autoim­mune dis­ease like scle­ro­der­ma. As a mat­ter of fact, they are!

Fat in the diet can also be a prob­lem in autoim­mune dis­ease. Roy Swank was warn­ing peo­ple about this prob­lem this start­ing in the late 1940s, but he was large­ly ignored, even though he pub­lished his results the world’s most pres­ti­gious med­ical jour­nals. The role of a high-fat diet in caus­ing mul­ti­ple scle­ro­sis has recent­ly been “dis­cov­ered” again. Unfor­tu­nate­ly, no one can make a for­tune from this dis­cov­ery, so I’m afraid that it will fall back through the “mem­o­ry hole” yet again.

If you want to put out a fire, the first thing to do is to stop pour­ing gaso­line on it. Like­wise, when you get a diag­no­sis of a dis­ease that is known to be relat­ed to diet, stop eat­ing the foods that are known to pro­voke that dis­ease! In gen­er­al, a low-fat, plant-based diet has been asso­ci­at­ed with a low risk of autoim­mune dis­ease. How­ev­er, a few peo­ple may have trou­ble with wheat or some oth­er plant-based food. Con­se­quent­ly, they should con­sult a reg­is­tered dietit­ian for advice about an exclu­sion diet. Peo­ple with autoim­mune dis­ease should also ask their doc­tor, physi­cian assis­tant, or nurse prac­ti­tion­er to mon­i­tor their vit­a­min D lev­els and test them for celi­ac dis­ease.