in the December 2011 issue of The Quarterly Review of Biology, Dr. Angelique Corthals, a forensic anthropologist and professor at the John Jay College of Criminal Justice in New York, suggests that MS is not an auto-immune disorder, but rather that it is caused by faulty lipid metabolism.
The Lipid Hypothesis
Dr. Corthals article asserts that the basic cause of MS can be brought back to transcription factors in cell nuclei that control the uptake, breakdown, and release of lipids (fats and similar compounds) throughout the body. Disruption of peroxisome proliferator-activated receptors (PPARs), causes a toxic byproduct of “bad” cholesterol called oxidized LDL to form plaques on the affected tissue. The accumulation of plaque in turn triggers an immune response, which ultimately leads to scarring. This is essentially the same mechanism involved in atherosclerosis, in which PPAR failure causes plaque accumulation, immune response, and scarring in coronary arteries.
“When lipid metabolism fails in the arteries, you get atherosclerosis,” Corthals explains. “When it happens in the central nervous system, you get MS. But the underlying etiology is the same.”
So basically, if I understand Dr. Corthal’s writings correctly, instead of screwing up your heart, the diet you’ve been eating has been screwing up your brain. (Heck, it may have been doing both!)
A major risk factor for disruption of lipid homeostasis is having high LDL cholesterol. So if PPARs are at the root of MS, it would explain why cases of the disease have been on the rise in recent decades. “In general people around the world are increasing their intake of sugars and animal fats, which often leads to high LDL cholesterol,” Corthals said. “So we would expect to see higher rates of disease related to lipid metabolism—like heart disease and, in this case, MS.” This also explains why statin drugs, which are used to treat high cholesterol, have shown promise as an MS treatment.
The lipid hypothesis also sheds light on the link between MS and vitamin D deficiency. Vitamin D helps to lower LDL cholesterol, so it makes sense that a lack of vitamin D increases the likelihood of the disease—especially in the context of a diet high in fats and carbohydrates.
This weirds me out a little as I had high cholesterol as a child but not as an adult. I know I’m not everyone.
Dr. Corthals’s framework also explains why women are more apt to get multiple sclerosis than men. It has to do with how our bodies metabolize lipids. Men metabolize them in their vascular tissue, while women’s bodies are more likely to metabolize it differently.
Dr. Corthal’s said, “[W]omen metabolize fat differently in relation to their reproductive role. Disruption of lipid metabolism in women is more likely to affect the production of myelin and the central nervous system. In this way, MS is to women what atherosclerosis is to men, while excluding neither sex from developing the other disease.”
There are several other risk factors for reduced PPAR function: pathogens like Epstein-Barr virus, trauma that requires massive cell repair, and certain genetic profiles. In many cases, Corthals says, having just one of these risk factors isn’t enough to trigger a collapse of lipid metabolism. But more than one risk factor could cause problems.
“In the context of autoimmunity, the various risk factors for MS are frustratingly incoherent, but in the context of lipid metabolism, they make perfect sense.” Dr. Corthals said.
Research is necessary to fully understand the role of PPARs in MS, but we all hope that this new understanding of the disease could eventually lead to new treatments and prevention measures, and maybe even a cure.
In any event, as the scientific community known as “they” go on and study this hypothesis, I’ll be sticking to the Paleo Diet to bring down my inflammation by staying away from dairy, grains, and legumes, lower my LDL cholesterol levels by sticking with lean meats and lots of fresh veggies, and keep up my Vitamin D levels with fresh whole food, time outside, and supplements.
We might not yet have a cure, but we certainly have ways to help ourselves in the meantime.