I've seen a couple of stories in the press about the death of Lorenzo Odone, who had adrenoleukodystrophy (ALD). ALD occurs when an essential protein that removes very long chain fatty acids (VLCFAs) is missing, resulting in a build-up of VLCFAs in the body which damage the brain. Most sufferers die within 1 to 10 years of showing symptoms.
Lorenzo Odone lived until the age of 30, despite doctors giving him little chance of surving beyond the age of 8 or so. His relative longevity has been ascribed to 'Lorenzo's Oil', a mixture of glycerol trioleate and glycerol trierucate. The oil was initially used as a treatment by Lorenzo Odone's parents, who were understandably unwilling to simply watch their son die. They undertook a considerable amount of research, despite being laypeople with no medical expertise. They thought that the oil would help inhibit the creation of VLCFAs. Lorenzo's condition apparently stabilised after the oil became part of his diet. Since two laypeople creating a therapy that had eluded the finest minds of medicine is quite a story, a film was made, titled 'Lorenzo's Oil'. The money the Odone's made from the film went into the Myelin project, which funds research into diseases like ALD and MS.
However, the Odones found the scientific community sceptical. In the Guardian obituary, Lorenzo's sister Cristina Odone writes "Not all members of the scientific community welcomed this approach; or, indeed, their portrayal on film as hard-hearted and arrogant. A backlash against the Odones saw various researchers from around the world denying the efficacy of Lorenzo's oil, and most doctors refused to prescribe it. In 2005, however, the world's top authority on ALD, the late Dr Hugo Moser, published the findings of a 10-year study which showed that a statistically lower incidence of ALD occurred in those boys whose diet included Lorenzo's oil". This is what interested me in the story, as it fits into a neat narrative about laypeople taking on the might of the scientific establishment, and being treated in a cold-hearted and callous manner as a result.
Firstly, I would say that an initial sceptical approach was sensible. The only evidence that Lorenzo's Oil might work was from the apparent stabilisation in the condition of Lorenzo himself. There could be a huge number of other reasons why this happened that had nothing to do with Lorenzo's Oil. The only way to find out whether it really worked or not was to conduct scientific trials. Until this had been done, it was sensible to be sceptical of a therapy for which there was essentially no evidence of efficacy.
So, what of Moser's study? This is certainly not my area of expertise, but I can at least have a look at the methodology of the paper. The trial followed 89 boys who were thought to be at risk of ALD based on an assay of VLCFAs in their plasma. All of the boys were given Lorenzo's Oil and 'moderate fat restriction' in their diet. The study concluded that treatment with Lorenzo's Oil caused a reduction in plasma hexacosanoic acid, which was associated with a reduced risk of developing abnormalities on an MRI scan. However, this was a single arm trial: there was no placebo group. I'm not criticising the study for this; if the treatment is likely to help, then it is probably unethical to withhold it from the subjects of the study. But it does make it more difficult to know whether the results are because of the therapy, or because of something else. What would be more interesting, I think, would be to look at whether there is a difference between subjects given Lorenzo's Oil and a reduced VLCFA diet, and those just given the diet. As far as I can tell, this has not been done. So it is difficult to know if the oil has any effect on its own. A more recent study in the journal Metabolic Brain Disease followed 11 subjects, all of whom were taking Lorenzo's Oil and were on a diet restricted in VLCFAs. Again, this doesn't allow us to separate the effects of the oil from the effects of the diet.
While these studies might show some evidence for an effect of Lorenzo's Oil before symptoms appear, it seems that the treatment doesn't work well in symptomatic subjects. This may be because the compounds that make up Lorenzo's Oil do not cross the blood/brain barrier.
Now, I'm not saying that Lorenzo's Oil doesn't work. This isn't homeopathy, after all, and there does seem to be a plausible mechanism by which it might work. I'm not even saying that what the Odones have acheived is not impressive. What I am saying is that the evidence that it does work is fairly weak, it is far from being a miracle cure, and the story is a little bit more complicated than the narrative that is being presented.