Adrenoleukodystrophy (ALD) is a rare genetic disease in which very long-chain fatty acids (VLCFAs) build up inside cells in males, causing a number of behavioral and neurological problems.
Here is some information about diet and certain dietary supplements, and how they may affect VLCFA levels in the body.
What are VLCFAs?
VLCFAs play a number of different roles in the body, including in the formation of the skin barrier, in liver function, in the maintenance of the insulating sheath around nerve cells known as myelin, and in the production of sperm cells.
VLCFAs can come from diet or be produced by the body. Both animal and plant foods, including fatty foods and the outer coverings of many fruits and vegetables, contain VLCFAs.
What causes ALD?
Mutations in the ABCD1 gene lead to a lack of a working ALD protein, which plays a key role in the breakdown of VLCFAs. This protein normally aids in the transportation of VLCFAs into specialized compartments inside cells called peroxisomes. This is where cells degrade VLCFAs into components that they can reuse later.
When the ALD protein is not available, VLCFAs cannot reach the peroxisome and begin to accumulate inside cells. This can become toxic, leading to disease symptoms.
VLCFA restricted diet, does it work?
Early research into treatment for the various types of ALD tested changes to patients’ diets.
Researchers knew that VLCFA levels were high in people with ALD, and that some of these VLCFAs came from diet. So they tested a specific diet that was very restrictive in VLCFAs. Their study covered seven patients with ALD placed on a highly restricted long-chain fatty acid diet for three months to up to two years.
Study results, published in 1984, found the restricted diet did not lower blood VLCFA levels or ease disease symptoms. This failure, they suggested, was because only a small portion of VLCFA comes from diet, and that dietary restriction may work best when combined with future therapies.
In an attempt to modify the body’s production of VLCFAs, a dietary mixture of 4:1 oleic acid and erucic acid was developed.
The effectiveness of Lorenzo’s oil, as this mixture is called, remains controversial. Several studies have shown that Lorenzo’s oil can successfully lower blood levels of VLFCAs. However, it does not seem to help patients with cerebral forms of ALD who already have symptoms. Studies in men with adrenomyeloneuropathy (AMN), done in the 1990s, are reported to have failed to show any effectiveness in slowing disease progression, and noted cerebral involvement began in “a few” of these men while using Lorenzo’s oil. These studies were open label, meaning they had no placebo control group for comparison.
A study in 89 boys with ALD with no neurological symptoms and normal MRIs investigated the effect of Lorenzo’s oil and a moderately restricted fat diet, following them for a mean of almost seven years. Over the course of the study, 24% of the boys developed MRI abnormalities and 11% also showed neurologic symptoms. Study researchers noted that, in the absence of any treatment, an estimated 35% of ALD patients develop neurological symptoms by age 10. They also pointed to a reduction in the incidence of symptoms to support Lorenzo’s oil potential in asymptomatic boys with normal brain MRIs.
Other researchers, however, found little evidence that this approach alters “the course of childhood or adult cerebral ALD” or is of benefit to adults with AMN.
Lorenzo’s oil is available as a treatment in some countries. In the U.S., it was available through an expanded access program (NCT02233257) that is now closed.
Lorenzo’s oil can lead to side effects that include lower levels of platelets and some types of white blood cells. It should, therefore, only be used under medical supervision, and with access to facilities that take MRIs and can test for VLCFA levels to determine if the treatment is showing effect.
Last updated: Feb. 17, 2021
Adrenoleukodystrophy News is strictly a news and information website about the disease. It does not provide medical advice, diagnosis, or treatment. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.
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