Current research suggests that an increased diet of ω-3 fatty acids is the key to treatment of common neovascular diseases, such as diabetic retinopathy.
Neovascular diseases comprise a broad spectrum of ocular disorders common in diabetes patients, premature infants, and elderly people. Neovascular diseases begin with neovascularization – the development of new blood vessels in the eye. These new vessels are very fragile and can easily rapture, leaking vessel contents to the inside of the eye and blurring the patient’s vision. Overtime, the rapture of blood vessels can lead to a significant loss of sight. Current treatment for these diseases is based on suppressing VEGF, the primary hormone involved in promoting new blood vessel development. VEGF blockers are far from a perfect solution to these problems, as they disrupt normal blood vessel development, and require frequent intraocular injections, putting the patients at risk of developing eye infections. Lipids and their metabolic precursors, namely ω-3 and ω-6 fatty acids are also important in blood vessel development, and have been recognized as targets for neovascular disease treatment. A recent scientific review published in the American Journal of Clinical Nutrition summarizes the current research on the effects of dietary ω-3 and ω-6 on neovascular disease progression.
For humans, ω-3 and ω-6 are essential fatty acids, meaning that they must be obtained through dietary means, as we lack the proper enzymes to synthesize them de novo. This makes ω-3 and ω-6 very attractive targets for disease therapy since they can be controlled through dietary intake. Retinopathy of prematurity (ROP) is a neovascular disease found in 10% of premature infants. Its high prevalence in this group has been linked to the fact that premature birth interrupts the baby’s intake of ω-3 and ω-6 fatty acids from the mother, preventing the baby from obtaining these essential nutrients. Premature infants who received fish oil supplements in their diet showed a decreased prevalence of the disease, indicating that ω-3 and ω-6 fatty acids protect the baby from developing ROP. The preventative role of dietary ω fatty acids continues well into adulthood. Diabetic retinopathy (DR) is a common disease among diabetes patients, and develops because the altered metabolism of diabetic cells releases of pro-inflammatory molecules and activates VEGF. Studies found that a dietary increase of ω-3 fatty acid decreases the production of pro-inflammatory molecules and reduces incidents of DR.
Although ω-3 and ω-6 are very similar in structure, they produce different metabolites when they are processed by metabolic enzymes. LOX, COX, and CYP2C are the three main enzymes that process ω-3 and ω-6 in the human body. When LOX and COX process ω-6, the resulting metabolite promotes the progression of neurovascular disease, but when they process ω-3, the resulting metabolite has a preventative effect. However, in the case of CYP2C processing, both ω-6 and ω-3 produce metabolites that promote disease progression. These findings suggest that the best way to approach neurovascular disease treatment may be through an increase in dietary ω-3, and a pharmaceutical treatment of CYP2C blockers that minimize the production of harmful ω-3 metabolites. For the daily reader these studies conveys a simple message – what we eat has a huge impact on all aspects of our health.
Written By: Irina Sementchoukova, B.Sc