SUPPLEMENTS rich in omega-3 oils might protect the sight of people with diabetes, a study in rats suggests.
Diabetes is the biggest cause of blindness among working-age adults in the west. To see if omega-3 could help, a team led by Algis Vingrys of the University of Melbourne, Australia, fed rats either omega-3-rich fish oil or safflower oil, which contains very little. To mimic insulin-dependent diabetes, insulin-producing cells were destroyed in half the animals.
After 24 weeks, the response to light of the photoreceptor cells in the retinas of diabetic rats on safflower oil had fallen by a third. 鈥淏ut diabetic animals raised on fish oil were no different to the non-diabetic animals,鈥� Vingrys told a meeting of the Australian Neuroscience Society in Melbourne last week.
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Blindness, like some other complications of diabetes, is usually blamed on high glucose levels damaging blood vessels. But the study suggests instead that diabetes directly affects the light-sensing cells. 鈥淭here was no obvious loss of blood vessels,鈥� says Vingrys.
The findings are likely to add to the hype over omega-3 oils (see 鈥楪ive livestock the omega-3 gene鈥�). Studies in people have shown they protect against heart disease but many claim they have other benefits, such as improving child behaviour.
Some experts fear that taking large amounts of omega-3 might have detrimental effects, as they are powerful oxidative agents that release free radicals. In Vingrys鈥檚 study, the rats were given the antioxidant vitamin E to counteract this. But other experts think only massive quantities would be harmful.