Researcher Sheila K West PhD, who is part of the Salisbury Eye Evaluation study. (Photo: Johns Hopkins School of Medicine/FIS)
Diets rich in omega-3 could protect against macular degeneration
Friday, December 03, 2010, 01:10 (GMT + 9)
A new study shows that diets rich in omega-3 fatty acids from fish and shellfish may protect against age-related macular degeneration (AMD). The condition is a frequent cause of blindness in the country.
The results of the study run by the Wilmer Eye Institute at Johns Hopkins School of Medicine appear in this month’s issue of Ophthalmology, the journal of the American Academy of Ophthalmology.
The findings are consistent with other recent epidemiological studies that indicate an inverse association between seafood consumption and risk of the condition, including the Blue Mountain Eye Study and the Age-Related Eye Disease Study (AREDS), MedPage Today reports.
Researchers said they observed that high levels of omega-3s in the eye’s retina may be necessary for favourable eye health.
“Our study corroborates earlier findings that eating omega-3 rich fish and shellfish may protect against [advanced age-related macular degeneration],” declared researcher Sheila K West, PhD, who is part of the Salisbury Eye Evaluation study, reports WebMD Health News.
She noted that participants in study groups averaged at least one serving of fish or shellfish per week, but that participants who had AMD “were significantly less likely to consume high omega-3 fish and seafood.”
No significant relationship was found between dietary zinc from the consumption of crab and oyster and advanced macular degeneration risk.
Because zinc is thought to protect against AMD, West surmised that the researchers did not find a correlation because the zinc levels attained from seafood were low compared to levels available from dietary supplements.
The researchers analysed information on seafood consumption over a period of one year for 2,391 people aged 65 to 84 who lived on Maryland’s eastern shore.
Participants were examined for macular degeneration once the dietary assessments were finalized. The researchers found that 1,942 people did not have the disorder and 227 showed macular degeneration; also, 153 participants suffered from intermediate-stage disease and 68 from advanced AMD.
The retinas of the people in the advanced macular degeneration group showed abnormal blood vessel growth and bleeding – a cause of blindness or severe loss of vision. The people in this group were also a lot less likely to eat omega-3-rich seafood.
“In conclusion, our results suggest a protective effect of selective fish and shellfish intake against the risk of advanced [age-related macular degeneration], most likely because of their omega-3 fatty acid content,” the authors reported.
By Natalia Real