Omega-3 polyunsaturated fatty acids (PUFAs) have long been considered a necessary staple of our diet. Specifically, many studies have linked omega-3s to better heart health, and a decreased risk of cardiovascular complications. Omega-3 PUFAs are essential fats, meaning that we need to get them from our diet or outside sources, because our bodies don’t make them on their own. That means the level of omega-3s that our body can use depends directly on the amount of food we eat that contains the essential fat. Nutritious foods like flaxseed, vegetable oils, walnuts, fish, and leafy vegetables all contain omega-3 PUFAs; however, with obesity and unhealthy eating habits common in America, it probably comes as no surprise to hear that many in the US don’t take in as much omega-3s as they really need.1
A study published this month in JAMA Ophthalmology researched the effect marine omega-3s, or PUFAs from fish and other seafood, has on the incidence of Diabetic retinopathy.2 Diabetic retinopathy is a condition that can be experienced by those with diabetes. Blood vessels in the eye, specifically the retina, can leak or lose function, distorting or eliminating vision. Although it is treatable if caught early, it also has the potential to progress to more serious disorders of the eye if allowed to go unchecked. The retina uses many omega-3 PUFAs in tumor suppressing and anti-inflammatory processes, so it makes sense that supplying the body with an ample amount of these could help promote a healthy retina, decreasing the incidence of diabetic retinopathy.3
The study used existing data from a nutrition intervention trial in Spain that investigated the effects of the Mediterranean diet, supplemented with other fatty acids, on cardiovascular disease in individuals with T2D. The data from this trial, known as the PREDIMED trial, was re-investigated to dig deeper, and analyze marine omega-3 PUFA intake as well. Data was collected from 3,482 patients who were 55-80 years old (average age 67 years), roughly half male and half female, and who had T2D. The researchers determined that the recommended amount of omega-3 PUFA intake was an average of 500mg/day, which amounts to about two servings of oily fish per week.
The risk of diabetic retinopathy decreased by 48% for those who consumed the recommended amount of marine omega-3s from the start of the trial through follow-up, which was, on average, 6 months later. This result indicates that those who consume more omega-3s may be slowing, or stopping, the progress of diabetic retinopathy. However, it is still unclear as of now whether omega-3 supplements will have the same effect as naturally occurring marine omega-3s.
One important thing to note is that this study was conducted in Spain, where fish and seafood is a common staple in the diet. Nearly 75% of participants met the recommended amount of omega-3s in their normal routine, a number that would be unheard of in the US. An editorial published in response to the article points out this fact, and indicates that these results can have the most effect if utilized in countries like the US, who don’t have a normal diet that meets omega-3 recommendations.4 If this pattern can be extrapolated down to the bottom of the omega-3 intake chain, where some individuals in the US lie, these results could show even more promise!
The Nutrition Source. “Omega-3 Fatty Acids: An Essential Contribution.” Available from: https://www.hsph.harvard.edu/nutritionsource/omega-3-fats/
Sala-Vila A, et al. Dietary marine omega-3 fatty acids and incident sight-threatening retinopathy in middle-aged and older individuals with type 2 diabetes. 18 Aug 2016. Available from: http://archopht.jamanetwork.com/article.aspx?articleid=2543478
National Eye Institute. “Facts About Diabetic Eye Disease.” Available from: https://nei.nih.gov/health/diabetic/retinopathy
Larsen M. Eat your fish or go for nuts. 18 Aug 2016. Available from: http://archopht.jamanetwork.com/article.aspx?articleid=2543475