Two servings of fish a week may be enough to lower the heightened risk for blindness that those with diabetes face, a new Spanish study suggests.
Diabetic retinopathy is a serious complication of type 2 diabetes resulting from a drop-off in blood supply to the patient’s retina. According to lead researcher Aleix Sala-Vila, it is the most frequent cause of diabetes-related blindness.
“We wanted to [see] whether regular consumption of seafood-fatty fish in particular- in the absence of any advice to increase seafood consumption or fish oil supplementation decreased the risk of diabetic retinopathy,” explained Sala-Vila, a researcher at the Centro de investigacion Biomedica en Red in Barcelona.
Sala-Vila’s team focused on patients whose overall diet was already composed of mostly low-fat or plant-based roods. That said, the team found that those who consumed at least two servings of fatty fish weekly had a lower risk for diabetic retinopathy than those whose diet included less fish.
Study participants were drawn from an earlier trial that had divided Spanish residents with type 2 diabetes into three different groups, each assigned to a different diet.
The first followed a low-fat diet. The second followed a Mediterranean (plant-based/red meat-free) diet, supplemented with extra virgin olive oil. And the third also followed a Mediterranean diet, supplemented by 30 grams a day of omega-3 rich walnuts, hazelnuts, and almonds.
The study found it was those in the second group who saw their vision risks fall.
Working with the same pool of participants, Sala-Vila’s team then asked about 3,600 diabetic men and women between the ages of 55 and 80 to report how often they consumed eight types of seafood before embarking on their assigned diets.
Once on their diets, Sala-Vila’s team tracked seafood consumption habits for nearly five years.
The result: The team found that those who routinely consumed 500 mg a day of omega-3 fatty acid in their diets (equal to two servings of fatty fish per week) were 48% less likely to develop diabetic retinopathy than those who consumed less.
Why? Sala-Vila pointed to a drop in systemic inflammation that occurs as overall omega-3 levels go up. Whether diabetics might realize even more protection by further increasing fatty fish consumption remains unclear, he said.
Sala-Vila also cautioned against interpreting the findings to mean that omega-3 supplements do the trick as well as eating fish did.
Sala-Vila is right about several things – omega 3 fatty acids do reduce systemic inflammation and a natural food source is superior to a supplement. Supplements are just that, a “supplement” to a good diet.
It is difficult to obtain enough omega-3 fatty acids in the diet, so I routinely recommend a daily supplement of 2,000 mg in addition to regular servings of fatty fish.
Please note that group two, the one that literally “saw” the benefit also consumed a lot of omega-6 fatty acids in the form of extra virgin olive oil. Omega-6 fatty acids are also anti-inflammatory for most, but can be pro-inflammatory in diabetics. Adequate sesame seed oil in the diet or as a supplement will help direct the omega-6 fatty acids into the anti-inflammatory pathways. Tahini and humus are excellent food sources of sesame seed oil.
What is hard to understand is how the Spaniards develop diabetes when the Mediterranean diet is an engrained part of their culture? I suspect a large percentage of the population has adopted the European diet that is high in red meat, bread, and beer.
The Bottom Line:
This study is another example of how important diet and the omega fatty acids are to good health. I also is another strike against the concept that “fat is bad”.
Source: August 18, 2016 National Institutes of Health