In the news: Diet Sodas & Diabetic Retinopathy; Antioxidant Rich Diet & Type 2 Risk

What is Diabetic retinopathy?

One complication of diabetes is diabetic retinopathy, where high blood sugar levels damage blood vessels in the retina. The vessels can swell and leak, or become blocked and reduce blood supply to the retina.

During the more advanced form of the condition, called proliferative diabetic retinopathy, new – but more fragile – vessels can grow in the retina and into the gel-like vitreous fluid. In turn, these vessels may leak blood into the vitreous, resulting in cloudy vision.

Diet Sodas & Diabetic Retinopathy: Connected?

Those with diabetes are aware that drinking sugary sodas has long been associated with an increased risk of diabetes and cardiovascular disease (CVD). But what about diet sodas which have been marketed as “healthier alternatives” to sugar-laden sodas?

Researchers from the University of Melbourne in Australia are the first to explore whether there’s relationship between diet soda intake and the severity of diabetic retinopathy.

To do this, they surveyed over 600 diabetic patients to assess their soda intake. Patients were categorized by their stage of diabetic retinopathy, ranging from no retinopathy, to mild to severe non-proliferative retinopathy, to severe proliferative diabetic retinopathy.

The researchers found that those drinking more than 4 cans of diet soda weekly were more than twice as likely to have proliferative diabetic retinopathy versus those consuming less than a can per week (1).

Diet Sodas & Diabetic Retinopathy in Perspective

In addition to this study, others (though not all) have also linked diet soda intake to obesity, type 2 diabetes and CVD. Keep in mind, though, that these studies are observational and can’t prove cause and effect.

If drinking too many diet sodas truly is unhealthy, why? The answer isn’t clear, but the researchers point out that the artificial sweeteners in diet sodas could increase the desire for more sweet and high-calorie foods. If that leads to weight gain, it can make it harder to keep blood sugar levels within a healthy range and may up the risk of diabetic complications.

Bottom line: Until there’s a better understanding of how diet sodas might impact health, it’s probably best to keep their intake to a minimum. One alternative is to substitute sparkling water with a dash of fruit juice or an added sprig of mint for flavor.

Antioxidant Rich Diet May Lower Type 2 Risk

Of course the best way to avoid diabetic complications is to avoid getting type-2 diabetes in the first place, if possible. In addition to losing weight if overweight, exercising and eating wisely, consuming an antioxidant rich diet may help as well.

Mounting evidence suggests that oxidative stress may contribute to the development of type 2 diabetes. Oxidative stress occurs when the production of free radicals exceeds the ability of our antioxidant defenses to handle them.

French researchers looked at the relationship between total antioxidant capacity and type 2 diabetes in over 64,000 women followed for 15 years. They used total antioxidant capacity (TOC), an index that estimates antioxidant capacity from all dietary antioxidants.

Compared with women with the lowest TOC capacity, women with higher TOCs had a lower risk for type 2 ranging from 26-30% (2).

Foods and beverages that contributed the most to the TOC were fruit, vegetables, alcoholic drinks (wine) and hot beverages such as tea, chicory and hot chocolate – all known to have abundant levels of antioxidant compounds. The researchers had previous shown that coffee intake was associated with lower risk of type 2.

References

1. Fenwick EK, et al. Diet soft drink is associated with increased odds of proliferative diabetic retinopathy. Clin Exp Ophthalmol. Epub Feb. 23, 2018.
2. Mancini FR, et al. Dietary antioxidant capacity and risk of type 2 diabetes in the large prospective E3N-EPIC cohort. Diabetologia. 61:308–16, 2018.