If you have diabetes, it’s important to get regular eye exams to look for changes in your eyes that can lead to vision loss. Many of these changes fall under the umbrella of diabetic retinopathy — damage to blood vessels in the back of your eye, an area known as the retina.
In people with diabetic retinopathy, fluid can leak out of blood vessels and cause swelling in your retina. This type of swelling is called diabetic macular edema, and it typically requires treatment to prevent vision changes and vision loss.
But medical treatments aren’t the only way to help keep this condition under control. In fact, lifestyle changes — including dietary changes — may be essential to avoiding ongoing medical treatments and actually stabilizing your vision.
“We do have a lot of treatments for diabetic retinopathy and diabetic macular edema, and all of those have a temporary effect,” says Kasra Rezaei, MD, an ophthalmologist and associate chief of service for ophthalmic surgery at the University of Washington in Seattle. “They don’t solve the issue until we control blood sugar.”
Here are some lifestyle changes that may help slow the progression of diabetic macular edema, as well as diabetic retinopathy more broadly.
Dietary Changes to Control Blood Sugar Are Essential
While medical interventions like drug injections in your eye can help stop the fluid leakage and swelling that define diabetic macular edema, these treatments won’t stop the condition from coming back. That’s because if your blood sugar (glucose) levels remain high, you’re likely to experience ongoing damage to blood vessels in your eyes.
“Swelling in your retina, or diabetic macular edema, that comes from the high level of sugar [in your blood] damaging the endothelial cells in your blood vessels,” Dr. Rezaei explains. Even when someone’s diabetic macular edema is treated promptly, “If we don’t control blood sugar, they end up losing vision because of scar tissue in the eye,” he says.
Unfortunately, Rezaei notes, the kinds of foods that are typically optimal for blood sugar control — such as fruits and vegetables, foods that contain slowly digested carbohydrates, healthy fats, and protein — tend not to be widely available at restaurants, and are often more expensive than less healthy options. But even if it comes with extra cost and inconvenience, a healthy diet is an essential part of blood sugar control, he says.
“I see the worst complications of diabetes,” Rezaei laments. He recommends working with a dietitian who collaborates with your primary care doctor or endocrinologist to come up with a detailed eating plan that’s designed to keep your blood sugar at the right level. In general, he notes, people with diabetes tend to have better blood sugar control when they eat nonstarchy vegetables, lean sources of protein, and carbohydrate-rich foods with a low glycemic index — meaning the carbs don’t spike your blood sugar.
Fruits, Vegetables, and Fish May Be Beneficial
In addition to following a diet that keeps your blood sugar under control, some specific foods may help with diabetic macular edema. A research review published in March 2022 in the journal Nutrients found that consuming fish regularly may help inhibit diabetic retinopathy. In one study, eating oily fish (such as salmon or herring) twice a week was linked to a 60 percent lower risk for retinopathy. In another study, eating 3 to 5 ounces (85 to 141 grams) of dark or oily fish weekly was linked to a 70 percent lower retinopathy risk.
The researchers also found that eating a wide variety of fruits and vegetables may help prevent or slow retinopathy due to the vitamins, minerals, fiber, and other nutrients they contain. These foods should be included in every meal, and the researchers recommended a minimum daily intake of 400 grams (14 ounces) — but ideally even more than this.
If you’re looking for an overall dietary strategy to follow, you might consider a Mediterranean diet — which emphasizes fruits and vegetables, whole grains, olive oil, nuts, fish, and poultry. One study found that a Mediterranean diet that emphasized olive oil, in particular, was linked to a 44 percent lower risk of developing diabetic retinopathy.
Coffee and Tea May Help Protect Vision
According to the Nutrients research review, tea — meaning beverages brewed from the plant that gives us black, green, white, and oolong teas — has been shown in lab experiments to help prevent the formation of abnormal blood vessels in the retinas of rats with diabetes. Other studies have shown that green tea, in particular, may help improve retinal health in a number of different ways.
Coffee has been shown to have anti-inflammatory effects that may also help improve your eye health, due to a number of beneficial compounds found in the beverage. Studies have shown that people with the highest coffee intake may be at lower risk for developing type 2 diabetes, although it’s unclear if coffee helps improve blood sugar once you have diabetes.
Physical Activity Offers Broad Benefits
Physical activity, along with diet, is a key element of blood sugar control, Rezaei explains. “Physical activity will increase the reception of glucose by muscle, and that will bring your sugar to a lower level,” he says. “Having routine physical activity five days a week will help control your blood sugar and benefit your overall physical health, as well.”
The Nutrients research review noted that both aerobic activity (cardio) and resistance (weight) training have been shown to have broad benefits that may translate to better eye health — including lower blood sugar, lower blood pressure, and better overall cardiovascular health.
High levels of activity may also be beneficial for diabetic macular edema, with one study showing that getting at least 30 minutes of physical activity five days a week was linked to slower progression of diabetic retinopathy.
Alcohol and Tobacco: Mixed Findings on Risks
A number of studies have shown that a moderate alcohol intake is linked to a lower risk for diabetic retinopathy, according to the Nutrients research review — including in type 2 diabetes specifically. This benefit may be due, in part, to reduced platelet activity from drinking alcohol — potentially leading to less growth of abnormal blood vessels. On the other hand, alcohol may promote inflammation, so the overall effect of alcohol consumption on diabetic macular edema is unclear.
Smoking tobacco, on the other hand, has been shown to be linked to worse cardiovascular health and worsening of diabetic retinopathy. One analysis, though, found that smoking increased the risk for diabetic retinopathy in people with type 1 diabetes, but not in people with type 2 diabetes.
Can Supplements Help Diabetic Macular Edema?
While a number of different nutrients are believed to play a key role in eye health — including vitamins A, B, C, D, and E, as well as zinc — there isn’t much evidence to support taking these nutrients as a supplement for people with diabetic retinopathy. The same can be said for omega-3 fatty acids, which can be found in fish oil supplements — studies have shown that they lead to potentially beneficial changes when it comes to retinopathy risk, but there isn’t definitive evidence that they actually help slow retinopathy progression.
Rezaei notes that there is no widely recommended supplement for eye health in people with diabetic macular edema. But if your doctor finds that you have low levels of a particular nutrient, then taking a supplement may be advised.
Instead of focusing on any single nutrient or supplement, it’s important to remember that an overall healthy lifestyle will be good for your eye health when you have diabetes. “Every time I have a patient who is working out, walking or running, and they’re controlling their diet, those patients tend to have fewer complications of diabetes,” Rezaei says.