Ultra-Low Carbohydrate Diets and Their Impact on Diabetes and Vision Loss

Discussing dietary habits for those with type 2 diabetes and vision issues can be complex, with various nutritional approaches gaining attention. In this article, we explore the efficacy of ultra-low carbohydrate diets, often referred to as ketogenic diets, with less than 15 grams of net carbs per day, and their potential for managing diabetes and improving vision health.

Evaluating Ultra-Low Carbohydrate Diets

Some individuals, particularly those managing type 2 diabetes, may wonder if ultra-low carbohydrate diets with less than 15 grams net carbs per day are safe and effective. While the question remains open, experienced individuals who have been following such diets for decades report no significant issues. This diet, however, is not the recommended maximum for individuals with type I diabetes, where only up to 15 grams per day is advised.

For those with type 2 diabetes, recommendations vary, but it is generally agreed that less than 20 grams of carbs per meal is preferable, with many experts suggesting aiming for 10 to 15 grams. This approach aligns with the guidelines for a low-carb diet, which is typically defined as having under 100 to 150 grams of carbs per day. The standard Western diet typically includes much higher carbohydrate intake, making the low-carb approach notably different.

How Much Carbohydrate is Recommended?

According to the Center for Disease Control and Prevention (CDC), people with diabetes should aim to get approximately 45% of their daily calories from carbohydrates. For females, this translates to 3 to 4 servings at 15 grams each, while males may require slightly higher amounts of 4 to 5 servings.

Using an average of 1800 calories per day for maintaining a healthy weight, about 800 to 900 calories can come from carbs. At 4 calories per gram, this equates to a range of 200 to 225 carb grams per day, significantly lower than the standard Western diet.

Impact on Vision and Eye Health

The eyes, particularly the retina, can benefit from certain nutrients, such as Lutein and Zeaxanthin. These carotenoids, found in leafy greens and other vegetables, may reduce the risk of age-related macular degeneration (AMD) and cataracts. Studies have indicated that a generous intake of Lutein and Zeaxanthin, found in broccoli and spinach, can offer up to a 40% reduction in the risk of AMD. A similar reduction of up to 20% in the risk of cataracts has also been associated with these compounds.

Lutein and Zeaxanthin can absorb potentially damaging blue light from sunlight, protecting the retina from harm. Additionally, these compounds act as antioxidants, neutralizing cell damage caused by free radicals, which are harmful particles produced during metabolism.

While there is no specific recommendation for including leafy greens in the diet solely for eye health, these vegetables are among the most nutritionally dense foods available. They are rich in vitamins A, C, K, folate, iron, and magnesium, making them a valuable addition to any diet. For those unfamiliar with these greens, a cooking guide is available.

Other sources of these beneficial compounds include corn, kiwifruit, red grapes, spinach, zucchini, yellow squash, orange peppers, and orange juice.

For those with diabetes, eggs offer an excellent source of Lutein and Zeaxanthin. However, dietary guidelines recommend limiting total daily cholesterol intake to 200 milligrams or less due to heart health considerations. While a large egg yolk contains around 212-220 mg of cholesterol, other fruits and vegetables are generally more healthful sources of these compounds.