Ketogenic diet may protect against diabetic eye damage in early research
Nutrients
Summary
This animal study tested whether low-carb and ketogenic diets protect against diabetic eye damage in rats. Rats were fed a high-fat diet for 8 weeks to cause diabetes, then switched to either a normal diet, low-carb diet, or ketogenic diet for another 8 weeks. The ketogenic diet worked better than the low-carb diet at reducing eye damage and inflammation. Both diets helped lower blood sugar and reduce harmful oxidative stress, but the ketogenic diet showed stronger protective effects on the retina. The ketogenic diet improved antioxidant defenses and reduced inflammation markers in the eyes. Rats on the ketogenic diet had healthier retinal tissue compared to those on the low-carb or normal diets. These findings suggest that very low carbohydrate intake may offer extra protection for diabetic eye complications beyond what moderate carb restriction provides. However, this was tested only in rats, not humans.
Study Design
Interventions
Study Type
Outcomes
Duration and Size
Study Population
Age Range
Sex
Geography
Other Criteria
Methodology
Researchers used adult male rats divided into four groups. One group ate a normal diet throughout. The other three groups were fed a high-fat diet for 8 weeks to induce diabetes. After diabetes developed, these rats were split into three diet groups for another 8 weeks: normal diet, low-carb diet, or ketogenic diet. Blood and eye tissue samples were collected to measure blood sugar, insulin, inflammation markers, and oxidative stress. Retinal tissue was examined under a microscope to check for damage.
Interventions
Rats received either a low-carb diet or a ketogenic diet after developing diabetes. The low-carb diet got 20% of calories from carbs, 20% from protein, and 60% from fat. The ketogenic diet got almost no carbs, 20% from protein, and 80% from fat. Both diets were given freely for 8 weeks. Researchers compared these diets to a normal diet to see which worked best at protecting the eyes.
Key Findings
Both low-carb and ketogenic diets improved blood sugar and reduced harmful oxidative stress. The ketogenic diet showed stronger effects with better antioxidant activity and less inflammation in the eyes. Microscopic examination showed that rats on the ketogenic diet had healthier retinal tissue with less damage than those on the low-carb diet or normal diet.
Comparison with other Studies
Earlier research has shown that low-carb and ketogenic diets can help manage type 2 diabetes and reduce inflammation. This study builds on that work by directly linking these benefits to eye health in diabetic animals. Unlike previous work that focused mainly on blood markers, this study examined actual eye tissue under a microscope. The findings align with other studies showing that ketones produced during very low-carb eating may have anti-inflammatory effects in various body tissues.
Journal Reference
Jawharji MT, Alshammari GM, Binobead MA, Albanyan NM, Al-Harbi LN, Yahya MA. Comparative Efficacy of Low-Carbohydrate and Ketogenic Diets on Diabetic Retinopathy and Oxidative Stress in High-Fat Diet-Induced Diabetic Rats. Nutrients. 2024;16(18):3074. doi:10.3390/nu16183074
© 2026 deDiabetes. Licensed under CC BY (Attribution)
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