Researchers looked at what 1,619 Korean adults over age 60 ate and whether it connected to cataracts—a clouding of the eye lens that makes vision blurry. They found that people who ate a lot of carbohydrates (like rice and bread) had a higher chance of developing cataracts. On the flip side, people who ate more protein and healthy fats had lower chances of getting cataracts. This suggests that as we get older, balancing what we eat—not overdoing carbs and including enough protein and fat—might help keep our eyes healthier.

The Quick Take

  • What they studied: Whether the amount and types of carbohydrates, proteins, and fats people eat are connected to cataracts in older adults
  • Who participated: 1,619 Korean men and women aged 60 and older who participated in a national health survey between 2015 and 2017
  • Key finding: People who got more than 80% of their daily calories from carbohydrates had 41% higher odds of having cataracts. Women who ate more protein and people who ate more fat had lower odds of cataracts.
  • What it means for you: If you’re over 60, eating a balanced diet with adequate protein and healthy fats—rather than relying too heavily on carbohydrates—may help protect your vision. However, this is one study and more research is needed before making major dietary changes.

The Research Details

This was a cross-sectional study, which means researchers looked at a large group of people at one point in time and compared their diets to whether they had cataracts. The researchers used data from Korea’s national health survey conducted between 2015 and 2017. Participants reported everything they ate in the previous 24 hours, and researchers calculated how much carbohydrates, protein, and fat they consumed. They then grouped people by how much of each nutrient they ate and compared cataract rates between groups. The researchers also adjusted their analysis to account for other factors that might affect cataracts, like age, smoking, and overall health.

This research approach is useful because it looks at real-world eating patterns in a large, representative group of older adults. By examining actual dietary intake rather than just asking people general questions about their diet, the researchers got more accurate information. However, because this is a snapshot in time rather than following people over years, it can show associations but not prove that diet directly causes cataracts.

The study used data from an official national health survey, which means the information was collected carefully and consistently. The sample size of 1,619 people is reasonably large. However, because this is a cross-sectional study, it can only show that certain eating patterns are linked to cataracts—not that they cause them. The researchers adjusted for many other factors that could affect results, which strengthens the findings. Some confidence intervals were wide, suggesting some uncertainty in the results.

What the Results Show

The most striking finding was about carbohydrates. People who got more than 80% of their daily calories from carbohydrates had 41% higher odds of having cataracts compared to those who ate less carbohydrate-heavy diets. This association was statistically significant, meaning it’s unlikely to be due to chance alone. In contrast, people who ate more protein—specifically women who got 12-15% of their calories from protein—had significantly lower odds of cataracts. Similarly, people who ate more fat (more than 18% of daily calories) had lower odds of cataracts. Both saturated fats and monounsaturated fats showed this protective pattern. These findings suggest that the balance of nutrients matters, not just individual nutrients in isolation.

The protective effect of protein and fat appeared stronger in women than in men, though the reasons for this difference aren’t clear from this study. The study also found that cataracts were very common in this age group—about 52% of participants had them. This high prevalence makes understanding preventable risk factors particularly important for public health.

Previous research has suggested that antioxidants and certain nutrients protect eye health, but this study adds new information about the overall balance of macronutrients. The finding that excessive carbohydrates may increase cataract risk is relatively newer and suggests that it’s not just about eating healthy foods, but also about the proportions of different nutrient types. The protective effects of protein and fat align with some earlier research suggesting that adequate protein intake supports eye health.

This study has several important limitations. Because it’s cross-sectional, it shows associations but can’t prove that diet causes cataracts—people with cataracts might have changed their diet after developing them. The study only included Korean adults, so results may not apply to other populations with different genetic backgrounds and typical diets. Dietary intake was based on people’s memory of what they ate in one day, which may not reflect their usual eating patterns. The study couldn’t account for all possible factors affecting cataract development, such as sun exposure or family history. Some of the statistical findings had wide confidence intervals, indicating uncertainty.

The Bottom Line

If you’re over 60, consider eating a balanced diet where carbohydrates don’t make up more than 80% of your calories. Include adequate protein (aim for 12-15% of daily calories) and healthy fats (aim for more than 18% of daily calories). Focus on whole grains, lean proteins, and healthy fats like olive oil and nuts. However, these recommendations are based on one study, so discuss major dietary changes with your doctor. Confidence level: Moderate—this is promising evidence but more research is needed.

This research is most relevant to adults over 60, particularly women, who are concerned about eye health and cataract prevention. It’s also important for people with a family history of cataracts. However, people with specific health conditions like diabetes or kidney disease should consult their doctor before making dietary changes, as their nutritional needs may be different.

If diet does affect cataract development, changes would likely take months to years to show benefits, since cataracts develop slowly over time. This isn’t something you’d notice improvement in within weeks. Think of it as a long-term investment in eye health rather than a quick fix.

Want to Apply This Research?

  • Track your macronutrient percentages daily: aim to keep carbohydrates at 70-80% of calories, protein at 12-15%, and fat at 18-25%. Use your app’s nutrition tracker to log meals and monitor these ratios weekly.
  • Replace one carbohydrate-heavy meal per day with a balanced meal that includes lean protein and healthy fats. For example, swap white rice with brown rice and add grilled chicken and olive oil-based vegetables.
  • Set a weekly goal to review your macronutrient balance. Create a simple chart tracking your carbohydrate percentage each week. Schedule an eye exam annually to monitor eye health, and share your dietary changes with your eye doctor.

This research shows an association between diet and cataracts but does not prove that diet causes cataracts. This study was conducted in Korea and may not apply to all populations. Before making significant dietary changes, especially if you have existing health conditions, consult with your doctor or a registered dietitian. This information is for educational purposes and should not replace professional medical advice. If you’re experiencing vision problems, see an eye care professional for proper diagnosis and treatment.