Introduction

Cataract is a leading cause of vision impairment and blindness worldwide. Majorly, cataracts develop in ageing populations due to the oxidative stress that causes changes in lens proteins, leading to opacification of the lens.¹ Research has shown that a diet rich in specific nutrients and antioxidants can enhance eye health and potentially delay the onset or progression of cataracts.³ In this article, you will learn about cataracts and dietary practices to prevent cataracts.

Cataract Overview

A cataract is a condition in which the eye's lens gradually becomes opaque over time as age progresses, leading to vision impairment. It is primarily associated with ageing but can affect individuals of all ages due to various risk factors.² 

Various risk factors for cataract development include:²

• Long-term exposure to sunlight (UV radiation)
• Poor Nutrition, such as a diet deficient in antioxidants and vitamins
• Smoking and alcohol consumption
• Exposure to radiation, such as X-rays
• Long-term use of corticosteroids
• Systemic diseases such as Diabetes mellitus, Hypoparathyroidism, Atopic dermatitis, etc.

The common signs and symptoms of cataracts include:²

• Blurring of the vision
• Double vision
• Coloured halos around the light
• Increased sensitivity to light and glare
• Disturbance in colour vision
• Increased frequency of changing prescribed spectacles 

Treatment and management of cataracts range from non-surgical management for early-stage cataracts to surgical intervention for more advanced cases. Surgery is the definitive treatment option. However, when vision changes are minimal in the initial stages of cataracts, it can be treated with glasses and pupillary dilatation. In severe cases, in aged patients, or in patients who fail to show improvement with other treatment methods, the only treatment option that is advised is surgical cataract removal with intraocular lens implantation.²

Cataract is related to ageing and cannot be completely prevented. Preventing cataracts involves managing risk factors, making lifestyle choices, and maintaining a healthy diet, such as one rich in antioxidants.¹ Nutrition plays a crucial role in eye health and the prevention or delay of cataracts, which is further elaborated in this article.  

The Role of Diet in Eye Health and Cataract Prevention  

A diet rich in antioxidants, vitamins, and minerals promotes eye health by protecting the lens and retina from oxidative stress, which is linked to cataract formation. Oxidative stress occurs when there is an excess of free radicals (unstable compounds formed during normal cell metabolism) in the eye. Excess formation of free radicles is caused by various factors such as UV exposure, smoking, diabetes, etc. They build up in cells and cause damage to lens proteins. This results in disruption of the structure of the lens, leading to the opacity of the lens, characteristic of cataracts.  Antioxidants, such as vitamins C and E, help counteract free radical damage, thereby delaying cataract development.¹

Dietary Recommendations for Cataract Prevention

Cataracts cannot be completely prevented, as it naturally occurs with age. However, a healthy lifestyle and certain dietary choices can slow down the formation of cataracts. These include:

Consuming Antioxidant-Rich Foods

Antioxidants are present naturally in food. They include lutein, Zeaxanthin, selenium, polyphenols, flavonoids, lycopene, and vitamins A, C, and E. Studies have shown that a diet high in fruit and vegetables containing antioxidants reduces the risk of cataracts. There are various sources of antioxidants. These include:^1,3

• Vitamin C: Good sources of vitamin C include citrus fruits (oranges, grapefruits, lemons, etc), berries (strawberries, blueberries), vegetables such as bell peppers, broccoli, spinach, etc 
• Vitamin E: Foods rich in vitamin E include nuts and seeds (almonds, hazelnuts, sunflower seeds, etc) and vegetable oils such as Sunflower oil, wheat germ oil, etc
• Vitamin A: Vitamin A is found in liver, fish oils, dairy, egg yolks, and plant foods like carrots, sweet potatoes, and leafy greens
• Carotenoids (lutein and Zeaxanthin) are found in dark leafy greens (Spinach, kale, collard greens, etc.) and other vegetables such as Peas, green beans, and corn
• Selenium: Selenium is found in Brazil nuts, seafood, grains, etc
• Polyphenols: Polyphenols are abundant in fruits (like berries, apples, grapes), vegetables, tea, coffee, red wine, dark chocolate, and olive oil
• Lycopene: Lycopene is primarily found in tomatoes, watermelon, pink grapefruit, papaya, and red peppers
• Flavonoids: Flavonoid-rich foods include berries, apples, citrus fruits, onions, dark chocolate, and green tea

Consuming a diet rich in Omega-3 fatty acids

Studies have shown that a diet rich in omega-3s lowers the risk of cataracts. Omega-3 fatty acids are essential fats that have anti-inflammatory properties, which help reduce oxidative stress and inflammation in the eyes. Fatty fish (like salmon and mackerel), walnuts, flaxseeds, and chia seeds are excellent sources of omega-3s.³

Embracing the Vegetarian Diet 

The Vegetarian diet has shown promising effects in reducing the risk of cataracts, primarily due to its high content of antioxidants, anti-inflammatory foods, and healthy fats. This diet emphasises a plant-based diet, comprising fruits, vegetables, whole grains, legumes, nuts, etc., rich in antioxidants like vitamins C and E and polyphenols. Research suggests that adherence to a Vegetarian diet is associated with a lower incidence of cataracts among older populations.³ 

Creating a Balanced Diet Plan with Food Variety

A balanced diet is an eating plan that provides the body with all essential nutrients, including carbohydrates, proteins, fats, vitamins, and minerals, in the right proportions. Different foods offer different nutrients. For example, fruits and vegetables of varying colours provide unique antioxidants, such as orange foods like carrots provide beta-carotene, while red foods like tomatoes provide lycopene.^1,3

Foods to Avoid

Certain foods should be limited or avoided for cataract prevention. These include:³

• High-glycemic index foods: Limit sugar and processed foods, as these can contribute to the risk of cataracts. Examples of high-glycemic index foods include refined sugars (candy, pastries, soda, and other sugary drinks), chips, processed snacks, white bread, white rice, fried potatoes, etc
• High-Sodium Foods: Elevated sodium also contributes to cataract risk. High-sodium foods include processed meats, canned soups, salted snacks, fast food, frozen meals, soy sauce, and pickled foods
• Trans Fats and Saturated Fats: Trans fats are partially hydrogenated oils found in many processed foods. Saturated fats include red meat, full-fat dairy products (cheese, cream), packaged foods, etc
• Alcohol: Excessive alcohol consumption is also linked to an increased risk of cataracts

Lifestyle Changes to Complement Dietary Practices

• Get regular eye check-ups: Regular eye check-ups can detect early signs of cataracts, allowing for timely intervention
• Stay hydrated: Proper hydration helps maintain the eye’s natural lens clarity
• Manage chronic conditions: Control conditions like diabetes and hypertension, which increase cataract risk
• Exercise regularly: Obesity and conditions like diabetes are risk factors for cataracts, so maintaining a healthy weight and blood sugar levels through balanced nutrition and regular exercise reduces the risk of cataracts
• Wear UV-protective sunglasses: Prolonged exposure to UV rays can increase the risk of cataracts, so wear sunglasses with 100% UV protection outdoors
• Limit alcohol intake: Excessive alcohol consumption can accelerate cataract formation
• Quit smoking: Smoking increases oxidative stress, which is linked to cataract development

Summary 

Overall, this article has highlighted the importance of diet and nutrition in maintaining eye health as one ages. A balanced diet plays an essential role in preventing cataract, a common cause of vision impairment and blindness especially in ageing population. Evidence indicates that specific nutrients help reduce the risk of cataract development.

Consuming a range of fruits and vegetables, whole grains, and healthy fats like omega-3 fatty acids contributes to eye health and reduces the risk of cataract formation. Incorporating antioxidant-rich foods, such as fruits and vegetables high in vitamins C and E, and carotenoids like lutein and zeaxanthin, significantly contribute to eye health. Limiting high-glycemic index foods, refined carbohydrates, and excessive alcohol consumption is also advisable for good eye health and overall well-being. Additionally, adopting healthy lifestyle habits, such as regular exercise, avoiding smoking, limiting alcohol intake, and protecting the eyes from UV radiation, are crucial complements to dietary choices. One can reduce the risk of cataract formation by prioritising eye health through these dietary and lifestyle strategies.