How Food Affects Cataracts

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Although research has not positively proved that nutrition can prevent cataracts, there is ample evidence that eating the right foods can help — and we know for certain it can't hurt!

The ultimate prevention for cataracts is simple: Never grow old.

For those of you who can't stop time, nutrition and lifestyle changes are your best bets for preventing or slowing the development of cataracts. Although research has not absolutely established that proper nutrition can prevent cataracts, there is ample evidence that eating the right foods can help — and we know for certain it can't hurt!

For cataract prevention, increasing foods rich in antioxidants and the B vitamins is your best line of defense. You’ll also want to dramatically limit your intake of low-quality carbs — sugary foods and beverages and refined, white starches.

ANTIOXIDANTS: VITAMIN C AND VITAMIN E

As the name suggests, antioxidants fight the oxidative stress caused by free radicals. There is no single antioxidant — rather, it is a broad category that includes vitamin C, vitamin E, lutein, beta-carotene, and any number of other substances that can neutralize free radicals. All vegetables and fruits contain antioxidants, so eating a diet rich in those foods may help prevent cataracts.

The Nurses' Health Study revealed that women who ate a very healthy diet full of all kinds of antioxidants from vegetables, fruits, and whole grains were half as likely to develop cataracts as women who did not eat such a healthy diet. In addition, numerous studies have observed that people with high dietary intakes or blood levels of antioxidants — particularly vitamins C and E — are at a significantly lower risk for cataracts. But when researchers took the studies to the next level by giving people supplements of individual antioxidants or combination pills with a mix of antioxidants, the results were disappointing. In fact, in most trials, antioxidant supplements did not prevent or slow cataract development.

These results aren’t as contradictory as they seem at first glance — there are many plausible reasons why supplements seem to have struck out. Antioxidants found in foods may act synergistically with other nutrients, and you miss out on these potential benefits when you take isolated antioxidants in pill form. In addition, people with higher intakes of antioxidants likely consume more produce, eat a better overall diet, and have healthier lifestyle habits, and these may, in fact, be the real reasons they’re at lower risk for cataracts. Regardless, the big-picture message is clear: Antioxidant supplements do not ward off cataracts, but eating plenty of vegetables and fruits, including those rich in vitamins C and E, may be protective (and will benefit the rest of your body as well!).

BEST SOURCES OF FOOD ANTIOXIDANTS: TOP 20 FRUITS, VEGETABLES, AND NUTS (as measured by total antioxidant capacity per serving size)

RANKFOOD ITEMSERVING SIZETOTAL ANTIOXIDANT CAPACITY PER SERVING SIZE1Small red bean (dried)1/2 cup13,7272Wild blueberry1 cup13, 4273Red kidney bean (dried)1/2 cup13,2594Pinto bean1/2 cup11,8645Blueberry (cultivated)1 cup9,0196Cranberry1 cup (whole)8,9837Artichoke (cooked)1 cup (hearts)7,9048Blackberry1 cup7,7019Prune1/2 cup7,29110Raspberry1 cup6,05811Strawberry1 cup5,93812Red Delicious apple15,90013Granny Smith apple15,38114PecanI ounce5,09515Sweet cherry1 cup4,87316Black plum14,84417Russet potato (cooked)14,64918Black bean (dried)1/2 cup4,18119Plum14,11820Gala apple13,903

BEST FOODS FOR VITAMIN C: Guava, bell peppers (all colors), oranges and orange juice, grapefruit and grapefruit juice, strawberries, pineapple, kohlrabi, papaya, lemons and lemon juice, broccoli, kale, brussels sprouts, kidney beans, kiwi, cantaloupe, cauliflower, cabbage (all varieties), mangoes, white potatoes, mustard greens, tomatoes, sugar snap peas, snow peas, clementines, rutabagas, turnip greens, raspberries, blackberries, watermelon, tangerines, okra, lychees, summer squash, persimmons

BEST FOODS FOR VITAMIN E: Almonds and almond butter, sunflower seeds and sunflower butter, wheat germ, hazelnuts, spinach, dandelion greens, Swiss chard, pine nuts, peanuts and peanut butter, turnip greens, beet greens, broccoli, canola oil, flaxseed oil, red bell pepper, collard greens, avocados, olive oil, mangoes

ANTIOXIDANTS: LUTEIN AND ZEAXANTHIN

Lutein and zeaxanthin are a pair of antioxidants that are of tremendous interest to eye-health researchers. Lutein and zeaxanthin belong to a family of nutrients called carotenoids (along with their more popular sister carotenoid, beta-carotene). Lutein and zeaxanthin stand out because they’re the only carotenoids found in the lens of the eye and may play a key role in keeping the lens clear of protein buildup. Like all antioxidants, lutein and zeaxanthin can defuse potentially damaging free radicals. In addition, they may also prevent the development of some free radicals by absorbing blue light — part of the cataract-causing, short-wave spectrum of sunlight.

Using data from the Women’s Health Study, researchers at Harvard University determined that women who consumed the highest combined amount of lutein plus zeaxanthin had an 18 percent reduced risk of cataracts when compared to women with the lowest intake. Similar results were reported from the Nurses' Health Study, the US Male Health Professionals Study, and the Beaver Dam Eye Study. Encouraging results for sure, but I can't recommend lutein and zeaxanthin supplements at this time. That’s because no one knows everything there is to know about the effects of individual nutrients, and it could be that lutein and zeaxanthin work best only when paired with other antioxidants, or with certain vitamins and minerals. Right now, the only solid information we have supports eating a diet full of lutein- and zeaxanthin-rich leafy-green vegetables, plus an abundance of other antioxidant-rich vegetables and fruits.

BEST FOODS FOR LUTEIN AND ZEAXANTHIN: Kale, spinach, Swiss chard, collard greens, turnip greens, dandelion greens, mustard greens, beet greens, radicchio, summer squash (all varieties), watercress, green peas, persimmons, winter squash (acorn, butternut, etc.), pumpkin, broccoli, brussels sprouts, lettuce (especially dark lettuces), asparagus, corn, green beans, okra, artichokes, green bell peppers

B VITAMINS

There is strong evidence that two of the B vitamins — riboflavin (vitamin B2) and niacin (vitamin B3) — may help prevent cataracts, and early research suggests that other B vitamins may also contribute to eye health.

Although these vitamins are not antioxidants, they provide some of the building blocks the body needs to make antioxidant compounds. So without enough riboflavin and niacin, the risk of cataracts increases. Indeed, several scientific studies have shown that people who eat a diet with plenty of foods rich in riboflavin and niacin can slash their risk of cataracts by about half compared with people who eat a diet with very little of those vitamins.

As with antioxidants, there need to be further studies about the benefits of B vitamin supplements. Although the results are quite encouraging, they are not so definitive as to provide specific recommendations. The Blue Mountain Eye Study, a large Australian study with about 2,900 participants, found that those who took riboflavin supplements had a 20 percent lower risk of cataracts compared with people who didn't take supplements. Niacin supplements lowered risk by 30 percent, and supplements of other B vitamins — thiamin, folate, and vitamin B12 — also seemed to show some benefit. Combining these vitamins may have an even greater effect. A large study conducted by the National Eye Institute in Bethesda, Maryland, showed that people who took a dual supplement containing both riboflavin and niacin reduced their risk of cataracts by 44 percent. Even general multivitamins providing 100 percent DV for these B vitamins seem to decrease risk by more than 30 percent. As promising as these results sound, the jury is still out on exactly how much of which types of B vitamins is necessary or optimal for cataract prevention. I can recommend only food sources, not pills (with the exception of a multivitamin providing 100 percent DV for riboflavin and niacin).

BEST FOODS FOR RIBOFLAVIN: Lean beef and lamb, venison, yogurt (fat-free, low-fat), milk (fat-free, 1% low-fat), mushrooms, almonds, eggs, spinach, coffee

BEST FOODS FOR NIACIN: Tuna (canned light), skinless chicken, lean beef and lamb, pork tenderloin, mackerel (not king), skinless turkey, wild salmon (fresh, canned), anchovies, kidney beans, peanuts and peanut butter, mushrooms, sunflower seeds and sunflower butter

LOW-QUALITY CARBS

Most studies have focused on nutrients that can help protect the eyes from cataracts, but emerging research suggests that certain foods may increase the risk, most notably low-quality carbohydrates. Low-quality carbohydrates include sugar, honey, and other sweeteners, soda and other sugary drinks, candy, baked goods, sugary cereals, anything made with white flour (including white bread and regular pasta), and white rice. Researchers categorize these foods as high-glycemic carbs, which means they are quickly digested and absorbed by the body, causing a rapid, steep, and unhealthy rise in blood-sugar levels. Glucose eventually moves from the blood into the eye, and scientists believe that exposure to high sugar concentrations in the eye’s lens may accelerate protein damage and clumping, thus contributing to cataract formation. A few studies have shown that people who eat lots of high-glycemic foods are at increased risk of developing cataracts. These findings may also explain why the incidence of cataracts is substantially higher in people with diabetes, who have chronically elevated blood-sugar levels.

We’re only beginning to understand the impact of low-quality carbs on eye health, but we already know for sure that they’re not doing our hearts, blood vessels, or waistlines any good. In your daily meal plans, I recommend bypassing junky, nutrient-poor carbs and replacing them with high-quality carbohydrates like vegetables, fruits, beans, and whole grains.

TEA

Tea contains powerful antioxidants, and some research suggests that drinking relatively large amounts of tea — the equivalent of about five cups daily — may help prevent or delay cataract development. But antioxidants may tell only part of the story. While investigating the effects of tea on blood sugar in diabetic laboratory rats, researchers from the University of Scranton discovered that the animals that drank tea had lower blood sugar than those that did not drink tea. But there was also a side benefit — drinking tea reduced the level of glucose in the eye lens, and there was a lower incidence of cataracts. In fact, the tea-drinking rats had about half the risk of cataracts as non-tea-drinkers. We’re still waiting to see if these results hold up in humans, but tea is an incredibly healthy drink all around, so in the meantime I encourage you to sip to your heart’s content. What’s more, unsweetened tea is a terrific substitute for sugary beverages like soda, sweetened waters, fruit drinks, and sugary coffee concoctions. Both green tea and regular black tea had the same effects, so feel free to choose the type you enjoy most.

 

 

 

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