The Carbohydrate-Eye Disease Connection

By Al Sears, MD

Editor: If you thought the damage caused by excess dietary carbohydrates, particularly refined carbs, wasn’t bad enough, it gets worse. Dr. Sears outlines the vision damage that can be caused by eating too many carbohydrates.

Article begins: Despite what your eye doctor may tell you, vision loss doesn’t have to be an inevitable part of getting older. And a new 20-year study backs up what I’ve been telling my patients for years…

Decades of eating a typical carb-heavy Western diet is what causes visual impairment – and even blindness – later in life.

The study, published in the British Journal of Ophthalmology, found an association between a diet full of carb-rich processed foods and age-related macular degeneration (AMD).

The researchers looked at the development of macular degeneration in 16,000 American adults. Using data on 66 different kinds of foods, they identified two distinct eating patterns. One they labeled “Prudent,” or healthy. The other, which included high levels of processed foods, grains, sweetened drinks, and sugar-laden desserts, they identified as “Western.”

The incidence of AMD vision loss was three times higher in the group that ate a Western diet.

I’m never surprised by studies like this. I’ve seen this pattern in the indigenous tribes I’ve studied for decades.

You see, the rate of vision loss among tribes has historically been very low. In fact, a century ago, the rate of visual impairment among Alaskan Inuits was less than 1%. Today it’s close to 50%!

And those numbers shot up in just a single generation.

So what’s changed for the Inuits?

Their diet. The traditional Inuit diet was stable for generations. It consisted of fish from the ocean; sea and land mammals including walrus, seal, whale, caribou, and polar bear; birds and eggs; seeds and berries.

A recent study found that only 16% of foods consumed by Inuit adults now come from their traditional diet. The other 84% is processed foods. 1

So it’s not surprising that one study found that only 2 out of 131 Inuit elders experienced vision loss. But more than half of their children and grandchildren — who grew up on processed foods — needed glasses. 2

The medical industry blamed compulsory schooling and “close [reading] work.” It’s a nice theory, but it doesn’t hold water. Here’s why…

There’s an island nation in the South Pacific called Vanuatu. The children here also attend school eight hours a day.

But they still eat a traditional diet. Most grow their own food — papaya, yams, coconut, and mangoes. They eat fish and raise fowl. The kids don’t eat cereal for breakfast or white bread sandwiches for lunch. And the rate of kids who need glasses in Vanuatu is just 2%.

Here’s what happens to your eyes on a carb-heavy diet…

The refined foods in the typical Western diet send a lot of sugar into your body. All that excess glucose — and your body’s insulin reaction — changes the shape of your eye.

On top of that, when your blood sugar constantly rises and falls, the delicate tissue and blood vessels in the eye get damaged. High sugar levels also make the lens of the eye swell. This causes blurry vision.

This is common in diabetics. But the truth is anyone with consistently high blood sugar is at risk of AMD.

One study from Tufts University found that people eating the most sugary carbs increased their risk of age- AMD by up to 42%. 3

High blood sugar levels cause damage to your vision in another way.

Cataracts are caused by sugar molecules attaching themselves to proteins in the lens of your eye, in a process called glycosylation. This causes the proteins to twist, bend over and clump together and as a result, your lens becomes cloudy and less elastic.

Three steps to rebuilding better vision

One: Go super-low carb. Your body’s requirement for carbs is zero. This means no grains, including so-called “healthy” whole grains, no processed sugars, and no foods from a box or bag. Avoid starchy vegetables like potatoes, parsnips, peas, and corn.

Also beware of hidden carbs. These include cashews, pistachios, almonds, bananas, apples, pears, grapes, and oranges.

Two: Eat more healthy fats. A study at the National Institutes of Health looked at the link between nutrition and AMD in more than 4,500 people. They found those who consumed the healthiest omega-3 fats from oily fish had the lowest rates of the disease. 4

But it’s hard to get what you need from food. I recommend supplementing with 600 mg to 1,000 mg of omega-3s from squid oil daily.

Three: Supplement with nature’s top two eyesight savers. The best nutrients for improving vision and protecting your eye health are lutein and zeaxanthin. In fact, your eyes can’t function without them. Studies have shown that eating foods rich in lutein and zeaxanthin can increase the pigment density in the macula and therefore lower the risk of macular degeneration.

Your best food sources for lutein and zeaxanthin are dark, leafy vegetables like spinach, kale, and collard greens. But it’s not easy getting enough from your food. I recommend supplementing with 20 mg of lutein and 1 mg of zeaxanthin.

To Your Good Health,

Al Sears, MD, CNS

References:

 

  1. Morgan R, et al. “Inuit myopia: an environmentally induced “epidemic”?” Can Med Assoc J. 19758;112(5):575–577.
  2. “Western Diet Fuels Spike in Blood Pressure of Canada’s Inuit.” Heart and Stroke Foundation of Canada. www.heartandstroke.com. Accessed on July 19, 2022.
  3. Cordain L, et al “An evolutionary analysis of the aetiology and pathogenesis of juvenile-onset myopia.” Acta Ophthalmologica Scandinavica. 80(2):125-135.
  4. “Risk Factors Associated with AMD.” Ophthalmology. 2000, 107(12): 2224–2232.