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Did A Low-Carb Diet Really Improve My Nearsightedness? [Plus: 7 ways to improve your diet that will improve your vision]

Posted Feb 25 2014 2:07am

eyes

Best eye makeup EVER. 

Wait, that sign has words? My whole world view was rocked one day in 5th grade when my parents took me to get my eyes checked. It turned out that not only was I near-sighted but I was so near-sighted that the fact that signs contain actual words and not just blurry pictures was a shattering revelation. I remember marching out of the optometrist’s office and reading every sign I could find – just because I could.

Ever since then my consistently worsening vision has provided my family with a trove of embarrassing and hilarious stories. Like the time when I was 16 and jumped on the back of a boy in the swimming pool, thinking he was my brother that I’d been horsing around with. I quickly realized that despite wearing the same color swim trunks as my brother, he was not related to me in any way when he turned his head and said dryly, “Excuse me, can I help you?” I still had my legs locked around his waist when I spotted my brother several feet away laughing so hard I thought he was going to aspirate his own tongue.

The day I got contacts was the third best day of my life, right after my kids’ births, the day I won the science fair and the matinee where I discovered Christian Bale in Newsies. (And yes, my wedding is not on that list. While marrying my husband is the best decision I ever made, our actual wedding day was a disastrous comedy of errors – starting with the mass deaths of all the betta fish I’d bought for centerpieces because I was stupid and thought living creatures made quirky-cute decorations because their fins matched my wedding colors. You know what does not signify the beautiful beginning of a new life together? Dead, rotting fishy corpses. If you learn nothing else from me, just remember that animals and weddings are a bad combo. Except maybe dwarf ponies. Or pot-bellied pigs. I hear they are very smart creatures. They probably could have planned my Big Day better than I did. Ponies and pigs: that will be the theme for any future wedding/renewal-of-vows/overblown excuse for a part-ay I may have. I should totally start a ponies-n-pigs wedding vision board on Pinterest. How has that not happened yet?) ANYHOW. I love my contacts. I’ve worn them every day for the past 20 years. (Except for the two awful weeks I had pinkeye .)

The one downside to contacts (besides not being able to find them when you drop them) is that every 1-2 years I have to go back in and get another eye exam where they always tell me that my eyes have gotten worse and that the price of contacts has gone up. So forgive me for not being excited today when I plopped myself into the big chair to play the which-looks-clearer-one-or-two? game.

“Good news! Your prescription has gone down! By a full point!” Record screech. 

“What did you just say?” I squeaked. Even though it just downgraded me from “so blind I’ve walked into an open pool” to “so blind I can’t tell the difference between ornamental grapes and real ones thereby ruining my friend’s artistic display”, I was still pretty pumped. But also leery.  ”How does that even happen?”

“Your vision isn’t as fixed as people think it is,” the doctor explained to me. “Lots of things can change it – weight loss, weight gain, certain diseases, blood sugar – and it can even vary slightly from day to day.”

“Is this happening because I’m getting old?” I demanded. Everyone knows things start to go wonky with age. It’s why Depends are the same backwards and front ways.

“No,” he answered, “usually your eyesight gets worse with age. It’s very unusual to see it improve by this much.” And then he dropped the bomb on me. “Are you doing a low-carb diet? Like for a New Year’s resolution or something?”

Funny thing: I kind of am. Thanks to the specter of ADHD permeating our entire lives, back in January our pediatrician recommended that we put our kids on what she called “the ADHD diet*.” It’s basically Primal/Paleo eating. No grains, no dairy, no legumes, limited sugar. (This was in addition to the Red 40 diet we were already trying that had us eliminate everything with artificial food dyes and colors.) It’s been a long couple of months. But the diet isn’t really low carb. We’ve been eating lots of starchy veggies (carrots, squash, sweet potatoes, jicama) and fruit. Yet it is pretty low in sugar and very low in processed foods.

The doctor continued, oblivious to the sound of my mind being blown, “Because the lens of  your eye absorbs sugar from your blood, the higher your blood sugar the worse your eyesight gets.” He added that he sees several patients each year whose eyesight improves somewhat thanks to going low-carb and/or losing weight.

I’ve heard the link between diabetes and eye problems before. And many research studies have linked high carbohydrate diets – defined as those containing over 200 grams of carbs per day – to an increased risk of macular degeneration, the number one cause of blindness. But does that also mean that by eliminating carbs you can fix myopia? There’s a difference between eating a healthy diet to prevent eye disease in later years and eating a certain type of diet to reverse nearsightedness now.

Is it possible to cure bad vision? I ran home, fired up ye olde laptop, and went a-searching on the interwebs. The answer I found? Maybe.

There are a lot of anecdotal stories of people going primal/paleo and seeing slight to total improvements in their vision. But what about the research? The first problem I encountered is that most of the studies that I looked at didn’t bother to differentiate between types of carbs – and there is a big difference (in my humble opinion) between 50 grams of fruit and beans and 50 grams of, ahem, jelly beans. Another issue is that it’s so difficult to tease apart cause and effect. Lastly, all the studies I found either simply supported the role of a healthy diet in protecting vision or showed a small benefit to vision. I found no studies that said a low-carb diet cured myopia, as in returning the nearsighted person to their 20/20 glory days. Lastly, a significant number of studies have linked vision loss to high insulin levels but can you say that the latter caused the former? Or are they both just a symptom of unhealthy habits?

I’m not the only one confused. As described in an article in New Scientist:

Seven years ago, evolutionary biologist Loren Cordain at Colorado State University in Fort Collins caused a stir by suggesting that myopia may be triggered by the excessive consumption of refined carbohydrates. The study compared diets and rates of myopia in different nations, and it seemed plausible that insulin levels which were raised in response to a high-carb diet could stimulate the eye to grow and become elongated, causing myopia.

This year, two independent studies, led by Frank Schaeffel at the University of Tübingen in Germany and Josh Wallman at the City College of New York, have provided further evidence that insulin can stimulate eye growth. Working with chicks that wore special lenses to provoke myopia, they found that injecting insulin into the chicks’ eyes increased the deterioration in their sight dramatically.

Yet whether this explains the link between diet and myopia remains hotly debated. “Initially we just didn’t believe Cordain’s carbohydrate story, but now that we know that insulin can interfere so much, I am not so sure,” says Schaeffel. Wallman remains more doubtful, arguing that a high-carb diet may not necessarily raise insulin levels in the eye enough to cause damage.

Cordain cites studies which found that people with high blood-sugar levels are more likely to be myopic, and says that insulin levels in the eye do seem to reflect levels elsewhere in the body. High blood sugar may also promote myopia by raising levels of the growth factor IGF-1, a substance which likewise stimulates eye growth, he says.

Mark Sisson put it in context on his post on the subject :

The numbers for myopia, for example, have skyrocketed in the last thirty years across the developed world, and children oddly appear to be the hardest hit. Singapore is often cited as the worst off. As many as 80% of 18-year-old military conscripts exhibit myopia as do 20% of children under seven and 70% of those graduating college ( PDF ). In Sweden, 50% of 12-year-olds have myopia ( PDF ).

In the U.S., the prevalence of myopia is  42% in people 12 to 54-years-old and 34% in 12 to 17-years-old . As for  other visual impairments , more than 17% of people over the age of forty are diagnosed with cataracts. For age-related macular degeneration, it’s more than 6%. For diabetic retinopathy, there’s another 3.4%. For glaucoma, it’s about 2%. Add it all up, and that’s a whole lot of us voted off Grok’s island.

That’s a lot of people stumbling blindly into pools…

Just for funzies, I also Googled research on vegetarian diets curing myopia and found a similar mix of anecdotal success stories and links between high vegetable intake and vision improvement. While the two don’t necessarily contradict each other – vegetarians and the primal crowd definitely intersect in the veggie patch – it did tell me that people are good at spinning research in whatever direction they want it to go.

Yet I could not ignore the fact that I was reading all this cool info with my new lower-powered contacts. Something had changed and my diet is a likely culprit.

Sisson points out that carb intake is just one of many nutritional factors that could effect vision. Other ways you can use food to help your eye sight:

- Breastfeed. Mommy mammary juice appears to offer some  protective benefit against myopia . Talk to your mom and see if she’s still lactating. If not, this ship has probably sailed for you (and me – right Mom?)

- Eat more fish. Getting plenty of omega-3 fatty acids in your diet  reduces the risk of developing macular degeneration and can even  stop it from getting worse .

- Cut out high glycemic carbs, particularly refined grains. (See all the study links above)

- Eat lots of fruits and veg. One  study  showed that people whose antioxidant intake was high were less likely to develop lens damage and certain kinds of cataracts.

- Especially greens. A Florida International University study found that greens contain a lot of lutein which they found to be protective of vision.

- Drink wine or eat red grapes. This  study  suggests resveratrol may help prevent diabetic retinopathy and AMD.

But there are non-food options as well. In all my searching, I also came across this bit of new research that showed that athletes playing an app called UltimEyes improved their vision to be better than 20/20. So apparently there is a mental component to go along with the dietary one. Of course I wanted to immediately try out this app myself but it’s not available for Android. Wah wah. But their conclusions are fascinating:

This week the peer-reviewd journal Current Biology  published  the results of those trials. Players who participated in the training enjoyed a 31 percent improvement in visual acuity. Seven players actually got down to 20/7.5 vision—they could read a line from 20 feet away that a normal person can only read from 7.5 feet away—which is very rare.

“Players reported seeing the ball better, greater peripheral vision and an ability to distinguish lower-contrast objects,” Seitz  said .

Tonight, as I sit here bloated from my research binge, it seems the relationship between diet and vision isn’t as simple as my doctor made it sound. Yet it seems clear that the incidence of myopia is getting worse worldwide and that there is a link between diet and vision – and that vision is more malleable than I thought!

At the end of my appointment, I asked my optometrist what I could do to make my eyes keep improving and he answered, “Whatever you’re doing, just keep doing that! Oh, and don’t age.” Eating whatever and building a time machine. Got it!

What about you – how is your vision? Has it changed over the years? Has anyone else seen a link between vision and diet? And has anyone else had a terribly embarrassing moment thanks to not having their glasses or contacts?

*For the record, while I saw a big improvement by taking out artificial food dyes, I saw zero change in my kids with the additional restrictions. Even the big bad gluten didn’t seem to make any difference for them in concentration or activity level. We’re a sample of six, so take that for what you will.

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