Preserving Vision Through Diet

Preserving Vision Through Diet
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More than a million Americans are blind. The good news is that all four of the most common causes of vision loss may be prevented with a healthy plant-based diet—age-related macular degeneration, diabetes, glaucoma, and cataracts.

See my 2-min. video Preventing Macular Degeneration with Diet for a discussion of the relationship between vision loss and Harvard’s Alternative Healthy Eating Index (Calculate Your Healthy Eating Score offers an alternative to the alternative). Diabetes is not only a leading cause of blindness, but also of amputations and kidney failure. Thankfully diabetes can be prevented and even reversed.

Glaucoma is a deterioration of our optic nerve, the nerve that connects our eyes to our brain, and is second only to cataracts as the world’s leading cause of blindness. Surprisingly, we still don’t know what causes it, so there’s been a desperate search for environmental and dietary influences.

As I show in my 2-min. video Prevent Glaucoma and See 27 Miles Farther, the most protective dietary component—decreasing the odds of glaucoma by 69%!—was found to be the consumption of at least one serving of collard greens or kale per month. Just once a month or more. The silver and bronze medals for most protective food went to weekly carrot and peach consumption, respectively.

We think it may be the lutein and zeaxanthin, two yellow plant pigments in greens that seem to know right where to go. When we eat them, they hone right into our retinas and appear to protect against degenerative eye disease. This is not a unique phenomenon. Lycopene is the red pigment in tomatoes found protective against prostate cancer.  Guess where it goes when a man eats a tomato? Straight to the prostate. Beta carotene in foods may prevent ovarian cancer and happens to build up in one’s ovaries.

These phytonutrients not only protect, but also may improve our vision. Their peak light absorbance just so happens to be the wavelength of the color of our planet’s sky. According to a recent study, by filtering out that blue haze, “individuals with high macular pigment [lutein and zeaxanthin phytonutrients from greens]” standing atop a mountain on a clear day “may be able to distinguish distant mountain ridges up to 27 miles further than individuals with little or no pigment.”

Don’t eggs also have significant amounts of these critical eyesight-saving nutrients? That’s the egg industry scrambling the truth—see my 2-min. video Egg Industry Blind Spot. I’d also encourage folks to stay away from lutein pills (and beta-carotene supplements).

Finally, the leading cause of blindness and vision loss: cataracts. In my 2-min. video Preventing Cataracts with Diet I profile a study of 27,670 people with a wide range of diets. The study included so-called “high” meateaters, moderate meateaters, “low” meateaters, and fish-only eaters, versus those eating vegetarian and those eating vegan.

The researchers went out of their way to choose health-conscious subjects to help factor out smoking, exercise, and other nondiet variables, and so the “high” meat consuming group? Only 100 grams a day–that’s just like 1 serving in one meal a day. In the U.S. we average more than 300 grams a day, so this is like reverse Starbucks labeling. You know how their “tall” is the small? Well here their “high” is really quite low by American standards.  Yet even compared to health-conscious light meat-eaters, those cutting back on meat even further could drop their associated cataract risk 15%. Those cutting all meat other than fish had 21% lower risk. Those cutting all meat—the vegetarians—appeared to drop their risk 30% and those going a step further and eliminating eggs and dairy had 40% less risk than the healthy one-serving-a-day meateaters.

The researchers conclude: “Overall, compared with meat eaters who consumed 100g meat and meat products/d[ay], fish eaters, vegetarians, and vegans had approximately 20%, 30%, and 40% lower risk of cataract, respectively.” Similar stepwise reductions of risk can be seen with other diseases such as diabetes, hypertension, and obesity. A stepwise drop in risk as one’s diet gets more and more centered around plants. 

-Michael Greger, M.D.

Image credit: fern0922 / Flickr

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  • BPCveg

    Given stepwise drop in risk as one’s diet gets more and more centered around plants, it is suprising that life expectancy of vegetarians has not been shown to be much greater than omnivores.

    • Henry Thoreau

      Studies show in general omnivores are living longer sicker lives. I agree, it would be great to get an extra twenty or more years but I would settle for more healthy years. 

      • http://poxacuatl.wordpress.com/ Strix

         I guess being propped up by drugs allows them to live longer ? For some reason I got a picture of “Weekend at Bernie’s”. Ugh. So sad. I’d rather expire earlier than live an extra 10 years in a “facility,” in pain, or as a burden.

    • http://poxacuatl.wordpress.com/ Strix

       I wonder if life-long healthy-eating vegans live longer? The key being “healthy-eating”!! I bet there aren’t many (so many are eating junk, and other semi-healthful, like Adventists also include fake meats and processed foods, salt and sugars).
      Apparently the Okinawans are the longest lived, but they are only near vegan. BUT they don’t consume dairy. So I wonder if dairy is the culprit here. Healthwise for humans, dairy has always seemed the most insidious and dangerous to me. I don’t know.

      • BPCveg

        Why do you think dairy is th most dangerous?  Would your statement also apply to skim dairy?

        • http://poxacuatl.wordpress.com/ Strix

           I guess, it’s just in everything in so many ways and although parts of “meat” are used as well, it’s just not as “offensive” to people’s senses — their eyes maybe. Dairy looks nice and its various forms (as additives and go by undetected) can be in so many things, seemingly harmless. Meat is a very specific thing that people would notice they are consuming. Not sure I’m making sense! I just think people in general, and vegetarians, specifically, give a pass to dairy as harmless or less harming…

          I think, healthwise the fat-free are just as bad if not worse: They take away some of the bad fat, sure,but then now you’ve got a chunk of concentrated protein! Not to mention concentrations of pesticides… Bad news.

          • BPCveg

            Thanks, Strix, for explaining your perspective. ‘The China Study’ by T. Collin Campbell makes a case against milk protein. Yet, the dieticians of USA and Canada are still promoting milk and fish as important health foods.

          • http://poxacuatl.wordpress.com/ Strix

             Yes, China Study is a great book!
            It’s going to be a while before dieticians, doctors, nutritionists and especially governments change. Individuals have to first. :^(

        • Dr.Paul DDS

          All Dairy products, because they are basically a “growth promoting food” for young animals has Growth Hormone in it. For a cow I believe it is something like 20-30X that of human breast milk growth hormone. So, you see, you are getting an “OVER Abundance” of Bovine Growth Hormone from a totally different species of animal which grows to be 20-30X larger than a human being….WAY TOO MUCH HORMONES!!! This same hormone also PROMOTES the GROWTH OF MALIGNANT tumors you may have festering inside you something like putting “gasoline on your cancer wildfire” , i.e. it grows wildly out of control so that even your own immune cells can’t keep up with its growth…..NO MILK PRODUCTS AT ALL FOR ME!!! I drink Soy milk-Vanilla flavored variety…..on my cereal and as a beverage post workouts…..Masters level Triathlete ( Marathon PR of 2hrs 56mins)….respectfully yours.

    • Jan

       Length of life is not nearly as important as quality of life. I grew up in the midwest on steak and potatoes. As my diet transitioned from heavily red meat based to plant based with occasional seafood and chicken, I have noticed a lot of positive changes in my physique as well as my energy, eyesight and more. I’ll take quality over quantity any day. Since my two grandmothers lived to 91 ad 92 and my mother turned 89 today, I’m not too worried about length of life either.

    • wdcurry

      in these open-minded debates, it would be best to describe human “omnivores” correctly as carnists, thusly as one who chooses to eat meat and dairy. That one eats a certain way does not imply their correct physiology to eat that way, only a *choice* to eat that way, regardless of the correctness of nutrition absorption. Simply by only eating grass, i would never correctly be called a ruminant.

      Eating meat and dairy is a choice, not a biological requirement or adaptation. Humans are herbivorous, as easily shown by multiple indicators and generally by our ill-health.

      • VegAtHeart

        This is an important point. Misuse of the term “omnivore” likely contributes to the continuance of the myth that eating meat is a biological requirement or adaptation when, in fact, it is a choice.

        • Scientific Squirrel

          Except scientifically we are in fact Omnivores. Meat is not a choice. Eating no meat for purely philosophical reasons is a choice.

          Even the Japanese eat fish. They are not meatless.

          • Thea

            Scientific Squirrel: It think it’s great that you care about the science when it comes to classifying where human fit in the animal world. Some people prefer to look at cultures to define where humans fit. But I agree with you that looking at biology makes more sense.

            However, I don’t think the evidence supports your belief that humans are omnivores. The following page includes *some* of the biological evidence showing that humans are far more herbivores than we are omnivores.
            http://michaelbluejay.com/veg/natural.html

            It’s a great read.

          • Scientific Squirrel
          • http://www.DonForresterMD.com/ Don Forrester MD

            Nice article Thea especially the table which is a nice overview of the differences between biologic systems. He leaves out Nathaniel Dominy’s work showing that we have more amylase genes to improve our ability to digest starches than the great apes and Katherine Milton’s work showing increase in volume of small intestine to absorb digested starches which are long chains of glucose molecules… our primary fuel. The choice to eat meat aka carnism (see Melanie Joy’s fine presentation, Carnism: The Psychology of Eating Meat) is different from our biologic system which is a hind-gut fermenting herbivore. The fact that we can consume meat products without immediate effects on our health doesn’t make it the best decision if one wants to delay death, avoid disability and improve quality of life. I appreciated the article by Scientific Squirrel as I have come across many “arguments” for eating meat but this one was a new one for me. It was an interesting hypothesis and use of statistics but for me not particularly persuasive. I hold to my belief that until we invented hunting tools we were actually “hunted gatherers”. Our urge to eat meat can be explained by two of the three principles of “The Pleasure Trap” (increase pleasure and conserve energy) and the fact that eating meat releases narcotic like substances in our brain. Of course given individual population variability it is possible that some individuals might do better with some animal products but as a recommendation for the general population given considerations for health, environment and animal suffering I would stick with whole food plant based diet centered on starches to maintain adequate caloric intake and supplemental Vitamin B12.

          • Thea

            Dr. Forrester: Great post! Thank you for your reply!!

            This issue comes up a lot. I knew that the page I referenced did not have all of the arguments, but it is very well written. It is easy for a a lay person to digest and has a lot of information. So, I like to refer people to it.

            I really like your phrase, “hunted gatherers”. It reminds me of yet another point I have heard about using biology to determine if humans are more at herbivore end of the spectrum or omnivore. The point was: There is no species on the face of the planet where the pregnant female isn’t able to provide for herself. (I don’t know if that’s true. It’s just what I heard.) Carnivores like say lions can hunt while pregnant. They have to be able to hunt in order to feed themselves. Imagine an 8.5 month pregnant human running after a rabbit to kill one. We are definitely prey, not predators.

            And I’m proud of it.

          • Thea

            Scientific Squirrel: I have to wonder if you actually read the page I referenced? I don’t see how one study on weaning time, with sentences like the following: “The independent contrast analysis did not suggest dependency of the
            brain mass and weaning time characters with the animals’ evolutionary
            history.” come anywhere close to countering the many, many scientific points raised in the page I sent you.

            I get that this is the conclusion: “Our findings highlight therefore the emergence of carnivory as a process
            fundamentally determining human life history and evolution.” But I’ve seen several arguments about what had to have happened for humans to develop the way we did. This one is not all that compelling to me. Especially not compared to all of the points in the reference I gave you.

            I understand that you find weaning time compelling evidence. I’m just saying that I don’t see it myself. To each her/his own.

  • HemoDynamic, M.D.

    This Blog is like Kale and Red Cabbage–so much useful nutritional information stuffed into such a small column! 

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