Tag Archives: myopia

Undisturbed Hunter-Gatherers Don’t Have Near-Sightedness

…according to an article at Nutrition Research. That’s in stark contrast to the developed world. Asian Scientist reports that:

In certain developed parts of East Asia, nearsightedness is skyrocketing, with the prevalence of myopia now at an estimated 80 to 90 percent of the population. In areas of the world where families cannot afford eyeglasses, poor vision from nearsightedness is a serious disability that can affect a person’s ability to learn and work.

Steve Parker MD, paleobetic diet,

Should have spent more time outdoors

The authors of the article at Nutrition Research suggest that the better vision of hunter-gatherers as compared to an agrarian culture is related to greater variety and larger quantities of phytochemicals in the H-G group. Here’s their abstract:

Myopia [near-sightedness] is absent in undisturbed hunter-gatherers but ubiquitous in modern populations. The link between dietary phytochemicals and eye health is well established, although transition away from a wild diet has reduced phytochemical variety. We hypothesized that when larger quantities and greater variety of wild, seasonal phytochemicals are consumed in a food system, there will be a reduced prevalence of degenerative-based eye disease as measured by visual acuity. We compared food systems and visual acuity across isolated Amazonian Kawymeno Waorani hunter-gatherers and neighboring Kichwa subsistence agrarians, using dietary surveys, dietary pattern observation, and Snellen Illiterate E visual acuity examinations. Hunter-gatherers consumed more food species (130 vs. 63) and more wild plants (80 vs. 4) including 76 wild fruits, thereby obtaining larger variety and quantity of phytochemicals than agrarians. Visual acuity was inversely related to age only in agrarians (r = -.846, P < .001). As hypothesized, when stratified by age (<40 and ≥ 40 years), Mann-Whitney U tests revealed that hunter-gatherers maintained high visual acuity throughout life, whereas agrarian visual acuity declined (P values < .001); visual acuity of younger participants was high across the board, however, did not differ between groups (P > .05). This unusual absence of juvenile-onset vision problems may be related to local, organic, whole food diets of subsistence food systems isolated from modern food production. Our results suggest that intake of a wider variety of plant foods supplying necessary phytochemicals for eye health may help maintain visual acuity and prevent degenerative eye conditions as humans age.

Who says low-carb paleo diets are mostly meat?

Certain fruits and vegetables are also linked with lower risk of macular degeneration

In the developed world, kids might prevent near-sightedness by basking in the bright sunlight of outdoors or simply by spending time outdoors. I suspect prevention has a lot to do with using our distant vision for hours instead of looking at a screen two feet away or the interior walls of our homes.

Steve Parker, M.D.

Reference: London, D.D. and Beezhold. A phytochemical-rich diet may explain the absence of age-related decline in visual acuity of Amazonian hunter-gatherers in Ecuador. Nutrition Research 2015 Feb;35(2):107-17. doi: 10.1016/j.nutres.2014.12.007. Epub 2014 Dec 31.

Get Your Kids Out in the Sunlight To Avoid Myopia

…according to an article at Slate. BTW, myopia is nearsightedness.

Steve Parker MD, paleobetic diet,

Should have spent more time outdoors

I thought spending time outdoors helped prevent myopia by using your distant vision more instead of texting to your buds on your smartphone all day long. Research suggests instead that the preventative aspect of being outdoors is related to bright light. Some quotes:

In the 1930s scientists observed that myopia was very rare in hunter-gatherer societies, and a 1960s study of native people in Alaska showed that older generations, who had not attended school, were much less likely to have myopia than younger generations, who had. Singaporean studies 20 years ago likewise linked educational attainment to myopia. If the problem is just a matter of light intensity, however, you could send your child outside to read, or purchase high-intensity light sources that mimic outdoor exposure.

According to a 2004 study from the University of Michigan, the average child in 2002 spent exactly half as much time participating in outdoor activities as did children in 1981. While myopia hasn’t yet reached the levels seen in much of Asian, prevalence in the United States is rising quickly. A 2009 study showed that the prevalence of myopia among Americans between the ages of 12 and 54 surged from 25 percent in the early 1970s to 42 percent around the turn of the millennium.

Read the whole enchilada.

More Time Outdoors Could Prevent Childhood Nearsightedness

Steve Parker MD, paleobetic diet,

Should have spent more time outdoors

I suspect that myopia (nearsightedness) is a modern phenomenon. If you don’t see well, you’re more likely to get bitten by a poisonous snake or overcome by a predator that you should have seen coming. Or you simply trip and fall over obstacles, incurring cuts or fractures. In prehistoric times, these circumstances would lessen your chances of passing your genes on to the next generation. In other words, there was strong selection pressure in favor of good vision.

(For now, I’ll ignore the possibility that poor vision may have beneficial aspects. “Parker, you don’t see good. Stay here with the women while we chase down that ibex.”)

Steve Parker MD, eye chart, eye exam

My eyes are this bad

I’ve worn glasses since the 3rd grade and I’ve never been happy about it. OK…. worse things can happen!

According to an article at PopSci, I may have avoided myopia by spending more time outside when I was a youngster:

A team of Australian researchers recently reviewed major studies since 1993 of kids, myopia and time spent outdoors. They found more than a dozen studies, examining more than 16,000 school-age kids in total, that found children were more likely to be nearsighted or to develop nearsightedness if they spent less time outdoors. A few of the later studies also found that being outdoors protected even those kids who did a lot of near work or had myopic parents. The studies included kids living in Europe, the U.S., Asia, the Middle East and Australia.

Read the rest.

Steve Parker MD, paleo diet, paleobetic

Nubian ibex in Israel

So get your kids outside. They may even benefit just from the sunshine.

And for my fellow myopics out there, note that your risk of a retinal detachment is higher than average. By the time that usually happens, our children are already grown, so there’s little or no selection pressure against it.

Steve Parker, M.D.