After a week of looking through studies related to blueberries, I have to ask, “Are blueberries good for eye health?”
The vitally important task of allowing us to see is one of our bodies’ most energy-consuming activities, and most of it happens within our retinas. The retina makes up nearly two-thirds of the eye’s interior surface.
Located at the back of the retina’s center is the fovea. We can thank the fovea for letting us view the world in its sharpest, most vibrant, and colorful form.
Our retinas are also packed with photoreceptors – 100 million rods and 6 million cones. Low light activates the rods. Without them, we’d all suffer from night blindness.
However, our rods can’t detect color. That’s why color loses its vibrancy as the light dims, and after dark, we see things in grayscale.
The light activates the cones populating the retina’s fovea. That’s why colors become brighter as the light around us gets stronger.
- 64 percent of our cones are red-receptive.
- 32 percent of our cones are green-receptive.
- Only 2 percent of our cones are blue-receptive.
Our red and green cones are concentrated within the fovea. The blue ones, which compensate for their minuscule numbers with greater color sensitivity, are outside it.
Having all 106 million of our rods and cones work as intended expends an enormous amount of energy and oxygen!
In fact, according to this 2014 study on eye health, the retina is one of the most “metabolically active tissues” in the human body!
The retinas literally burn through oxygen. A review on blueberry health benefits asserts that the retina has “the highest respiratory rate” of any human tissue.
And this 2014 eye health review claims that the retina’s oxygen consumption “per tissue weight” exceeds that of the brain.
Considering that the brain accounts for only 2% of our body weight yet uses 20% of the oxygen, we take in, the retina is a true glutton for energy and oxygen!
How Are Blueberries Good for Eye Health? As Vascular Health Protectors!
Having such a ravenous appetite makes our eyes particularly susceptible to inflammation, oxidative stress, and metabolic stress.
Take inflammation. It’s suspected as an underlying factor in many serious retinal diseases, including:
- age-related macular degeneration (AMD)
- diabetic retinopathy (DR)
- retinal vein occlusion (RVO)
and retinitis pigmentosa (RP)
Oxidative stress develops when reactive oxygen species such as free radicals disturb our normal cellular functions.
In the retina, metabolic stress occurs with the disruption of cellular metabolism. It often results because the cells aren’t receiving enough oxygen.
What might cause oxygen deficiency?
The 2014 review states that diseases of the retina “with a vascular component” are linked to 75 percent of visual loss. In other words, they involve the failure of our blood vessels to deliver adequate oxygen and nutrients to our tissues.
And this is where we find the answer to the question, “How are blueberries good for eye health?”
We’ve already established blueberries’ positive effects on vascular health are good for heart disease, weight loss, and diabetes. And if any of our bodily organs and tissues depend on healthy blood vessels, they’re our eyes -especially our energy-consuming retinas!
Are blueberries good for eye health? It definitely looks that way!
Plantbased.com has reviewed a vast body of evidence supporting a plant-based diet’s direct link to healthier blood vessels. Tomorrow we’ll look at more research on anthocyanin-rich berries, looking for answers to a similar question, “Are berries good for your eyes?”