Take all my info with a grain of salt, I’m not a scientist, just someone who is interested in diet for health.
I was watching a video of Dr. John McDougall rebutting an argument that eating a diet of only potatoes will cause blindness. He argues that it may cause temporary night blindness, but not total blindness. He goes on to argue that a person can live healthily on a diet of only potatoes.
People have lived on potatoes with NO blindness, even tho the classic potato has <1% vitamin A content.
I’ve been watching a lot of McDougall’s videos lately, he has never said the vitamin A in sweet potatoes is bad, but what he has said is that supplementing with beta carotene or vitamin A is bad.
If you take vitamin A and mineral supplements you cause nutritional imbalances like for example beta-carotene, beta-carotene when you eat it as pill for example if you eat it as a carrot no big deal because it’s properly balanced with other carotenoids, but you take a supplement of beta-carotene concentrated isolated beta-carotene and it goes into your gut into your bloodstream and then into the cells well there are 50 different carotenoids that the body interacts with they’re about 600 different carotenoids in nature but 50 of them that we have to uh to deal with with terms of good health they are all they are all activated by an attachment to a carotenoid receptor in other words all these 50 carotenoids they have to attach to the inside of the cell to this carotenoid receptor before they can function well when you flood the system with beta-carotene just one of the 50 carotenoids there’s no more room for the other carotenoids and you increase your risk of getting cancer, heart disease, dying that’s basically what all the studies show.
Excerpt from transcript of Dr. John McDougall in this video: https://www.youtube.com/watch?v=s0JfIRhwiLs
The country with the one of the highest sweet potato consumption Papua New Guinea has one of the highest rates of blindness in the world.
“The first national survey on eye health in Papua New Guinea (PNG) has found that the prevalence of blindness among people aged 50 years and older is 5.6%, which is one of the highest rates in the world.” – The International Agency for the Prevention of Blindness
Wow, so consuming potatoes with no vitamin A doesn’t affect eye health, but a diet of potatoes WITH vitamin A is associated with decreased eye health.
Over 90% of blindness and vision impairment in PNG is avoidable. The main cause is untreated cataract and uncorrected refractive error. There are approximately 11 ophthalmologists performing surgery for a population of nine million, whereas the World Health Organization (WHO) advises that countries of this size should have at least 90 ophthalmologists.
PNG also faces the rapidly rising challenge of noncommunicable diseases (NCDs), including diabetes, which if poorly managed can lead to diabetic retinopathy (DR). Left untreated, DR can result in irreversible vision loss and blindness. The current lack of DR services in PNG, means every person with diabetes is at high risk of vision loss.
Image and quote from https://www.hollows.org.nz/
Vitamin A may also be associated with diabetes as well.
Google: “Papua New Guinea Diet”
“Papua New Guinean cuisine is largely vegetarian, with lots of tropical fruits and starchy root veggies, including sago, taro and sweet potato. Seafood, chicken and pork are also popular, though pork is usually reserved for special occasions.”
Out of all meats, pork is the worst for accumulating retinoic acid (vitamin A).
Google: “cataracts diet association”
“Foods rich in vitamins C and E, zinc, lutein, zeaxanthin, and omega-3 fatty acids have been linked to lower risks of age-related macular degeneration (AMD), cataract and other eye conditions later in life. It’s also possible that diet plays a role in glaucoma, though it’s not yet clear how.” – American Academy of Ophthalmology
Sweet potato vs potato content
- Vitamin A – Sweet potato: 14,187 IU, potato: 2IU.
- Vitamin C – Sweet potato: 2.4mg per 100g, potato: 19.7 mg per 100g. Sweet potatoes have less vitamin C than regular white potatoes.
- Vitamin E – Sweet potato: 2%, Potato: 0.4%
- Zinc – Sweet Potato: 0.30 mg, Potato: 0.30 mg
- Lutein & Zeaxanthin – dont know.
- Omega-3 – Sweet potato: 10mg / 100g, Potato: 20mg / 100g
- Protein – Sweet Potato 1.6 g, Potato 3g.
Grant Genereux theorized that scurvy in sailors was caused mostly by a poisoning of a vitamin A rich soup made with the offal of animals. However vitamin C was protective against the vitamin A poisoning. See his article here: SCURVY, and read his books!
This is just another example of how vitamin A is not good for eyes or health in general, it’s a poison.
Lots of vegans abandoning the vegan lifestyle and turning to meat because of vitamin A poisoning symptoms. Lots of carnivores running into problems with consuming lots of animal vitamin A. Vitamin A is such a sleeper.
In my current state, I feel the vegan diet could be superior, but it must be without vitamin A.
People restricting vitamin A in their diet are getting back their health, reversing celiac! and other autoimmune conditions. If you have the time, watch these interviews with people who have made pretty miraculous recoveries in their health by restricting vitamin A, eating fiber, and beans, and other detox helping supplements: https://www.youtube.com/@thortorrens/videos
Main solutions:
Soluble Fiber helps remove vitamin A toxic bile from our body. A diet without fiber will cause 95% of toxic bile to be reabsorbed by the body.
Protein and Zinc from muscle meat helps export vitamin A from your liver. Said another way, vitamin A depletes protein and zinc, selenium. Where do vegetarians go when their bodies crave zinc, selenium, the body must crave something that is high in these and low in vitamin A. May be best to eat meat and do vegan right with a level of vitamin A the body can consistently deal with. Pumpkin seeds have vitamin A and fat, so maybe not the best option.
It’s inevitable
Vitamin A restriction will eventually be super popular, it’s just a matter of time.