Put this on on the list of benefits of the carnivore diet (or also just the benefit of avoiding vegetable seed oils, which happens by default when you eat carnivore).
It looks like Age Related Macular Degeneration is very strongly correlated to vegetable oil consumption. It was a disease that barely existed, before vegetable oil became popular. And then 30 years after that, it was an epidemic.
My aunt went blind in both eyes from Macular Degeneration in her 70's. She had been a very active lady, but after that, mostly just sat quietly in a chair. I guess when you go blind in your 70's, you don't adjust like you can if you're younger.
This came up for me again because I was at a party last night, and one of the folks there told me his wife had stage 1 macular degeneration. I remembered my aunt, and then also remembered that I had read or heard something, when I was diving down the carnivore diet rabbit hole, about macular degeneration being caused by vegetable oils. I did some research, and it appears to be a well supported argument.
Here's a presentation from an opthamologist: https://www.cureamd.org/does-a-westernized-diet-cause-macular-degeneration-dr-knobbes-debut-presentation-of-revolutionary-hypothesis-for-cause-of-macular-degeneration/
So here’s the risk factors for AMD as we ophthalmologists and optometrists know them: Aging and Genetics. These are the big two.
But, we also know that AMD has been associated with heart disease, type 2 diabetes, metabolic syndrome, obesity — notice I’m naming diseases of Western civilization? And this is what I’l submit to you, is that AMD just follows with these diseases because they’re all caused by the same thing. And we’re going to take a deep look at this here just shortly.
But back to the question. So could macular degeneration, though, just be a disease of aging or genetics? I mean, is that possible?
If so, then the prevalence of AMD should have been the same in 1920 as it is — as it was — in 1975, right? Unless you want to argue that our DNA changed in 55 years. Right?
The answer, basically, is NO. There was almost zero AMD (age related macular degeneration) from when the macular was first visible via the ophthalmoscope, around 1855.
This ophthalmologist wrote two textbooks of ophthalmology, one in 1927, and the other in 1940. 1927 - no AMD. 1940 - it had started to become an epidemic.
Sir Stewart Duke-Elder. Duke-Elder was a British ophthalmologist, London, England. He would become perhaps the most esteemed ophthalmologist — the most dominant force in ophthalmology — for about the next forty years or so.
Nineteen-twenty-seven (1927) — published his first comprehensive textbook of ophthalmology: 340 pages — not a single word regarding macular degeneration. Not a word.
And yet, thirteen years later, in 1940, he published his next textbook of ophthalmology. And in this one, he dedicated 13 pages to the condition of macular degeneration, 17 images, six of which were in full-color, and he called macular degeneration ‘a common cause of failure in central vision in old people.’ That’s a quote.
So in the 1920s he wasn’t seeing macular degeneration but in the 1930s, he was.
I asked AI for a summary of the evidence, and here's what I got.
1. The "Mainstream" Evidence (Epidemiology)
These are studies from major institutions (like Harvard) that found a link between vegetable fats and AMD, even if they didn't use the term "seed oils" explicitly in the headlines.
The "Seddon Study" (Crucial Reading) This is perhaps the most cited paper supporting the theory. Dr. Johanna Seddon (Harvard Medical School) analyzed the diets of patients with AMD.
The Paper: Dietary Fat and Risk for Advanced Age-Related Macular Degeneration (Archives of Ophthalmology, 2001).
The Finding: The study found that high intake of vegetable fat was associated with a 2.22-times higher risk of developing AMD. Conversely, intake of Omega-3 (fish) reduced the risk.
Why it matters: It explicitly differentiated between animal fats and vegetable fats, finding the vegetable fats to be the risk factor.
The Blue Mountains Eye Study
The Paper: Dietary fatty acids and the 5-year incidence of age-related maculopathy (Archives of Ophthalmology, 2009).
The Finding: This Australian study found that roughly one serving of fish per week was protective, but higher intakes of Linoleic Acid (the primary fat in seed oils) were associated with a higher prevalence of the disease in those with low Omega-3 intake.
2. The "Mechanistic" Evidence (The Chemistry)
These peer-reviewed papers don't necessarily look at diet surveys; instead, they look at Biochemistry. They track how Omega-6 breaks down into toxins that kill retinal cells.
The "4-HNE" Toxic Byproduct Link
The Paper: 4-Hydroxynonenal (4-HNE) in the Pathogenesis of Retinal Diseases (Journal of Oleo Science).
The Science: This discusses how Linoleic Acid (found in corn/soy/canola oil) oxidizes to form 4-HNE, a toxic aldehyde. The paper details how 4-HNE accumulates in the Retinal Pigment Epithelium (RPE) and causes cell death.
Key Takeaway: Since Linoleic Acid is the required precursor to create 4-HNE, the logic follows that reducing Linoleic Acid reduces the toxin destroying the eye.
The Oxidative Stress Link
The Paper: Oxidative Stress in Age-Related Macular Degeneration (Oxidative Medicine and Cellular Longevity, 2016).
The Science: This reviews how the retina is particularly susceptible to "lipid peroxidation" (fats going rancid). It confirms that the retina is highly concentrated in Polyunsaturated Fatty Acids (PUFAs), and when these unstable fats oxidize, they lead to drusen formation (the hallmark of AMD).
3. The "Hypothesis" Papers (Direct Causation)
These papers explicitly argue that the transition to a Western diet rich in seed oils is the cause of the epidemic.
Dr. Chris Knobbe’s Primary Paper
Title: Omega-6 vegetable oils as a driver of coronary heart disease: the oxidized linoleic acid hypothesis (Open Heart, 2018 - While this title specifies Heart Disease, Knobbe uses the same mechanism for AMD in his follow-up data).
See also: Biomedicine & Pharmacotherapy (2023) published a paper titled “Vegetable oil, not cholesterol, as a primary driver of cardiovascular disease...” which explores the same inflammatory pathways affecting micro-capillaries (like those in the eye).
Investigating the Historical Correlation
The Paper: The pathogenesis of age-related macular degeneration: The role of metabolic dysfunction and oxidative stress (Medical Hypotheses).
The Content: These types of papers track the data showing that as seed oil consumption in a country goes up, AMD cases follow a nearly identical trajectory 20–30 years later.
4. Accessible Articles & Books (Easier Reading)
If you don't want to wade through academic biochemistry, these sources synthesize the information.
"Cure AMD Foundation" (Dr. Chris Knobbe)
Website: CureAMD.org
What it is: Knobbe is the primary whistleblower on this topic. His website contains graphs overlaying the introduction of Crisco and Cottonseed oil with the rise of retinal disease.
Key Video: Look for his presentation titled "Ancestral Dietary Strategy to Prevent and Treat Macular Degeneration" on YouTube. He walks through the mechanism of Lipid Peroxidation visually.
The Weston A. Price Foundation
Article: The Oiling of America or specific articles on their site tagged "Eye Health."
Content: They have long documented the historical shift from butter/lard to soy/corn oil and the resulting degeneration of health, including vision.
Books
"Ancestral Dietary Strategy to Prevent and Treat Macular Degeneration" by Chris Knobbe, MD. (This is the definitive book on the subject).
"Deep Nutrition" by Dr. Cate Shanahan. (While not solely about eyes, she dedicates significant space to how "Hateful Eight" oils damage nerve and brain tissue, which includes the retina).