Word. And why I don't take fish oil pills but am considering small amounts of sardines and/or oysters in my CR profile. Cod liver oil's Vitamin A toxicity: your thoughts? SFA doesn't lead clogged and inflamed blood vessels?
What do you eat, Kismet? What's your typical food day like?
The RDA for vitamin A (2,600 IU) is inadequate, and even then, over 25% of American consume less than half of the recommended amount. Native populations such as the traditional Inuit – which were free of modern, degenerative disease – got much more vitamin A than the average American. The Greenland Inuit of 1953, prior to much contact with the Western world, got about 35,000 IU of vitamin A per day. It is true that vitamin A is potentially toxic. Some evidence suggests that excess vitamin A increases the risk of osteoporosis. For example,
this study showed both low and high serum A carried double risk of fractures as did optimal levels.
Given that beta-carotene is poorly utilized by many and that vitamin A (retinol) is only found in significant amounts in organ meats, it explains why many Americans don't get enough of it. That said, I believe the claims of vitamin A toxicity are greatly misconstrued. If we dig deeper we find that excess vitamin A only causes problems against a backdrop of vitamin D deficiency. In his excellent article
Vitamin A on Trial: Does Vitamin A Cause Osteoporosis, researcher Chris Masterjohn summarizes evidence demonstrating that vitamin D decreases the toxicity of and increases the dietary requirement for vitamin A. Studies show that supplementing with vitamin D radically increases the toxicity threshold of vitamin A. In a hypothetical 160 lb person, vitamin D supplementation increases the toxicity threshold of vitamin A to more than 200,000 IU/d. You'd have to eat 22 ounces of beef liver or take 5 TBS of high vitamin CLO each day to get this amount. Not likely!
The study discussed by Masterjohn:
Vitamin A and retinol intakes and the risk of fractures among participants of the Women's Health Initiative Observational Study"
No association between vitamin A or retinol intake and the risk of hip or total fractures was observed in postmenopausal women. Only a modest increase in total fracture risk with high vitamin A and retinol intakes was observed in the low vitamin D-intake group."
As for saturated fat, I completely disagree that it promotes inflammation. Most of the studies either on low-carb or saturated fat are horribly constructed (
like including 14% of calories from trans fat...) or fail to control for confounding factors (such as lifestyle, glycemic load of the diet, or even PUFA). But even with all the bad research, there is still plenty of evidence showing saturated fat to be beneficial and or neutral.. such as the nurses study. I know Kismet hotly disagrees with me on the topic of saturated fat and since I've hashed out my argument for saturated fat countless times on these forums, i'll refrain from repeating myself once again. I will say this... my cholesterol got worse when I cut back dramatically on my fat intake and began consuming a higher carbohydrate, plant based diet. For what it's worth, and I would hate to get someone on a dietary plan that harmed them, my body seems to respond to a low-carb diet rather favorably.
(On a side note about the Harvard study... Even Walter Willett and his team of Harvard researchers failed to make this distinction between saturated and trans-saturated fat until the 1990s. Once they took trans fats into account, they discovered that trans fats are often the real culprits in causing heart disease, cancer, diabetes, obseity and other modern, degenerative diseases. Working with the refined data, Walter Willett confirmed, in the Nurses Health Study II, that nurses with higher rates of cancer were those who consumed more margarine and vegetable shortenings – not those who ate butter, eggs, cheese and meat. Funny how that works... )
Edited by Skötkonung, 25 February 2011 - 07:46 AM.
LongeCity
