Monday, August 22, 2011 at 10:00AM
In last weeks post, as predicted, I took some heat for my suggestion that higher-carb, lower-fat diets reign supreme when compared to similar diets with less carbohydrate.
This should be news to no one however; high-fat diets are gaining less and less popularity as people wise up to the anti-metabolic effects of carb-o-phobia. The movement is exemplified with paleo giants like Richard Nikoley promoting fruit consumption, Don Matesz becoming a born again vegetarian, and Stephan Guyenet d-i-s-m-a-n-t-l-i-n-g the carbohydrate hypothesis.
In part two of my jihad with fat I wanted to go over how fat, saturated or not, isn't always helpful or even benign for those with thyroid disorders.
In a hypothyroid state (read: diseased state), one cannot properly synthesize bile acids to emulsify and absorb dietary fats. While there is no inherent problem with saturated fats, an excess may not be utilized properly and instead can contribute to inflammation:
"Hypothyroidism has been shown to impair gallbladder function, causing the organ to become distended and contract sluggishly, thus not releasing enough bile. A sluggish gallbladder also causes the liver's detoxification pathways to become sluggish and backed up, that the organ cannot fully detoxify hormones, toxins, and other metabolites." Dr. Datis Kharazzian
Dr. Ray Peat jives with the above in his article, "Cholesterol, longevity, intelligence and health." Peat explains that cholesterol from dietary fat must be combined with thyroid (and vitamin A) to have a desirable effect:
"In the healthy organism, cholesterol is constantly being synthesized, and constantly converted into steroid hormones, and, in the liver, into the bile salts that are secreted to emulsify fats in the intestine. Thyroid hormone and vitamin A are used in the process of converting cholesterol into pregnenolone, the immediate precursor of progesterone and DHEA. Anything that interfered with these processes would be disastrous for the organism. The supply of cholesterol, thyroid and vitamin A must always be adequate for the production of steroid hormones and bile salts."
Substituting fat with fruit calories should improve fat absorption. Not simply by reducing the amount of fat that the body has to process, but by the radical increase in vitamin C, which may have a prominent role in producing bile:
"Research also suggests that vitamin C is involved in the metabolism of cholesterol to bile acids, which may have implications for blood cholesterol levels and the incidence of gallstones."
What about the love affair between Ray Peat and coconut oil?
While I'm sure coconut oil is extremely useful in some situations, anecdotally I have never had success loading up on it. While coconut oil has some really interesting properties (not needing bile for digestion and increasing metabolic rate), I was always left feeling very "heavy" after consuming a small portion. This speaks volumes about my own physiology rather than the usefulness of coconut oil, but I have no issues with smaller amounts. I'm sure there are others in the paleosphere who have had similar experiences.
Take Home
Paleo peeps love high fat diets, but why? To support a crippled theory of insulin spiking that no one buys anymore?
If suspect your thyroid to be an issue, you may be served by reducing dietary fat as an experiment to see what happens. Consuming a majority of your calories as fat seems silly unless you have the metabolic balls (T3) to deal with it.
