Saturated Fat

Saturated fat is the class of fatty acids that the human body is fundamentally designed to recognize and oxidize, and its consumption actively blocks the stress reaction while the polyunsaturated fats (PUFA) systematically turn on stress hormones. 10 Peat argued that the body can synthesize all the saturated fat it needs from sugar, starch, and amino acids, yet dietary saturated fat remains important because it makes food more palatable, stimulates the intestine to digest protein and carbohydrate efficiently, and signals satisfaction to lower stress. 2 The properly functioning body, under stress, would mobilize its own stored saturated fats to inhibit stress hormones and break the stress cycle, but the modern accumulation of PUFA in tissues subverts this logic. 10

The specific saturated fatty acids palmitic acid, stearic acid, and lauric acid are among the very few fats that do not inhibit pyruvate dehydrogenase, the enzyme complex essential for oxidizing glucose. 5 Dinkov has written that stearic acid functions as an estrogen receptor antagonist, capable of suppressing the downstream transcriptional effects of ER-alpha activation by 50–60% at physiologically achievable concentrations, while palmitic acid is also an antagonist and oleic acid is neutral on that receptor. 11 Peat noted that cocoa butter, rich in stearic acid, protected the heart against damage caused by dietary linoleic acid, and more recent experiments show that increasing dietary stearic acid can reduce visceral fat percentage. 4 Saturated fats also interrupt the free radical oxidation chain reactions of accumulated polyunsaturates, providing an anti-inflammatory and somewhat antioxidant effect that becomes more important therapeutically as metabolic rate slows with aging. 2

Saturated fats protect the gut barrier and mitigate the inflammatory cascade triggered by starch and endotoxin. Dinkov explained that long-chain saturated fats stimulate bile acid release and chylomicron formation, and that stearic acid and palmitic acid can block the TLR4 receptor, the main receptor for endotoxin, so that eating starch with butter or coconut oil produces almost no post-meal endotoxin response. 3 In advanced cirrhotic patients with a nearly non-existent gut barrier, saturated fat administration has demonstrated curative effects on hepatitis and cirrhosis, while fish oils and seed oils exacerbate liver disease and inflammation. 2 The saturated fatty acids found in the nucleus associated with chromosomes are resistant to dietary change and are essential for cell division, gene regulation, and cell survival, whereas unsaturated fats in the nucleus change according to diet. 9

The preferential oxidation of saturated fat and the storage of PUFA creates a vicious cycle during lipolysis, where weight loss predominantly releases stored PUFA into circulation. 8 Dinkov noted that rubbing stearic acid or vitamin E onto fatty areas can change the composition of adipose tissue much faster and prevent many of the bad effects of lipolysis. 8 Peat emphasized that increasing dietary sugar lowers lipolytic activity, keeps fat stored where it belongs, and prevents the Randle effect shift to fat oxidation, which is primarily driven by PUFA blocking the ability to use glucose. 4 Because PUFA are many times more water-soluble than saturated fats of the same length, they can displace thyroid hormone and vitamin A from their carrier proteins, with efficiency increasing with the number of double bonds. 9 Only palmitic acid functions as a surfactant in the lungs to keep air sacs open, while unsaturated fats cause lung edema and respiratory failure. 9