PUFA Depletion

PUFA depletion is the gradual reduction of stored polyunsaturated fatty acids, which Peat identified as the main cause of hypothyroidism and a central driver of degenerative disease. 2 The goal is to approach 0% PUFA intake, because even the ~2% PUFA in butter, coconut oil, and ruminant fats can slow the depletion process. 4 Peat argued that when PUFA stores are successfully lowered, the resting metabolic rate rises, inflammation after injury decreases, and the organism develops tremendous resistance to stress. 2

The body has two distinct routes for eliminating stored PUFA. The safer, preferred pathway is hepatic detoxification: the liver recognizes PUFA as toxins and selectively attaches glucuronic acid to them, excreting them through the kidneys without requiring oxidation. 2 The alternative is oxidation, which becomes dangerous because liberated free fatty acids block liver enzymes and amplify stress signals. 8 Dinkov has written that PUFA depletion depends primarily on two factors: how much PUFA is ingested and how good a shape the liver is in, since the liver is the organ predominantly responsible for glucuronidating and excreting PUFA. 10

The rate of depletion is governed by metabolic rate and fat cell turnover. Peat explained that if metabolic rate stays high relative to calorie intake, PUFA will be burned quickly without shaping physiology. 5 However, the process is inherently slow because it depends on the size of the fat cell rather than the size of the organism; fat cells randomly renew their composition over years. 2 Peat noted that fat cells themselves can slowly oxidize stored fat internally—someone calculated that fat cells alone could consume about three pounds in a couple of years even if fat never leaves the cell. 7 To accelerate depletion, Peat shifted his own diet to obtain at least half his calories as sugar, minimizing fat intake to reduce incoming PUFA while keeping blood sugar steady to suppress lipolysis. 2

Blocking the release of stored PUFA into the bloodstream is essential during depletion. Saturated fats, sugar, niacinamide, and aspirin all inhibit the stress hormones that trigger fat liberation. 2 Peat recommended keeping carbohydrate intake high enough to supply nearly 100% of energy, so that free fatty acids are not drawn from stores and any small amount of dietary PUFA can be oxidized safely. 3 Niacinamide at 100 mg twice daily acts as an anti-lipolytic agent, and vitamin E can be used topically to reduce oxidative damage from any PUFA that does circulate. 2 Dinkov has noted that a fat-free diet is a short-term intervention for PUFA depletion and excess weight, not a permanent recommendation. 11

Practical indicators of successful depletion include a higher resting metabolic rate, reduced tendency to sunburn, and less hypoglycemic stress during hunger. 2 Peat observed that bacterial endotoxin is probably fairly harmless when there is no PUFA present, and that as PUFA intake approaches zero, other factors like methyl donors, phosphate excess, and the iron-to-copper ratio become relatively more important. 2 The depletion timeline varies: one experimenter saw benefits after only three months on a fat-free diet, though animal evidence suggests full tissue depletion confers far greater protection. 2 Roddy has raised the question of transgenerational effects, and preliminary animal work by Mamounis found that feeding pregnant mothers PUFA versus saturated fat made offspring more insulin-resistant, though it did not change obesity. 6