Cheese

Cheese is a concentrated dairy food whose value in Ray Peat's framework rests primarily on its casein protein and calcium content, which together exert anti-stress and metabolic-regulating effects. 4 Peat argued that the casein fraction retained in cheese is anti-inflammatory and anti-stress, helping to suppress cortisol production, while the discarded whey fraction lacks these protective factors and is deficient in calcium. 4 He advised eating cheese specifically for its high calcium and protein, though he cautioned that its caloric density varies enormously, from nearly fat-free varieties to those resembling soft butter. 8

The metabolic benefits of cheese are inseparable from its mineral profile. Peat emphasized that the ratio of calcium to phosphate is more important than the absolute amount of calcium, and that hard cheeses like Parmigiano-Reggiano can supply a meaningful quantity in a typical four-ounce serving. 5 He cited epidemiological evidence that when a high dietary phosphate load comes from milk and cheese, it is paradoxically associated with reduced blood pressure, unlike the vascular calcification and increased systolic pressure driven by phosphate from other sources. 2 Mechanistically, calcium inhibits the fat-forming enzyme fatty acid synthase while simultaneously activating mitochondrial uncoupling proteins, which accelerate calorie burning and protect against free radical damage—a dual action Peat believed was unique to dairy. 4 Fructose consumed alongside high-phosphate foods further reduces intestinal phosphate absorption. 3

Peat became increasingly alarmed by the near-total industrial takeover of cheese production by genetically modified microbial enzymes, marketed under labels like "vegetable rennet" or simply "enzymes." 2 He documented that over two-thirds of global cheese had abandoned traditional animal rennet in favor of single enzymes produced by genetically engineered microorganisms, which he argued carry allergenic debris from the source microbes such as Aspergillus. 2 Peat personally experienced intestinal inflammation after eating cheeses that had switched to these substitutes, observing that the texture became softer and moister, and he warned that even cheeses labeled "organic" could legally contain them. 1 He considered real animal rennet still safe, but noted that industrial citric acid used for clotting also poses allergenic risks due to contaminants absent from natural fruit citric acid. 5 When asked directly whether regularly consuming enzyme-modified cheese that is well tolerated could cause long-term damage, Peat replied that it increases the risk of future inflammation. 7

For individuals experiencing digestive or sinus reactions to cheese, Peat recommended systematic experimentation with different types, suggesting that homemade skimmed-milk cottage cheese might be a tolerable starting point. 9 He explained that the ability to digest dairy components like lactose can often be re-induced by consuming very small amounts—two or three ounces at a meal—over a period of weeks, providing enough exposure to stimulate dormant enzyme systems without feeding problematic bacteria significantly. 9 He also noted that the tryptophan content of cheese varies somewhat with the production method, though the calcium content varies far more dramatically, especially in cheeses like ricotta where separation by acid versus bacterial proteolysis determines the final mineral composition. 5