Glucose

Glucose is the fundamental sugar of energy metabolism, and Ray Peat argued that it is a crucial, protective substance when supplied in the right metabolic context, directly aiding in the regeneration of the pancreas. 1 He identified polyunsaturated fats as the primary dietary factor that misdirects glucose metabolism, creating the epidemic of diabetes, obesity, and degenerative diseases, rather than the sugar itself. 1 The body's need for glucose is so absolute that on a pure meat diet, it will break down protein to produce it, a process that can disrupt physiology. 2

The primary regulator of stable blood sugar is the liver's ability to store glucose, a function that is fundamentally dependent on thyroid hormone. 2 Adequate thyroid function allows tissues to oxidize glucose efficiently, making high levels of insulin unnecessary and suppressing the liver's stress-driven glucose production. 3 When glucose oxidation is impaired, the body initiates a stress response. The first reaction to insufficient glucose is a surge of adrenaline to mobilize stored glycogen. 4 If glycogen is depleted, the body resorts to the deadlier arm of the stress response, releasing cortisol, which breaks down tissue protein to manufacture glucose, leading to a loss of function and strength. 4 Peat noted that simply tripling the amount of glucose in the bloodstream can prevent even deadly anaphylactic shock by overcoming the need for the inflammatory stress response. 4

Peat distinguished between sources of glucose, cautioning that the dextrinization of starches through harsh cooking creates mutagenic and carcinogenic compounds via the browning reaction with amino groups. 5 He consistently recommended obtaining sugar from fruit rather than grains and starchy vegetables, partly because poorly cooked starches support bacterial growth and endotoxin production, which synergizes with other pro-inflammatory factors. 7 In therapeutic contexts, Peat observed that simple sugars like honey or white sugar can be powerfully restorative, citing cases of rapid weight regain and the cessation of hair loss upon adding sugar to the diet. 7 He also noted that sugar itself can act as a mucolytic, quieting inflammation in the lungs by activating taste receptors on the involved tissues. 9

The chronic elevation of stress hormones to maintain blood sugar is a central mechanism of aging and degeneration. 8 Peat described how drinking milk or orange juice to raise blood sugar was sufficient to lower adrenaline and cortisol, allowing him to return to sleep. 8 He experimented with substances that sustain blood sugar through the night, such as antihistamines, to decrease the need for the catabolic stress response. 8 While injected dextrose has been used in prolotherapy to strengthen connective tissue by inducing inflammation, Peat argued that the underlying weakness is typically caused by low thyroid and high estrogen, and that correcting thyroid function and supplementing pregnenolone or DHEA is a more natural way to strengthen ligaments and tendons. 6