Rhonda Patrick on health: what the evidence says · JRE #1054
“There's studies in men where like they give men 75 grams of refined sugar and their testosterone drops by 25%. I mean, it's changing a lot of things, you know, in the body in a negative way.”
What the evidence says
A 2013 study in Clinical Endocrinology (Caronia et al.) gave 74 men a standard 75-gram oral glucose tolerance test and found mean total testosterone fell by about 25% within 120 minutes (P<0.0001), with some men's levels dropping into the hypogonadal range; the effect was consistent across normal, impaired, and diabetic glucose tolerance, and testosterone remained suppressed at the two-hour mark. The specific figures Patrick cites, 75 grams and a 25% testosterone decline, match this study closely. However, the test used a single acute glucose bolus administered as a diagnostic procedure (an oral glucose tolerance test), not habitual dietary sugar intake, and testosterone was measured only over a two-hour window, so the study demonstrates a short-term hormonal response to an acute glucose challenge rather than a lasting or cumulative effect of ordinary sugar consumption. The study authors frame the finding as relevant to clinical screening practice (non-fasting testosterone tests may be unreliable after glucose ingestion), not as evidence of chronic harm from sugar consumption. Current evidence supports the acute physiological finding but does not establish that ordinary refined-sugar consumption durably lowers testosterone.