Casein, a primary protein in milk, can function as a mu opioid receptor agonist within the gut. This activity can lead to an increase in prolactin levels, which in turn can suppress dopamine and the hormones that stimulate testosterone production.
Cannabinoids (THC, CBD) don't directly reduce testosterone. Instead, the act of smoking marijuana increases the enzyme aromatase, which converts testosterone into estrogen. Higher estrogen then signals the pituitary to reduce testosterone production, creating an indirect negative feedback loop.
Your food cravings may not be entirely your own. Harmful gut microbes can release compounds that chemically increase your desire for the ultra-processed, high-sugar foods they feed on, effectively sabotaging your health goals from within.
The impact of caloric restriction on testosterone is context-dependent. While it can improve testosterone levels in men with obesity or metabolic syndrome, the same dietary stress will likely decrease testosterone in young, healthy, lean men.
Over 95% of the body's serotonin originates in the gut, not the brain. Its primary role is not just mood regulation but managing gravity's physical toll by stabilizing blood pressure when standing, coordinating muscles for balance, and supporting lymphatic flow, making it a key 'gravity management molecule.'
The universal appeal of cheese could be linked to our limbic system, which stores memory and smell. Because milk is our first food memory, cheese—a concentrated milk product—may tap into this primal, positive association from infancy, explaining its powerful emotional resonance.
The satiation signal from GLP-1s to the brain stem also down-regulates dopamine and the desire for it. This explains anecdotal reports and active studies on their effect in reducing cravings for nicotine, alcohol, shopping, and gambling.
While low testosterone can cause poor sleep, starting TRT can also lead to sleep issues. It drastically increases the risk of sleep apnea and can initially put the body into a hypersympathetic (fight-or-flight) state, disrupting sleep patterns.
Beyond lacking nutrients, processed foods contain additives like emulsifiers that are actively harmful. These chemicals, added for shelf stability, are known to disrupt the gut's critical mucus layer. This erosion of the natural barrier between your gut microbes and your body can directly lead to inflammation and contribute to metabolic syndrome.
The fitness trend of consuming very high amounts of protein (e.g., 1g per pound of body weight) is not supported by data. Amounts exceeding 1 gram per kilogram, especially from animal sources, can lead to systemic inflammation and promote the development of atherosclerosis (clogged arteries).
Contrary to popular belief, women's bodies contain substantially more total testosterone than estradiol. This misunderstanding arises because tests use different units (nanograms vs. picograms) or focus only on "free" testosterone, understating its overall prevalence and importance.