In people who do have chronic inflammation, high levels of indoleamine dioxygenase (IDO) break down the 5-HTP and tryptophan before it can be transported across the blood-brain barrier. So they do not get as much benefit from 5-HTP and tryptophan, and they often notice a kind of malaise (a not-quite-right feeling or a non-specific lack of wellbeing) from the toxic byproducts of tryptophan catabolism (which are known) and 5-HTP catabolism (which are not known). Such people rarely share your enthusiasm for 5-HTP.

There is a patch. Predigested collagen protein 1) contains peptides that solublize tryptophan and 5-HTP in water, so they can be absorbed faster and more gets into the brain, and 2) does not contain amino acids that compete with tryptophan and 5-HTP at the large-neutral-amino-acid transporter. So people with inflammation may be able to enjoy the benefits you notice by dissolving their 5-HTP or tryptophan in water with predigested collagen protein (also called hydrolyzed collagen protein). This combination amplifies the serotonin response regardless of inflammatory status, so you could try it, too. I get a roughly ten-fold amplification; 200 mg of L-tryptophan (from Ajinomoto) with collagen gives me the effect of 2000 mg without collagen. My best ratio is 200 mg tryptophan to 2 rounded teaspoons of collagen powder in a full glass of water. It works best on an empty stomach.

If the oxidant overwhelms the adaptive capacity of the system, there is potential for an opposite reaction. The most common forms of this are 1) exercise over-training, where free radicals from exercise become toxic and result in maladaptation, and 2) medical imaging (X-rays, CAT scans, SPECT scans, etc.), where the oxidant stress is too quick for the body’s systems to adapt. Increased radiation that is gradual can be easily accommodated, like if you moved from San Francisco (sea level) to Denver (a mile high). The radiation doubles, and 99.9% of people adapt seamlessly, with no observable pathology (e.g., cancer).

There may be other, indirect, effects on energy systems, neuroendocrine regulation and immune function that might also be involved. It is clear that inflammation plays a major role in aggravating Alzheimer’s disease. Oxidants like hypochlorite, hydrogen peroxide, hyperbaric oxygen, ozone, UVI, hypericin, negative ions (superoxide) and nitric oxide may mitigate inflammatory processes.

Most inflammatory reactions activate aromatase and indoleamine oxidase. Aromatase converts energy-enhancing testosterone and progesterone into energy-sapping estradiol and estrone, which damages antioxidant defenses (NADH generation at the mitochondrial level). Indoleamine dioxygenase catabolizes tryptophan and 5-hydroxytryptophan (5-HTP), which can interfere with sleep, mood and wellbeing, which can further sabotage neuroendocrine regulation. So there are many ways that oxidants and antioxidants might affect Alzheimer’s risks.