In the 1980s and 1990s, published studies in Europe showed incredible increases in the lifespan of animals given a drug called deprenyl, which reduces the breakdown of dopamine. For example, treated elderly rats had their remaining lifespans doubled (Mech Aging Dev), and immune-suppressed mice in another study lived up to around 200% longer of deprenyl (Arzneimittelforschung). This led to a surge in demand for the drug, which was originally approved to treat Parkinson's disease, for anti-aging purposes, however, it was very expensive for US consumers. Fortunately, a cheaper alternative exists: an extract of green oats, otherwise known as Avena sativa. This herb in extract form is available in the student clinic at my college, and until now very undervalued by me. (References in original Life Extension article, The Most Sought After Anti-Aging Drug).
So how do green oats work against aging? By preserving levels of dopamine. "Normally", dopamine levels in the brain decrease by about 13% each decade after the age of 45. Once dopamine levels drop to 30% of (youthful) normal, symptoms of Parkinson's disease may appear; a drop to 10% is fatal. As people age, levels of Monoamine Oxidase-B (MAO-B) increase, which degrades dopamine and other neurotransmitters. Dopamine is a "feel-good" neurotransmitter, and it wouldn't be surprising if a decline in this is behind the negativity that is often radiated by many elderly people. Negativity is bad for your health, and the negative older people in your life are not more "realistic", they are likely to have low dopamine and therefore cannot psychologically respond as well to whatever it is you've done to make the world better. Specifically, motivation and reward are what dopamine is involved in, so low dopamine means you are less able to see the point or positive side in things. MAO-B also decreases acetylcholine, an essential neurotransmitter for cognitive function; Alzheimer's disease also features a loss of acetylcholine.
This sounds frightening - who would want to lose their youthful levels of dopamine, acetylcholine and other neurotransmitters? It isn't really, as the quite accessible green oat extract has been found to protect against it. One study of people aged 30-60 years showed increases in electrical brain activity during concentration tests after supplementation with green oat extract. After two hours, delta and theta brainwave activity were increased by 38% and 25% respectively compared to placebo. Delta and theta brainwaves are associated with raised focus, concentration, perpetual speed and executive functioning. Another trial with 36 elderly people found a 65% improvement in cognitive function compared to placebo, and even those with a mild cognitive impairment showed an over 26% improvement on their test scores. A third study involving 42 people with self-reported cognitive decline, with an average age of 59 years, showed an amazing 180% increase in scores of a test called "global speed of performance" compared to the placebo group. There were also small but significant improvements in executive function, working memory and episodic memory.
When people come to me with signs of low dopamine, or are looking for something with anti-aging effects on the nervous system, I will recommend green oat extract more often. Just because it sounds less exotic than Ashwagandha or reishi mushrooms doesn't make it less effective.