Aging is not a uniform or deterministic phenomenon.
It can be influenced by various factors, such as genetics, lifestyle, environment, and hormones.
One of the hormones that may play a key role in modulating the aging process is melatonin.
Melatonin is an endogenous compound that is synthesized mainly by the pineal gland in the brain, but also by other cells and tissues in the body. Melatonin is best known for regulating the sleep-wake cycle and the circadian rhythm, which are essential for maintaining a healthy and balanced life.
However, melatonin has many other functions and benefits that go beyond sleep regulation. In fact, melatonin has been shown to have potent antioxidant, anti-inflammatory, immunomodulatory, and neuroprotective properties, which may help counteract the harmful effects of aging at the cellular and organ level.
How Does Melatonin Work Against Aging?
Melatonin works against aging by scavenging free radicals and reducing oxidative stress. Free radicals are highly reactive molecules that are generated as by-products of normal metabolism or by exposure to environmental factors, such as UV radiation, pollution, smoking, etc. Free radicals can cause damage to the DNA, proteins, lipids, and other components of the cells, leading to cellular dysfunction, inflammation, and disease.
Oxidative stress is the imbalance between the production of free radicals and the ability of the body to neutralize them with antioxidants. Oxidative stress is associated with aging and various age-related diseases, such as cardiovascular disease, neurodegenerative disease, diabetes, cancer, etc.
Melatonin acts as a powerful antioxidant that can neutralize free radicals and reduce oxidative stress. Melatonin can also stimulate the production of other antioxidants, such as glutathione, superoxide dismutase, catalase, etc., which enhance the body’s defense system against oxidative damage.
Moreover, melatonin regulates inflammation, which is another factor that contributes to aging and disease. Inflammation is the body’s response to injury or infection, but it can also become chronic and harmful when it is excessive or prolonged. Chronic inflammation can cause tissue damage, organ dysfunction, and systemic complications.
Melatonin can modulate inflammation by inhibiting the production of pro-inflammatory cytokines (such as TNF-alpha, IL-6, IL-1beta) and by activating anti-inflammatory pathways (such as NF-kappaB). Melatonin can also regulate the immune system by enhancing its function and preventing its decline with age.
Furthermore, melatonin protects the brain from age-related degeneration and cognitive impairment. The brain is one of the most vulnerable organs to oxidative stress and inflammation due to its high metabolic rate and low antioxidant capacity. Aging can affect the structure and function of the brain cells (neurons) and their connections (synapses), resulting in memory loss, dementia, Alzheimer’s disease, Parkinson’s disease, etc.
Melatonin can protect the brain from oxidative damage and inflammation by crossing the blood-brain barrier and reaching high concentrations in the brain tissue. Melatonin can also prevent neuronal death by activating survival pathways (such as BDNF) and by inhibiting apoptotic pathways (such as caspase-3). Melatonin can also improve synaptic plasticity and neurotransmission by modulating glutamate receptors (such as NMDA) and by increasing acetylcholine levels.
Additionally, melatonin may influence other hormones that are involved in aging and health span. For instance, melatonin may stimulate the secretion of growth hormone (GH), which is essential for tissue repair and regeneration. Melatonin may also regulate insulin sensitivity and glucose metabolism, which are important for preventing diabetes and metabolic syndrome.