Alcohol consumption often leads people to focus on the liver, heart, or brain, but it also affects the appearance and health of hair. Alcohol does not directly damage the hair shaft or follicle. Instead, it indirectly influences hair vitality through systemic physiological changes. These effects are typically noticeable with chronic or excessive intake and can lead to hair that is dull, brittle, and prone to shedding.
Dehydration’s Impact on Hair Structure
Alcohol acts as a diuretic, causing the body to increase urine production and expel more fluid than usual, leading to overall dehydration. This systemic lack of moisture affects all tissues, including the scalp and the hair shaft. When the body is dehydrated, the moisture available to the hair follicles and strands is significantly reduced.
Hair lacking hydration becomes dry and loses its natural elasticity, making it brittle and vulnerable to breakage. The outermost layer, the cuticle, may become rough, resulting in a dull appearance and increased susceptibility to split ends. Dehydration also compromises the scalp’s moisture barrier, potentially leading to dryness, flakiness, or dandruff.
Disrupting Essential Nutrient Absorption
Chronic alcohol consumption significantly interferes with the body’s ability to absorb and utilize the vitamins and minerals necessary for robust hair growth. Alcohol metabolism places demands on the liver, impairing its function in processing nutrients. This interference often leads to deficiencies in micronutrients fundamental to forming the hair protein keratin and maintaining the hair growth cycle.
Deficiencies in B vitamins, particularly folate (B9) and Vitamin B12, are common in heavy drinkers, and these are essential for cell division and red blood cell production. Iron is also affected, as its role is to transport oxygen to the hair follicles; a deficiency can slow growth and lead to shedding. Zinc, necessary for hair tissue growth and repair, is poorly absorbed or quickly lost with excessive alcohol intake, compromising the strength and thickness of the hair.
Hormonal Influence on the Hair Growth Cycle
Alcohol consumption can trigger endocrine changes that negatively impact the normal hair growth cycle, which is governed by hormonal signals. One significant effect is the elevation of cortisol, the stress hormone released by the hypothalamic-pituitary-adrenal (HPA) axis. Alcohol activates this stress response system, leading to sustained high levels of cortisol in the bloodstream.
Prolonged exposure to elevated cortisol can prematurely shift hair follicles from the active growth phase (anagen) into the resting or shedding phase (telogen). This disruption results in telogen effluvium, characterized by noticeable, widespread hair shedding that typically occurs a few months after the hormonal trigger.