TLDR Not eating enough protein can cause hair roots to shrink and lose color, and hair to become thinner.
The study involved eight male subjects aged 24 to 29 who underwent protein deprivation for 15 days, resulting in severe atrophy and decreased pigmentation of the hair bulb, with hair diameters significantly reduced from 0.250 to 0.550 mm to 0.025 to 0.075 mm. The absence of the external root sheath in atrophied bulbs and frequent absence of the internal root sheath were also noted. The findings suggest that examination of hair roots can serve as a diagnostic tool for protein-calorie malnutrition.
26 citations,
March 1986 in “Clinical and Experimental Dermatology” Scalp hair grows at 0.37 mm/day, forearm hair at 0.18 mm/day, and thigh hair at 0.30 mm/day, with no significant differences found in people with certain hair conditions.
26 citations,
November 1968 in “The Lancet” Malnourished Andean Indian children had abnormal hair roots compared to healthy children.
November 2019 in “Harper's Textbook of Pediatric Dermatology” Understanding normal hair growth and loss in children is key to diagnosing and treating hair disorders.
20 citations,
November 1968 in “The Lancet” Potassium levels affect blood sugar and insulin during dialysis, and malnutrition changes children's hair roots.
20 citations,
May 2020 in “Experimental Dermatology” Aging scalp skin contributes to hair aging and loss, and more research is needed to develop better hair loss treatments.
