Survey data suggests that about half of the global population has grey hair by the age of 50. Certain nutritional deficiencies and health conditions are thought to be at the root of premature greying. But separate evidence suggests other environmental factors, such as stress, may play an equally important role. According to one study, curry leaves may help “prevent” greying by retaining hair pigmentation.
Hair greying is one of the inevitable consequences of ageing.
“Your hair follicles produce less colour as they age, so when hair goes through its natural cycle of dying and being regenerated, it’s more likely to grow in as grey beginning after age 35,” explains Harvard Health.
“Genetics can play a role in when this starts.”
“Most grey hair is not related to stress. In fact, hair doesn’t actually turn grey at all.
The health body continues: “Once a hair follicle produces hair, the colour is set. If a single string of hair starts out brown or red or black or blond, it is never going to change its colour.”
Evidence suggests the degeneration of the body is responsible for a shortfall of melanocytes, which gradually brings the production of melanin to a halt.
Melanin is the pigment that gives hair its colour, so as its production comes to a halt, new hair follicles are produced void of colour.
Experts suggest consumption of certain foods may help hamper this process.
Curry leaves, in particular, may act as a buffer against greying due to their vitamin composition.
A report in the International Journal of PharmTech Research suggested that topical use of the herb may slow hair-whitening without causing damage to hair pigments.
“Murraya koenigii will retain the black colour of the hair or in other words, will prevent the premature greying of the hair,” wrote the authors of the report.
The herb is a good source of Vitamin D, Vitamin B, Vitamin C and iron.
Previous studies have demonstrated that Vitamin D and B play particularly important roles in preventing the loss of hair colour.
In fact, there is mounting evidence that individuals with premature greying are often deficient in one or both nutrients.
Foods to avoid
According to one 2020 study published in Nature, the greying process starts with the stimulation of nerve cells that use the adrenal gland to secrete norepinephrine.
The secretion of norepinephrine triggers the division of cells in the hair follicles, which leads to a depletion of melanocytes.
Studies have linked high salt intake to chronic kidney disease and high blood pressure, with anything over 2300 mg per day deemed to be unhealthy.
In fact, studies have suggested a high hair-whitening could be associated with an increased risk of heart disease.
Similar effects have been noted with refined sugar intake.
It is widely known that sugar intake can have repercussions for hair loss, but some experts suggest sugar may also have adverse effects on hair pigmentation.
This is because sugar may increase the generation of free radicals in the body – one of the hallmarks of premature ageing.