What happens when you swallow a hair?
Let’s say you are at your favourite restaurant and you have just ordered a bowl of soup. You grab your spoon and when you have just begun to dive into it, you spot a strand of hair. You have these options: send the soup back to the kitchen, pick out the hair and eat it anyway, or just slurp down the soup with hair in it. But what will happen to your body if you swallow a hair strand?
A single strand of hair probably won’t do much harm. The only scenario in which hair would pose a health threat is when you eat a whole clump, as it could form a giant hairball in your stomach. Hair is made up of a densely packed protein called Keratin. Humans are not capable of breaking down keratin, because to do so, it has to be treated at very acidic and alkaline conditions at a temperature of over 100 degree Celsius for a long duration. However, in the human’s digestive system, such conditions do not exist. So, small amounts of hair would just pass right through your body, along with everything else you can’t digest.
Cats swallow fur all the time and also can’t digest their hair. Whatever doesn’t pass through their digestive systems builds up in their stomachs as a firm, dense, hairball. Eventually, most cats can vomit up hairballs before they get too bad.
Hair isn’t biodegradable for example, when Egyptian mummies are discovered, their hair is usually intact. Ingesting a large volume of hair over a long period of time could lead to formation of a firm, dense, hairball, called trichobezoars, in your stomach which could cause severe abdominal pain and other symptoms.
There has been a report of an 18-year-old girl who was suffering from stomach pain, vomiting and losing at least 18 kg over a period of five months. But later, gastrointestinal endoscopy revealed a giant hairball blocking her stomach. Upon questioning, the girl said that she had had a habit of eating her hair for many years. This disorder where one is compelled to eat his or her own hair is called trichophagia.
Is it okay to eat food with a hair in it?
For the most part, it's not a health threat. It’s so benign that the Food and Drug Administration in its Food Code guidelines doesn’t even place a limit on strands per plate. The FDA has received no reports of people getting ill from ingesting hair found in food.
Losing hair and shedding
Hair follicles work in cycles as part of their normal processes. There are 3 cycles of hair growth, 1) anagen is the growth cycle, 2) catagen is the cycle where hair breaks down, and 3) telogen or resting cycle is where hair shedding normally occurs. Anagen hair grows for about 2 to 8 years and at the end of this growth cycle, the brief (2 to 4 weeks) catagen phase ‘kicks’ in and the hairs start to break down. Hair then goes into the telogen or resting cycle which can last for 2 to 4 months. Eventually, the growth cycle starts again (anagen) where a new hair begins to emerge.
On a normal scalp, hair loss in the telogen or shedding phase is not noticeable as only 50 – 100 hairs are shed each day. And, no more than about 10% of all follicles on the scalp are in the resting (telogen) phase at one time. Since the normal scalp has over 100,000 hairs, the hair loss part of the cycle is not noticed since hair is normally shed on a random basis.
Shedding is NOT the same as “losing hair”. Shedding is in fact just the transition of follicles from growth phase to resting phase. On a normal scalp, follicles don’t generally die, never to return to growing hair. They in fact “go to sleep”, to return to producing hair several months later.
Hopefully your shedded hair doesn't end up in your soup !