They swear by a mouthful of clay!

Nairobi / AFP

When Beatrice Athiambo pulls the plastic covering off her stall in the Kenyan capital of Nairobi in the morning, her first customers are already waiting.
They want to buy the earth that she sells – to eat. In Africa, geophagia, the eating of clay or stones, is widespread, especially among pregnant women, though estimates vary widely from between 28 to 84 per cent of pregnant women. Some collect it themselves, from quarries, termite mounds or river beds, while others buy their favourite soil at the supermarket, where it’s often sold fired and looks like large stones.
Athiambo, whose stand “Mawe ya kula” (meaning “Stones to eat” in the Kisuaheli language) is nestled between others selling trousers, pans and torches in Nairobi’s Toi market, sells all kinds.
From orange-coloured blocks which crumble to sand in the mouth, to rougher, harder, grey blocks which are actually otherwise used for building and are much too hard for teeth, Athiambo has a full range.
She buys her wares directly from a clay pit in 100-kilogram sacks and hacks the earth to brick-sized pieces with a machete. She charges 5 Kenyan shillings (5 US cents) for a block the size of an apple. The smaller pieces cost 3 shillings.
Athiambo launched her business four years ago because she herself enjoyed snacking on clay.
But why do people like eating earth, sometimes several hundreds grams a day?
A group of researchers at the Medical University of Vienna led by medical anthropologist Ruth Kutalek set out to ask consumers.
The survey in Uganda and neighbouring Kenya cannot be representative of Africa as a whole, Kutalek says, but it does give scientists some insight into the little-studied phenomenon.
The team questioned 50 people including men, pregnant and non-pregnant women and medical experts, and concluded that the practice was most widespread among pregnant women, who said they had cravings for clay.
They said it helped combat morning
sickness and heartburn and that it was the smell which appealed to them, of fresh earth after rainfall, or of freshly fired bricks.
“It’s addictive. My mouth starts watering when I see it,” says Joyce Andalo. She’s a regular customer of Nicolas Mutesia, who also sell clay at the Toi market.
The 34-year-old saleswoman first tasted clay as a young girl when her mother bought some and now she tries to see it as a reward, like having a cold drink after a long day at work.
During her last pregnancy she ate four to five of the big blocks every day, she admits, with a rather embarrassed expression.
Some scientists believe iron deficiency is the main reason for geophagia. There are no studies that confirm this theory, according to researchers from French-Guiana, but there’s lots of evidence that points in that direction.
The structure of clay can mean it acts as a detoxifier, which evolutionally has been very important.
Humans have been eating clay since time immemorial and people still eat it in parts of the United States, Latin America, and India as well as Africa. It can also be purchased in certain supermarkets in Europe.
At Nairobi Hospital, gynaecologist Samson Mabukha Wanjala treats women who eat earth every day. “The body reacts physiologically by craving something that it needs,” is his explanation for the phenomenon. Pregnant women, for example, need a lot of calcium.
Wanjala has been practising in Kenya since the 1970s and says geophagia is as common in the cities as it is in rural areas and has hardly changed over the years.
But, he says, clay-eating is not without risks.
“While they’re satisfying their cravings, they often catch other illnesses, like infections.”
The clay isn’t usually hygienically treated and – like building material – lies around on the ground. Diarrhoea and worms are common side effects. There have been no reliable studies about the effect of clay-eating on the human body, says Kutalek.
But many of the clays sold contain heavy metals which could be dangerous.
The French-Guiana researchers believe eating clay could even make iron-deficiency worse and is possibly poisonous – they therefore recommend people refrain from it.
Mother-of-two Andalo did give up her habit briefly during her last pregnancy, when her doctor gave her some supplements.
“But just a few months after the birth…,” she says with a laugh and pops another nut-sized piece in her mouth.