Most of us know camels as curiosities at zoos. As beasts of burden highly adapted to hot and dry climates, they’ve served the trade routes that helped build civilizations, and may indeed flourish in our increasingly hot and dry world. We value their hide, meat, and especially their milk.
Camels are unusual, biologically speaking. And that may be why their milk can alleviate some aspects of autism.
A camel. Image credit: Peggy_Marco via Pixabay (Free Pixabay licence)
“Camel milk sounds weird to American ears, but camels are a domestic fact of life elsewhere. Although the US classifies them as ‘exotic” animals, they actually have early origins here; fossils have been found in Los Angeles. But the true reservoir of knowledge on camels is found in rural cultures and universities in the Middle East, Asia, and Africa,” Christina told me.
Got Camel Milk?
In 2005, Christina met a camel at a children’s book fair in Orange County CA. Rather than hauling kids around, the animal was standing near a display of lotions and soaps made with camel milk. When the owner started to tell Christina how the milk is hypoallergenic and helps premature babies in the Middle East, she glanced over at 7-year-old Jonah. He’d already had four years of costly treatments for autism.
“Might it help ‘reboot’ my son’s immune system and help his autism symptoms?” she recalls thinking, aware of a link to immune dysfunction. “Cow milk and cheese made him hand-flap and walk in circles, which he described as feeling like ‘having dirt in my brain.’ Vegan substitutes like rice, nut, or soy increased his allergic response.”
Camel Crazy details Christina’s two-year journey to find the milk. Once she started giving it to Jonah, four ounces at a time, mixed in with food like cereal, his behavior changed quickly.
He became calm. Inquisitive. Caring. His language became more emotional and focused. He held his head straight instead of rolling it. Eating became neat, not a mess fest. He dressed and began making eye contact. He even got his shoes and backpack on and was calmer in the car going to school.
By the third dose, Jonah was sleeping through the night. “He became more fluid, social, and attuned. Within days he could cross the street without me holding on to him. Within weeks his skin grew smoother. The milk also reversed his skin irritation, agitation, mental distraction, hyperactivity, and stomach pain,” Christina recalled.
So she did research and spread the word, first in an article – “Got Camel Milk?” – that went viral, then in a peer-reviewed case report, “Autism Spectrum Disorder Treated With Camel Milk,” published in Global Advances in Health and Medicine. After describing Jonah’s early difficulties, she wrote “on October 10, 2007, two weeks before my son’s tenth birthday, he drank his first half cup (4 oz) of thawed raw unheated camel milk.” The case report documents Jonah’s “sustained symptom improvements” associated with drinking half a cup a day from 2007 to 2013.
Christina then began traveling the world, giving presentations on camel milk and autism, and consulting with scientists and vets. Camel Crazy details her immersion into the world of camels and ‘cameleers’, from Tuareg, Amish and Somali people in America to herders in India, Dubai, and Abu Dhabi. She serves on the editorial board of the new International Journal of Camel Science.
I was a beta reader for Camel Crazy and loved it. Being a nerd I searched for the science, and wasn’t disappointed. The milk indeed has some startling differences from other milks, yet tastes, Christina says, like cow’s milk.
Camels drink a lot, pee a little, exhale minimal vapor, have insulating coats, and their red blood cells balloon and shrink as the water content in the bloodstream shifts. Natural selection has favored persistence of these traits that provide adaptation to heat, aridity, and exposure to intense ultraviolet radiation and choking dust. Body temperature ranges from 93.2-104°F (34–40°C).
Being specifically a genetics nerd, I delved deeper into the DNA that encodes the unusual versions of proteins that might explain the magic of camel milk, as well as other details of the physiology. Much of the info below comes from the article Desert to Medicine: A Review of Camel Genomics and Therapeutic Products, from three researchers at United Arab Emirates University.
Fighting an Opioid Released from Casein Breakdown
The first technical paper Christina found was “The etiology of autism and camel milk as therapy,” from Ben Gurion University researchers Reuven Yagil and Yosef Shabo. Parent reports inspired their work.
They zeroed in on an opiate-like effect. Casein, the most abundant milk protein, breaks down into peptide pieces. And one of them, beta-casomorphin-7, is an opioid. It can slip through the “leaky gut” of a person with autism and enter the brain. Could an opiate bathing the brain affect social interactions and lack of interest in surroundings?
Other breakdown peptides of casein (β-casein and no β-lactoglobulin), which are more abundant in cow’s milk, may spike milk allergies.
Upping Anti-Oxidants
Camel milk delivers potent anti-oxidants that might temper autism symptoms, wrote King Saud University researchers Laila Al-Ayadhi and Nadra Elyass Elamin in a 2013 report. People with autism are more sensitive to oxidative stress, which is damage from unstable forms of oxygen called oxygen free radicals.
The researchers measured levels of three anti-oxidants in the blood of 60 kids with autism: superoxide dismutase, myeloperoxidase, and an enzyme needed to make glutathione. Over a two-week period, 24 children drank raw camel milk, 25 drank boiled camel milk, and 11 drank cow’s milk. The trial was double-blinded and randomized, but it wasn’t a crossover, in which each child would have had all three milk experiences. Nevertheless, raw camel milk was superior in anti-oxidant levels and a behavioral rating scale.
Special Tiny Antibodies
Camels share with only their camelid brethren (llamas, alpacas, vicunas, and guanacos) tiny antibodies in milk, called nanobodies. Most antibodies have one or more Y-shaped subunits; a nanobody is one arm of one Y, the variable region that distinguishes species. A student discovered camel nanobodies in a lab course at the University of Brussels in 1993, analyzing a dromedary’s blood serum. Camels make large antibodies too.
A camel’s nanobodies consist of only variable regions of single Y-shaped immunoglobulin subunits.
Nanobodies can squeeze into places more bulbous antibodies cannot, vanquishing a wider swath of viruses and bacteria. They look strikingly like monoclonal antibodies, and so have become darlings of pharma, particularly in cancer drug discovery.
A camel’s streamlined nanobodies arose from a mutation that removed the hinges that connect the Y-shaped arms of more conventional antibodies. Sometimes a mutation is a good thing!
Further infection protection comes from the milk protein lactoferrin, which fights hepatitis C.
Tolerating High Blood Sugar
A camel-herding people in India, the Raika, drink camel milk and don’t get diabetes. That’s because camels tolerate high blood glucose levels, and some of that ability seeps into their milk.
P. Agrawal, at the SP Medical College, Bikaner, India, and colleagues have conducted clinical trials that show that camel milk decreases blood glucose and hemoglobin A1c (a three-month-measure of blood glucose), and, in people with type 1 diabetes, reduces the insulin requirement by up to 30 percent.
How can camels have high blood sugar yet low HbA1C? In most animals, the beta chains of hemoglobin bind glucose at several points, upping HbA1C. This doesn’t happen in camels. If glucose binding to hemoglobin in us is like Velcro, then in camels, it’s like contact between a boot and slippery ice.
Conserving Water
Milk requires water, and camels are masters at conserving it. A “self-contained cooling system,” as Christina describes it, cycles body water from a camel’s nostrils to its mouth. The multi-layered eyelids and double row of eyelashes keep out blowing sand. “Their unique oval blood cells compress as camels safely dehydrate, then swell up again as they refill with water, keeping their blood flowing in extreme conditions.”
Camels don’t dry out in the desert, as we would, thanks to variants of the genes that encode the cytochrome P450 (CYP) enzymes. They enable camels to resorb lots of water while tolerating high salt conditions, without their blood pressure spiking. Their kidneys are keenly attuned to taking back water.
Camel milk is also high in the calming neurotransmitter GABA, low in lactose, and has more vitamin C than cow’s milk.
Beyond Milk
The astonishing adaptations of the camel aren’t restricted to its milk. Here are a few more that have their roots in the animal’s genes.
- The urea cycle conserves nitrogen, used to make protein in the face of limited food.
- The heart makes a lot of the protein α-actinin, enabling it to beat steadily through fluctuating drought and wetness.
- Hiked enzyme levels in the brain and liver keep up energy supplies.
- Vimentin protein in cells in the hump mobilizes fat, releasing energy.
Variations on the Camel Theme
About 94% of the world’s 35 million camels are the domesticated, one-humped dromedaries (Camelus dromedaries) of northern and eastern Africa, the Arabian Peninsula, and southwest Asia. A feral branch lives in Australia. Wild dromedaries are extinct and are in a separate genus, Camelops hesternus. They dwelled in western North America.
About 2 million two-humped domesticated Bactrian (Camelus bactrianus) camels live on the steppes of central Asia, and each weighs about 1,000 pounds. Fewer than 100 wild Bactrian camels remain; they split from a shared ancestor about 700,000 years ago. Today they live in Mongolia and in northwest China’s Xinjiang Province, in an area that was a nuclear testing site for 45 years. In 2008 the wild Bactrians were designated a distinct species, Camelus ferus.
When bactrian and dromedary camels interbreed, most offspring have one hump, some with a dip in the middle.
Camel Genomics
Camel genomes are remarkably diverse with many mutations, perhaps because people haven’t controlled their breeding. Doing so is challenging.
The jelly-like consistency of camel semen complicates both freezing and using artificial insemination. Still, researchers from Oman and France recently published a report about possible genetic improvements: selecting for traits that ease of using milking machines, provide resistance to infections, improve racing ability, and enhance beauty. Camels are, after all, gorgeous creatures.
The first camel genome sequence, published in 2012, revealed 20,821 genes splayed out among 37 chromosome pairs. Some 2,730 genes have evolved faster in camels than in their cattle relatives, many involved in carbohydrate and lipid metabolism. Perhaps the unusual variants contribute to the camel’s ability to conserve water.
Researchers from Kuwait University report in PLOS One that they analyzed DNA from the blood, spit, and hair of nine camels, concluding that tail hair follicle DNA is the best tissue source to create a biobank. The International Camel Consortium for Genetic Improvement and Conservation promotes camel genetic conservation.
The milk isn’t cheap. Camel Milk Coop lists $36.99 for a week’s supply. And as Christina’s book explains, there’s little to no incentive to conduct a clinical trial or to attempt to replicate nature’s magical mix of milk ingredients. Camel Crazy includes a user’s guide and directory of global sources.
The milk is available in liquid, frozen, and powdered form. Camel-milk-containing products include skin cream, cheeses, ice cream pops, chocolate milk, and a delectable-looking sweet called barfi, which means “snow” in Persian (not vomit).
Source: PLOS EveryONE