Kefir: A Wonder Beverage from the Ancient World
The people who inhabit the Caucasus Mountains of the former USSR are very long-lived, remaining healthy, vital and, legend has it, even becoming parents well into advanced old age. There are stories about some people living into their 160s. However, when researchers went there, looking to verify some these claims, it seemed that Shirali Musilov, who claimed to be 168 year old when interviewed by National Geographic1, may have been using his father’s passport as his own, making him a spry young man likely only in his 120s. Regardless of the veracity of Mr. Musilov’s claim, there are an abundance of centenarians living in these mountains on the border of Iran.
Is it the clean, mountain air that allows so many people to live so well for so long or is it something else? In its article on the remarkable longevity of the Caucasus Mountains, the New York Times makes reference to a milk beverage that people drink there that is not yogurt, but is similar to it. The drink that is enjoyed regularly by those who live there is kefir, a fermented milk beverage that is slightly effervescent and tastes like sour, unsweetened yogurt. Kefir and similar fermented dairy beverages have long be consumed for their health promoting properties.
Kefir has been consumed in the Caucasus Mountains for thousands of years, according to archeological evidence, and was considered a gift from God (Allah) by the Muslim people who lived there. It is said that the Prophet Mohammed personally blessed the kefir “grains,” but warned that if the grains or recipe were given away the beverage would lose its power. Families passed down their prized kefir grains (the microbial bodies that ferment the milk into kefir) to their children.
The kefir grains, which were considered a source of wealth, were carefully guarded and renowned in the ancient world for their health benefits. Some scholars believe that kefir grains were in fact the “manna” described in the Bible as being provided by God to feed the Israelites as they wandered the desert for forty years before Moses led them to the Promised Land. They also think that kefir is what that angels taught Abraham to make, which he credited for his long life and many children. Its name, kefir, may have come from the Turkish word “keyif” that means “good feeling” and got its name because traditionally, drinking kefir was associated with general well-being.
In the early 1900’s, the All-Russian Physicians’ Society who heard about this amazing elixer tried to obtain some kefir grains from a Caucasian prince, Bek-Mirza Barchorov. They sent over a beautiful female employee, Irina Sakharova, to beguile him to share. While her efforts were unsuccessful in getting him to give her the grains, he did propose marriage to her and kidnapped her when she tried to leave. She was eventually rescued and later threatened Prince Bek-Mirza with legal action. After refusing his offer of jewels in reparation, and to avoid further prosecution, he gave her kefir grains that were brought back to Russia. There, the probiotic kefir that was produced became widely used to treat tuberculosis (before the availability of antibiotics), digestive disorders, atherosclerosis and even cancer, with apparent success. Kefir became an extremely popular drink in Russia, and later throughout Europe, because of the excitement over its purported health benefits.
Though it is believed that kefir originated in the Caucasus Mountains, similar lactic acid fermented milk beverages are also cultivated elsewhere in the world. People in Tibet make a beverage known as “Tibetan Yogurt Mushroom” or “tara” that has very similar qualities to kefir. Other traditional fermented milk beverages are made in Taiwan, northern Europe, central Asia and Africa.
So what makes this slightly carbonated, slightly tart, yoghurt-like drink so special? Dr. Nicholas Perricone, the anti-aging skin expert who has an eponymous, outrageously expensive skin care line, has called kefir a superfood.
Kefir contains large numbers of probiotics – the microbes that live in our bodies and provide us with important health benefits such as boosting immunity, calming inflammation, assisting in digestion, creating amino acids and vitamins, and aiding in digestion. Kefir, which can be made from any type of mammalian milk, also contains partially digested proteins, enzymes (including lactase, which is good for people who are lactose intolerant), vitamins (A, B1, B3, B9/folate, B12, D and vitamin K), minerals and essential amino acids.
The beverage is fermented from fresh milk (can be cow, goat, ewe, buffalo, horse or even human milk) by the microorganisms contained in the living kefir grains. There have been reports that successful kefir has been made from soy milk and coconut milk, too. As part of the fermentation, probiotics enter the kefir, but have different microbiological mix than the grains themselves. During fermentation, several components are produced including alcohol (in minute quantities), lactic acid, carbon dioxide, enzymes and vitamins. Lactose that was originally in the milk is reduced so many people who are lactose intolerant can drink it without problem.
Kefir has been used for the treatment of atherosclerosis, allergies, diseases like eczema that are related to allergies, gastrointestinal disorders, tuberculosis and cancer. However the studies that had been conducted, until recent times, have been inaccessible to most researchers in the West because they were written in Slavic languages, where kefir was popular and the research had been done. Additionally, those studies often lacked random assignment to control groups or other requirements for validity.
As interest in our microbiomes has increased, however, medical researchers in the Western world have started to take an interest in finding out if there is any truth to the wide-ranging claims about kefir. Western and Asian researchers have undertaken multiple studies with extremely encouraging results. We should all hope that the fact that kefir can be made at home, at a cost no more than the price of the fresh milk used to create it, will not slow down or deter future research into its health benefits, given the potentially low commercial potential of this product to major pharmaceutical companies who typically fund such research.
Immune System. Several studies have confirmed that the immune system response is enhanced by kefir, although it is not yet clear whether it is the bacteria in the kefir, metabolites produced during fermentation or an element of the kefir grains themselves that cause this effect. A stimulated immune system is better at identifying and combatting disease2. Kefir is very effective at maintaining a balanced and healthy gut microbiome, which boosts the ability of the gut to fend of pathogenic microbes.
Gastrointestinal Disturbances. Kefir consumption has been shown to be helpful both in preventing constipation as well as preventing and treating diarrhea. It has also been shown to reduce flatulence. Lactose intolerant subjects have been shown to be able to tolerate kefir without symptoms.
Allergies. It has been shown that consuming kefir has reduces asthma symptoms in mice. It can decrease the allergy response to symptom triggering allergens, according to research34. Kefir has also been shown to reduce food allergies in study participants5.
Anti–Inflammatory Effects. In mouse studies, kefir has been shown to reduce inflammation.
Cancer. There have been many promising studies on the effect of kefir (including the probiotics in kefir) and cancer. The probiotics in kefir have been shown to bind to mutagens that are potentially cancer causing, thereby reducing their potential harm to the body – anti-mutagenic effects. Those people who drink kefir regularly are statistically much less likely to get colon cancer than those who do not6. It has been shown to have anti-mutagenic effects with respect to colon cancer and thus may play a role in colon cancer prevention7. The kefir grains themselves have been shown to have tumor inhibiting capabilities for sarcomas, melanomas, lung and breast cancer cells – anti-carcinogenic effects8. It will be really exciting to see the results from studies on cancer and probiotics that are currently underway.
Antibacterial and Antifungal. Kefir has shown anti-microbial activity against a wide range of harmful bacteria and fungi. Kefir can help to control rotavirus and Clostridium difficile (C. difficile) infections as well as ulcers related to Helicobacter pylori. It can be used as antibiotic therapy. It has been effectively used to treat travellers’ diarrhea.
As people have been drinking kefir for thousands of years without concern, it is apparent that the microorganisms in kefir are not generally pathogenic. However, the microbes in kefir might be potentially harmful for people with significantly compromised immune systems and anyone with this concern should consult with their physician before taking any probiotics, including kefir.
People who make and drink their own kefir tend to be a bit fanatical about it and believe that it can provide a wide range of benefits to those who drink it. To the best of my knowledge, the following claims, while widely believed, do not have much, if any, research behind them. If any of you are scientist wanna-be’s like me, it’s fun to conduct your own informal studies to test some of the purported benefits of kefir with your friends and family. Some of kefir’s potential benefits, that haven’t already been discussed, are:
Cleanses the body of Toxins
Nourishes hair and potentially reduce the gray
Treats liver disease
Treats gallbladder, dissolves gall bladder stones
Treats gum disease
Lowers LDL cholesterol
Treats Irritable Bowel Syndrome
Treats Candida and other fungal infections
Treats psoriasis and eczema
Treats lung infections
Normalizes metabolism to help with weight loss
Lowers blood sugar
Helps with sleep
Comparison to Probiotic Supplements
Typical probiotic supplements are made by manufacturers or laboratories who culture one or several different bacteria and yeasts species for inclusion into capsules with nutrition to keep the colonies alive. The manufacturers may claim that each capsule has several billion CFUs (Colony Forming Units) of live probiotics, but in actual fact, by the time the capsule arrives in your stomach, the actual numbers can be greatly reduced. Because the probiotics are living microbes, over time they die – so age of the supplement is a factor. Exposure to heat can further hasten the decline in numbers of CFUs in the capsule. Finally, not all of the probiotics in the supplements survive the digestive process – the acid in the small intestine can kill them.
Kefir, meanwhile, can be made and consumed fresh in the home so the issues of time and storage are less of an issue as your home is your laboratory. Milk Kefir can contain up to fifty strains of helpful bacteria and yeasts. The quantities of the probiotics are typically many times higher in kefir than what are found in a capsule – a cup of homemade kefir can contain 2.35 trillion CFU’s. The kefir itself contains protective ingredients that enable more of the probiotic bacteria to make it to the lower intestine, where they do their hard work.
What are these highly prized grains that can inspire intrigue the likes of which could be described in a chapter of the Arabian Nights? The grains are an actual living ecosystem that is composed of multiple strains (up to 400) of friendly bacteria and yeasts that are held together in a structure composed of proteins, lipids, and polysaccharides. Because the grains are alive and reproduce, with care and constant feeding the grains can be kept alive and continue producing kefir indefinitely. Kefir grains are often compared in looks to cauliflower heads, but have a gelatinous texture.
Different strains of kefir grains do not contain exactly the same mix of bacteria and yeasts, but certain probiotic microorganisms are almost always present. Many of the probiotics that are often found in kefir grains, and in varying degrees in the kefir, have been extensively studied by medical researchers with multiple positive health effects.
A sample of the bacteria in kefir and associated health benefits are as follows:
Lactobacillus acidophilus. Increase appetite, reduce stress, reduce acne, reduce rosacea, reduce irritable bowel syndrome, reduce asthma, reduce high cholesterol, assist in lactose digestion, prevent or treat diarrhea.
Lactobacillus casei. Increased appetite, produce collagen binding proteins, preventing antibiotic associated diarrhea and Clostridium difficile infections, treating diarrhea, treating pancreatic necrosis, treating SIBO.
Lactobacillus rhamnosus. Increased appetite, treat or prevent diarrhea, reduce anxiety, prevent eczema, support weight loss, produces Hyaluronic Acid for skin health, preventing abdominal obesity, produce collagen binding proteins, reduce inflammation in Crohn’s disease, reduce risk for respiratory infections in children, preventing or treating atopic dermatitis, preventing urinary tract infections (UTIs), reducing intestinal permeability (“Leaky Gut”)
Streptococcus thermophiles. Reduce anxiety, produces Hyaluronic Acid for healthy skin, increases skin ceramides, encourage steady growth rate in children, improves diet induced obesity and insulin resistance, preventing chemotherapy induced mucositis, reduce instances of lung cancer, prevent antibiotic induced diarrhea
Saccharomyces cerevisiae. Reduce constipation, reduce acne, stimulate immune system, anti-tumor action
Kefir Production – Traditional
Traditional kefir is made by putting kefir grains in mammalian milk, most commonly cow’s milk. Purists prefer raw milk, but excellent kefir can be made with regular, homogenized store bought milk. UHT milk does not seem to work as well as fresh milk.
Depending on the temperature at which the fermentation takes place, the kefir grains are typically left in the milk for 12 – 48 hours. When the kefir starts to thicken and take on the consistency of runny yoghurt, the grains are then strained out. They can be immediately reused to make a new batch. With proper care, they will continue to produce indefinitely. To slow down the fermentation process, the kefir grains can be kept in milk in the refrigerator for up to two weeks. If the grains are not given a steady supply of milk, they will gradually die.
Grains cannot typically be readily obtained in a store as they are living organisms that require continuous feeding with milk. Craigslist or other local classified sites sometimes have listings of people who are willing to share extra grains for a nominal cost. We, at HealthyGutBugs, were lucky enough to obtain our kefir grains from a very kind woman found on a local list-serve focused on nutrition and health, and have been freely sharing our new “babies” with eagerly interested friends. Cultures for Health reportedly ships live kefir grains internationally but we don’t have any experience with them. If anyone has stories about procuring your own kefir grains, please share your story in the comments section below.
See my “how-to” guide for making your own milk kefir at home.
Powdered Kefir Starter
Kefir starter cultures are readily available. They are added to milk and contain typically about 7-9 bacterial strains that have been selected for inclusion by the manufacturer. Powdered kefir starter is a good option for people who do not want to regularly make kefir because the powdered starter can be kept in the freezer until used.
Reserved kefir from the first batch made from powdered kefir can be used to start several new batches, until eventually the bacteria lose strength and can no longer ferment milk.
Consumers can buy pre-made kefir in some grocery stores and health food stores. It is often flavored and pre-sweetened, and is delicious and very convenient. Quality and taste are consistent. The manufacturer uses powdered kefir starter to produce it and it contains only the particular probiotic microbe strains that the manufacturer chooses to include – typically less than 10 of them. However, the quantities and variety of probiotics found in commercial kefir is much higher than would be found in store-bought yoghurt.
Commercially manufactured kefir cannot be used as a starter to make new batches.
There is a different type of grain, the water kefir grain, which is fermented in sugar and water. It is also known as tibicos, tibi, Japanese water crystals, or sugar kefir. No milk is necessary to create the probiotic beverage. This variant on kefir is refreshing in hot weather and offers an alternative to milk kefir for people who are allergic to dairy products. It tastes slightly sweet and fermented, but can be mixed with juice to make it taste more interesting.
The water kefir grains are smaller than the milk kefir grains and look like crystals. The strains of microbes in the water kefir are different than what is found in the milk kefir. Typical strains of water kefir grains contain a mix of Lactobacillus, Streptococcus, Pediococcus and Leuconostoc bacteria species and Saccharomyces, Candida, Kloeckera yeast species. The variety of probiotics found in water kefir is lower than is found in milk kefir. If properly cared for and fed the grains will continue to produce kefir and reproduce indefinitely, like the milk kefir grains.
The finished beverage is a yeasty smelling, slightly carbonated drink with a very low alcohol content (approximately 0.08%). The beverage typically ferments for about 48 hours.