You may want to consider taking a sip of this drink; it may be doing much more good for your gut than you thought. A new study from Japan suggests that kefir, a fermented beverage long considered friendly to the digestive system, may also help slow aging processes and even reduce some of the changes that come with age.
The timing, it seems, is no coincidence. In the coming decade, the number of older Americans is expected to surpass the number of children, for the first time in U.S. history. The implication is clear: Maintaining health in older age is becoming one of the most important issues of the coming decades.
What happens to the body as we age?
Over the years, the immune system weakens. Immune cells slow their rate of division, which impairs the body’s ability to fight infections. At the same time, a low-grade chronic inflammation develops—one that is not felt in daily life but is linked to a long list of age-related diseases. Vital organs such as the thymus and the liver also gradually lose function.
Scientists from Shinshu University in Japan set out to examine whether fermented dairy products such as kefir could influence these processes. In the study, elderly mice were fed for eight weeks with a specific strain of lactic acid bacteria derived from kefir, called Lentilactobacillus kefiri YRC2606. The condition of their immune systems was then examined.
The findings were encouraging: Mice that received the bacterium showed fewer age-related changes in key organs such as the thymus and the liver. In addition, lower levels of inflammation and of proteins that inhibit cell division were found—a process considered one of the central drivers of tissue aging.
According to the lead researcher, Hiroka Sasahara, these are preliminary but unique findings that may indicate potential for maintaining a stronger immune system in older age.
The researchers emphasize that this is not a magic solution. However, they believe that the bacterium studied could in the future be incorporated into functional foods or dietary supplements designed to maintain immune function in older adults. Strengthening the immune system, they note, is a key factor in preserving independence and quality of life with advancing age.
Why is kefir considered so healthy?
Kefir is a fermented milk drink that originated in the mountainous region between Asia and Europe. It is similar to yogurt, but thinner and with a tangy flavor. Its name is derived from the Turkish word “keyif,” meaning a feeling of well-being after eating.
One cup of kefir provides about 9 grams of protein and more than one-third of the recommended daily intake of calcium, which is essential for bone health. It also contains phosphorus, magnesium, and important vitamins such as B12, B2, D, and K2.
Kefir is rich in probiotics—beneficial bacteria that have been linked to improved digestion, balancing of the gut microbiome, support for mental health, assistance with weight management, and even contributions to heart health through the reduction of “bad” cholesterol.
Previous studies have shown that another bacterium found in kefir, Lactobacillus kefiri, is capable of inhibiting the development of harmful bacteria such as Salmonella and E. coli.
The bottom line
Despite the benefits, experts recommend not rushing or overdoing it. Probiotic foods and drinks may initially cause bloating, gas, or digestive discomfort, so it is advisable to introduce them gradually.
People who take medications that suppress the immune system should consult a physician before consuming kefir, as it contains live bacteria and yeasts that are usually controlled by a healthy immune system.
The Japanese study adds another interesting layer to the growing body of knowledge surrounding kefir and health. It does not promise eternal youth, but it does point to the possibility that a simple and accessible drink may help support immune health and bodily function over the years. As always, the recommendation remains the same: A balanced, varied, and personalized diet is preferable to any single solution.