By Dr. Jeremy Girmann
A large number of you have probably heard of stem cells but may not be particularly familiar with the topic beyond what often appears in the news and entertainment media. Much of what makes headlines relates to human embryologic stem cells. These cells have the natural ability to turn into any type of tissue – a characteristic that is known as pluripotency. Because of this, embryologic stem cells have huge therapeutic potential but consideration of their use in research and clinical settings is also extremely controversial since they are ultimately fated to form a fetus. In recent years, however, exciting scientific discoveries have identified ways in which to essentially reverse engineer fully matured adult cells, turning them back into cells that can become various types of tissue. This is known as induced pluripotency. In 2012, Dr. Yamanaka was awarded a Nobel Prize for demonstrating, in what seems to be the stuff of fantasy, the ability to turn mature fibroblast cells back into stem cells. While there is still much work to be done, this discovery could perhaps skirt much of the controversy related to pluripotent stem cells and allow for the advancement of many medical treatments.
Pluripotent cells aside, many are surprised to learn that all of us have stem cells within our bodies. Without these self-renewing cells, we would not live longer than a day since our bodies are engaged in a constant cycle of replacing damaged and dying cells. Generally known as adult stem cells, the various stem cells in our bodies are either multipotent or unipotent in nature (rather than pluripotent). In the case of multipotency, these stem cells give rise to multiple cell types. An example of this is a hematopoetic stem cell which can give rise to the different cell types within our blood (red blood cells, neutrophils, plasma cells, etc). A unipotent stem cell, on the other hand, gives rise to only a singe cell type, as in a skin stem cell forming a mature epithelial (skin) cell.
Unfortunately, as we age, the number of stem cells within our bodies decreases precipitously. This is one of the central reasons that we do not heal as well as we get older. Dr. Arnold Caplan described the decline in hematopoetic stem cells within our bone marrow over time (see figure 1).
Since stem cells are essential for maintaining tissue health and facilitating repair, figuring out ways to optimize the number and function of our stem cells would seem worthwhile. (Of note: Multipotent stem cells are being used in various medical procedures to treat a range of conditions. While this is beyond the scope of the current article, you can learn more about the use of stem cells and how stem cell therapy is applied within my medical practice at InertiaMedical.com.)
To date, a number of interesting studies have examined ways in which various nutraceuticals and food constituents influence stem cell populations and activity. Here is a bit of research rapid-fire:
In a 2015 publication of the journal GeroScience, Bickford and colleagues authored an article titled Nutraceutical intervention reverses the negative effects of blood from aged rats on stem cells. During their study, the scientists fed young and aged rats either a standard diet or a diet supplemented with blueberry, green tea, carnosine, and vitamin D3 for 28 days. At the end of the study, blood serum was taken from rats in each of the two groups and was applied to cultures of rat stem cells. Serum from the aged rats that consumed the standard diet significantly reduced cell proliferation whereas serum from the supplemented group resulted in cellular activity that was the same as young rats. The researches concluded that nutrient supplementation has the potential to rescue aging stem cells.
Another study used a rat model of multiple sclerosis in order to study neural stem cell response to vitamin D supplementation. Appearing in the European Review for Medical and Pharmacological Sciences in 2015, the results of this study indicated that vitamin D was able to reverse nerve cell damage and promote proliferation of neuronal stem cells.
In a 2014 study published in PLOS, a rat model of traumatic spinal cord injury (SCI) was used to study the effects of treatment with either stem cell therapy alone or in combination with curcumin. The study revealed that stem cell therapy improved recovery from moderate SCI, however, it had a limited effect on recovery after severe SCI. Curcumin in combination with stem cell therapy induced profound recovery from severe SCI as evidenced by improved functional recovery, increased body weight, and greater muscle mass.
In 2010, Backstetter and colleagues published a research article in PLOS demonstrating that the blue-green algae, spirulina, could prevent inflammation-induced decreases in brain stem cell proliferation that accumulates with aging.
Last year, a group of researchers collaborated on an elegant study titled Vitamin A-Retinoic Acid Signaling Regulates Hematopoietic Stem Cell Dormancy, which appeared in the journal Cell. In their study, they revealed ways in which vitamin A influences stem cell activity and proliferation, ultimately finding that vitamin A is critical for stem cell self-renewal and population maintenance.
A research group out of the University of South Florida, having provided laboratory evidence that transplantation of human placenta-derived cells in stroke models promotes functional recovery, worked to elucidate underlying mechanisms for the observed therapeutic benefits. In 2011 the group published a study in the Journal of Pineal Research in which they examined the expression of two discrete types of melatonin receptors and their roles in proliferation and differentiation of cultured human placenta-derived cells. Their work revealed that the proliferation of cultured amniotic cells was increased when treated with melatonin in a dose-dependent manner and the viability of cultured amniotic cells could be further enhanced by melatonin.
While the studies mentioned above describe the potential influences of nutritional supplements on stem cells, let’s consider more broad implications of the various study findings. Should we consider supplementing with blueberry extract, vitamin A, curcumin, spirulina, vitamin D, and melatonin? Perhaps. And I do supplement with several of these. But I find the list of supplements to be suggestive of something more foundational – lifestyle.
• Blueberries, vitamin A, curcumin, spirulina = Eat nutrient dense foods
• Vitamin D = Enjoy some sunshine
• Melatonin = Get adequate sleep