By Mary Sabo, L.Ac. DACM
A Reproductive Endocrinologist recently contacted me asking what the Traditional Chinese medicine (TCM) diagnosis of “weak kidneys” meant. She was reviewing a scientific study published in the journal Fertility and Sterility that explored the effect of Chinese herbs administered in the three months leading up to and during an IVF on pregnancy rates. The herbs used in the study were in the category of “kidney yin tonics” and were given to a group of women with the TCM diagnosis of weak Kidney Yin. The study group showed significantly higher pregnancy rates and improvements in follicular fluid quality after taking the Chinese herbs.[i] How may the herbs have helped?
The "Kidney" in TCM includes functions of the actual kidney organ from a western perspective as well as the adrenals (they didn't separate the two). It is thought of as the energy battery in Chinese medicine and has several functions. Like the actual kidney, it helps with fluid metabolism and filtration, therefore characteristics of weak kidney energy may include edema, blood pressure abnormalities, and urinary problems. But it also goes deeper.
TCM doctors in ancient China had some general concept of genes and epigenetics in that they understood traits were passed down from parents to children, including resilience and a propensity for certain diseases. They called this "Jing", which is basically thought of as a primordial energy that can be turned into whatever energy is needed in the body (yin, yang, blood, qi). People born with abundant "jing" were more resistant to disease and aged well. People with poor jing were the opposite. Jing is stored in the KD and is necessary for providing the energy for the next generation (i.e. fertility). People who abuse their body with poor diet and lifestyle habits dip into their jing more frequently and deplete it. People who have great healthy diets and habits conserve their jing. This explained why some people can abuse their bodies and be fine, while others are delicate and sickly even with good habits. It all depends on the abundance of jing in your kidneys.
The Kidney also stores the kidney Yin and the kidney Yang, which are created from jing combined with the energy provided from our food, the air we breathe and the water we drink. Yin controls the more fluid, nourishing, lubricating, and cooling energies and functions in the body. In fertility it is associated with estrogen levels, endometrial lining thickness, follicular fluid, cervical mucus quality, vaginal lubrication, the responsiveness of the ovary, and egg quantity. Yang controls movement, metabolism, warmth and action (think thyroid function, adrenal function, metabolic processes, strength of ovulation, hormonal transitions, egg quality, progesterone levels, and the spark of life). When the Kidney yin or yang is low, it can disrupt fertility, thus many "Kidney tonifying" herbs help with fertility. There are kidney yin tonic herbs and kidney yang tonics. There are some herbs that are thought to help jing, but mostly we are born with what we have and either abuse it or conserve it. The formula in the study mentioned above is a classic herbal formula for low Kidney yin, which is why it may affect the follicular fluid and improve pregnancy rates in women diagnosed as having weak Kidney yin.
The interesting aspect about the TCM approach to fertility is that treatments, including herbal formulas, are always customized. It is tempting to read this study and think “all women who are struggling to conceive should take this formula!”, but it will not help all women. It will only likely help women who are low in Kidney Yin. From a Western medicinal perspective, there are many reasons women struggle to get pregnant. There are different diagnoses in Chinese medicine as well. It is important to work with an acupuncturist who is experienced in fertility care if you are taking Chinese herbs, which can be powerful tools to improve fertility. Getting on the correct formula, however, is the most important part.
[i] F. Lian, H. Wu, Z. Sun, Y. Guo, L. Shi, M. Xue. The effects of chinese medicines for tonifying the kidney on proteomics change in follicular fluid of infertile women. Fertility and Sterility September 2013 Volume 100, Issue 3, Supplement, Pages S472–S473