Scientific Update: The One-Carbon Cycle and Improving Ovarian Reserve
Trying to improve the likelihood of success for fertility cycles can be challenging as there are so many factors to consider and analyze. But for couples who have undergone In-Vitro-Fertilization multiple times with no success, the pressure to improve their chances prior to their next cycle is very strong.
Here we will discuss a new scientific review highlighting the evidence of supporting the One Carbon Cycle as a means of mitigating the effect of Environmental Endocrine Disrupting Chemicals on the epigenetics of eggs and improving egg quality. The quality of eggs and embryos is a major factor that influences the chances of a successful cycle, so working to improve the egg quality before an IVF can make a immense difference in the outcomes of that cycle.
Chemicals Disrupting the One-Carbon Cycle (methylation):
Environmental Endocrine Disrupting Chemicals from our food, air pollution, plastic, pesticides from our food, etc. can interfere with a chemical process known as "methylation." When eggs are being developed they go through a process of "de-methylation" (this is the removal of a one-carbon molecule - CH3 - from the genes of the oocyte). Then, this process must be reversed prior to conception to help ensure proper follicle and embryo development. This "re-methylation" process is absolutely necessary in order to facilitate proper follicle and embryo development prior to implantation in the uterus (once conception has already occurred). The problem is that these endocrine disrupting chemicals bind to estrogen receptors in the body and create oxidative stress, and oxidative stress interferes with the methylation process, which has been correlated with impaired egg development.
The One-Carbon Cycle:
Very simply the cycle looks something like this:
HOMOCYSTEINE ---> METHIONINE ---> SAM ---> SAH ---> HOMOCYSTEINE
| _ _ _ > CH3 (methylation)
Supporting the methylation cycle is important, because elevated Homocysteine levels on their own will contribute to damaged eggs. Homocysteine itself is toxic if it is elevated, so one must ensure that they are properly converting it to methionine and supporting the production of CH3 and supporting methylation of the egg DNA.
Supporting the one-carbon cycle in Women with multiple failed IVF cycles has been shown to improve spontaneous pregnancy rates. It also improved Anti-Mullerian Hormone (AMH) (a measure of egg reserve) approximately by 0.5 ng/mL. All Women included in the study saw an improvement, regardless of what their starting AMH level was. AMH has an important role in modulating egg development as well.
In the recently published study, 1 out of every 6 Women included in the study conceived during the 4 month period of treatment to support the one-carbon cycle.
How to Support the One-Carbon Cycle:
The methylation process can be supported by ensuring supplementation with Vitamin B2, B3, B6, B9 and B12 injections (if deficient or levels are low). Other important nutrients also play an important role in supporting this one-carbon cycle and indirectly support the production other antioxidants that help protect the follicles from oxidative stress, inflammation, and damage.
This article is in no way a replacement for medical advice or medical care, it is advised that anyone concerned about their Health should speak with their Naturopathic Doctor or Primary Care Provider.
1. Silvestris, E., Cohen, M., Cornet, D., Jacquesson-Fournols, L., Clement, P., Chouteau, J., Ménézo, Y. (2017). Supporting the One-Carbon Cycle Restores Ovarian Reserve in Subfertile Women: Absence of Correlation with Urinary Bisphenol A Concentration. BioResearch Open Access, 6(1), 104-109.