An article in this month's "Fertility & Sterility" caught my eye today. It's about the "Olive Tree Hypothesis." As you know, we at Olive focus a lot on eggs - their quality and count - when predicting and treating fertility. There is little we can control about eggs except the medication and environmental exposures we receive. It is well-know that certain toxins can damage egg count and quality. For example, tobacco smoke has a major negative impact, as do certain medications (e.g. chemotherapy).
What we are learning is that you can recover from these toxins and the recovery takes about six months. The theory behind the ability of the ovaries to heal toxin damage is the "Olive Tree Hypothesis." In southern France, olive trees survive serious cold spells that strike every 40 years or so. Typically the leaves die, leaving bare, seemingly dead, trees. Yet these later resuscitate, regrowing branches and leaves, and soon produce new olive crops. Thus, the trunk and leaves of the olive tree react differently to cold. The is analogous to an ovary where the growing eggs (leaves) die or are damaged when exposed to cigarette smoke or chemotherapy but the non-growing pool of eggs (trunk) are not affected. As it takes about six months for a non-growing egg to start growing and develop to the point it can be fertilized, this recovery of eggs in a damaged ovary also takes six months.
Recent work in smokers supports this hypothesis. Smokers who had stopped smoking more than six months ago had egg counts and egg quality similar to non-smokers but current smokers had evidence of a low egg count (by AMH) and poor egg quality compared to non-smokers. Therefore, women wishing to conceive should discontinue all exposure to toxins, including tobacco smoke, for six months. Time to quit smoking!