HoldsUp

DavidPerlmutterMD · 2026-02-03 · David Perlmutter (host), Rachel Swanson

Optimizing Fertility: What Actually Moves the Needle | Rachel Swanson

28 research-tied claims examined: 3 overstated 25 supported

3

Overstated

0:17:16Rachel Swansonoverstatedmoderate

Individuals with PCOS are at increased risk of long-latency chronic diseases including heart disease, neurodegeneration, and some cancers.

"So basically, what I can confidently say is that individuals with PCOS, which as you know one of the primary underlying reasons for that is insulin resistance, there is hundreds and hundreds of very high-quality studies showing that they are at increased risk of pretty much every long-latency chronic disease that there is." (said at 0:17:16)

While extensive observational research and meta-analyses demonstrate that individuals with polycystic ovary syndrome (PCOS) have an elevated risk for cardiometabolic disorders (including composite cardiovascular disease, myocardial infarction, and stroke) as well as specific hormone-related malignancies such as endometrial cancer, claiming that 'hundreds and hundreds of very high-quality studies' link PCOS to 'pretty much every long-latency chronic disease that there is' (including neurodegenerative diseases) is an overstatement. The association varies substantially depending on the disease entity, and evidence for many chronic conditions is either mixed, null, or constrained by residual confounding (such as obesity).

0:30:18Rachel Swansonoverstatedvery low

A healthy, Lactobacillus-dominated vaginal microbiome without dysbiosis is associated with a shorter time to conceive, successful embryo implantation, and improved IVF success rates.

"So whereas a healthy vaginal microbiome, so that means absent of dysbiosis, dominated by certain lactobacilli, it really it really sets the stage for amazing things to happen. And that includes getting pregnant faster. So that's associated with a shorter time to conceive. This helps embryos implant successfully. Of course, this is like a window into the endometrial microbiome as well. Um, this also predicts better IVF success." (said at 0:30:18)

The evidence for an association between a Lactobacillus-dominated vaginal microbiome and reproductive outcomes is mixed and limited by low certainty. In assisted reproduction (IVF), a systematic review and meta-analysis found that vaginal dysbiosis is associated with a higher risk of early pregnancy loss and lower clinical pregnancy rates, but found no statistically significant impact on live birth rates, with overall evidence quality rated as very low under GRADE criteria. Additionally, prospective evidence in non-assisted conception found that cultivable vaginal Lactobacillus was not significantly associated with fecundability or shorter time to conceive.

0:57:12David Perlmutter (host)overstatedlow

Micro- and nanoplastics make up as much as 0.5% of the brain's weight (about a teaspoon).

"As much as a teaspoon, 0.5% of the brain's weight is now characterized as being made of plastic." (said at 0:57:12)

Published postmortem research examining human tissue samples confirms that micro- and nanoplastics (MNPs) accumulate in decedent human brain tissue at significantly higher concentrations than in kidney or liver samples, with polyethylene being the predominant polymer. However, stating that 0.5% of the brain's total weight (or a teaspoon) consists of plastic overstates the findings. Reported estimates near ~0.5% reflect concentrations calculated relative to dry tissue mass rather than total wet brain weight. Conflating dry weight percentages with wet tissue mass drastically exaggerates the physical volume of plastics present in the brain.

Unverified means no publication matching the claim was located; it does not prove the claim false. Spotted an error? See the corrections policy - disputes from the people quoted are prioritized.