The ZRT Laboratory Blog

The ZRT Blog is an extensive resource for patients and health care providers searching for health and hormone testing information. Here, you can read about ZRT’s cutting edge research, advances in testing, wellness advice, and health industry highlights.

Dr. David Zava

David Zava, PhD is the founder, CEO and Chief Scientist at ZRT Laboratory. He has been instrumental in developing research projects with physicians and academic groups to understand the role of steroid hormones in health and disease for the past decade.
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Recent Posts

Natural Progesterone as a Preventive for Breast Cancer

Posted by Dr. David Zava on Wednesday, 19 September

Patient getting a breast examination from doctorEditor’s Note: After the publication of Dr. David Zava’s last Health Watchers News and Views post, Hormone and Breast Cancer: the Latest Findings from the WHI, he received an attacking comment from a doctor who has been making claims for years that natural progesterone has the same effects as the synthetic progestins.

Although, as an editor, I do not publish comments that attack, Dr. Zava wrote an eloquent, if technical response which adds to the dialogue about progestins, progesterone and breast cancer. We share it here for the reading pleasure of hormone biochemistry geeks everywhere! 

I very much disagree with the comment that “Progestins cause more breast cancer than estrogens because they act like progesterone.” Yes, synthetic progestins increase breast cancer, but there is no evidence that progesterone does the same. Quite the contrary. Below is my argument in favor of natural progesterone as a preventive for breast cancer, with reference to the Fournier studies that address this issue.

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