The History of Saliva Testing: An Interview with Kyle McAvoy, NP and Dr. David Zava

I had the privilege of sitting down with Dr. David Zava, the founder of ZRT Laboratory and somebody I’ve had the pleasure of realizing for over 20 years. Throughout our dialog, Dr. Zava shared insights into his fascinating journey from finding out environmental chemical compounds on the College of Tennessee to founding ZRT in Beaverton, Oregon. Through the years, Dr. Zava’s pioneering analysis and unwavering dedication to advancing hormone testing haven’t solely enhanced my observe but additionally deepened our friendship.

As a practitioner, I’ve all the time been deeply impacted by Dr. Zava’s work. His relentless pursuit of data and his progressive spirit have influenced not solely my medical observe but additionally my method to affected person care. One of Dr. Zava’s most impactful contributions was his collaboration with Dr. John Lee on the e book What Your Physician Could Not Inform You About Breast Most cancers, printed in 2002. The launch coincided with the Ladies’s Well being Initiative (WHI) examine, which linked hormone substitute remedy to the next danger of breast most cancers, inflicting widespread concern. Dr. Zava and Dr. Lee’s e book provided another view, distinguishing between artificial progestins and pure progesterone and advocating for bio-identical hormones as a safer possibility. Their work offered readability throughout a time of uncertainty and continues to information knowledgeable choices about hormone remedy.

I encourage you to look at the complete interview by way of the offered hyperlink, and for individuals who favor to learn alongside, a synopsis of our dialog is included under. This can be a distinctive likelihood to listen to from one of the foremost consultants in hormone testing and uncover the science and ardour fueling ZRT Laboratory’s work. Whether or not you’re a healthcare skilled or just enthusiastic about your individual well being, Dr. Zava’s insights will go away you with a deeper understanding of hormone well being and the cutting-edge approaches being developed to advance it.

Watch Full Video Right here:

Learn the Synopsis Right here:

Kyle: Dr. Zava thanks a lot for taking the time to sit down down with me at the moment. Having identified you for over 20 years, I understand how busy you might be with all of the work that you just do however I do assume it’s so vital that suppliers and sufferers study extra about you, your journey and your infinite data about biochemistry, hormones, varied sorts of testing in addition to many illnesses.  Please inform me about your educational background and the way you wound up right here in Beaverton, OR founding this laboratory.

DZ: I began out on the College of TN finding out environmental chemical compounds and their impression on the event of most cancers.  The major chemical I studied was dimethylbenzanthracene which causes most cancers in sure animal species. Dimethylbenzanthracene appears to be like very related in chemical construction to estradiol. Once we gave rats this chemical, they developed mammary cancers however didn’t develop most cancers wherever else of their our bodies. I studied this impact on the mammary glands of rats throughout my time on the college.

After this, my postdoctoral fellowship was in San Antonio, TX the place I started to review the results of estrogen. This work was with people and we started to have a look at the receptors inside breast most cancers cells. This led to evaluating each estrogen and progesterone receptors and their relationship to most cancers.

My subsequent transfer was to Switzerland the place I labored because the director of

a lab finding out principally the identical issues. At the moment, there was a global breast most cancers examine and we have been wanting on the results of Tamoxifen, an anti-estrogenic drug that may inhibit the expansion of breast most cancers, in addition to these of chemotherapy brokers on breast most cancers.  Our work analyzed girls’s breast most cancers tumors in phrases of their estrogen and progesterone receptors. What we discovered is that Tamoxifen does certainly work to inhibit the expansion of breast most cancers however just for about 5 years and then its impact diminished. I used to be very disillusioned by this and determined to shift my work in the direction of discovering methods to forestall relatively than simply deal with breast most cancers.

Kyle: I appear to recall that your work in Switzerland was pivotal in phrases of the way you seen the results of hormones on the event of breast most cancers. Are you able to clarify what occurred there?

DZ: We have been receptors of estrogen and progesterone in breast cancers. What I noticed within the tumors, relying on the age of the lady, is that the morphology of the tumors was totally different, relying on her age. For girls within the perimenopause, the place you tend to have estrogens uncontrolled by progesterone, their tumors have been rising quicker. So they’d a a lot greater price of progress, not essentially extra aggressive, however undoubtedly quicker rising.  Ladies within the perimenopause have been clearly uncovered to extreme quantities of estrogen.

Kyle: So from that analysis, is it honest to say that girls within the perimenopause are at greater danger for breast most cancers growth?

DZ: Sure in the event that they don’t management the surplus estrogen. Estrogen causes down regulation of estrogen receptors and up regulation of progesterone receptors , which within the presence of progesterone would then down regulate the estrogen receptors, which is what occurs throughout a menstrual cycle. This can be a suggestions loop however throughout the perimenopause, there may be insufficient progesterone so this suggestions loop will not be working.

Kyle: What did you do after you left Switzerland?

DZ: I moved to California round 1995 and labored at a gaggle referred to as Aaron Life Cycles, once more doing work on breast most cancers. However not solely did I take a look at estrogen receptors but additionally how these may be affected by girls taking estrogen exogenously in addition to getting it from varied meals sources. I wished to know if this stuff would enhance a girl’s danger of breast most cancers. At the moment, there was rather a lot of curiosity in these points and the Ladies’s Well being Initiative was additionally began round this time. I grew to become very enthusiastic about creating assays that might monitor the degrees of estrogen in girls. I used to be notably enthusiastic about wanting on the phytoestrogens in meals, similar to soy, to see if they might stimulate the expansion of a breast most cancers as a result of they’re estrogenic and can bind to estrogen receptors.

I developed a strategy for this sort of testing.  I subsequently utilized for and obtained a grant to review this. In an effort to do that work, I developed assays in saliva as a non-invasive solution to monitor the results of environmental elements(similar to from meals) on the degrees of estrogen and progesterone.

Kyle:  When did you cross paths with Dr. John Lee, the household observe physician who did rather a lot of work with progesterone? I do know you ended up writing a e book with him about breast most cancers. Are you able to inform us about this important (essential?) time for you?

DZ: Proper round this time, I met Dr. Lee in CA at a lecture that he gave during which he was speaking about pure progesterone. By then he had already written three books. The first one was about hormones, the second was “What your doctor may not tell uou about post menopause”, and the third one was about perimenopause. I used to be in all probability the one man within the viewers amongst a room full of girls. 

I grew to become very interested in progesterone at this lecture.  Sharon McFarland was additionally there with the ‘Progest people’(those that manufactured progesterone) and had been working with wild yams. I took some of their product again to the lab and measured the extent of progesterone on it. At the moment, round 1998, it was referred to as ‘progest’, not progesterone. Dr. Lee and I started to do lectures collectively and at some  level, he requested me to co-write a e book on breast most cancers with him and I agreed. He had intensive expertise working as a household observe doctor with girls and progesterone. I bear in mind listening to that he had a really low incidence of breast most cancers in his sufferers. We went on to write down the e book

“What your doctor may not tell you about breast cancer”.

Through the years I’ve heard related tales from many practitioners who prescribe progesterone for his or her sufferers: decrease incidence of breast most cancers for these sufferers and in those that do get breast most cancers, a much less aggressive kind. The dose getting used is normally between 20-40 mg /day of topical progesterone cream.

When a pathologist appears to be like at a breast most cancers tissue specimen beneath the microscope, on a affected person who had been taking progesterone, it was nearly not a most cancers because it was so properly differentiated. I had been the one who usually labored with these pathologists and developed  strategies to have a look at the proliferation index, which is how briskly a tumor is dividing(utilizing immunohistochemistry, which appears to be like on the chromosomes and cell division).

Kyle: Superb: you actually are ‘the man behind the curtain’. You’ve gotten all of this data and expertise that most individuals who use your laboratory don’t find out about. I heard that you just had some fairly humble beginnings when your first began your lab in California. Are you able to inform us about how that every one began?

DZ: I truly was the lab director at a lab in CA and we didn’t agree on some issues so I left and got here to OR and began the lab right here. I used to be on what they name the “J curve”: no cash so I offered my home, took the cash from that and moved up right here and used that cash to get began. On the similar time, I used to be writing that e book with

Dr. John Lee, which got here out in 2002.

Kyle: That was on the similar time that the WHI(Ladies’s Well being Initiative)examine halted their challenge and printed their findings. What unbelievable timing. That almost all have blown issues up. Have been folks shocked by what your e book mentioned versus what the WHI was saying?

DZ:  Appropriate. WHI was saying ‘get everyone off of hormones, estrogen is bad for you’. That’s what the preliminary response was: taking estrogen(Premarin) precipitated breast most cancers so that everybody thought that estrogen was dangerous. However it turned out that the ladies on Premarin alone truly had a decrease incidence of breast most cancers however these on Premarin plus progestin had the next incidence. Progestin, NOT progesterone. And it actually didn’t matter what type of artificial progestin it was.

The firms that make progestins make many differing kinds as a result of they are often patented and that’s how they make their cash. Progesterone is similar molecule that Mom Nature made a gazillion years in the past and it’s a substance that’s NOT dangerous to the human physique.  Artificial progestins might be dangerous.

Kyle: As a practitioner at the moment,  I had fairly just a few sufferers on HRT and when the WHI findings got here out, there was fairly a bit of panic within the U.S. and I didn’t fairly know what to do. I did find yourself studying about bio-identical hormones from a particular on public tv and then sought out steering from an area compounding pharmacist. However this was a really unsettling time and I had a tough time discovering folks to mentor me. By way of a sequence of occasions, I discovered your lab which was extremely lucky for me. Your lab is thought not just for the superb testing that you just do but additionally for the tutorial help you supply to suppliers and sufferers.

DZ: The early occasions have been exhausting for me financially : I had a spouse and 2 kids to help however failure wasn’t an possibility and I used to be enthusiastic about what I used to be doing. I used to be additionally working with Dr. Lee and Sharon McFarland at Transitions for Well being( they make Professional-gest, topical progesterone). We have been on the lecture circuit collectively and there was rather a lot of demand for testing ranges of estrogen and progesterone so every part was transferring in the correct course. Ladies wished to know: what’s my stage? Is it too excessive, is it too low, is it excellent?

Kyle: How do you know to make use of saliva as the suitable physique fluid?

DZ: Once I was in Europe, I knew any individual who was truly simply starting to develop a strategy for saliva testing. I assumed that was very attention-grabbing  so I visited him. It’s a physique fluid that you would be able to gather non-invasively  and it had a superb reflection of the bioavailable stage of hormones. Many hormones, similar to estradiol, progesterone and testosterone are certain up by proteins(about 98% of them are certain)in order that solely 2% are bioavailable. Saliva represents what is definitely bioavailable which is the quantity that’s going to get into the remaining of your physique, mind, uterus, breast, pores and skin and each different half of your physique.

Half of the issue with early saliva testing is that early on, it wasn’t very correct so I developed a instrument to assist standardize testing . We truly then began sending out saliva samples with identified quantities of hormones, as a result of by this time, I had developed ‘mass spec technology’, which was extraordinarily correct. We despatched these samples out to different labs in order that they might measure their outcomes towards this identified amount. Some labs participated, others didn’t of course, however we discovered which of them did a greater job of measuring hormone ranges in saliva. There was no oversight apart from cortisol ranges. Because of this many individuals can’t get this sort of testing paid for by insurance coverage.

It’s simpler to measure cortisol than different hormones as the degrees are a lot greater. Measuring estradiol is much more difficult however we now have mastered that.

Kyle: I do know that you’ve got confronted many obstacles alongside the best way, between the challenges of creating testing assays and of course the controversial nature of hormones basically. How do you keep the course typically?

DZ: If I had been in a industrial enterprise, I might have had a tough time with it however we do an incredible quantity of analysis. That has been very satisfying. Alongside with our testing, we gather knowledge from sufferers in phrases of signs and we now have developed an enormous knowledge base over time.  Our lab additionally developed blood spot testing, which is an alternative choice to saliva testing and serum testing. Notably throughout the COVID pandemic, folks didn’t need to go in to a lab and have their blood drawn so this sort of testing allowed folks to check from house and ship their kits in to our lab for analysis.

Andifferent take a look at we developed was in dried urine metabolites. We will truly see how estradiol is damaged down within the physique.

Kyle: Are you able to speak briefly in regards to the estrogen pathway? I do know that you’ve got spoken at size about this , how estrogen tends to be damaged down alongside two major pathways. One results in the next danger of breast most cancers whereas the opposite one doesn’t. Are you able to handle this?

DZ: It’s actually a narrative of the “two and the 4’ pathways. In case your physique is uncovered to rather a lot of air pollution, the estrogen that you just both make or take will then be metabolized to a ‘bad one’, referred to as fork catechol, the 4 hydroxy pathway. That is going to partially oxidize, bind to DNA and trigger mutations.  Issues that may trigger this to occur are trans fat, dry cleansing fluids, heavy metals, pollution, weight problems, and so on. This isn’t one thing that may occur in a single day: it might take years. We talked about this within the e book on breast most cancers that we wrote.

But when as an alternative, you eat soy, inexperienced leafy and cruciferous greens, the estradiol will go down the two hydroxy pathway. That is the specified route and one that may be influenced by life-style. DIM is a complement that may assist drive the estradiol down the two OH pathway. As well as, getting extra sleep, train, dietary adjustments, taking such dietary supplements as B12, folic acid, B nutritional vitamins, vitamin C, D, selenium and iodine can all be fairly useful.

Andifferent major impression on hormone metabolism is stress. Once I seemed on the cortisol profiles of girls with breast most cancers, they have been flat though the evening time cortisol is excessive at evening. This occurs after they’ve been elevated for awhile and then come down. That is one other space that we will have an effect on with our interventions.

Kyle:  I can testify to the worth of utilizing ZRT’s testing over the past 22 years. I nearly all the time order the Hormone Profile III, which assessments estradiol, progesterone, testosterone , DHEA-S and 4 cortisol ranges.  I all the time love going over these outcomes with my sufferers and I’m able to establish the patterns of stress by their cortisol curves. Sufferers simply love studying why they’re feeling the best way which can be . I can then advise them to take sure dietary supplements in addition to hormones that may assist make impactful adjustments of their lives. Thanks for creating these vital assessments. They have guided so many suppliers in serving to sufferers go away more healthy lives.

DZ: The experiences that we generate come from the degrees of hormones plus the solutions that sufferers give on the ‘symptom reporting’ part of the questionnaire. This creates augmented intelligence and spits our individualized outcomes.

Kyle: Not solely do you give every affected person an individualized report however you present further assets for them, similar to books and references for them to turn out to be extra educated. Individuals achieve this recognize this data.

Kyle: Are you able to clarify why there may be nonetheless a lot controversy about transdermal progesterone? I’ve usually heard that the degrees don’t get excessive sufficient to guard the endometrial lining.

DZ: The drawback is that almost all suppliers use serum testing and that doesn’t present correct ranges of transdermal progesterone. They additionally don’t see it in urine. We see it in saliva and capillary blood, as measured with the blood spot technique. And if anybody would trouble to learn the literature, research have been carried out in Taiwan and France that exhibit that progesterone utilized transdermally truly does get into the breast tissue(Inhibiting the expansion of mammary epithelial cells) though it doesn’t present up within the serum. The progestereone utilized to the pores and skin will get into the lymphatics. This was additionally seen within the World Anti-Doping Affiliation . They discovered excessive ranges of testosterone in saliva and in capillary blood however they didn’t discover this in serum. Within the final 5 years, they’re now utilizing saliva and blood spot to detect doping. 

It’s exhausting to shift folks’s paradigms however that could be a change.

Kyle: What else are you engaged on?

DZ: Neurotransmitter testing: we now have been doing this for years however now we’re ADHD. We’re working with OHSU medical college children with ADHD by measuring ranges of neurotransmitters.  We’re additionally starting work on premenstrual dysphoric dysfunction and autism.  We take a look at neurotransmitters in dried urine so this will also be carried out at house.  

Kyle: Not too long ago there was a present on Netflix in regards to the blue zones. They talked about why some folks in varied areas of the world reside to be 100. There are fairly just a few elements however the primary ones have been consuming a Mediterranean fashion weight loss plan, managing stress, common train, discovering pleasure and most significantly, feeling related with their group.  Clearly this all segues with the work you may have carried out and have carried out for a really very long time.

Thanks Dr. Zava for taking the time to speak with me at the moment. Your background is fairly unbelievable and you may have labored tirelessly for many years. Not solely have you ever developed progressive laboratory assessments however you may have been obsessed with educating suppliers and their sufferers. I hope this dialog helps the general public have a better appreciation of who you might be and the work of your workers at ZRT.

DZ: Thanks Kyle as properly for all that you’ve got carried out for ladies, who you may have helped and handled. And thanks for being a pal.