Just read an interesting pos about the use of AIs during cycle , would be great to hear your opinions!!!!!
Its well known (atleast I think it is) that estrogen is a carcinogen. In fact, its a Group 1 IARC classified estrogen, which means it a pretty potent one really. The risks of estrogen and carcinogenic activity are then again confirmed in 'estrogen only' conraceptive treatment(s). Although the data is somewhat confusing (as some data is on estrogen+progestagen treatment), the links to various forms of cancer rates increasing is pretty clear in my book.
To quote from a paper looking at the effects of estrogen only contraceptive treatment and estorgen+progestrogen contraceptive therapy:
"Four studies (one cohort study and three large case-control studies) reported increased risk of endometrial cancer with estrogen repla***ent therapy (Cushing et al. 1998, Shapiro et al. 1998, Persson et al. 1999, Weiderpass et al. 1999), and three of these studies reported strong positive associations between risk of endometrial cancer and duration of estrogen use."
"Two of four case-control studies found that estrogen-only repla***ent therapy was associated with an increased risk of breast cancer (Heinrich et al. 1998, Magnusson et al. 1999)."
"One study found that estrogen therapy was associated with ovarian cancer (Purdie et al. 1999)."
"In 2009, IARC concluded there was sufficient evidence of the carcinogenicity of estrogen-only therapy in humans based on increased risks of endometrial cancer and ovarian cancer and limited evidence based on increased risk of breast cancer (Grosse et al. 2009). The findings for ovarian cancer were based on two meta-analyses (Greiser 2007, Zhou 2008). Since then, another meta-analysis has estimated a significant overall increase in ovarian cancer risk related to duration of use of estrogen-only therapy (Pearce et al. 2009)."
"In rodents, steroidal estrogens caused benign and malignant tumors, as well as pre-cancerous lesions, in a variety of organs, including the mammary gland and female reproductive tract (IARC 1999). Estrogenic compounds generally caused endometrial, cervical, and mammary-gland tumors in mice, mammary- and pituitary-gland tumors in rats, and kidney tumors in hamsters"
I think you get my point...
Although there is mixed data in that study, the theory that estrogen is carcinogenic is overwhelming.
So what does that all tell us? It tells us that when exposed to estrogen (steroidal) that it can cause some serious problems. Yes, these studies are done on females (I didnt miss that), but women are a hell of a lot more tolerable to estrogen than men are. Males are not designed for increased levels of estrogens at all, womens are (during pregnancy for a start). Womens levels can hit 500pg/ml, the top end of males is 50pg/ml 10x lower.
Estrogen role in males is important. Its important for GH and IGF synthesis, bone density, lipid profile, glucose uptake and utilisation, AR sensitivity and activation, immuno function, anti-inflammitory effects and a host of other benifits. Without it, we (males) would't function properly.
There are studies for and against the importance of sex hormones on CHD and mortality, but the hypothsis is plausable. Why?
- Estrogens inhibit smooth muscle proliferation and decrease smooth muscle tone
- Their effects on lipid profiles
- High-affinity estradiol receptors are present in both vascular smooth muscle and endothelium
- Estrogens enhance the release of nitric oxide and prostacyclin from endothelial cells, thus inducing vasodilation
- Estrogens exert indirect effects on the cardiovascular system through their influence on lipoprotein metabolism and the coagulation, fibrinolytic, and antioxidant systems
So one can not see the importance estrogen have on the cardiovascular system, CHD, therefore mortality rates. Here is a good solid article on estrgens links to CHD, found here.
How else does estrogen negatively effect males?
Well, recent research has confirmed its role in the most common form of cancer in males - prostate cancer. The basics of which are shown here. These are very recent findings and more research is to be done. However, the links and risks are evident and whilst DHT was thought to play as the main role (10 years ago), estrogen and also prolactin (which worsesns prostate cancer) have been shown to have positive effects on expression and proliferation in cancerous prostate cells in vitro and vivo. On the plus side Tamoxifen has been shown to inhibti expression and proliferation, much like it does in female breast cancer patients.
When I see someone argue that an AI just isnt needed on a cycle, I think to myself, why is it not needed? Based on what? Because you haven't got gyno? The user may not experience side effects such as gyno, water retention, acne, but there estrogen level is sure as f*ck high.
Aromasin (Exemestane) at 10mg/ED will keep most people estrogen level under 50pg/ml on cycle IMO. It does me and I am sensitive to estrogenic side effects (very).
The common reason for not using an AI is, that it may limit gains made... But do they?
AI's have little impact on IGF-1 levels and Exemestane does not have any effects at all, as shown here. If IGF-1 was somewhat lowered, we also need to understand that exogenous testosterone and other anabolic steroids are going to increase IGF-1 and further negate these effects. To realise how little effect AI's have on IGF-1, read this study.To summarise; Nine young healthy men who received femara at 2.5 mg daily for 28 days had a 15% reduction in IGF-1, a 24% reduction in leptin, and a 14% increase in LDL (bad cholesterol).
As for Exemestane on lipid levels, it has far less impact than other AI's although it does not have the benificial effects of SERMs. Some data, such as this one, it has no "no clinically significant effect on the serum lipids". Another study stated, "Overall, exemestane has no detrimental effect on cholesterol levels and the atherogenic indices, which are well-known risk factors for coronary artery disease. In addition, it has a beneficial effect on TRG levels"
Here is one on young males thats slightly more applicable, this study states, "Plasma lipids and IGF-I concentrations were unaffected by treatment."
Finally, because of the LongFeedback Mechanism (google it), controlling estrogen means we can help control prolactin. So there is more of a reason to use an AI when using 19-Nors (if you experience increased PRL). I'd also keep a D2-agonist on hand though.