Basically, no controlled studies have been done on HRT. They are sure it eases hot flashes, and based on years of using regular women as guinea pigs, they have determined it prevents some bone loss. Other than that, there's no proof of any of it's supposed benefits:
The main lesson from this turnaround is the importance of conducting clinical trials of medical treatments whenever feasible. Most of the evidence suggesting wide benefits from hormone replacement therapy came from observational studies, in which large numbers of women were followed for years, and those who chose hormone therapy were compared with those who did not. But such studies have an inherent weakness. One can never be sure that the women who choose a treatment and stick with it are not inherently healthier than those who shun the treatment. NYTimes [requires registration]
Many claims of safety, benefit and danger of drugs and therapies are not based on controlled studies at all. Soy is being pushed on women now as a sort of natural HRT, but in fact may depress thyroid function as well as production of androgens which help spur natural hormone production in women's bodies.
I'm all for alternative therapies being out there, and I really don't want to see natural supplements pulled off the market, but maybe we should question the labeling of these things. Most supplements simply say what they contain and make no claims at all. As far as I know, the is the FDA standard. Lately, I've been seeing a lot of soy supplements or isoflavones in pill form that make direct beneficial claims right on the jar. Who, exactly, is claiming that we need to supplement our SOY intake?
I wish I could say that the pharmaceutical industry has done a better job researching benefits and dangers of HRT, but clearly they have not. Big pharma pushes half-assed prodcuts on us to get them to market with as much patent time as possible, and then the natural food industry tries to imitate their product...meanwhile neither product is being adequately tested but perversely winds up being touted as a MIRACLE BREAKTHROUGH.
I have my doubts that it's possible to do any long-term controlled studies on benefits or risks of drugs. Look at cigarettes, for instance. I know people will find this a regressive statement, but do we really know smoking is as dangerous as we are being told? Now a Swedish study that claims bread and potatoes are dangerous is going to be taken up by the WTO because the results are so disturbing. Bread and potatoes, people.
As far is smoking is concerned, how on EARTH do you isolate smoking as a cause of, say, heart disease in an individual eating a lousy diet? Why does the rest of the world smoke heavily and why does it not impact their death rate? Because they eat a different diet. Always, ALWAYS people end statements of health dangers with the statement "it's still less dangerous than smoking." How do they know?
We are told obesity is a major cause of death and disease in the U.S. We can look around and verify that one for ourselves. When an obese person dies of heart disease, the cause of death goes down as obesity. If that person happens to smoke, the cause of death goes down as smoking-related. What percentage of their risk is from smoking? We truly have no way of knowing because there is no way to separate out the Big-Mac-a-day risk from the smoking risk.
The same occurs with long term drug studies -- how can we know what the real dangers are? The moral of the story is that we all need to do our homework before we believe that anything being marketed towards us is actually safe.