Soy & Testosterone

Once praised as the ultimate health food, now criticized for its status as a highly genetic modified crop and common food sensitivity, many people are confused about whether or not to eat soy. One question I’ve gotten lately is whether or not soy has a feminizing effect on males.

Most studies on soy in general are done on concentrated soy protein extracts, with varying levels of soy isoflavones genistein and daidzein. Daidzein is metabolized by gut bacteria present in 30-50% of people to an isoflavone called equol. Genistein, daidzein and equol are the components of soy that have been shown to exert the most hormonal effects in tissue cultures. In vitro (outside of humans, in Petri dishes) they have been shown to inhibit enzymes required for male hormone synthesis.

In humans, studies show variable effects of soy on male hormones. In a study published in 2007 by the American Society of Nutrition¹, men that ate 107mg soy isoflavones daily in the form of soy protein isolate had decreased expression of male hormone receptors in the prostate, which could be beneficial for reducing prostate cancer, but no significant effect on circulating male hormones. The authors of the study also noted the majority of prior human studies (14 out of 22) showed no significant effect of soy on male hormone levels, with the remaining studies being inconclusive. In a review published in 2002², no significant effect on semen quality or circulating hormone levels was found in 3 human studies. A 2005 study³ compared male hormone levels in Japanese men to those in men from New Zealand. Japanese men have a lower than average rate of prostate cancer thought to be due to dietary factors. In the men studied (ages 21-31) there were increased levels of isoflavones and male hormones in the Japanese men compared to the New Zealanders, leading the researchers to conclude there may be another mechanism for reduced prostate cancer rates.

In summary, I see some effect of soy protein on male hormones and receptors, but no effect on male sex characteristics such as abnormal breast development, penile or testicular shrinkage or low sperm counts. Moderate intake (i.e. 1 serving of soy up to 4 times weekly) of organic soy products – especially traditional soy foods such as natto, miso, tempeh, and tofu - seem unlikely to create feminization in men based on research thus far and are potentially protective against not only prostate cancer, but also cardiovascular disease. Consult your naturopathic physician for more information about ways to reduce prostate cancer and cardiovascular disease risk and enhance male virility.

Claire Graser, ND Candidate 2012, Bastyr University

Sources:

1. Isoflavone-rich soy protein isolate suppresses androgen receptor expression without altering estrogen receptor-beta expression or serum hormonal profiles in men at high risk of prostate cancer. Hamilton-Reeves JM, et al. J Nutr. 2007 Jul;137(7):1769-75.

2. Hormonal effects of soy in premenopausal women and men. Kurzer MS. J Nutr. 2002. Mar;132(3):570S-573S.

3. Circulating levels of isoflavones and markers of 5alpha-reductase activity are higher in Japanese compared with New Zealand males: what is the role of circulating steroids in prostate disease? Lewis JG, et al. Steroids. 2005 Dec 15;70(14):974-9. Epub 2005 Aug 30.

The Latest on Osteoporosis Drugs

Hi there,

You may have heard this on NPR already, but I wanted to spread the word about this Canadian study on long-term use of bisphosphonates i.e. Fosamax, Actonel and Boniva - published last week in the Journal of the American Medical Association.

Bone health is a topic of particular concern for many women (and is important for men to consider as well!) and the decision about whether or not to take these drugs is something people need to be educated about.

The take-home message from NPR's report? 

 

"Don't start one of these drugs too early; wait until you actually have osteoporosis. And once you start, don't stay on one of these drugs longer than necessary . . . Five years on a bisphosphonate drug may be good enough." You and your doctor can use a web calculator called FRAX (http://www.sheffield.ac.uk/FRAX/) to assess your 10-year risk of a fracture. "Some doctors recommend a patient not start taking a bisphosphonate drug unless her 10-year risk of hip fracture is at least 3 percent, and the risk of any fracture is at least 20 percent."

Check out the following link for the full report . . .

http://www.npr.org/2011/02/28/134064950/rare-fractures-linked-to-drugs-for-weak-bones

Of course, building good bone structure early in life  - especially in the teens - is essential to healthy bones in older age, and never underestimate the power of weight-bearing exercise at any age!

A Healthy Stress Response

Why should I care about managing my stress?            

It’s the rare person I encounter that says they don’t feel the effects of stress in one way or another, and I’d like to point out; it’s completely natural. Life wouldn’t be life if there were no challenges, and the body reacts to them in very intelligent ways. In an acutely stressful situation, our blood pressure
increases to push oxygen and nutrients to our muscles so we can run away. The body also shunts blood from the digestive system (it’s less important to digest food than it is to escape a hairy monster) and suppresses the immune system (also non-vital in an emergency situation). These are transient changes that are usually reversed when the stress is over. The reason stress is such a problem in our society is that it’s chronic. The stresses we experience overwhelm our ability to adapt to them. Chronic stress leads to inflammation, and inflammation leads to chronic disease. The 4 leading causes of death in the U.S. are heart disease, cancer, stroke and lung disease, all of which can be influenced by the stress you experience on a daily basis.

 

Hidden sources of stress

Stress can come from places we don’t always consciously think about – if you work in an office, for example, the constant humming of computers all around you and the fluorescent lights glaring down might be causing a low level of stress without you knowing it. I think chronic stress is common in our society especially because we have so much sensory input from cell phones, the internet, television,
traffic that our nervous system has to work constantly to tune all of it out and deal with acute stressors on top of that. Additionally, the load of toxins in our bodies, another form of stress, is higher than ever, and it’s compounding with each successive generation.

 

What can I do to reduce stress in my life?

Be aware of things in your environment that are contributing to your baseline stress level.
Check out the environment in which you spend the majority of you time. If it’s sitting in front of the computer, have an ergonomic evaluation of your workspace to ensure the way you’re sitting isn’t contributing to poor posture. Did you know that Botox for the forehead has been used to treat people with anger management issues? Apparently, if you can’t squinch your forehead into a grimace, it’s a lot harder to get angry . . . same with tense shoulders and anxiety. Get regular massage and exercise before going to work, or on lunch hour. Practice conscious breathing. Meditate. Do yoga. Take Epsom salt baths with lavender essential oil. Take an assessment of the relationships in your life, not only with people, but also activities. Which ones build you up? Which ones suck your energy? Which relationships do you choose to cultivate? Consider how your lifestyle affects your body. Do the choices you make about diet enhance your quality of life? Foods high in antioxidants reduce the effects of inflammation in the body - think blueberries, blackberries, raspberries, dark greens, orange squash and spices like turmeric and cayenne. Eat protein and a green vegetable with every meal to avoid energy crashes from low blood sugar. Get enough sleep. Going to bed between 8-10pm and waking between 6-8am gives your nervous system and hormones time to recover so your energy can be balanced throughout the day.  Do your leisure activities provide energy or deplete it? Take a vacation! Studies have shown that people are actually more productive at work if they take regular breaks and have adequate vacation time.

Welcome!

Hello out there,

Thanks for visiting . . . This blog is meant to be a forum for sharing exciting and interesting things I'm learning in my education as a naturopathic physician and as a practicing massage therapist that I think you'll want to know about! Feel free to comment on topics you'd like to explore further - I always like to have new research ideas.

Disclaimer: I am not a licensed physician (yet!) and as such do not give medical advice. Anything I write about will be for education purposes only. Please see your own doctor for medical advice.