DOES DHEA HELP WITH LOW LIBIDO IN WOMEN?

When the “pink pill” for women came to market late this past year I had a number of women asking me for it. This reminded me to look into the different options for libido. Without going into too much about the new medication, it is only approved for use in premenopausal women and most of the requests came from my postmenopausal patients. Overall, the literature also seems to suggest it carries a number of significant risks with minimal gain. Maybe I’ll do a little reassessment of this drug in the future but for now trying to see if any more “natural” remedies were available to suggest my patients. So, one of the first things on my topic list is to evaluate is DHEA.

What is DHEA ?

Keeping it simple – DHEA, also known as dehydroepiandrosterone (but we’ll just stick with DHEA), is a steroid. It is primarily made the adrenal gland but also is produced in small amounts in the brain (Strous 2006). As part of the cholesterol biochemical pathway, DHEA goes through multiple transformations leading to increased levels of testosterone and estrogen. (Callahan et al, 2004).

Do androgens matter for libido?

Studies have shown that women need a certain amount of estrogen and testosterone to maintain libido and sexual response (Clayton 2010, Davis 2005) and women with supplemented hormones show improvement in sexual functioning (Davis 2008). In premenopausal women with low scores of sexual response and arousal, lower DHEA levels were found (Turna 2005) but correlation doesn’t necessarily mean a cause.

My next question is:

What do the studies suggest about DHEA supplementation in libido improvement?

There are only a handful of studies that reviewed DHEA specifically and the results are mixed. Two small studies with higher DHEA doses [100mg] administered showed improvement in sexual function (Hackert & Heiman 2002; Schmidt 2005) but other studies with lower doses of DHEA [50mg] and more women included didn’t show a difference (Kritz-Silverstein 2008; Panjari et al 2009). A more recent study (Bloch 2013) conducted a randomized, double blind trial of 100mg DHEA supplementation for postmenopausal women. After 6 weeks the women supplemented with DHEA showed improvement in sexual arousal and satisfaction.

So, while the results are mixed and there are only a few studies, this may be something that could potentially help some of my patients.

What is the appropriate dose of DHEA?

This is a good question. Most supplements suggest 25mg daily, however, the studies used a minimum of 50mg and many of those that noted significant effects used more, 100mg. It is possible that for some women the smallest amount would be effective but with increasing doses come increasing side effects and risks.

Who should avoid DHEA?

As with any medications or supplements, there are potential side effects and risks. Individuals with any contraindication to other steroids should avoid DHEA. For instance, women with any estrogen positive cancers, individuals with liver dysfunction, insulin resistance could be worsened for those with diabetes and it may have central nervous system effects so those with psychiatric disorders may want to avoid DHEA. It also seems that women with elevated testosterone as a result of polycystic ovary syndrome would be harmed more than helped by DHEA. Those already on any hormone replacement should avoid additional hormones.

What are potential side effects?

As with any increasing androgens, the potential side effects are oily skin, acne, hot flashes and increased hair growth in a male pattern. In high enough doses or potentially if someone is very sensitive other significant risks are deepening of the voice, clitoral enlargement, and breast size reduction to name a few. Interestingly enough, in the Bloch et al (2013) paper the side effects were similar in the DHEA as in the placebo groups with short-term use.

Who might be helped by DHEA?

The studies seem to suggest that postmenopausal and potentially peri-menopausal woman, or any woman with low hormone levels as the cause of low libido, could benefit by DHEA supplementation.

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REFERENCES:

Bloch M, Meiboom H, Zaig I, Schreiber S, Abramov L (2012). The use of dehydroepiandrosterone in the treatment of hypoactive sexual desire disorder: A report of gender differences. European Neuropharmcology, 1-9.

Callahan T., Caughey A., Heffner L (2004) Blueprints, Obstetrics and Gynecology. Pages 202-204.

Clayton AH, (2010).  The pathophysiology of hypoactive sexual desire disorder in women. Int J. Gynecol.Obstet. 110, 7-11.

Davis SR, Davison SL, Donath S, Bell RJ et al (2005). Circulating androgen levels and self-reported sexual function in women. JAMA 294, 91-96.

Davis SR, Moreau M, Kroll R, Bouchard, C, Panay N, Gass M, Braunstein et al (2008). Testosterone for low libido in postmenopausal women not taking estrogen. NEJM. 359, 2005-2017.

Genazzani AR, Stomati M, Valentino V, Pluchino N, Poti E, Casarosa e, Merlini S, Giannini A, Luisi M. (2011). Effect of 1-year, low dose DHEA therapy on climacteric symptoms and female sexuality. Climacteric 14, 661-668.

Hackert L, Heiman JR (2002). Acute dehydroepiandrosterone (DHEA) effects on sexual arousal in postmenopausal women. J Womens Health Gender Based Medicine 11, 155-162.

Kritz-Silverstein D, Von Muhlen D, Laughlin GA, Bettencourt R (2008). Effects of dehydroepiandrosterone supplementation on cognitive funtion and quality of life: The DHEA and wellness (DAWN) trial. J Am Geriatric Society 56, 1292-1298.

Morales AJ, Haubrich RH, Hwang JY, Asakura H, Yen SSC (1998). The effect of six months treatment with a 100mg daily dose of dehydroepiandrosterone (DHEA) on circulating sex steroids, body composition and muscle screnght in age-advanced men and women. Clin Endocrinol. (Oxf), 49, 421-432.

Munarriz R, Talakoub L, Flaherty E, Giola M, Hoag L, Kim NN, Traish A, Goldstein I, Guay A, Spark R (2002). Androgen replacement therapy with dehydroepiandrosterone for androgen insufficiency and female sexual dysfunction: Androgen insufficiency and female sexual dysfunction: Androgen and questionnaire results. J Sex Marital Ther 28, 165-173.

Panjari M, Bell RJ, Jane F, Wolfe R, Adams J, Morrow C, Davis SR (2009). A randomized trial of oral DHEA treatment for sexual function, well-being and menopausal symptoms in postmenopsual women with low libido. J Sex Med 6, 2579-2590.

Schmidt PJ, Daly RC, Bloch M, Smith MJ, Danaceau MA, Simpson St Clair L, Murphy JH, Haq N, Rubinow DR (2005). Dehydroepiandrosterone manotherapy in midlife onset major and minor depression. Arch Gen Psychiatry 62, 154-162.

Shifren JL, Baunstein GD, Simon JA, Casson PR, Buster JE, Redmond GP, Burki RE, Ginsburg ES, Rosen RC, Leiblum SR, Caramelli KE, Jones KP, Daugherty CA, Mazer NA (2000). Transdermal testosterone treatment in women with impaired sexual function after oophorectomy. NEJM 343, 682-688.

Simon J, Braunstein G, Nachtigall L, Utian W, Katz M, Miller S, Waldbaum A, Bouchard C, Derzko C, Buch A, Rodenberg C, Lucas J, Davis S (2005). Testosterone patch increases sexual activity and desire in surgically menopsual women with hypoactive sexual desire disorder. J Clin Endocrinol Met 90, 5226-5233.

Strous RD, Maayan R, Weizman A (2006). The relevance of neurosteroids to clinical psychiatry: from the laboratory to the bedside. Eur Neuropsychopharmacol. 16, 155-169.

Turna  B, Apaydin E, Semerci B, Altay B, Cikili N, Nazli O (2005). Women with low libido: Correlation of decreased androgen levels with female sexual function index. Int J Impot Res 17, 148-153.

*You should consult with a qualified healthcare provider regarding your specific health risks/benefits before making decisions about therapies and/or health conditions.

Conscious Clothing

The recent Bangladesh garment factory tragedy reminded me once again how much our lives impact the lives of others thousands of miles away.  In our daily lives, we simply walk in a store and purchase items at low cost without any thought to the cost imposed on others. 

 

 

While the owner’s of this facility were aware that cracks were forming, they used fear tactics, threatening job loss, if employees didn’t come to work that fateful day.  Greed caused, as of a report today (NPR, 05/13/13), more than 1,127 people to lose their lives.  At least charges were brought against the owner but that isn’t any condolence to the families who lost love one’s.

 

 

We, as in the collective Western World ‘WE’ can’t continue to distance ourselves and plead ignorance.  The companies that manufacture products under poor conditions can’t say “we didn’t know what was taking place in these factories”.  I’m sorry, but if your products are manufactured somewhere you need to know the circumstances under which it is produced, you are ultimately responsible. Corporations need to stop treating people as expendable.

 

 

However, as consumers we are ultimately responsible. We can refuse to spend our money on items that cause undue suffering anywhere along the supply chain. We can demand that others are treated fairly and provided fair wages and standards of working conditions.  We need to be willing to pay a little more for items that are produced under more just conditions. We can seek out locally produced and sourced items to our best ability and we can voice our desire for information about the conditions that our fellow humans exist.  Some of these work circumstances are essentially slavery.  In fact, we all have any number of slaves working for us depending on how extravagantly we live.  You can calculate your own number of slaves at http://slaveryfootprint.org/.  I have 29.

 

 

Admittedly, even when you try, it is difficult.  I have tried not to buy anything new, choosing to purchase from used clothing stores.  Around the Tri-valley I frequent any number of thrift stores for various causes as well as Picket Fences in Livermore and Savvy Seconds in Pleasanton.  Sometimes though I would like to purchase new items made in a responsible and sustainable manner.  From what I’m finding though, well, it’s hard to find! 

 

 

I’ve started trying to search out shops with clothing made local or made by collectives internationally who benefit directly from the clothing, and if at all possible also sustainably produced.  One I like for children’s clothes is Tomat.  They are made in the US with organic cotton and it’s a business operated by a mom.  Certainly this route is a fair bit more costly than buying from your local big box retailer, but you can purchase them in good conscience and that to me is priceless. 

 

 

Have been trying to find other potential places to purchase items for myself.  Searching Etsy I found a few clothes designers who sew special order sizes.  I’ve also found a few potential on-line companies with some interesting finds:

 

 

http://www.fairindigo.com/

 

 

https://www.globalgirlfriend.com/

 

 

http://site.fashionethic.com/

 

http://vautecouture.com/

 

 

If you have any retailers to add, please don’t hesitate to let me know about them, I am always on the lookout.

 

Menopause – Alternatives

…to hormone replacement therapy and anti-depressants

 

Exploring our local health food store yesterday, Van’s, reminded me to complete and post this article I’ve been working on way too long.  It also reminded me how many “natural” products are out there that tout miracles for menopausal symptoms.

‘Van’s Health Foods ‘ shelf – Natural hormone remedies

On daily basis women with menopausal symptoms often ask me if there are any “natural” remedies for their hot flashes and mood issues.  It seems lately that I’ve had more and more women asking this question.  The only thing that I have to offer them is hormone replacement therapy, some women just aren’t the best candidates for this method, and anti-depressants have their own list of unpleasant side effects.

Especially for women who are just starting the menopausal transition or having milder symptoms, natural and/or herbal remedies may be an ideal option but I wasn’t familiar enough to recommend anything in particular.  In an attempt to come up with some alternatives, I headed to the literature.

BREATHING EXERCISES:

The least invasive and least risky are the behavioral therapies.  Few studies have looked at these methods of managing symptoms but a couple studies show promise with a particular kind of breathing, paced respiration.  This method of slow, deep breathing has been compared with progressive muscle relaxation, doing other relaxing leisure activities, and biofeedback.  In all cases, the paced respiration group demonstrated decreases in hot flashes (Kronenberg et al, 2002).  This is an easy practice that women can incorporate into daily life to help cope and reduce the hot flashes experienced in menopause, especially if mild severity.

ACUPUNCTURE:

While I am very much a believer in acupuncture for many things, its efficacy in menopause symptoms is still in question.  There is one study that looked at acupuncture and one issue with the study is that the treatment and control groups may’ve been too much alike; one received standard acupuncture and the other a shallow acupuncture treatment, but at the same points.  From pre-treatment to post-treatment, both groups showed a significant decrease in hot flashes but between the two there was not a difference (Kronenberg et al, 2002).  Since both groups showed an improvement following treatment, this actually suggests that acupuncture or pressure may work to help alleviate the symptoms.

HERBALS:

As mentioned previously, the only tools I have available are hormone replacement and anti-depressants, which have their issues.  I was hoping a review of the literature would reveal more herbal options to offer but sadly it is still limited.  While many things have been touted as working: black cohosh, dong quai, evening primrose, ginseng, red clover, vitamin E, chasteberry, soy, wild yam, and progesterone creams, there are limited remedies with proven evidence that they are beneficial.

It seems that only one really has any evidence, that being black cohosh, and another soy, has promising but mixed results.  The others seem to have no clinical benefit, at least based on current literature. (Kronenberg et al, 2002; Low Dog, 2005) and while women using progesterone cream seemed to note “improvement”, it came with a risk of postmenopausal bleeding and subsequent endometrial biopsies (Leonetti et al., 1999).  This finding suggests any estrogen or progesterone-containing product over the counter may influence the uterine lining.  In women who still have a uterus, when physicians prescribe these medications, both are given in an amount to attempt and reduce the risk of uterine lining stimulation that can result in development of endometrial cancer.  Therefore, I tend to caution my patients who are using over the counter products to avoid those that are basically hormones and carry those same risks.

Black cohosh, in the form of Remifemin, is relatively well studied and has the most support for its use.  A review article found 5 controlled studies and all found that black cohosh reduced psychological symptoms, improved vaginal epithelium, and decreased measures of menopausal symptoms, particularly hot flashes and sweating (Low Dog, 2005).  It does seem to be helpful for a multitude of symptoms but a concern I have is that no studies exist on long-term use regarding hormonal stimulation on breast or uterus, so women with a history of breast cancer or at risk for endometrial cancer I would advise use with caution.

Ironically, while working on reviewing the literature for this post our pharmacy department came out with a memo that addressed soy as a recommended “pharmaceutical” for reducing mild menopausal symptoms.  The studies I found suggest only modest benefits, mostly for hot flashes, and the benefits by 6 weeks decreased.  Interestingly, there was a 50-60% reduction in symptoms in both the soy and placebo groups in the studies.  Foods containing soy certainly seem a safe addition and may help with mild symptoms so supplementing your diet with beans is a benign way to start.  However, it is difficult to make a statement about high-dose isoflavones, with the most common doses being between 50-150mg daily and in women with a history of breast cancer it’s best avoided (Umland, 2008).  Like most things, the lowest dose possible to help with the symptoms should be the guiding principle.

While less than I had hoped to offer patients with menopausal symptoms, at least this provides a few options to suggest to my patients with some confidence thanks to support from the research.

REFERENCES:

Kronenberg F and Fugh-Berman A. Complementary and alternative medicine for menopausal symptoms: A review of randomized controlled trials.  Annals of Int Med. 2002;137:10:805-813.

Leonetti HB, Longo S, Anasti JN.  Transdermal progesterone cream for vasomotor symptoms and postmenopausal bone loss.  Obstet Gynecol. 1994;94:225-8.

Low Dog T.  Menopause:  A reiew of botanical dietary supplements.  Am J of Med. 2005;118:12B:98S-108S.

Umland EM. Treatment strategies for reducing the burden of menopause-associated vasomotor symptoms.  Suppl to J Managed Care Pharm. 2008;14:3:S14-S19.

 

Fluoride for a 3-year old?

Yes or No? (as my son often says)

Due to indecisiveness we have both a fluoride and a non-fluoride toothpaste to choose from.

As San Jose begins to add fluoride to the drinking water my husband and I have been wavering about whether or not to provide fluoride to our son.  In fact, he has both a tube of fluoride and non-fluoride toothpaste and from day to day I alternate.  My husband seemed to think that someone was profiting at the expense of children receiving fluoride and wasn’t convinced it was safe, and in all honesty, I wasn’t certain.

In the United States, more than two-thirds of households served by public water systems are fluoridated (ADA, 2005).  Livermore, where we live, happens to be in the minority, there is no fluoride added to our water (California Department of Public Health Website, 2012).  Because of this, our pediatrician mentioned that our son should be taking fluoride supplements.  A prescription sits in the pharmacy until I come to a conclusion on fluoride use and convince my husband fluoride supplementation is not the result of some greater conspiracy that may hurt his son.  So, I decided to start with a little history lesion.

How was it that fluoride was even discovered as a way to reduce cavities?

In 1920’s Colorado Springs a dentist named Dr. Frederick McKay noted that many residents had dark stains on their teeth and began documenting reports of this “mottled enamel”, discoloration of the teeth that ranges from bright white spots to brownish-dark discoloration, which today is called fluorosis.  What ultimately was most remarkable about these individuals was that their teeth didn’t rot although fluorosis also is of cosmetic concern.

After many studies it was discovered that these individuals had naturally occurring elevated levels of fluoride in their water supplies, around 13.7 parts per million or milligrams per liter of water (ppm or mg/L).  As a side note, the optimal amount of fluoridation in the water has been determined to be 0.7-1.2ppm (California Department of Public Health, 2012) so their levels were 11 to nearly 20 times more than what is now thought of as an “ideal” amount.

Fast-forward 25 years and numerous studies of those initial cities receiving fluoridation in their water (Grand Rapids, Michigan; Newburgh, New York; Brantford, Ontario, and Evanston, Illinois) and it was found that overall fluoride helps to reduce rates of cavities.

However, this didn’t directly apply to young children, their temporary teeth, and didn’t address if any harm to their developing brains. Before giving it to my son I wanted to know more.  Basically, I needed to decide for myself if fluoride prevents cavities in temporary teeth and if there are any harms?

Is there a risk of fluoride use in young children?

Since it is known that in animal models damage can occur to the brain and in adults, acute fluoride poisoning can occur, it is reasonable to assume that children would also be at risk.

One review in 2012 looked at 27 epidemiologic studies that evaluated IQ scores and cognitive function measures and compared those in high fluoride areas and low areas.  Inevitably, most of these studies take place in China because fluoride is found in nature.

Since fluoride crosses the placenta, it’s possible that significant exposure may occur to the developing brain where fluoride levels are high. This review concluded that children in high fluoride areas had lower IQ scores and cognitive performance than those in low fluoride areas.  From reviewing the ranges of fluoride there are broad differences in the amount of exposure between studies.  Some of the areas with high fluoride noted that they also found high levels of other chemicals (such as arsenic!).  This suggests that there may be other risks to those children in the high fluoride areas compared to those in the low fluoride areas that led to lower mental function (Choi et al, 2012).

The more accurate randomized controlled trials in areas without fluoride in the water noted that increasing levels of fluoride in toothpaste was associated with an increased risk of fluorosis (comparing low 440-550ppm with high levels 1000-1450ppm).  When looking at age separately, a reduction in fluorosis was found if brushing with fluoride began after a year, with inconsistent findings prior to 24 months.

Does fluoride make a difference in cavity rates for children?

One of the most recent Cochrane reviews from 2010 included 75 studies but only six of these studies looked at fluoride concentrations on early teeth and ultimately found no difference.  Meaning that the studies were too conflicting to recommend that prior to permanent teeth that fluoride makes a difference (Walsh et al 2010).

Another review in 2008 looked specifically at the benefit of fluoride in children under 6-years, when permanent teeth start to develop, and only one of those studies looked at 6-month to 3-year olds (Ismail, 2008). They reviewed an area of China with less than 0.3ppm fluoride in the water.  Only a small percentage of children in this region participated (<17%) for the 180-day supplementation, with high withdrawal rates (Hu et al, 1998).  After 3 years, those who used fluoride daily had a 47.2% lower rate of decayed, missing, and filled primary teeth compared with those in the control group, but this is a small sample, it’s only looking at primary teeth that eventually are lost, and there may be other reasons for these differences.  It said nothing about any health concerns from over-ingestion.

In a study looking at supplementation in expectant mothers and then supplementing those children for 3 years, there was no benefit in preventing cavities (Leverett et al, 1997). In other studies supplementation did not translate to less cavities in children’s permanent teeth when used up to age 5 (Mann et al, 1989).

In older children, there seems to be a benefit with fluoride in terms of reducing cavities, however, the authors also note that there is increasing benefits and risks when >1000ppm fluoride is used (Wong et al).  However, a discussion on permanent teeth is for another day.

What did we decide about starting fluoride in our son?

The results of the studies in young children on their temporary teeth and potential risks are too conflicting for me to decide to administer fluoride to my son.  For now, we’re not picking up the fluoride supplements.  As he gets older, around age 5 or 6 and he starts getting his permanent teeth, we’ll starting using fluoride.  That is, once he’s not simply licking it off his toothbrush!

I’ve decided that in children younger than 24 months, I definitely would not give fluoride.  For my son, age 3, I tend to think that a healthy diet, good teeth hygiene, and brushing habits along with taking him for check-ups (which, admittedly, we need to do!) can make up for taking in excess fluoride without any potential additional risk.

Anyone know a good kid’s dentist in the Tri-Valley area?

Time to brush our teeth! We’ll use the one without the fluoride.

**To see if your water is fluoridated:

–>  In California you can go to http://www.cdph.ca.gov/certlic/drinkingwater/pages/fluoridation.aspx

 

REFERENCES

1.  ADA Website; www.ada.org.  Fluoridation Facts.  Accessed November 23, 2012

2.  California Department of Public Health Website; http://www.cdph.ca.gov/certlic/drinkingwater/pages/fluoridation.aspx.  Accessed: December 1, 2012

3.  Choi AL, Sun G, Zhang Y, Grandjean P (2012).  Developmental fluoride neurotoxicity: A systematic review and meta-analysis.  Environ Health Perspect, Oct;120(10):2362-89.

4.  Hu D, Wan H, Li S (1998).  The caries-inhibiting effect of a fluoride drop program: A 3 year study on Chinese kindergaten children.  Chinese J Dent Res, 1;3:17-20.

5.  Ismali AI, Hasson H (2008).  Fluoride supplements, dental caries and fluorosis: A systematic review.  J Am Dent Assoc;Nov;139;11:1457-1468

6.  Leverett DH, Adair SM, Vaughan BW, Proskin HM, Moss ME (1997).  Randomized clinical trial of the effect of prenatal fluoride supplements in preventing dentlal caries.  Caries Res, 31;3:174-179.

7.  Mann J, Horesh E, Ran F, Gedalia I (1989).   The effect of fluoride drop administration on dental caries increment: A longitudinal stud.  Isr J Dent Sci, 2:3:148-152

8.  Tubert-Jeannin S, Auclair C, Amsallem E, Tramini P, Gerbaud L, Fuffieux C, Schulte AG, Koch MJ, Rege-Walther M, Ismail A (2011).  Fluoride supplements (tablets, drops, lozenges or chewing gums) for preventing dental caries in children.  Cochrane Database Syst Rev. Dec 7;(12):CD007592.

9.  Walsh T, Worthington HV, Glenny AM, Appelbe P, Marinho VC, Shi X (2010).  Fluoride toothpastes of different concentrations for preventing dental caries in children and adolescents.  Cochrane Database Syst Rev.  Jan 20;(1):CD007868.

10.  Wong MC, Clarkson J, Glenny AM, Lo EC, Marinho VC, Tsang BW, Walsh T, Worthington HV. (2011).  Cochrane reviews on the benefits/risks of fluoride toothpastes.  J Dent Res. May;90(5):573-9.

 

Chasteberry and fertility

An added bonus for those trying to conceive

Chastetree, vitus-agnus-castus
Top Tropicals Website

While reading about chasteberry for other gynecologic issues, one of the review papers mentioned a secondary effect of influencing both follicle stimulating hormone and luteinizing hormone, both hormones important in ovulation (Roemheld-Hamm, 2005).  This led me to look into the potential effect of chasteberry on fertility.

One reason that many patients find their way to my office is when they’ve been trying to have a baby without success.  At least being able to offer another option for women trying to conceive, when unable or unwilling to pay for more invasive infertility treatment methods, is a bonus.

I only found 3 randomized controlled studies evaluating chasteberry for fertility, two of which were published in Germany and one that was published in the United States.  If anyone found others, please share!

In 1993, a German study of 52 patients found that women taking chasteberry normalized the second half of their menstrual cycle by improving luteal phase progesterone and estradiol levels.  However, this study didn’t note any fertility outcomes (Milewicz et al, 1993).

Another study of 96 women suggested those individuals taking chasteberry in the form of Mastodynon® (a German product not available in the US containing 5 additional herbs – cyclamen, tiger lily, ignatius bean, blue cohosh and iris) became pregnant more often than those taking a placebo.  In women with amenorrhea or luteal phase problems, pregnancy occurred in the active treatment group twice as often as the placebo.  Of note, however, is that the absolute percentage of women conceiving over the three-month study was small (16%)(Gerhard, 1998).

After finding benefits with a pilot study, the final study performed by Stanford School of Medicine found Fertilityblend®, a United States nutritional supplement, led to more pregnancies.  It contains chasteberry, but also other antioxidants, vitamins, and folic acid.  This study evaluated 93 women, ages 24-42, who had been trying to conceive 6-36 months, one group received Fertilityblend and the other a placebo.  Mid-luteal progesterone levels, luteal-phase basal temperatures, and pregnancy outcomes were recorded over 3 months.

The group characteristics were very similar.  After 3 months of supplementation, those taking the supplement had an increase in mid-luteal phase progesterone levels, especially noted in those with the lowest values.  This also translated into normalized cycle lengths in those taking the supplementation. Interestingly, however, in their graph there was also an increase in the placebo group’s progesterone levels after 3 months (although not significant), which you would expect to stay relatively stable.  Made me wonder if the placebo group had some patients actually doing something different?

In terms of actual fertility outcomes, after 3 months those taking Fertilityblend® were more likely to conceive.  Twenty six percent (14 of 53 women) in the supplement group became pregnant compared to 10% (4 of 40) of the women in the placebo group.

Following completion of the study, the supplement was offered to both groups with 3 additional pregnancies in the remaining 17 (18%) women in the continuing supplement study compared to 4 of 36 (11%) of women who had previously been in the placebo group.  This value is significantly lower than would be expected based on the initial 3 months with the treatment group.

It’s difficult to make any conclusions about the open-label study based on these final results because they mention that not all women continued for an additional 3 months.  It would be interesting to know how many of the women in both groups actually continued with open-label supplementation with Fertilityblend® vs. went on to more intensive treatment or stopped trying all together.  The open-labeled segment of the study may demonstrate benefit of longer supplementation or may suggest that something may be different with the entire group that was in the initial placebo group, something not accounted for in their review of the characteristics initially.

Still, it seems in women who are not ready or able to move on to more invasive fertility treatments this offers an alternative by taking supplements.  From prior research, if nothing else, this may regulate their cycles, reduce breast tenderness during their periods, and potentially decrease symptoms of premenstrual syndrome (PMS).

In terms of pregnancy, younger women with irregularities of their periods or reduced progesterone levels may benefit most from chasteberry.  In older women with fewer follicles remaining (less eggs), more aggressive treatment will likely still be necessary. However, for some of my younger patient’s, with otherwise normal work-ups but short second halves of their cycles, I am going to start recommending chasteberry, in the form of Fertilityblend®.

REFERENCES:

1.  Gerhard I, Patek A, Monga B, Blank A, Gorkow C.  Mastodynon ® bei weiblicher Sterilitat Forsch Komplementarmed 1998; 5:272-8.

2.  Milewicz A, Gejdel E, Sworen H, Sienkiewicz K, Jedrzejak J, Teuher T, et al.  Vitex agnus castus extractin the treatment of luteal phase defects due to latent hyperprolactiemia.  Results of a randomized placebo controlled double-blind study [in geran].  Arzneimitteiforschung 1993; 43:752-6

3.  Roemheld-Hamm B (2005).  Chasteberry.  Am Fam Physician; 72,5:821-824.

4.  Westphal LM, Polan ML, Sontag T. (2006).  Double-blind, placebo-controlled study of Fertilityblend®: A nutritional supplement for improving fertility in women.  Clin Exp Obstet Gynecol, 33(4):205-8.

 

DISCLAIMER:  **Speak to your own gynecologist before starting any medication, as this product hasn’t been FDA approved.  Your personal physician should evaluate potential causes of your infertility before recommending management.**

 

Chasteberry, Vitex agnus-castus

An Herb for the Gynecologist’s Toolbox

Chastetree, vitus-agnus-castus
Top Tropicals Website

 

Chastetree (Vitex agnus-castus) has been used since ancient Greece and is thought to have many gynecologic uses due to some of the plants compounds similar to human sex hormones.  In medieval Europe, it was thought to reduce sexual libido and was used by clergymen, hence it’s other name of “monk’s pepper”.  The plant found it’s way to Germany and in the 1940-50’s; research took place supporting its use in menstrual disorders, without affecting sexual libido.

Irregular periods, premenstrual syndrome (PMS), and cyclic breast pain encompass a majority of the common gynecologic complaints in my daily practice.  Really, the only conventional pharmaceuticals available are hormones, in the form of birth control pills to regulate cycles or anti-depressants for the psychological symptoms.  For women who don’t need a contraceptive method, I find most want to avoid taking hormones.  Others with the emotional premenstrual symptoms fear the side effects of anti-depressants.

In an attempt to offer alternatives that are supported by current evidence and potentially with fewer side effects, I came across chastetree.  This plant sounded like a good alternative and I wanted to see if there was actual research to support its use for some of these common gynecologic issues.

At it’s mechanistic level it appears the main way chastetree works is by its effects on prolactin and progesterone.  By binding dopamine receptors in the brain it inhibits prolactin, which has been shown to reduce breast pain.  Additionally, it also seems to increase progesterone secretion, and that can help regulate the second half of the menstrual cycle (Du Mee 1993).

Compared to some of the side effects of the normal hormonal methods or anti-depressants that I often prescribe, the side effects described are mild.  These include gastrointestinal complaints, dizziness, headache, tiredness and dry mouth (Roemheld-Hamm 2005).

In other countries, herbal medicine seems to be much more accepted and many physicians in Germany prescribe chastetree formulations to their patients, so why can’t we?  Specifically, in the case of chastetree, the German Commission E, a group evaluating the use of herbs, has approved it for irregular cycles, PMS and breast pain (Blumenthal 2000).  Maybe it’s time that the United States researches and, if evidence suggests, embrace alternative methods for the health benefit of its citizens.  The bulk of research in the United States is conducted by pharmaceuticals and they have little to gain from herbal remedies (but that’s for another blog entry) so the little research that is out there comes from other countries or in some cases, from academic institutions.

So, what is out there in terms of research?  Very little randomized studies, but a couple that supports its use.

In one randomized study, after 3 months more than half of 170 women experienced a 50% or greater reduction in premenstrual symptoms (Schellenberg 2001). Another showed improvement in self-reported severity of PMS symptoms, with global improvement and overall benefit versus risk (p=0.001; NNT=4). In another trial, chastetree reduced symptoms of edema, constipation, irritability, depressed mood, anger, headache, and breast pain (Roemheld-Hamm 205).  Cyclic breast pain was the focus in another study that demonstrated a decrease compared to placebo after 3 menstrual cycles (Wuttke et al 1997).

Other vitamins may be as effective in helping with menstrual symptoms.  For instance, another study found that Vitamin B6 and Chasteberry both decreased symptoms by nearly 50%, but the sample size was small (Lauritzen et al 1997).

Another issue is that the studies use varying doses and formulations. Fruit extract dose is 20-40mg daily but I also came across doses of 240-500mg daily and higher doses (up to 1800mg daily) being used.  Extracts (40 drops daily) and tincture (35-45 drops three times a day) are also available.  In the United States there is a marketed product called Femaprin (325mg), which also contains Vitamin B (100mg) by Nature’s Way, which would likely be safest to recommend to patients.

Based on these findings and the fact that physicians in other countries recommend chastetree, I feel comfortable now making the recommendation for irregular periods, premenstrual symptoms, and cyclic breast pain.

Finally, another tool in my gynecology toolbox that can potentially benefit my patients!

 

REFERENCES:

1. Blumenthal M (2000).  German Federal Institute for Drugs and Medical Devices.  Commission E.  Herbal Medicine:  Expanded Commission E monographs.  1st ed, Newton, Mass:  Integrative Medicine Communications.

2. Du Mee C (1993).  Vitex agnus castus.  Aust J Med Herbalism; 5:63-65.

3. Lauritzen C, Reuter HD, Repges R, Bohnert KJ, Schmidt U.  Treatment of premenstrual tension syndrome with Vitex agnus castus.  Controlled double-blind study versus pyridoxine.  Phytomedicine 1997;4:183-9.

4. Roemheld-Hamm B (2005).  Chasteberry.  Am Fam Physician; 72,5:821-824.

5. Schellenberg R (2001).  Treatment for the premenstrual syndrome with agnus castus fruit extract: Prospective, randomized, placebo controlled study.  BMJ 322:134-7.

6. Wuttke W, Splitt G, Gorkow C, et al.  Treatment of cyclical mastalgia; Results of a randomized, placebo-conrolled, double-blind study [in German] Geburtshilfe Frauenheilkd 1997;57:569-74.

 

DISCLAIMER:  **Speak to your own gynecologist before starting any medication, as this product hasn’t been FDA approved.  Your personal physician should evaluate potential causes of your symptoms before recommending management.**

 

 

 

Environmental Laws – California 2012

COMPLETED!

Food & Water – For your protection!

I’m continuing the saga of learning about all the new environmentally oriented laws that were enacted for 2012, just about in time for those that will be enacted in 2013! Because I am obsessive I had to complete the project…and now I am finally DONE!  In the 745 new California laws taking effect or continuing this year, 9 are aimed at protecting your food and water supply.

Admittedly, it continues to take time to read through each of the actual bills and decipher what is being said, it really is taking me until the beginning of October to get through all of this!

If you want to refer to any of these bills in their entirety, anyone can access the PDF with links to the bills as they passed through Congress, including the amendments and the final enacted bill:

www.leginfo.ca.gov/pdf/BillsEnactedReport2011.pdf

FOOD & WATER –>

AB0054

Drinking Water: Insuring Safe Drinking Water

This bill is a long one with multiple components.  The current California Safe Drinking Water Act requires the State Department of Public Health to administer provisions relating to the regulation of drinking water to protect public health and laws already exist to provide funds.  Here comes the legalese of this bill.  It does a few different things.  First, it allows a public water system that is a lead applicant for a project to be funded by the Safe Drinking Water Revolving Fund and would make expenditures related to the project potentially reimbursable.  Second, it authorizes the commission to review and decide on consolidation of territory in the jurisdiction of a mutual water company.  Finally,  it authorizes the commission to include in the service review, whether the drinking water sources comply with safe drinking water standards.

AB0222 

Food and Agriculture: Biotechnology

There is already a bill in place that regulates the Food and Agriculture fund programs.  All this amendment does is eliminates the requirement of the Department of Food and Agriculture from being required to report issues to the Governor and the Legislature.  Not sure the new oversight committee of these funds and programs is any longer, self-regulation?

AB0337

Ocean Protection: Sustainable Seafood

Enacts a voluntary seafood promotion program to promote sustainable fishing industry practices, provide grants/loans for limited activities, and develop labeling standards for these sustainable fishing companies.

AB0983

Safe Drinking Water: State Revolving Fund

Makes minor amendments to the already enacted California Safe Drinking Water Act, basically just addressing actions pertaining to the fund.

AB1152

Groundwater: Groundwater Elevations

Establishes rules for the Department of Water Resources in terms of monitoring groundwater elevations within each basin or sub-basin and the well water management.  Prevents counties from being eligible for water grant/loans administered by the state if they decline to accept responsibility for monitoring groundwater elevations (from unmonitored private wells included).

AB1194

Drinking Water: Safety

The Calderon-Sher Safe Drinking Water Act of 1996 requires the State Department of Public health to adopt regulations regarding contaminants in water potentially ingested by people.  The new addition is that this law permits the department to issue citations if a public water system is in violation and defines the specifics.

AB1292

Safe Drinking Water Funds: Revenue Bonds

Already in place is a bill where money is appropriated into the State Department of Health budget to design and construct projects for public water systems to assist in providing safe drinking water.  This bill authorizes the bank to issue taxable or tax-exempt revenue bonds to provide funding.

SB0267

Water Safety: Pollutant Discharge

Under current law, the State Water Resources Control Board and California Regional Water Quality Control board define waste discharge requirements in accordance with the Clean Water Act and Porter-Cologne Water Quality Control Act.  The Porter-Cologne Water Quality Control Act is a state act requiring any proposal to discharge pollutants or fill material to file a report at least 180 days in advance of the date on which it is desiring to discharge the materials.  This bill only changes the date requirement by 5 days, to 185 days before.

SB0818

Food Labeling: Olive Oil

Since I am particularly fond of olives, I found this one interesting.  Currently, the State Department of Public Health enforces laws regarding manufacture, blending, production and sale of olive oil and any violation is a crime.  This law pertains solely to the edible oil obtained solely from the fruit of the olive tree.  The hierarchy from highest to lowest: extra-virgin olive oil, virgin olive oil, and virgin oil not fit for human consumption (lampante virgin olive oil), olive oil, and refined olive oil.  These are all described in detail in the bill.

In 2013, I think I will pick and choose.

Acupuncture and In Vitro Fertilization (IVF)

Together – does it equal more babies?

Ironically, this past week the question of acupuncture and IVF came to me from two different directions.  First, I received an e-mail from a patient who was going to be starting IVF in the near future and wondered if the addition of acupuncture would help increase her chances. Second, my sister mentioned she has a friend who is on her third cycle of IVF and plans to try acupuncture this time around, because she knows others who did it and now have children.

Because I didn’t know the answer I thought I’d look into so I could make a recommendation.  Being a little short on time this week I went straight to reviews and meta-analysis on this topic.

For both my patient and my sister’s friend, the answer is promising!  The best study I found was a meta-analysis from the British Medical Journal, suggesting that acupuncture done at the time of embryo transfer increased one’s chances of pregnancy and live birth.

The study by Manheimer 2007 identified 7 randomized controlled trials with a total of 1,366 participants that met their specific criteria.  They specifically were evaluating acupuncture as it pertains to embryo transfer, and there are many steps before one gets to this stage in the IVF process.  However, this review included those women who didn’t make it to the embryo transfer point, as they were often randomized at the start of their IVF “cycle”.   A cycle begins when a woman starts stimulating her ovary to produce eggs that are ultimately retrieved, fertilized with her partner’s/donor’s sperm, and then placed back into the uterus.  This has the effect of actually underestimating the potential benefits of acupuncture once a woman reaches the embryo transfer stage, however it prevents the researchers from saying there is a difference when in actuality there isn’t any.  They required that acupuncture be administered within one day of the procedure, which could be before, after or done both before and after an embryo transfer.  In fact, most of their studies had two sessions.

Ultimately, the bottom line is that they found the odds of a clinical pregnancy were increased by 65% in the group who underwent acupuncture compared to those who didn’t.  When they calculated the number of women who would need to be treated for one additional pregnancy, they found that for every 10 patients who received acupuncture an additional pregnancy would result.

After reading this article, it is something I’d recommend patients try, if they are open to the idea of Eastern medical practice.  Given the high cost of IVF treatment, in terms of actual monetary cost and time expended, it seems that anything that may increase the chances for success are worth trying and if nothing else, may give someone the sense of control over something where there is very little.  If one finds a reputable acupuncturist the risks are low and the benefits potentially life changing.

 

REFERENCES:

Manheimer E, Zhang G, Udoff L, Haramati A, Langenberg P, Berman B, Bouter L (2007).  Effects of acupuncture on rates of pregnancy and live birth among women undergoing in vitro fertilization: Systematic review and meta-analysis.  British Medical Journal; Online First; pg1-8.

Mercury Amalgam Dental Fillings

Should I take them out?

My husband went to the dentist the other day for a regular check up and came home asking about replacing his mercury fillings.  Almost every tooth in my mouth with a spot for a filling contains that dull silver color.  I began to wonder what really is the risk of my mouth full of mercury amalgam and should we both take them out.

Our dentist hands out a fact sheet about the different types of filings, which I suspect is a California law.  Mercury is on the California list of chemicals known to cause reproductive toxicity, and is particularly harmful to the developing brain of a child or fetus.  Yes the United States has not banned mercury as other countries such as Sweden and Norway have done, but we are often slow to react, such as is the case with BPA and many other environmental toxins.  The mercury filings in my mouth were created by mixing around 43-54% of elemental mercury with 46-57% of an alloy powder that is composed primarily of silver, tin and copper (Dental Board of California, 2004).

Some basics.  Mercury can exist in several forms, the type that is most harmful to humans are the organic compounds, which can be readily absorbed in the body and particularly damaging to the brain (Roberts, 2009).  The main way the organic type of mercury is transmitted, in the form of methylmercury, is via ingestion of fish.  This is why we always recommend to pregnant women to avoid certain types of fish during pregnancy [this is for another review].  The type of mercury used in dental fillings is the elemental type of mercury, while volatile, is less absorbed in humans.

In most experiments, inorganic mercury, which is less toxic than mercury vapor, was found more toxic than composite compounds, like the combination used to create the dental amalgam.  Less toxic does not mean non-toxic.  Multiple studies have shown that small amounts of mercury vapor are released with chewing or grinding teeth with mercury filings, on average 1-3 micrograms daily (Richardson, 2003).   As a reference, it has been estimated that a can of tuna contains 52.7 micrograms of methylmercury (Yess, 1993; PBS, 2005).  Other studies suggest, in addition to the chewing releasing mercury vapor, that the mercury from dental amalgam is transformed into organic mercury compounds by the microorganisms that exist in our saliva and gut (Heintze et al 1983; Leistevuo 2001).

In animal and human experiments the outcome reported is mercury levels in blood, hair and urine.  However, when there are low/normal mercury levels in blood, hair and urine; potentially high mercury levels may be found in critical tissues such as brain and kidney. Excretion does not necessarily correlate with absorption.  Meaning that potentially those who excrete the mercury more effectively are less likely to have accumulation in body organs.  Where some reports state that the body half-life of mercury is 20-90 days, others have found that mercury in the brain has a half-life greater than 17 years (Mutter 2011).

Protestors against FDA approval of continuing use of mercury amalgam (Tim Boyle/Getty Images)

“Amalgam disease” as it’s reported is most frequently associated with complaints of: chronic fatigue, depression, headaches, concentration, memory and sleeping problems, joint and muscle pain, susceptibility to infections, and complaints of abnormal heart sensations and digestion disorders.  Many of these complaints are vague and common so it’s difficult to link directly to mercury fillings.  However, the removal of amalgam fillings have been reported to improve overall health and certain disease states such as Multiple Sclerosis and other autoimmune diseases (Mutter 2011).

A concern I had with removing my fillings was ingesting the released mercury particles.  There is a study that measured mercury levels of 12 patients following removal of fillings – as measured in blood and urine.  Initially there was an average increase of mercury levels by 32%.  Following was an exponential decline of mercury measures.  After 60 days, mercury levels declined to approximately 60% of pre-extraction levels.  In individuals who were followed long term, levels approached ranges comparable to patients without any mercury fillings (Sandborgh-Englund et al 1998).

As a side note, not only is dental amalgam potentially a concern for medical health but also impacts environmental health.  In the United States approximately 1000 tons exist in the mouths of the residents and is the 3rd most significant source of environmental mercury (Bender 2008) after coal burning power plants and mining of gold and mercury (EPA Website, 2012).

So, even knowing that mercury is a toxin, I’ve decided not to take mine out.  Since it is already there and I’m not experiencing any unexplained concerning symptoms, the risk of removing the fillings, sending the mercury back into the environment, and replacing with something else seems greater.  Additionally, it seems that removing the mercury fillings could lead to weakening of the teeth and potentially more problems.

For individuals experiencing any symptoms without any found medical explanation, removing their fillings may be a reasonable step in trying to identify a cause.  Because the literature is contradictory, it may benefit some individuals.  For myself, however, I am skeptical. It is in the financial interest of dentists to encourage removal of the mercury amalgam but I think risks of removal outweigh benefits I might experience.

However, would I allow a dentist to fill my son’s cavities with mercury amalgam?  I’d have to say “no”.  Because of the potential health risks, the known risks to exposure for those who work in dental offices, and the environmental impact from mercury I’m going to avoid it in the future.

As one author puts it, “for medical reasons, amalgam should be eliminated in dental care as soon as possible. This will confer gains in three respects: The prevalence of side-effects from patients’ mercury exposure will decline; occupational exposure to mercury can cease in dental care; and one of our largest sources of mercury in the environment can be eliminated” (Maths, 2002).

This past week I returned to my dentist for a check-up and fortunately, I didn’t need to address fillings. No cavities!  I even asked her about my mouth full of fillings and she said, “you don’t have many”.  It made me feel a little better about deciding NOT to remove my fillings.

Because of the effects beyond my mouth, I’ve also decided to look for a local dentist who doesn’t use mercury at all in his/her practice.

Anyone know of any?

—————————————————————————————————————————————————-

Reference:

Bender M.  Taking a bite out of dental mercury pollution.  New England zero Mercury Campaign. http://mpp.cclearn.org/wp-content/uploads/2008/08/neznm_report_card_on_dental_mercuryfinal.pdf

Dental Board of California (2004).  “The Facts About Filings”, pamphlet.  California Department of Consumer Affairs.

EPA Website. http://www.epa.gov/hg/about.htm (Accessed: July 1, 2012)

Guzzi G, Grandi M, Cattaneo C, Calza S, Minoia C, Ronchi A, Gatti A, Severi G (2006).  Dental amalgam and mercury levels in autopsy tissues: Food for thought.  Am J Forensic Med Pathol, 27:42-45.

Heintze U, Edwardsson S, Derand T, Birkhed D (1983).  Methylation of mercury from dental amalgan and mercuric chloride by oral streptococci in vitro.  Scan J Dent Re, 91:150-152.

Leistevuo J, Leistevuo T, Helenius H, P L, Osterblad M, Huovinen P, Tenovuo J (2001).   Dental aamalgam fillings and the amount of organic mercury in human saliva.  Caries Res, 35:163-166.

Maths B (2002).  Mercury in dental fillings materials – an updated risk analysis in environmental medical terms.  An overview of scientific literature published in 1997-2002 and current knowledge.  The Dental Material Commission –– Care and Consideration Kv. Spektern, SE–103 33 Stockholm, Sweden. (Final report provided by REGERINGSKANSLIET, Government Offices of Sweden)

Mutter J (2011).  Is dental amalgam safe for humans?  The opinion of the scientific committee of the European Commission.  Journal of Occupational Medicine and Toxicology, 6:2-17.

PBS Article (2005).  The Mercury Story: http://www.pbs.org/now/science/mercuryinfish.html.  Accessed 07/29/12.

Richardson, GM (2003).  Inhalation of Mercury-Contaminated Particulate Matter by Dentists: An Overlooked Occupational Risk, Human and Ecological Risk Assessment, 9:1519-1531 (2003). A fact sheet on ADA’s website says, http://www.ada.org/public/media/releases/0207_release01.asp

Roberts, James (2009).  Mercury Toxicity.  Medscape.  (website accessed: June 10, 2012).

Sandborgh-Englund G, Elinder CG, Langsworth S, Schutz A, and Ekstrang J (1998).  Mercury in biological fluids after amalgam removal.  Journal of Dental Res, Apr; 77(4):615-24.

Yess, NJ. (1993).  Average for Chunk White Canned Tuna. “US Food and Drug Administration Survey of Methyl Mercury in Canned Tuna,” Journal of AOAC International, Vol. 76(1), pp. 36-38.

 

Science of Yoga

for practitioners – it’s self-evident

 

Having just completed my first full year of regular yoga practice, I decided to celebrate by reading the book “The Science of Yoga” by William Broad.

Prior to reading the book, I can tell you that yoga has made a huge difference in my life.  Although the evidence suggests decreased metabolism, I’ve lost weight since starting yoga and feel more healthy overall.  This is probably secondary to the other influence yoga has on one’s life such as eating better, being more active in general, and improvement in overall attitude.  My improvement in mood permeates all aspects of my life.

I practice Bikram, also known as ‘hot’ yoga, because it found me.  After trying many styles, this is the one I enjoyed most.  With over 20 million people in the United States practicing any number of yoga styles, it is apparent others have experienced similar benefits!

As for the book, it mostly confirmed what I have experienced but now I learned the science behind the outcomes, without having to pull all the research myself.  It starts out with a little information on the history and evolution of yoga.  It then addresses the scientific evidence of benefits as well as false claims over the years.  Finally, the book ends with evaluation of the more obscure aspects of yoga, such as creativity and the Kundalites.

Without giving the entire book away, there were a few interesting things, in regards to the research, that I found and will take forward to encourage myself to continue my yoga practice and share with my patients if they ask me about yoga benefits.

1.  Yoga appears to slow the biological clock.  This is suggested by the finding that when telomerase activity, the enzyme that adds DNA at the end of chromosomes, is measured it is increased in men who underwent yoga training.

2.  Yoga improves mood.  It’s been shown to increase GABA levels, a neurotransmitter linked to mood.  In a small study in Boston, GABA was measured before and after an hour-long session of yoga and compared it to a control group who read magazines and popular fiction for an hour.  It was found that GABA increased an average of 27% in yoga practitioners and interestingly, those who had practiced the longest demonstrated the greatest rise in GABA levels.

3.  Yoga increases right brain activity.  Iyengar yoga students who practiced for 3 months demonstrated increased activity on the right side of the brain, the side responsible for higher order conscious functioning.

4.  Yoga improves many general health measures.  In a 2010 review article, yoga was shown to improve balance, reduce fatigue, decrease anxiety, cut stress, improve sleep, reduce pain, lower cholesterol, and overall improve measures of quality of life (social lives, family relations, and sex lives).

However, the studies also suggest that yoga is not the perfect exercise as some of the claims, about physical fitness, and certain position’s safety have come into question.

1.  Yoga decreases metabolic rate.  It is not aerobic exercise and in fact in studies show that the VO2 (a measurement of oxygen consumption/aerobic activity) decrease.  This suggests that weight loss is not a key function of yoga.  However, in a study comparing Hatha yoga practitioners, stationary bike riders, and those who did no activity for 4 months found, while bike riders had an increase in aerobic capacity, yogis felt better about themselves and thought they looked better.

2.  Yoga can be dangerous.  Reports exists of nerve damage from extended periods in one position by cutting off blood flow and certain postures such as neck stands, head stands, and shoulder stands have been linked to strokes.  The heat of the Bikram studio also poses some dangers of overstretching.  I’ve experienced directly some of the benefits, but have also pulled a muscle while stretching beyond my limits in the heated room.  Consciously practicing yoga, and being aware of the potential dangers, is one way to reduce these risks.

Overall, I found it to be an interesting and well organized read, going back through the history of yoga and discussing the scientific research on an array of topics organized by topic: health, fitness, mood, sexuality, and creativity along with thoughts regarding the future direction of yoga.

Since yoga has a bit of an on the fringe beginning and yogis were notorious for making false claims and performing magician like acts for a fee, learning about this was enlightening.  While the beginning with the history and the chapters organized by topics I found it easy to sit down and read a chapter at a time.  It wasn’t a book I couldn’t put down because it had natural stopping points.  It’s written from both a practitioner and scientific writers perspective, with only a few places where commentary suggested a bias.  While the evaluation of creativity and the story of the Kundalites may be interesting, I found these areas to be much more abstract and diverge from the truly scientific evaluation of yoga.  This last chapter I found my mind wandering a bit, due to a lack of scientific evidence, but overall appreciated the straight scientific discussion of the literature elsewhere in the book.  Although research has been done over the years on yoga benefits, there are many more areas of research to pursue.

For anyone who practices yoga, you should definitely read this book, but then again you probably already know the benefits from your own experience!