"Electro-Cut" Your Body Fat - Study Shows 5.6 cm and 4.9% Reduction in Waist & Body Fat in Young Women in 6 Weeks

No sweat, just some wires? Study shows: It does not take much effort to lose belly fat.

Liposuction is an invasive procedure that is not without risk. Against that background it's no wonder that people are marketing alternative methods like high-frequency current therapy as allegedly safe go-to methods to rid yourself of unwanted body fat. The question is: Do these currents actually help you to lose body fat? That is: Can electrocuting your belly "electro-cut" significant amounts of body fat? Practitioners who use this technology will say "yes". From a scientific standpoint, though, the question is difficult to answer, because the use of high-frequency current therapy has been given little attention in the scientific community.

As Kim et al. point out in a recent paper in the J. Phys. Ther. Sci., some previous studies have failed to provide evidence for the effectiveness of high-frequency current therapy in women with obesity, whereas more recent studies have indicated that a high-frequency current therapy decreases female abdominal obesity (Kang. 2005; Han. 2010). Accordingly, their latest study aimed to determine whether high-frequency current therapy can be effectively used to reduce female abdominal obesity.

Some people claim coffee applied to the skin will also burn fat, but... well, you better drink it

Remember: With Coffee More Won't Help More

Coffee - The Good, Bad & Interesting

Three Cups of Coffee Keep Insulin At Bay

Caffeine's Effect on Testosterone, Estrogen & SHBG

The Coffee³ Ad- vantage: Fat loss, Appetite & Mood

Caffeine Resis- tance - Does It Even Exist?

To this ends, the researchers recruited twenty-two female volunteers who were randomly allocated to either the experimental group (EG) (n = 12; age, 21.17 ± 0.72 years; weight, 63.17 ± 7.91 kg; height, 159.63 ± 4.56 cm) or the control group (CG) (n = 10; age, 21.10 ± 0.74 years; weight, 68.79 ± 11.73 kg; height, 161.69 ± 5.25 cm). Inclusion criteria were as follows:

• a body mass index (BMI) of ≥23 kg/m2 and a waist-hip circumference ratio of  ≥ 0.8013
• no past or present neurological, musculoskeletal, or cardiopulmonary disorders that would have affected health condition;
• no smoking and drinking habits; and
• no psychological problems.

Futhermore, pregnant women were excluded as well. The subjects of both groups were asked to keep a regular dietary habit during the experimental process. A nutritionist drew up a diet plan of 2,000 to 2,500 kcal/day across 3 meals (8 a.m., 1 p.m., and 6 p.m.) for the 6-week intervention. In addition, subjects were asked to avoid extra activities and exercises beyond daily routine activities.

Figure 1. Changes in BMI, waist circumference, subcutaneous body fat and total body fat (%) after 18 sessions of high-frequency current therapy in Korean women (Kim. 2015).

Only the subjects in the EG group were subjected to high-frequency current therapy, with a frequency of 0.5 Mhz. The treatments were performed exclusively on the abdominal region while subjects were supine using specific equipment (CWM-9200; Chungwoo Medical, Seoul, South Korea) for 60 minutes, 3 times per week, for 6 weeks (a total of 18 sessions).

"High-frequency current therapy was performed in 2 phases: 2 sets of 15-minute applications of capacitive electric transfer (CET) and resistive electric transfer (RET) with the pulsed current option (current conduction time, 0.7 seconds; rest interval, 0.3 seconds) for the fist 3 weeks, followed by a 30-minute application of the CET and RET modes with continuous current conduction in the final 3 weeks. The intensity was individualized within a range of 6–7 mA to comfortably adjust the heating sensation during the intervention. An insulated electrode and a stainless steel electrode (8 cm in diameter) were used for the CET and RET modes, respectively. Conductive gel (Body Rubbing Cream; SA’COS, Incheon, South Korea) was used to facilitate skin moisture and current conduction, and high frequency current therapy was delivered by making circular motions of the electrode over the abdominal region at a moving speed of 5 cm/s, avoiding focused pressure on therapeutic areas" (Kim. 2015)

The comparison of the pre- vs. post-data showed here significant main effects of time with respect to waist circumference, abdominal obesity, subcutaneous fat mass, and body fat percentage, which differed significantly between the groups (see Figure 1), "suggesting the effects of high-frequency current therapy in decreasing obesity" (Kim. 2015).

Bottom line: I must say that I am impressed. I haven't been there to control whether the scientists cheated, but considering the fact that the control group received the same controlled diet as the women in the experimental group, the loss of body fat and the reduction in waist circumference that was achieved within only 6 weeks in young women is impressive.

High frequency currents are also been used for cellulite treatment, but there are other options, as well | learn more

In the end, the mechanism of action is simple and is believed to rely mostly on the heat induced dilatation of subcutaneous vessels and the subsequent facilitation of the lipolytic process (Song. 2006). Which would also explain why the effect was highly localized and there were no significant inter-group difference with respect to the BMI of the women in the study at hand. A study that is yet limited by the low number of participants, a lack of safety data (no blood analyses, for example), the absence of measurements of the reductions in visceral fat and the lack of a rigid dietary and activity control as it would be possible in a metabolic chamber | Comment on Facebook!

References:

• Han, J. S., Y. O. Park, and C. K. Zhoh. "The effect of high frequency treatment and meridian massage on the abdominal fat pattern of obesity women." J Korean Soc Esthet Cosmeceutics 6.1 (2010): 1-8.
• Kang SO, Won YK. "The effect of high-frequency therapy on women’s obesity." Kor J Aesthet Cosmetol 3 (2005): 121–131.
• Kim, Jin-seop, and Duck-won Oh. "Effects of high-frequency current therapy on abdominal obesity in young women: a randomized controlled trial." Journal of Physical Therapy Science 27.1 (2015): 31-33.
• Song MY, Kim HJ, Lee MJ. "The review on the evidence: effects of nonsurgical localized fat treatments." J Korean Med Obes Res 6 (2006): 1–10.

Dietary Zinc & Copper Improve Glucose & Lipid Metabolism. High Cortisol Amplitudes Counter Belly Fat. Hypoxic Hearts Love Creatine + Ribose. Apples Counter Cancer & Obesity

I guess this is about as close as we have hitherto gotten to understand why we got fat. Wrt to the hilarious pace at which we got fat and are still getting fatter, we are much better informed though.

After you've learned about the general importance of exercise for your health and a couple of tweaks that may or, as in the case of sugary "energy drink", may not help you maximize the benefits and performance gains on Saturday. The focus of today's SuppVersity article is on the results of non-exercise related studies that highlight non-exercise related confounders of your health.

Before we get to the actual news, I would yet like to invite all of you to take a look back at the increasingly obese history of the US... I suppose those of you who have not yet seen the link on my Facebook wall, will enjoy the animated obesity map in the Atlantic article from April 11. I mean, even if we still don't have anything but over-simplistic cookie-cutter "explanations" of why we get fat, the map shows that we do at least know how fast we got fat!

You don't feel knowing about how fast we got fat is good news? Ok, maybe you'll like one the following results from recent studies better:

• Dietary zinc & copper influence glucose & lipid metabolism in women (Shab-Bidar. 2013) According to a recent study from the Obesity Research Center at Shahid Beheshti University of Medical Sciences in Tehran, Iran, there is a gender specific effect of copper and zinc in the diet on glucose and lipid metabolism of men and women in Iran - statistical significant effects were observed only in women with...

  

  Odds ratios for the MetS and low HDL across quartiles of copper intake (Shab-Bidar. 2013)

  • higher zinc intakes being associated with higher HDL-C, lower triglycerides (TG) and lower 2-hour blood glucose, and 
  • higher copper intake correlating with higher HDL-C, lower fasting blood glucose (FBG), significantly lower TG and a huge 81% reduction in the risk for suffering from metabolic syndrome (highest vs. lowest copper intakes)
  These observations stand in contrast with the current notion of the "bad" copper and the "good" zinc and reamphasize the importance of both nutrients for metabolic health.

  ---

  Remember: Two questions that will still have to be resolved pertain to (a) the gender-specificity of the effects and (b) confounding effects of food quality / choice and thus whether the same beneficial effects would be observed with the standard American diet.
  For both, but espicially for copper a little more than the RDA does not appear to hurt: What's particularly interesting, is that contrary to the zinc intakes in quartile 4 (>14mg/day; RDA 9mg/day) the copper intake in quartile 4 was more than 3x higher than the current RDA for women (0.9 mg). In fact, even the copper intake in the lowest quartile ~1.5mg/day was way above the RDA. If that's something we have to be surprised about is yet questionable, after all, there is not exactly much research on "optimal copper nutrition" (much contrary to zinc, by the way) and the RDA is based on age-old depletion-repletion studies and will thus probably reflect the absolute minimum to maintain "normal" serum levels.

• Evidence from human study: Flat cortisol profile not averages or spikes are associated with increased adiposity and visceral obesity (Sharp. 2013) In their most recent paper that's soon going to be published in the American Journal of Human Biology Dan S. Sharp and his colleagues from the Center for Disease Control and the State University of New York provide conclusive evidence for the irrelevance of mean cortisol levels with respect to the purported negative effects of cortisol on visceral obesity.

  

  Associations between sextiles of within-subjects cortisol standard deviation (SD) in 217 Buffalo policemen and adjusted lean-mass trunk index (Sharp. 2013)

  As the data in the figure above clearly shows, the police officers with the greatest cortisol fluctuations (spikes and troughs) had the highest ratio of lean body mass to trunk mass. It is thus, as the scientists phrase it,
  

  "not the average level of salivary cortisol among 18 specimens on each officer that drives the association; it is the variation among specimens."

  The oral cortisol measures were taken on 3 subsequent days in standardized procedures that involved a venipuncture and a standardized high protein meal as "challenges", on day 1, six measures that were taken by the police officers over the course of the day, on day 2, and series of tests that was taken after a dexamethasone challenge after waking on day 3 (the subjects had ingested 0.5mg of dexamethasone the night before).

  ---

  Bottom line: While the scientists are careful in pointing out that it will still have to be established that the results translate to other populations. The results corroborate the uselessness (if not potential detrimental effects) of "cortisol blockers", I've discussed in my previous in the Science Round Up Seconds on March 29, 2013 (read more).

• Combination of creatine and d-ribose heals damaged, but unscarred rodent-hearts (Caretti. 2013) While the many of the "daggered" claims* on the boxes of various "advanced" creatine products (learn more about their uselessness) are probably a little overblown (*the dagger refers to the "not verified by the FDA"), that's nothing compared to the absolutely disappointing results trainees had with d-ribose. Meanwhile, it seems as if even the last jerk knew that the unbearably sweet simple sugar is nothing worth spending his/her money on.
  
  

  

  Ribose regulates the novo synthesis and restoration nucleotides, can relieve the energy toll of ischemia  and its usefulness in the context of CVD is backed by rodent and human studies (Shecterle. 2011)

  In view of it's physiological role in the recovery of ATP levels (Helsten. 2004), it was assumed that supplementatal D-ribose would ameliorate the ATP depleting effects on exercise and improve endurance in glycolytic and/or long endurance activities, yet...
  

  "[...s]tudies examining the effect of ribose on performance during intense intermittent exercise and rowing have not been able to demonstrate improved performance in humans." (King. 2012)

  Other than the non-existence of side-effects, pertaining studies, which used up to ∼40 g/day, as well as acute and chronic supplementation regimen did  yet not yield any positive results
  
  Now, the aforementioned studies on the ergogenic effects of d-ribose were conducted in healthy individuals, in whom the ATP re-synthesis obviously does not depend (and not even benefit) from the provision of the monosaccharid that was discovered by Emil Fischer in 1891, when he analyzed the carbon structure of gum arabic (Prince. 2012). "Healthy" would yet not be the correct term to describe the rodents in the recently conducted study by Caretti et al. who observed that five week-old mice who were exposed to an atmosphere containing 10% O2 for 10 days in order to induce right ventricle hypertrophy and left ventricle apoptosis did not show any signs of cardiac damage, when they were gavaged creatine + D-ribose, every day.
  
  And while both phenotypes, i.e. the hypertrophy of the right and apoptosis of the left ventricle, were blunted to a certain degree by creatine or d-ribose, only their reversed the pathogenic changes to the heart muscle "almost" completely, by normalizing the expression of AMPK and Akt signaling in the hearts of the rodents.

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  Light micrograph of representative nuclear pro-files (background, red = atypical, green = normal nuclei; my emphasis) and volume (%) of atypical cardiac cells in anterior left ventricle of rodents on caffeine + nicotine + ephedrine combo (learn more)

  Bottom line: While they may not be beneficial for the average trainee, people "on" the literally heart-breaking combination of nicotine + caffeine and ephedrine, could be able to reduce their detrimental effects on the heart (learn more), by adding this combination of proven (creatine) and disproven (d-ribose) ergogenics to their supplement regimen. People with sleep-apnea and other conditions which will leave the heart poorly oxygenized for longer time-periods should obviously benefit, as well.
  
  Based on the likewise promising results of previous studies in (human!) subjects with congestive heart failure (e.g. Omran. 2003), a daily dose of 5g d-ribose, along with the tried an proven chronic ingestion of 5g of creatine appears to be a good starting point, until respective human trials have been conducted.

• Further evidence for the "An apple a day..." theory (Rago. 2013) In an allegedly methodically complicated, but very comprehensive analysis of the effects of raw, whole apples on the plasma metabolome of rodents, researchers from the University of Copenhagen found
  

  

  Total antioxidant activity (µmol vitamin C equivalents/g) of various fruits (Boyer. 2004)

  "that the intake of fresh apple in rats has a considerable and specific impact on the plasma metabolite profile, reflecting altered gut microbial metabolism, retarded lipid- and protein catabolism, and lowered metabolic, oxidative and steroid-related stress". (Rago. 2013)

  These results stand in line with the recent observations a group of Spanish researchers made, when they added a polyphenol extract from apples to the chow of rodents on an obesogenic high-fat + high sugar (HFS) diet:
  

  "Our results from histological studies demonstrated that supplementation of HFS with AP markedly reversed the enlargement of adipocyte volume induced by HFS diet intake in the epididymal fat pad, reducing it by almost 28% [...it also] reversed the increase in the population of large epididymal adipocytes, especially with diameters higher than 130m." (Boqu. 2013)

  The visceral specific effects of the apple polyphenols in the Boqué study could thus be interpreted as supportive evidence for the real-world significance of the metabolomic changes Rago et al. observed in the afore-cited study.

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  Bottom line: No reason to be scared of the "high fructose fruit" apple. It comes with all HFCS sweetened beverages don't have. Polyphenols, vitamins, minerals and most importantly a flesh from which the fructose is extracted only slowly. Still, I have to warn you: Apple consumption can have profound beneficial effects on your health, such as (random examples)
  
  •  - 17% colorectal cancer risk (Michels. 2006)
  •  - 37% wheeze risk in your offspring (Willers. 2007)
  •  - 21% reduced risk for cancers of the oral cavity and pharynx (Gallus. 2005)
  •  - 25% reduced risk for oesophagus (Gallus. 2005) 
  •  - 18% / -15% / -9% risk red. for breast / ovary / prostate cancer (Gallus. 2005)
  and obviously the - 15% reduced breast cancer risk, the if you want to avoid these, you should thus better keep obsessing about the high fructose content of apples and stick to sausages and lard ;-)

References:

• Boqué N, de la Iglesia R, de la Garza AL, Milagro FI, Olivares M, Bañuelos O, Soria AC, Rodríguez-Sánchez S, Martínez JA, Campión J. Prevention of diet-induced obesity by apple polyphenols in Wistar rats through regulation of adipocyte gene expression and DNA methylation patterns. Mol Nutr Food Res. 2013 Mar 25.
• Boyer J, Liu RH. Apple phytochemicals and their health benefits. Nutr J. 2004 May 12;3:5.
• Caretti A, Bianciardi P, Marini M, Abruzzo PM, Bolotta A, Terruzzi C, Lucchina F, Samaja M. Supplementation of creatine and ribose prevents apoptosis and right ventricle hypertrophy in hypoxic hearts. Curr Pharm Des. 2013 Apr 10. [Epub ahead of print]  
• Gallus S, Talamini R, Giacosa A, Montella M, Ramazzotti V, Franceschi S, Negri E, La Vecchia C. Does an apple a day keep the oncologist away? Ann Oncol. 2005 Nov;16(11):1841-4. 
• Hellsten Y, Skadhauge L, Bangsbo J. Effect of ribose supplementation on resynthesis of adenine nucleotides after intense intermittent training in humans. Am J Physiol Regul Integr Comp Physiol 2004;286:R182–8.
• Michels KB, Giovannucci E, Chan AT, Singhania R, Fuchs CS, Willett WC. Fruit and vegetable consumption and colorectal adenomas in the Nurses' Health Study. Cancer Res. 2006 Apr 1;66(7):3942-53. PubMed PMID: 16585224.  
• Omran H, Illien S, MacCarter D, St Cyr J, Lüderitz B. D-Ribose improves diastolic function and quality of life in congestive heart failure patients: a prospective feasibility study. Eur J Heart Fail. 2003 Oct;5(5):615-9.  
• Price, NPJ. The Name of the–ose: An Editorial on Carbohydrate Nomenclature. J Glycobiol. 2012; 1(e105).
• Rago D, Kristensen M, Gözde G, Federico M, Morten P, LarsOve D. LC–MS metabolomics approach to investigate the effect of raw apple intake in the rat plasma metabolome. Metabolomics. 2013; 1573-3882.
• Shab-Bidar S, Hosseini-Esfahani F, Mirmiran P, Mehran M, Azizi F. Dietary intakes of zinc and copper and cardiovascular risk factors in Tehranian adults: Tehran Lipid and Glucose Study. Nutrition & Dietetics. 2013
• Sharp DS, Andrew ME, Fekedulegn DB, Burchfiel CM, Violanti JM, Wactawski-Wende J, Miller DB. The cortisol response in policemen: Intraindividual variation, not concentration level, predicts truncal obesity. Am J Hum Biol. 2013 Apr 20.
• Shecterle LM, Wagner S, St Cyr JA. A sugar for congestive heart failure patients. Ther Adv Cardiovasc Dis. 2011 Apr;5(2):95-7.
• Willers SM, Devereux G, Craig LC, McNeill G, Wijga AH, Abou El-Magd W, Turner SW, Helms PJ, Seaton A. Maternal food consumption during pregnancy and asthma, respiratory and atopic symptoms in 5-year-old children. Thorax. 2007 Sep;62(9):773-9. Epub 2007 Mar 27.
   

Tongkat Ali - Malaysian Viagra W/ Anti-Belly Effect: More Than 30% Reduced Omental Fat Pad Size + Corresponding Increases in Testosterone W/ Human Equiv. of 4g+/Day

It's efficacy in situations like this has more scientific back-up than any of the muscle building of fat burning promises some Tongkat Ali supps come with.

By now, most of you should have read the article on the testosterone "boozing" effects of alcohol and realized that the post workout Margarita probably comes off second best, when we compare it to whey and may - at least until we don't know otherwise - actually be pathological (=the result of a disturbance of the normal hormone metabolism in the liver). That being said, we better go back the "tried(!) and proven(?)" stuff. I mean a herb that goes by the name "Long Jack" does already sound way more promising than a "Blood Mary" doesn't it?

"Long Jack? ;Malaysian viagra? Ok, I am in!"

As the popular name already implies, the root of Eurycoma longifolia Jack, an evergreen plant that belongs to the family Simaroubaceae has a long (all puns intended) tradition in folk medicine. For which purposes? Well, in Malaysia, where people obviously like it a little more explicit, it's called "Tongkat Ali" (TA) and means (literally translated) "Ali's walking stick"... if that ain't explicit enough for you, just call it the "bushman's viagra", or whatever you like.

What's interesting and important to know though is that medicinal value highly of the root extract depends on the soil the plant was grown on. Tongkat Ali from the Malaysian Peninsular, for example, has higher concentrations of phytochemical compounds, such as eurycomaride, tannins, high molecular weight polysaccharides, glycoproteins, mucopolysaccharides and alkaloids of the quassinoid group, than TA from Thailand, Vietnam or Indonesia (Jiwajinda. 2001; Miyake. 2009). This is an important fact to keep in mind, when you buy your TA and a potential reason why you (a) may require way higher dosages than science would suggest seeing any effect or (b) may not experience any of the benefits you may have hoped for (e.g. raging libido, increased testosterone and, as you are about to learn in today's article, loss of belly fat).

"Did I hear fat loss?" Yeah, you did!

I have to concede, the hitherto unrecognized fat loss effects Solomon et al. report in their latest paper that's about to be published in the peer-reviewed journal Andrologia were actually the main reason the 14-day rodent experiment the South African researchers conducted eventually made it into the SuppVersity news. The meager testosterone increase of +30% alone doesn't give me a kick, at all. I mean there are way more potent natural testosterone boosters out there that don't exert any beneficial downstream effects on your physique. So why should we bother?

Figure 1: Relative (in % of pre values) body weight, testes weight, prostate weight, weight of the epididymal and omental fat pads, the gastrocnemius muscle and the testosterone levels of the rodents after 14 days on the high or low dose of the extract (

And in fact, the 5.7% reduction in body weight the rodents in both the low (200mg/kg) and high dose (800mg/kg) arm of the study experienced would be quite the opposite of what you'd usually expect as a downstream effect of increased testosterone levels in otherwise healthy rodents. With a statistically significant increase in sperm vitality in the low dose and a less pronounced statistically non-significant increase in sperm vitality in the high dose group, as well as the highly significant increases in sperm count in both groups, it is yet very unlikely that the already small amount of body weight the rodents lost in the course of the 14-day experiment was a sign of toxicity or whatever.

What's more likely is that the overall weight loss effect is simply the result of the highly significant -31.9% reduction in omental and probably other not explicitly measured body fat (not the epididymal fat, i.e. the fat around the reproductive organs, though).

"How much of this stuff do I need?"

Don't be fooled: The testosterone and libido boosting effects we see in the study at hand is something dozens of other herbs can do as well, thin of the study on Nigella Sativa from one of the past installments of "On Short Notice", for example.

Provided you can get your hands on a correspondingly potent extract, it probably would not be necessary, and certainly a waste of valuable resources to take more than the low dose regimen (HED 4g/day), which is, compared to what we have hitherto seen in human trials, still hilariously much.

For the fertility part of the equation, way smaller doses of as little as 300mg of a freeze-dried water extract from TA (brand name Physta(R)) have shown quite astonishing results in a group of 30-55 year old male subjects who achieved a 44.4% higher sperm motility, 18.2% higher semen volume and subjectively improved erectile performance after 12-weeks on this commercially available product (Ismail. 2012).What you should at least keep in mind though is the fact that financing of the study was provided by Biotropics Malaysia Berhad, the producer of Physta.

Similar fertility related results were also reported by Tambi et al. in 2010 (another "proprietary extract" ;-) and a handful of older and in some cases non-peer-reviewed studies. As far as more physical culture related effects are concerned, a recent review by Chen et al. concludes that

"Eurycoma longifolia Jack, or 'tongkat ali', has not appeared to elicit any ergogenic effect on endurance performance in a limited number of studies of these herbs. However, future studies of this herb are definitely warranted because there might be a dose-dependent response and the supplementation duration of the previous studies might have been too short." (Chen. 2012)

It would, therefore, appear as if TA was more of "classic" libido & testosterone booster than an ergogenic. Something like tribulus and maca and just as those two probably of very dubious usefulness for young athletic men in the prime of their reproductive years.

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Bottom line: That being said, Long Jack could be worth a try for everyone with already (or temporarily ;-) reduced testosterone levels, at least if we trust the judgement of Tami et al. who conclude their 2012 study into the effects of 1 month on 200g of a water-soluble TA extract with the words: "The standardised water-soluble extract of Tongkat ali proved to be a suitable herbal supplement in overcoming symptoms of LOH [late onset hypogonadism]." (Tambi. 2012)

The veterans among the SuppVerity readers may remember that I also covered the 2012 study by Tambi et al. on the usefulness of TA for men hypogonadal men (learn more)

If you still insist on trying it, you should keep an eye on the eurycomanone and 13α(21)-dihydroeurycomaone content of whatever product you are buying, because these are the two fractions which will increase LH and FSH production and are thus probably responsible for jacking up your testosterone and sperm production (Low. 2013).

What? You cannot find a product that's standardized for those? Not even a supplement producer losing a word about their existence? Well, that's how this business works. Cite the studies and discard all the nasty details you don't like...


References:.

• Chen CK, Muhamad AS, Ooi FK. Herbs in exercise and sports. J Physiol Anthropol. 2012 Mar 8;31:4. doi: 10.1186/1880-6805-31-4. Review.
• Ismail SB, Wan Mohammad WM, George A, Nik Hussain NH, Musthapa Kamal ZM, Liske E. Randomized Clinical Trial on the Use of PHYSTA Freeze-Dried Water Extract of Eurycoma longifolia for the Improvement of Quality of Life and Sexual Well-Being in Men. Evid Based Complement Alternat Med. 2012;2012:429268.
• Jiwajinda S, Santisopasri V, Murakami A, Hirai N, Ohigashi H. Quassinoids from Eurycoma longifoliaas plant growth inhibitors.Phytochemistry. 2001; 58:959–962
• Low BS, Das PK, Chan KL. Standardized quassinoid-rich Eurycoma longifolia extract improved spermatogenesis and fertility in male rats via the hypothalamic-pituitary-gonadal axis. J Ethnopharmacol. 2013 Feb 13;145(3):706-14.
• Miyake K, Tezuka Y, Awale S, Li F, Kadota S.Quassinoids fromEurycoma longifolia. J Nat Prod. 2009; 72:2135–2140. 
• Solomon MC, Erasmus N, Henkel RR. In vivo effects of Eurycoma longifolia Jack (Tongkat Ali) extract on reproductive functions in the rat. Andrologia. 2013 Mar 6.
• Tambi MI, Imran MK. Eurycoma longifolia Jack in managing idiopathic male infertility. Asian J Androl. 2010 May;12(3):376-80. doi: 10.1038/aja.2010.7. Epub 2010 Mar 29.
• Tambi MI, Imran MK, Henkel RR. Standardised water-soluble extract of Eurycoma longifolia, Tongkat ali, as testosterone booster for managing men with late-onset hypogonadism? Andrologia. 2012 May;44 Suppl 1:226-30.