|Other news: Classic cardio ramps up GLP-1 and "posing" increases your maxes by up to 8%.|
If I recall that correctly, I did in fact forget to mention something that's actually important if you want to get the whole picture - the gut microbiome! But before we tackle this one, let's not forget that there are a couple of other news stories which did not make it into the 60min show, news on the effects of LISS on GLP-1 and the potentiation of the post-activation potentiation effect. Sounds interesting, then let''s go for it!
Is stevia toxic, does it cause cancer and infertility?Let me start with the bottom line first. The currently available scientific evidence clearly suggest that stevia is safe to consume. Or, as "real" scientists (not that I would not consider myself a scientist, but without a single published paper in this domain of science, I am certainly not an authority ;-) write in their papers:
And with respect to the infertility claim, Geuns et al. write in their very detailed review from 2003:What was that about the microbiome? I forgot to mention that the "bad" aglycol aka "steviol" is also produced from the benign and usually not even absorbed pure steviosides and is thus not something you'll find only in "natural" stevia products. That being said, Wingard et al. observed in 1980 already that steviol is readily excreted via the billary pathway in the feces (Wingard. 1980; confirmed by Nakayama. 1986). You may thus be exposed to small amounts of steviol no matter what, but that's nothing your body cannot dispose of."The recent suggestions that steviol glycosides present a muta-genic – and therefore carcinogenic – risk to consumers are not sup-ported by actual test results. The paper making this claim by Matsui et al. (1996a) was published prior to most of the papers assessing the genotoxic risk of steviol glycosides as well as several expert panel reports and a review by Brusick in 2008. The database of genotoxicity studies for steviol glycosides and steviol as it currently stands, combined with a lack of evidence for neoplasm development in rat bioassays (Aze et al., 1991; Xili et al., 1992; Toyoda et al., 1997; reviewed by Carakostas et al., 2008, 2012; EFSA, 2010), is adequate to establish the safety of these food ingredients with respect to their genetic/carcinogenic potential." (Urban. 2013)
"The results of a decrease of live birth rate in rats (Planas and Kuæ, 1968) by Stevia decoctions were refuted by Shiotsu (1996) who did more reliable experiments with many more animals using methods as similar as possible to the methods used by Planas and Kuc. No effect on general condition, body weight, water consumption, live birth rate or litter size was found. No effects of stevioside were found on fertility or reproduction in mice (Akashi and Yokoyama, 1975), rats ( Mori et al., 1981, Xili et al., 1992 and Sinchomi and Marcorities, 1989) or hamsters (Yodyingyuad and Bunyawong, 1991).Much ado about nothing? Well, in the end it may seem so and the preponderance about freakin' out over every potential and 0.5% marginal possibility that something you do or eat could be wrong or toxic certainly ain't healthy. On the other hand, it's always good to exhibit a certain degree of suspiciousness - just do me favor: Do that towards both the good and the bad news!
No significant effect was found on spermatogenesis, nor on the interstitial cell proliferation and tumor formation in the testes of F344 rats fed a ration containing up to 1% stevioside (95.2% purity) for 22 months (Yamada et al., 1985).
Whereas Melis (1999) suggested a possible decrease of the fertility of male rats by a very high dose of Stevia extract, Oliveira-Filho et al. (1989) who administered extracts with similar stevioside content stated that there is certainly not an effect on male fertility. It is not sure that the observed effects were due to the stevioside present in the extract. It should also be mentioned that the used extract concentrations were extremely high, at the start of the experiments even 5.34% of the body weight (or around 5.3 g stevioside/kg bw). For an adult person of 65 kg this means 3.47 kg of dry Stevia leaves or about 34.7 kg fresh leaves/day, i.e. more than 50% of the body weight! The significance of such experiments where only one extremely high concentration was tested, should be questioned. Melis' results are also in contradiction with the above and below cited studies that could not reveal any effect on fertility of male or female animals." (Geuns. 2003; my emphases)
If you are either a newcomer to the SuppVersity or simply cannot remember the summary of selected stevia research from September last year, I suggest you go back in the archives and read up on "More Than Super Sweet: More Scientific Evidence, More Potential Implications for Weight Loss & -Maintenance, Anti-Diabetic & -Autoimmune and Even Pro-Anabolic Effects" (learn more) Some of the benefits are btw. mediated by the same stuff that's toxic in in-vitro studies...hormesis, you know ;-)
Scheduled news that did not make it into the live show
|The fat burning benefits of hydroxypropyl-distarch phosphate from waxy maize starch (WMHDP) are - at least in part - also mediated by increases in GLP-1 production (read more)|
In a soon to be published paper, Shin-ya Ueda and colleagues report that chronic exercise, in this case 3x/week 60min of light intensit (65% of VO2max) cardio on a treadmill and/or cycle ergometer results in a statistically highly significant increase in GLP-1 in response to exercise.
Usually I don't like to repeat myself, but I would probably have missed the main important message here, if I were just skimming the above: The 20 healthy middle-aged women who participated in the 12-week experiment did not simply have higher GLP-1 levels after a meal. No, the post-exercise levels of GLP-1 and the other satiety hormone PYY increased hours before the ladies even got their next meal.
"[...] that the ability of exercise training to create a negative energy balance relies not only directly on its impact on energy expenditure, but also indirectly on its potential to modulate energy intake." (Ueda. 2013)So, does exercise "just make you hungry". No, it turns you into a satisfied fat burning machine - and that even if it's just 3x60min of LISS per week.
Training increases the efficacy of 5-6s maximal contractions to before a maximal voluntary effort (Miyamoto. 2013) I guess you will be aware that Superman usually does a 5-6s maximal voluntary contraction (MVC) while checking out if everybody is watching before he eventually does the deed and lifts the car that has just overrun the beautiful blond bombshell with a "single-armed deadlift", right? Good, because if you know that, I don't have to explain why the scientists from the Waseda University in Japan 21 healthy male subjects perform a 5s MVC before they did their maximal voluntary concentric knee extensions 1, 3 and 5 minutes, thereafter.
|Figure 2: Voluntary concentric torque on knee extensions after previous peak contractions before (left) and after (right) in the trained and untrained study participants.|
That is it, for the day - at least for the Seconds. If you don't know what to do before the weekend begins, browse over to the SuppVersity Facebook Wall and check out news on
If you have not done so, already, click here and teach yourself "How to Make the Correct Fish choices"? There is luckily way more swimming around in our oceans than farmed salmon with it's more than 4x elevated n6:n3 ratio (compared to wild salmon, learn more)
- Alpha lipoic acid (ALA) helps otherwise healthy schizophrenics on heavy anti-histamine regimen to lose weight - 2x 1gram of regular ALA does the trick (read more)
- People who were breastfed as kids have healthier eating habits in their adulthood - Interestingly, this effect did not depend on social class at birth or later in life and occurred irrespective of smoking status, alcohol intake or reported physical activity.
- Akashi H, Yokoyama Y. Security of dried-leaf extracts of Stevia. Toxicological tests. Food Industry. 1975; 18:34–43.
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