7-Keto MuscLEAN is Beverly International’s attempt at a mostly non-stimulant weight-loss supplement, a key ingredient of which is…you guessed it: 7-Keto DHEA. The product also contains a few other non-stimulant ingredients which have demonstrated varying degrees of efficacy as a well as a moderately small dose of Caffeine…[Skip to the Bottom Line]
7-Keto DHEA is a non-hormonal metabolite of DHEA, lower levels of which have been noted in non-obese males as opposed to obese males, and it is alleged that 7-Keto levels are negatively correlated with obesity. A 2000 study found that 200mg 7-Keto given to subjects who were on a calorie restricted diet resulted in more weight loss than the placebo group (consuming the same diet) over an 8 week period. A 2007 study, published in “The Journal of Nutritional Biochemistry”, found that 200mg of 7-keto DHEA raised the metabolic rate of subjects on a calorie restricted diet by 1.4%, whereas the placebo group experienced a 3.9% reduction in metabolic rate (the normal reaction to calorie restriction). However the length of this particular study was only 7 days, not long enough to measure weight loss, though this provides a likely mechanism of action for the first (2000) study. Other studies have noted similar results but have included 7-Keto along several other ingredients, so definite conclusions cannot be drawn from those. Overall though, it appears 7-Keto may definitely be able to play a role in long-term weight-loss. 7-Keto MuscLEAN contains 100mg of 7-Keto per serving, meaning two servings daily achieves a scientifically validated dose of 200mg.
GREEN TEA EXTRACT 4:1(CAMELLIA SINENSIS)(LEAF):
Multiple studies have confirmed Green Tea Extract appears to be able to induce fat-loss. Although this effect was originally thought to be related to caffeine content, more recent research has pointed to a green tea catechin known as Epigallocatechin gallate as the compound primarily responsible for these effects. Epigallocatechin gallate (EGCG) is an antioxidant found in green tea, and is a member of the group of antioxidants known as catechins. In addition to these antioxidant properties, EGCG has demonstrated the ability to induce fat–loss when combined with caffeine, more than just caffeine alone. EGCG works synergistically with caffeine in regards to its effect on noradrenaline. Caffeine boosts noradrenaline while EGCG inhibits catechol-o-methyl transferase (COMT), the enzyme responsible for the degredation of noradrenaline. So, caffeine increases noradrenaline, while EGCG prevents its breakdown, the net effect of which is increased levels of noradrenaline (which induces the breakdown of fat). Although caffeine is generally used along-side EGCG to induce catecholamine release, EGCG can be synergistic with endogenously produced catcholamines (from exercise) as well as other fat burning compounds that release catecholamines. Unfortunately, Beverly International doesn’t disclose the percentage of EGCG present in the Green Tea Extract present in the 7-Keto MuscLEAN formula. Generally speaking, Green Tea Extract is standardized to 45-50% EGCG, and if this is the case, 7-Keto Lean contains a scientifically validated amount of EGCG.
GUARANA EXTRACT (22% CAFFEINE) (PAULLINA CUPANA)(SEED):
Guarana is a plant native to the Amazon, the fruit of which contains caffeine. Although guarana is touted as being a sort of “slow-release” form of caffeine, a study published in the “Journal of Pharmacy and Pharmacology” found there was no difference in the absorption rates of caffeine from guarana as opposed to caffeine anhydrous (synthetic) in rats. Human studies have yet to be confirmed, but given these preliminary findings, there is certainly no reason to believe guarana would absorb any differently in humans. In regards to weight loss, the efficacy of guarana for burning fat is limited to the caffeine content, and there is no evidence to suggest guarana has any additional benefit beyond that of caffeine alone. Guarana has become somewhat popular in recent years as a result of an overall movement toward ‘natural’ products because consumers see it as a ‘natural’ source of caffeine but in terms of function, it is the same as any other source of caffeine. 7-Keto MuscLEAN contains 110mg of caffeine (500mg of Guarana standardized to 22% caffeine), which is certainly towards the lower end of what we generally see in fat-burners.
Hoodia gordonii is a small shrub, the extract of which has been alleged to reduce appetite and result in weight-loss when supplemented. A 2004 study from “Brain Research” found that injections of the active component found in Hoodia (P57) increased ATP in the brains of rats, a mechanism that is known to suppress appetite. These findings were replicated in 2007 with oral supplementation in rats, as opposed to injections. However, a 2011 study, published in “The American Journal of Clinical Nutrition”, found that 15 days of Hoodia extract supplementation (1110mg/day) failed to reduce appetite and thus had no influence on weight. Furthermore, this study noted adverse side effects, indicating that Hoodia may be slightly toxic.
Bromelain, also known as Pineapple Extract, contains protein-digesting enzymes called proteases, which possess moderately potent anti-inflammatory properties. Because of these properties, Bromelain appears mostly in joint-related supplements, with not much research focusing on weight-loss implications. A 2012 in vitro study found that Bromelain was able to inhibit adipogensis, the process by which pre-adipocytes become adipocytes (fat cells), from occurring. However, one in vitro study isn’t enough to draw conclusions and until animal and human studies are published we don’t have much to go on. Still, the pre-preliminary evidence looks promising.
Grapefruit contains several polyphenols, the most important of which are Naringenin, Narinjin, and Nootkatone. which are thought to underly its weight-loss effects. A 2010 study, pubslished in the “American Journal of Physiology-Endocrinology and Metabolism”, found supplementation of Nootkatone (isolated) resulted in an increase in metabolic rate which ultimately prevented weight-gain in rats fed a high fat diet. A 2012 study, published in “Metabolism”, found that overweight adults who consumed a half grapefruit at meal-time (3 times/day) for six weeks experienced moderate weight-loss. These findings were in-line with an earlier (2006) study which found that whole grapefruit, grapefruit juice, and grapefruit extract (capsules) resulted in weight loss in obese subjects, with the grapefruit extract being most effective. Finally, a 2008 study published in “Phytomedicine” found that supplementation of SINETROL (a patented combination of grapefruit polyphenols and caffeine) at 1.4g daily reduced body fat in overweight subjects over a 12 week period. Ultimately, grapefruit extract (or even whole grapefruit) is an effective fat-loss agent, though the fat-loss may be not be extremely potent. Unfortunately, 7-Keto MuscLEAN only contains 45mg of Grapefruit Extract, yielded far less than the amount of polyphenols which have been demonstrated to influence body weight.
THE BOTTOM LINE:
7-Keto MuscLEAN contains a few ingredients with a relatively well-established track-record for weight-loss, but the doses of the latter ingredients may be insufficient. At two servings per day, combined with exercise, there may be some slight weight-loss, mostly due to 7-Keto and the combination of caffeine EGCG. However, at about $1 per serving, there are more economical options out there.
Dave, Sandeep, et al. “Inhibition of adipogenesis and induction of apoptosis and lipolysis by stem bromelain in 3T3-L1 adipocytes.” PloS one 7.1 (2012): e30831.
Kaiman, Douglas S., et al. “A randomized, double-blind, placebo-controlled study of 3-acetyl-7-oxo-dehydroepiandrosterone in healthy overweight adults.”Current therapeutic research 61.7 (2000): 435-442.
Zenk, John L., Joy L. Frestedt, and Michael A. Kuskowski. “HUM5007, a novel combination of thermogenic compounds, and 3-acetyl-7-oxo-dehydroepiandrosterone: each increases the resting metabolic rate of overweight adults.” The Journal of nutritional biochemistry 18.9 (2007): 629-634.
Sedláčková, B., et al. “7-oxygenated derivatives of dehydroepiandrosterone and obesity.” Prague Med Rep 113 (2012): 147-155.
Thielecke, Frank, et al. “Epigallocatechin-3-gallate and postprandial fat oxidation in overweight/obese male volunteers: a pilot study.” European journal of clinical nutrition 64.7 (2010): 704-713.
Lu, Hong, Xiaofeng Meng, and Chung S. Yang. “Enzymology of methylation of tea catechins and inhibition of catechol-O-methyltransferase by (−)-epigallocatechin gallate.” Drug metabolism and disposition 31.5 (2003): 572-579.
Keränen, Tapani, et al. “Inhibition of soluble catechol-O-methyltransferase and single-dose pharmacokinetics after oral and intravenous administration of entacapone.” European journal of clinical pharmacology 46.2 (1994): 151-157.
Brown, A. L., et al. “Health effects of green tea catechins in overweight and obese men: a randomised controlled cross-over trial.” British Journal of Nutrition106.12 (2011): 1880-1889
Bempong, Daniel K., and Peter J. Houghton. “Dissolution and Absorption of Caffeine from Guarana.” Journal of Pharmacy and Pharmacology 44.9 (n.d.): 769-71.
Blom, Wendy AM, et al. “Effects of 15-d repeated consumption of Hoodia gordonii purified extract on safety, ad libitum energy intake, and body weight in healthy, overweight women: a randomized controlled trial.” The American journal of clinical nutrition 94.5 (2011): 1171-1181.
MacLean, David B., and Lu-Guang Luo. “Increased ATP content/production in the hypothalamus may be a signal for energy-sensing of satiety: studies of the anorectic mechanism of a plant steroidal glycoside.” Brain research 1020.1 (2004): 1-11.
van Heerden, Fanie R., et al. “An appetite suppressant from< i> Hoodia species.” Phytochemistry 68.20 (2007): 2545-2553.
Zygmunt, Katarzyna, et al. “Naringenin, a citrus flavonoid, increases muscle cell glucose uptake via AMPK.” Biochemical and biophysical research communications 398.2 (2010): 178-183.
Murase, Takatoshi, et al. “Nootkatone, a characteristic constituent of grapefruit, stimulates energy metabolism and prevents diet-induced obesity by activating AMPK.” American Journal of Physiology-Endocrinology and Metabolism 299.2 (2010): E266-E275.
Dow, Caitlin A., et al. “The effects of daily consumption of grapefruit on body weight, lipids, and blood pressure in healthy, overweight adults.” Metabolism61.7 (2012): 1026-1035.
Fujioka, Ken, et al. “The effects of grapefruit on weight and insulin resistance: relationship to the metabolic syndrome.” Journal of medicinal food 9.1 (2006): 49-54.
Dallas, Constantin, et al. “Lipolytic effect of a polyphenolic citrus dry extract of red orange, grapefruit, orange (SINETROL) in human body fat adipocytes. Mechanism of action by inhibition of cAMP-phosphodiesterase (PDE).”Phytomedicine 15.10 (2008): 783-792.