Citrus peel extract is a rich source of Polymethoxylated Flavones (PMFs) – flavonoid compounds with extra (“poly”) methoxy groups compared to “regular” flavones. Like all flavonoids, the PMFs deliver potent antioxidant and anti‐inflammatory activity, but the PMF version is approximately 3‐times more potent in its ability to reduce cholesterol levels (20‐30% reduction in clinical studies) and in balancing cellular cortisol exposure by inhibiting the activity of the fat‐storing enzyme, HSD‐1, inside of abdominal fat cells. The three primary PMFs are nobilitin, tangeretin, and sinensetin.

PMFs can inhibit the activity of HSD‐1 (11‐beta‐Hydroxy‐Steroid‐Dehydrogenase‐1), an enzyme inside of adipose (fat) cells responsible for cortisol “reactivation” and fat‐ storage. By inhibiting HSD‐1 activity, PMFs are thought to be active and important natural agents for reducing cellular exposure to cortisol (which serves a potent fat‐storage signal) and thus, for maintaining metabolic hormone balance. Because the HSD enzyme plays such an important role in the cellular interconversion between active and inactive cortisol, it also plays an important role in a number of health imbalances associated with cortisol overexposure. For example, HSD amplifies local cortisol concentrations in target tissues, even when circulating cortisol levels are low. In overweight individuals, levels of HSD are elevated inside of fat cells – and increased HSD levels are known to lead to abdominal obesity, insulin resistance, and diabetes. Slowing, or inhibiting the activity of HSD (the main benefit of PMFs from citrus peel extract) results in a reduction in cortisol exposure and enhanced insulin sensitivity (improvement in diabetes-related symptoms).

Citrus peel extracts and PMFs are extremely safe – and at the effective doses, users will benefit from the antioxidant and anti‐inflammatory effects in addition to the cholesterol/triglyceride reducing, hormone‐balancing, and abdominal‐fat‐reducing effects. Toxicity studies have suggested that Citrus peel extracts and PMFs are safe up to more than 14 grams daily (14,000mg) for a 150‐pound human (many times higher than the daily dose found in the Eleviv formulation). Unlike some flavonoids like naringin from grapefruit, there are no known risks of drug interactions with citrus‐derived PMFs (certain grapefruit flavonoids can interfere with liver enzymes needed to metabolize many prescription drugs). When combined with the testosterone-balancing effects of Eurycoma root extract, the cortisol-balancing aspects of Citrus peel extract (PMFs) help to restore the Metabolic Balance between cortisol/testosterone and thus improve “physical” energy levels. The other half of the Vigor equation (mental energy) is delivered by the unique combination of green tea catechins plus theanine that will be the subject of the next blog installment.

About the author: Dr. Shawn Talbott holds a MS in Exercise Science (Univ Massachusetts), an EMP in Entrepreneurship (MIT), and a PhD in Nutritional Biochemistry (Rutgers). He is the author of more than 200 articles and 8 books on health and wellness, including his new book, “Vigor – 7 days to Unlimited Energy, Focus, and Well-Being” (www.VigorBook.com – 100% of profits support Operation Smile). Dr. Talbott is a scientific advisor to XANGO.

Eurycoma contains a group of small peptides (short protein chains) that are referred to as “eurypeptides” and are known to have effects in improving energy status. The testosterone “boosting” effects of eurycoma appears to not have anything to do with “stimulating” testosterone synthesis, but rather in increasing the release rate of “free” testosterone from its binding hormones (SHBG, sex‐hormone‐binding‐globulin). In this way, eurycoma is not so much a testosterone “booster” but rather a “maintainer” of normal testosterone levels (testosterone that your body has already produced and needs to release to become active). This would make eurycoma particularly beneficial for individuals with sub‐optimal testosterone levels, including those who are under increased metabolic stress, such as those dieting for weight loss, sleep-deprived individuals (less than 8 hours of nightly sleep), middle‐aged individuals (testosterone drops after age 30), and intensely training athletes who may be at risk for overtraining.

The vast majority of what we know about eurycoma comes to us from rodent studies, test tube binding evaluations, and a handful of open‐label human feeding trials. In the test tube binding studies, we find that eurycoma peptides and related compounds do indeed help to release more free testosterone from its binding proteins. In the rodent studies, we have more than a dozen reports of increased energy levels, improved hormonal profiles, and enhanced sex drive (all compared to “suppressed” levels induced by various forms of aging or stress). In the limited number of human feeding trials, we see a clear subjective indication of reduced fatigue, heightened energy and mood, and greater sense of well‐being in the subjects consuming eurycoma.

Until relatively recently, there were very few human supplementation studies in athletes, dieters, or individuals with chronic stress – which are perhaps the key customers for eurycoma‐based products. Over that last few years, there have been four US‐based research trials of eurycoma, 1 in endurance athletes (in mountain bikers, presented at the International Society of Sports Nutrition, ISSN, Annual Scientific Meeting in 2006) and 3 in chronically–stressed subjects (in moderately stressed subjects, presented at the North American Association for the Study of Obesity, American College of Sports Medicine, American College of Nutrition, and Experimental Biology, in 2006 thru 2009). These studies used eurycoma (combined with citrus PMFs, green tea extract, and theanine – as Eleviv) and found a balancing effect on normal testosterone levels (compared to a typical drop in cases of stress overexposure).

Whether the stress overexposure comes from caloric restriction (“dieting”) or excessive exercise (“over-training”) or sleep deprivation (less than 8 hours), or simple “everyday” psychological stress, it would be expected for cortisol (a stress hormone) to rise and testosterone (an anabolic hormone) to drop. This change in “Metabolic Balance” (cortisol up and testosterone down) is an important cause of the familiar “plateau” that many dieters hit (when weight loss stops) after 6‐8 weeks on a weight loss regimen. By maintaining normal testosterone levels, a dieter could expect to also maintain their muscle mass and metabolic rate (versus a drop in both subsequent to lower testosterone levels) – and thus continue to lose weight without plateauing. For an athlete, the same rise in cortisol and drop in testosterone is an early signal of overtraining – a syndrome characterized by reduced performance, increased injury rates, suppressed immune system activity, increased appetite, moodiness, and weight gain. Obviously, a maintenance of normal testosterone levels could prevent some of these overtraining symptoms as well as help the athlete to recover faster/better from daily training bouts.

There are no reported side effects in animal or human studies of eurycoma. It is important to note that the majority of these studies have been conducted on hot‐ water‐extracts of eurycoma (which is the traditional Malaysian preparation). Many of the eurycoma extracts currently on the US market are alcohol‐extracts, which provide a completely different (and potentially toxic) chemical profile, which may not be as effective or as safe as the studied hot‐water‐extracts. The Eleviv formula combines a patented and standardized eurycoma root extract with standardized hot-water extracts of Citrus peel and Green tea, plus pure L-theanine (an amino acid) to provide a unique and proprietary approach to restoring Metabolic Balance, reducing stress, and improving Vigor for enhanced mental and physical performance.

About the author: Dr. Shawn Talbott holds a MS in Exercise Science (Univ Massachusetts), an EMP in Entrepreneurship (MIT), and a PhD in Nutritional Biochemistry (Rutgers). He is the author of more than 200 articles and 8 books on health and wellness, including his new book, “Vigor – 7 days to Unlimited Energy, Focus, and Well-Being” (www.VigorBook.com – 100% of profits support Operation Smile). Dr. Talbott is a scientific advisor to XANGO.