Calories in, calories out: That’s the fundamental calculus of weight management, and its foundations are as solid as the laws of physics underlying them. But with more than one-third of Americans over age 20 either overweight or obese, according to the Centers for Disease Control and Prevention (CDC)—and with the success rate for the nation’s some 50 million dieters standing at a dismal 5%—something is clearly missing from today’s weight-loss equation.
It’s not zeal; weight-watchers can be a determined lot. Nor is it that longed-for magic elixir that’ll render calorie restriction and exercise obsolete. Rather, the missing element may be something that can amplify diet and exercise’s benefits by turning up the body’s own furnace. And that something may be the class of dietary supplements known as thermogenics.
Of course, thermogenics are no silver-bullet weight-loss tool. As Bob Green, president, Nutratech Inc. (West Caldwell, NJ), puts it, “We have always stated outright that the only way to lose pounds and maintain a healthy weight is to eat right and exercise.” But all else being equal, dietary supplements containing thermogenic ingredients can give dieters “the jumpstart they need to help shed unwanted pounds,” he says.
And helping Americans shed unwanted pounds shouldn’t just be a target in advance of beach season; it’s an effort at addressing a genuine public health concern. As Benjamin Voiry, business manager, Naturex (Avignon, France), points out, “High body mass index is a major risk factor for chronic diseases such as cardiovascular disease, diabetes, musculoskeletal disorders, and some cancers. As people become more and more overweight, their risk of mortality increases.”
Indeed, the American Heart Association estimates that if obesity rates continue climbing, the toll they take on the healthcare system could reach as high as $957 billion by 2030. And yet while obesity’s societal consequences will require society-wide solutions ranging from education and legislation to changes in how we structure our communities, workplaces, and lifestyles, excess weight on an individual level cries out for a more immediate response.
Turning Up the Heat
And that’s where thermogenics come in. “Understanding thermogenesis is essential,” Green says, “because it is a scientifically proven method of losing weight and toning muscle. In fact, I’d go so far as to say that you really can’t be in the weight-management business without a proven thermogenic component in your diet product.”
Why? In a word: metabolism. In many respects, weight management boils down to metabolism management, as metabolism directs how our bodies spend or store caloric energy. Thermogenesis simply revs the metabolic engines, increasing the rate at which the body releases and breaks down fat—via the process of lipolysis—to generate heat and burn calories.
Thermogenesis happens all the time. Extreme cold weather can trigger it, as can exercise. “When you exercise,” explains Scott Steil, president, Nutra Bridge (Shoreview, MN), “your metabolism goes up because it’s very strongly linked to the amount of lean muscle mass that you have in your body.”
Conversely, aging slows thermogenesis, as does calorie-restricted diets—which “tell” the body to conserve energy for what it interprets is a scarcity situation. Again, explains Steil, “When you start cutting calories, the body recognizes very quickly and says, ‘Whoa, slow the furnace down’—meaning the calorie-burn rate.”
Certain supplements have also demonstrated a scientifically proven ability to increase thermogensesis. Some of these products aren’t safe; some are even illegal drugs. “But,” says Steil, “it’s not too much of a leap to say that there are natural products that can help your body burn stored fat and keep your metabolism where it needs to be so that you get better weight-loss benefits than you could without a supplement.”
Some—including green tea, yerba mate, guarana, and others—work in a stimulant fashion. Among those that are non-stimulant are pyruvate, carnitine, metabolites of dehydroepiandrosterone (DHEA), fucoxanthins from the brown seaweed—even calcium.
Whether stimulant-based or not, thermogenic agents share the key characteristic of helping the body convert fat to acetyl coenzyme A (acetyl CoA), which Steil calls “the fuel” that runs the Krebs cycle that harvests either adenosine triphosphate (ATP), the body’s basic energy currency, or heat. And while dissipating precious stores of energy as heat is, evolutionarily speaking, extremely inefficient, with our twenty-first century bodies awash in energy as excess weight, Steil says, “that’s exactly what you want.”
To see the metabolic power that an effective thermogenic can have, consider the results of a crossover-design study (Zenk JL et al.) in which 45 middle-aged men and women adhering to a 1,200-kcal/day diet were given either two 100-mg doses daily of the thermogenic 7-Keto or a placebo. When the subjects were in the placebo phase, they saw their metabolic rate drop an average of 3.9% during the seven-day phase; while on the thermogenic treatment, average metabolism rose 1.4%.
With the addition of physical activity to the protocol, results improved even further: Two studies found that subjects following a 1,800-kcal/day diet and engaging in three days of light exercise lost approximately 200% more weight while using the thermogenic than when relying on diet and exercise alone (Kalman DS et al.; Zenk JL et al.). When the researchers analyzed the composition of weight lost, Steil says, they found that “it was anywhere between 70% and 80% pure body fat,” with the rest coming from water; lean muscle mass, crucially, was spared.
The 7-Keto supplement used in the studies—a patented thermogenic product from Humanetics Corp. (Minneapolis)—is “a very potent activator of thermogenic fat-burning enzymes,” says Steil. More specifically, it’s 3-acetyl-7-oxo DHEA, a steroidal metabolite of DHEA that the human body produces naturally. However, Steil notes, “by the time you’re 40, you have lost 50% of the normal 7-Keto levels in your body.” Once you hit 65, you’re down by 70%–75%. The supplement, Steil says, simply “puts back what nature takes away.”
Those familiar with DHEA—and wary of its effects on estrogen and testosterone levels—will appreciate that 7-Keto is not an anabolic steroid and does not convert to those hormones in the body. Moreover, says Steil, it has a better thermogenic track record than DHEA. Its manufacturer has submitted two separate New Dietary Ingredient (NDI) notifications to FDA and received acceptance of both—and, Steil adds, has yet to receive a serious adverse event report. And as a non-stimulant thermogenic, the product does its job without producing jitters.
Success without Stimulants
That’s no small matter for users, many of whom would just as soon avoid the nervousness and heart palpitations that some stimulant thermogenics produce. And with memories of ephedra still fresh in mind, some consumers remain concerned about the potential central nervous and cardiovascular system danger that thermogenic supplements might pose.
“That’s the beauty,” Green says, of his company’s thermogenic, Advantra Z. An all-natural extract of Citrus aurantium, or bitter orange, the product “activates thermogenesis without causing negative cardiovascular and central nervous system side effects,” he says. That’s because its dominant amine, p-synephrine, stimulates only beta-3 receptor sites. These sites, present on every cell wall, trigger thermogenesis and lipolysis without producing negative cardiovascular reactions. That’s in contrast to the excitatory alpha-1 and -2 and beta-1 and -2 receptors with which, Green says, “Advantra Z has very minimal contact.”
The supplement also differs from stimulant thermogenics in that it doesn’t cross the fatty membranes of the blood-brain barrier—a passage that leads to unwanted central nervous system side effects. In fact, Green points out that because the product is not lipophilic, “it prefers retention in peripheral tissues rather than passage into the brain.”
Of the more than 30 research studies that Green says support its safety and efficacy, the most recent (Kaats GR et al.) appears in the May 2013 issue of Food and Chemistry Toxicology and addresses safety in particular. A double-blind, placebo-controlled study, it involved 75 healthy subjects who received two 49-mg doses of the bitter orange supplement daily for 60 days. The researchers found no significant changes in systolic or diastolic blood pressures, blood chemistries, or blood cell counts among the subjects during administration of either the treatment or the control; similarly, they found no adverse cardiovascular, hepatic, renal, or hemopoietic effects. “They also noted,” Green adds, “that the lack of negative cardiovascular and central nervous system side effects agree with previous, shorter-term studies in which bitter orange was administered in combination with caffeine and other ingredients.”
Of course, anyone who follows the buzz surrounding thermogenics knows that green coffee bean extract is enjoying its time in the spotlight, thanks in no small part to the advocacy of a certain telegenic doctor. As Voiry notes, “Green coffee bean extract has become one of the most popular proven weight-loss solutions available today, resulting in an explosion of generic variations on the market.” However, he says, not all extracts are created equal.
His company’s Svetol, a natural extract of decaffeinated green Robusta coffee beans (Coffea canephora robusta Pierre) stands out, he says, because its proprietary extraction process yields a “well-defined and balanced” profile of the chlorogenic acids responsible for its thermogenic action, and at concentrations of at least 45%. What’s more, the process removes compounds associated with negative side effects—for example, the diterpenes cafestol and kahweol (linked to elevated serum cholesterol levels), as well as most of the caffeine.
Its efficacy and mechanism of action have emerged through multiple studies, Voiry says. In one (Dellalibera O et al.), 50 male and female volunteers, aged 19 to 75, received either a placebo or the coffee extract at 200 mg, twice daily, for 60 days. After the study period, the researchers found a 10.96-lb (5.7%) mean reduction in weight among the treatment group, compared to a mean reduction of 5.40 lb (2.9%) for the control.
As for its mechanism of action, Voiry posits that the extract decreases intestinal glucose absorption while simultaneously inhibiting glucose-6-phosphatase enzymes, which stimulate glucose release into the blood stream. “This means that the liver releases less glucose, inducing the use of fat as a source of energy,” he says. Additionally, a recent independent study (Ho L et al.) evaluated the extract with a new protocol, revealing another means of action—namely, Voiry says, “that Svetol has a direct impact on a gene to improve mitochondrial energy metabolism and influence the gene involved in metabolism.”
Like green coffee beans, green tea has thermogenic effects, but they trace back to different compounds. These compounds, called catechins, are most frequently hailed for their antioxidant effects, but research indicates that the chief catechin in green tea—epigallocatechin-3-gallate, or EGCG—also enhances metabolism, increases fat oxidation, and assists weight management.
Teavigo, a green tea extract from Pharmachem Laboratories Inc. (Kearny, NJ), has several studies supporting its thermogenic effects. According to the results of a 2007 pilot study of six overweight men, published in the Journal of the American College of Nutrition (Boschmann M and F Thielecke), 300 mg of EGCG (as Teavigo) taken daily for two days may on its own have the potential to increase fat oxidation in men, and may contribute to green tea’s anti-obesity effects.
Mitch Skop, senior vice president of new product development at Pharmachem, says the company extracts the ingredient “through a proprietary process that ensures a potent and pure extract with a minimum of 90% EGCG to maximize health benefits.” The all-natural ingredient, derived from the Camellia sinensis plant, is GRAS for use in foods and beverages and is safe in supplements. For edible applications, he points out that it’s caffeine free and water soluble and leaves no bitter aftertaste, as do some other green tea ingredients.
Another antioxidant-rich supplement with thermogenic potential is fucoxanthin, a major marine carotenoid found in edible seaweeds like wakame (Undaria pinnatifida). In addition to its radical-scavenging and inflammation-fighting benefits as an antioxidant, fucoxanthin appears to “initiate the breakdown of fats accumulated by the body’s store of unburned protein,” says Nichole De Block, marketing director, Nutraceuticals International Group (Paramus, NJ).
To understand how, first consider the different types of fat and how they metabolize. Brown adipose tissue—also known as “brown fat,” BAT, or “the good fat”—actually promotes thermogenesis through its expression of tissue-specific mitochondrial uncoupling protein 1, or UCP1. Additionally, says De Block, “BAT is considered to affect the whole-body metabolism and may modify sensitivity to insulin and induce the body to resist weight gain.”
Alas, adult humans store most of their fat in WAT, or white adipose tissue, which collects around the hips and abdomen and “is the type of fat responsible for excess weight gain and obesity,” De Block says. But by triggering UCP1 expression in both WAT and BAT, we might clear a path for reducing abdominal fat and its deleterious health effects.
Researchers at Hokkaido University demonstrated fucoxanthin’s ability to oxidize fat and release energy thermogenetically in the WAT fat cells of mice fed wakame lipids containing fucoxanthin (Maeda H et al.). “In the fucoxanthin-fed animals,” De Block explains, “WAT weight significantly decreased and UCP1 was expressed in the WAT, while there was no difference in WAT and little expression of UCP1” in control mice fed glycolipids.
The implications for the weight-control industry, she says, “are clear.” Her company produces a 10% extract of fucoxanthin, FucoPure, which concentrates the fucoxanthin levels found naturally in wakame while eliminating the iodine and other heavy metals that might cause harm in large quantities. Yet the process preserves the ingredient’s dietary fiber, healthful minerals, amino acids, vitamins, and effective fucoxanthin content. And as a non-stimulant, “it has no effect on the sympathetic nervous system and can be taken without concerns of cardiovascular exhaustion or blood pressure deregulation,” De Block says.
From Fruits and Flowers
Another thermogenic agent that goes for the gut (and the hips) is a proprietary blend of natural plant extracts from Sphaeranthus indicus flower heads and Garcinia mangostana (a.k.a. mangosteen) fruit rind. Called Meratrim and produced by InterHealth Nutraceuticals (Benicia, CA), it “has been clinically shown to reduce inches off these particular areas, helping to slim the stomach and hips,” says Paul Dijkstra, InterHealth CEO.
The product encourages the thermogenic breakdown of fat via several avenues. For one, it increases levels of the hormone adiponectin, which itself promotes lipolysis. For another, it suppresses the expression of a protein, called perlipin, which coats the lipid droplets of adipocytes, or fat cells. Absent this suppression, perlipin would otherwise block lipase enzymes from catalyzing lipid breakdown.
But the ingredient also has anti-adipogenic effects—that is, it reduces the expression of compounds that promote fat accretion and storage. For example, Dijkstra says, it suppresses expression peroxisome proliferator-activated receptor gamma (PPARG), a hormone that normally aids the creation and growth of fat cells. And by suppressing adipocyte differentiation-related protein (ADRP) and the trans-membrane receptor known as cluster of differentiation 36 (CD36), it inhibits the uptake of fatty acids that go on to become lipid droplets in fat cells.
In a randomized, double-blind, placebo-controlled study (Stern JS et al.), 56 participants took either 400 mg of Meratrim or a placebo twice daily for eight weeks, while also following a standard 2,000-kcal/day diet and walking 30 minutes five times per week. After the eight-week trial, the supplement had reduced body weight in participants by 11.2 lbs—almost quadrupling the effect of the placebo—and trimmed waist circumference by 4.66 inches (also an improvement over the placebo). Further, treatment subjects saw their adiponectin levels rise 25 times greater than those on the placebo and significantly modulated their cholesterol and triglyceride levels.
Another hormone that’s a key target in weight management is leptin, a “master hormone” secreted by fat cells to signal the brain about levels of fat in the body. Ideally, when those levels rise too high, leptin levels follow suit, generating satiety, appetite control, blood sugar balance and, importantly, thermogenesis.
However, the chronic inflammation associated with obesity can lead to leptin resistance, says Bruce Abedon, PhD, director of scientific affairs, NutraGenesis LLC (Brattleboro, VT). “In that case,” he says, “high levels of leptin are associated with the opposite effects: increased appetite, lower metabolism, and high blood sugar, which make it difficult to lose weight.”
Among the supplements that improve leptin function are NutrGenesis’s WellTrim iG (IGOB131), a patented extract from Irvingia gabonensis, the African mango seed; and LeptiCore, a patent-pending blend of plant polysaccharides—guar gum, locust bean gum, and gum Arabic—ellagic acid, pomegranate extract, beta-carotene, and blue-green algae.
“In randomized, double-blind, placebo-controlled clinical trials,” Abedon says, both products “led to significant reductions in weight, body fat, and waist size” and improved cardiovascular health, blood sugar balance, and overall metabolic wellness. The WellTrim product also increases levels of adiponectin, driving thermogenesis even more, and helps inhibit glycerol-3-phosphate dehydrogenase, an enzyme that converts blood sugar into fat.
Expectations in Check
Abedon is happy to share studies supporting his company’s products and believes other thermogenic suppliers should follow suit. “One of the most important things for weight-management ingredient suppliers and finished-goods marketers is to market ingredients that are efficacious with clinical trial evidence and also which possess excellent safety records,” he says.
After all, consumers—the whole world at their fingertips—are quick to catch on when products don’t work or, worse yet, do harm. And they are watching, as the weight-management category continues courting strong demand. But Mathieu Dondain, marketing and communications director, Nexira (Rouen, France), cautions consumers, and industry, to keep expectations in check.
“I think consumers will always be interested in weight-management products,” he says, “because we are always looking for that miracle solution to feel and look good. But this miracle solution does not exist, and consumers are now aware of this reality.” However, by coupling the right thermogenic formulation to a sensible diet and exercise plan, safe and effective weight loss can be their reality.