The Supreme Qualities of Hoodia

The Supreme Qualities of Hoodia
byStephen Holt, M.D.

Hoodiagordonii is a succulent plant from the botanicalfamily Asclepiadaceae. Thisplant has a spiny appearance resembling a cactus, and has been used forcenturies by the San Bushmen of South Africa as a way of controlling hunger andthirst during hunting expeditions in the Kalahari desert. The folklore use ofhoodia as an appetite suppressant and recent research on its benefits havepiqued worldwide interest among doctors and scientists engaged in the fightagainst the global epidemic of obesity. Likewise, the consistent demonstrationof the appetite-controlling effects of hoodia has led to massive public interestin the use of this plant as the basis of a dietary supplement for weightcontrol.

Whole hoodia powder contains variable amounts of fiber,organic material, antioxidants and biologically active substancesincludingsteroidal glycosides, which appear to fool the brain into thinking the stomach is full.¹

Weight control is all about calorie control. Recent scientificstudies have confirmed the ability of hoodia to suppress appetite, helping obesepeople and free-feeding rats lower dietary calorie intake to a degree thatpromotes weight loss, at least in the short term.^2,3 Controlled clinical andlaboratory experiments show both animals and humans will restrict the calorieintake in their diet when hoodia is taken orally. Some experiments have involvedelaborate studies where obese people have taken hoodia in a controlled metabolicenvironment; and they have been able to reduce their calorie intake by 1,000 calories per day.⁴

Being overweight is often associated with high blood pressure,high blood cholesterol, and insulin resistance. This is the metabolic SyndromeX, which affects 70 million Americans and is a common cause of premature deathand or disability. Hoodia could be an important nutritional factor to combatSyndrome X, if it fulfills its promise of appetite control and weight loss.

Some researchers believe they have pinpointed the activeconstituent(s) responsible for hoodias appetite-suppressant actions, withoutmuch investigation into the plants other potential mechanisms of biologicalaction. However, hoodias active constituent(s) may have only been partiallyidentified. Government researchers in South Africa have focused attention on thesterol glycosides. Part of a group of naturally occurring substances calledcardenolides, glycosides are best known for their effects on cardiac function.However, measurable effects on Na/KATPase, the target of action of cardiacglycosides, are not believed to be associated with the administration of hoodia.

One prevailing hypothesis implies steroidal glycosides actdirectly upon the hypothalamus, triggering a message that blood glucose is high.⁵ This is an effect related to the glucostatic mechanism of weightcontrol.⁶ Animal experiments found intracerebroventricular injection of hoodiaextracts (termed P57AS3 by Phytopharm PLC) resulted in increased ATPcontent or production in the hypothalamus, which may be a signal for theenergysensing of satiety. Specific receptors for the steroidal glycoside (P57)have not been identified in the rat brain, but administration of these compoundsinto the brain reduces food intake by a factor of up to 60 percent and increasesthe content of ATP hypothalamic neurons of the rat by up to 150 percent. Thesensing of energy input by the hypothalamus may be signaled by increases inintracellular neuronal energy, in the form of ATP.

These animal experiments suggest one potential mechanism ofaction of hoodia components on brain signals that may regulate appetite, hungeror thirst; but, there are many complex factors that control feeding behaviorsoperating through many messenger molecules.

Any focus on a single system or unitary mechanism for thecontrol of food intake must be questioned, because these controls are extremelycomplex. For example, does hoodia alter factors that are involved in the aminostaticor lipostatic theories of regulation of food intake? The difference in themany regulatory systems for energy balance in the body is well documented. In mynew book on hoodia, I discuss the ability of plants to talk to the brain andinclude examples where actual receptors for the actions of these plant compoundsexist in the central nervous system.

Safety, Sourcing Concerns

The San Bushmen have used hoodia as whole fresh plant or driedwhole plant (without flowers or root) for thousands of years in their diet, andat times of famine, they have relied on hoodia as a staple in their diet. Thiscircumstance creates a great precedent for the safety of the hoodia plant, butit does not create precedence for the safety or effectiveness of a drug derivedfrom the hoodia plant.

The effects of hoodia on the central nervous system exhibitpowerful potential for weight control, where behavior modification can reducecalorie intake. The San Bushmen report an energizing effect of hoodia, and theyhave used the plant during their strenuous hunting expeditions.

This implies that hoodia supplements would be safe whencombined with aerobic exercise, a major factor in promoting weight loss andhealth, and in combating insulin resistance (the metabolic Syndrome X). Oneinteresting, but apparently inconsistent, side effect of hoodia is itsaphrodisiac properties.

In South Africa, the hoodia plant is processed most often bysun-drying the plant to produce powder or concentrates. These substances can beused as dietary supplement ingredients or perhaps as food ingredients.

Unfortunately, there is evidence emerging that bulk suppliersof some material used in hoodia supplements are providing cactus-like bulkmaterial imported from Mexico or China. I have been involved in testing somebulk supply labeled hoodia and have found circumstances where steroidalglycoside content is very low, or even negligible, in some samples.

It seems prudent for manufacturers and marketers to use onlyhoodia from approved South African sources operating as government-approvedcultivators. Recent directives from South Africa warn that the supply of hoodiahas been outstripped by the demand.The response from the South Africangovernment has been to limit export permits to control and conserve hoodiaresources. Therefore, purchasers should research their supply channel and testimported material to ensure they are supplying consumers with safe, effectivehoodia.

Properly formulated hoodia supplements appear to alter thebody function of appetite control in a manner that affords great promise for thenew, healthy diet revolution. Hoodia may be ideal for use in combinationwith other supplements that can benefit weight control, such as green teapolyphenols and chromium compounds. While more research may be required to fullyunderstand hoodias mechanism of action in weight control, there appears to bemounting open-label experience of its use as a dietary supplement to suppressappetite, control weight and provide minor energizing effects, without anycontent of stimulant substances.

To have a safe dietary supplement that can help to switchoff appetite, or at least provide behavioral reinforcement to controlappetite, is an outstanding new promise. Hoodia likely will be one of the mostpopular dietary supplements of 2005, but the pathway forward may be hampered bymany negative, emerging commerce issues.

Stephen Holt, M.D., is a New York-based physician andscientific advisor to Natures Benefit Inc. He is the author of CombatSyndrome X, Y and Z... (Wellness Publishing); his bookabout Hoodia gordonii (The Supreme Promise of Hoodia) isin press. For more information, contact Holt at [email protected].

Jan. 31, 2005 - Natural Products Industry INSIDER
"The Supreme Qualities of Hoodia Gordonii" References

1. Tulp OL et al. "Effect of Hoodia plant on food intake and body weightin lean and obese LA/Ntul//-cp rats." FASEB J. 15, 4:A404, 2001.

2. Tulp OL, Harbi NA, DerMarderosian A. "Effect of Hoodia plant onweight loss in congenic obese LA/Ntul//-cp rats." FASEB J. 16, 4,2002.

3. Habeck M. "A succulent cure to end obesity." Drug DiscoveryToday. March 2002, pp 280-1.

4. MacLean DB, Lu-Guang L. "Increased ATP content/production in thehypothalamus may be a signal for energy-sensing of satiety: studies of theanorectic mechanism of a plant steroidal glycoside." Brain Res.1020, 1-2:1-11, 2004.

5. ibid.

6. Goodhart RS, Schils ME [eds]. Modern Nutrition and Disease, 6th Ed.Lea & Febiger, Philadelphia, pp 560-77.

7. Habeck M. op cit.