Articles
Nonprescription weight loss substances
Obesity is increasing in Australia. The best line of approach is to modify behaviour, increase physical activity and to eat a healthy low fat diet. In the next 3 weeks I will be looking at this.
Many people want a quick fix. They feel that alternative remedies may give the instant weight loss with out change or application. As a consequence there is a big demand for weight loss medications.
The lackof effective>prescribed medications has meant that nonprescription drugs haveflourished>but testing for some products may be inadequate.
A recent article published on the internet by the Medical Journal of Australia (www.mja.com.au 6/20 December 1999) reviews The Effectiveness of Popular, Nonprescription Weight Loss Supplements. A resume of this study is very helpful in evaluating some of the products currently on the market.
In preparation for the report the researchers ‹ Garry Egger, Adjunct Professor of Health Sciences, and Director, Centre for Health Promotion and Research in Sydney, David Cameron-Smith a nutrition lecturer and Rosemary Stanton, a consultant nutritionist ) made a detailed literature search including all relevant medical and supplementary medicine databases.
The results of their findings and the products which contain them are listed below. Keep this as a handy reference if you are contemplating purchasing any weight loss products.
Brindleberry (Garcinia cambogia/indica):
Source: Rind of an exotic citrus
fruit (Malabar tamarind). Active ingredient is hydroxycitric acid.
Products: "Slim Life", "Brindleslim", "Medislim", "Beer Belly Busters".
Proposed action: Reduces conversion of carbohydrate into fat storage but most fat comes from eating fat not carbohydrate.
Conclusions: There is no strong support for the use of brindleberry in weight loss. The theoretical basis of claims made is also questionable.
Capsaicin:
Source: Major pungent ingredient of hot chillies and peppers.
Products: "Optislim 2000". Also found in spicy foods.
Proposed action: Increases metabolism; decreases appetite.
Risks: Very spicy food can cause short-term pain.
Conclusions: Capsaicin in low-fat, spicy foods may add variety to a low energy diet, with some possible benefits on energy balance. There is no support for taking the substance as a supplement.
Caffeine/Guarana:
Source: Caffeine is found in coffee, tea, cocoa and cola drinks and guarana, which is extracted from the leaf of a South American vine (Paullinia cupana).
Products: "Slim Life", "Beer Belly Busters", "Body Lean".
Proposed action: Increases alertness and decreases fatigue; may increase availability of free fatty acids for oxidation.
Risks: Large doses of caffeine can cause nervousness, anxiety,gastrointestinal discomfort, insomnia, heart arrhythmias and mild hallucinations, and may lead to dependence.
Conclusions: Caffeine, as part of a normal diet, may, at best, have some minor effects on energy balance. However, this has not been proven by research on caffeine alone. No studies are reported of the effects of guarana on weight loss.
L-Carnitine
Source: An amino acid found in meat and dairy products or made in the liver
and kidney from the amino acids lysine and methionine.
Products: "Fat
Metaboliser", "Pro-sport L-Carnitine" and "ProteCol".
Risks: Oral
supplementation may cause diarrhoea, but no other major adverse effects have
been noted.
Proposed action: Increases fat metabolism.
Conclusions: There
is no evidence that L-carnitine assists weight loss.
Chitosan
Source: Chitosan is an amino polysaccharide derived from the powdered shells
of marine crustaceans such as prawns and crabs.
Products:
"Chitorich", "Exofat", "Fatsorb", "Fat Breaker" and a number of other products
labelled Chitosan".
Proposed action: Binds to dietary fat,
preventing digestion and storage.
Risks: Some malabsorption of essential
nutrients is possible. If chitosan was effective fatty diarrhoea could be a
potential problem.
Conclusions: Malabsorption of fat in the digestive tract
may have a limited effect on restricting energy uptake. However, in the absence
of a low energy diet, the available evidence does not show that chitosan can
assist in weight loss in humans.
Chromium picolinate:
Source: An organic derivative of chromium, an element required for normal
carbohydrate and lipid metabolism.
Products: "Body Lean", "Chromaslim",
"Medislim", "Beer Belly Busters" and "Protecol".
Proposed action: Increases
satiety. Increases energy expenditure through the ability of the body to get rid
of excess energy through heat production.
Risks- Possible tissue accumulation
and damage to DNA. Also reports of renal damage following chronic ingestion of
large does of chromium picolinate.
Conclusions: There is no good-quality
evidence to support any benefits of chromium picolinate in fat loss.
Fucus vesiculosus:
Source: Fucus vesiculosus is a seaweed.
Products: "Cellasene",
"Medex", and "Bioslim" diet patches.
Proposed action: Iodine in
Fucus vesiculosus increases thyroid response, leading to excess energy
expenditure.
Risks: Possible hyperthyroidism if taken in
excess.
Conclusions: Obesity can result from hypothyroidism, but it is a rare
cause. The human thyroid gland can tolerate wide fluctuations in iodine levels
and there is no evidence that increasing iodine intake in non-thyroid-deficient
individuals has any effect on weight loss.
Ginkgo biloba:
Source: The leaves of the maidenhair tree (Ginkgo
biloba).
Products: "Cellasene", "Cellusense" and related
products.
Proposed action: Stress reduction, leading to reduced
eating.
Risks: Possibility of "serotonin syndrome" if combined with
antidepressant medications, or some non-prescription preparations. (Serotonin
syndrome can cause a variety of symptoms including hallucinations, confusion,
fluctuating blood pressure, seizures, high temperatures, stiffness, irregular
heart beats and even death.)
Conclusions: Gingko may have some effect on
stress and therefore theoretically help in cases where obesity is due to
stress-related overeating. However, there is no available evidence to support
this, and gingko could be contraindicated in some cases.
Pectin:
Source: Soluble fibre extracted from fruit.
Products: "Zellulean",
"Beer Belly Busters", "Exofat" and "Fatsorb".
Proposed action:
Satiation and decreased energy density leading to decreased food
intake.
Risks: Low for most fibre, particularly soluble.
Conclusions:
There is no long-term evidence of weight loss from fibre supplements. A diet
high in fibre-rich foods, on the other hand, is known to be of benefit in weight
loss.
Grapeseed extract:
Source: Grape seeds.
Products: "Cellasene".
Proposed
action: Not specified.
Risks: None known.
Conclusions: There is no
evidence or rationale for grapeseed extract in weight loss.
Lecithin:
Source: Phospholipid found in or soybeans, egg yolk and also made within the
intestine.
Products: "ProteCol", "Cellasene", "Cellusense" and
related products.
Proposed action: Prevents deposition of fat in fat
cells.
Risks: None known.
Conclusions: There is no support for the theory
or practical use of lecithin in weight loss.
Horse chestnut (escin):
Source: Seed extract from horse chestnut.
Products: "Cellasene"
and related products.
Proposed action: Aids circulation and prevents
oedema.
Risks: None known.
Conclusions: Although reduced oedema may cause
weight loss through loss of body fluid, this does not imply fat loss, so escin
does not appear to be an effective treatment.
Sweet clover/soy beans (isoflavones):
Source: Phytoestrogens from soybeans or sweet clover.
Products:
"Cellasene" and related products.
Proposed action: Not
specified
Risks: None known for adults.
Conclusions: There is no evidence
to support the use of isoflavones in weight loss.
St John's wort:
Source: St John's wort is a herb.
Products: "Beer Belly
Busters".
Proposed mechanisms: Not specified, but an antidepressant
effect may reduce depression eating.
Risks: Not known.
Conclusions: While
St John's wort has been shown to have antidepressant effects, there is no
evidence that it is effective in reducing weight.
Other ingredients
Other substances in weight loss preparations include milk thistle, inositol, collagen hydrolysate, citrin K, glycerine, aminogen, pyruvate, various amino acids, potassium sorbate, sodium benzoate and demineralised water. There is no theoretical or practical rationale for the effectiveness of any of these substances in weight loss and no published data supporting their effectiveness, either singly or in combination.
Conclusion of researchers:
There is little positive evidence that any of the ingredients reviewed here are effective in weight loss. For most, the data are equivocal or lacking in either quantity or quality. There is limited support for capsaicin, caffeine and fibre, but only when they are consumed in foods and, even so, the evidence is not strong. Only caffeine combined with ephedrine appears to be effective, but side effects limit the usefulness of this combination. More detailed future research may show advantages for these and other non-prescribed substances. The possible benefits of a combination of ingredients working together can not be ruled out and needs further study. Average long-term weight losses, even with proven prescribed medications, are poor and only exist while a drug is being taken. If non-prescribed substances are to be successful, lifetime use may be needed, as in other chronic disorders. Consumer protection demands that weight loss claims should be based on evidence. Manufacturers of weight loss supplements should prove the effectiveness of their products through impartial, well-controlled trials. Lack of positive evidence, while not necessarily disqualifying sale of a particular product (provided safety issues are satisfied), should certainly disqualify the use of unverified claims relating to these products. The next three weeks will support safe proven methods of weight loss with life style changes.
Added to site on : Wednesday, 19 January 2000