Bitter orange fat burners - do they work and are they safe (part 2)

Continued... Bitter orange fat burners - do they work & are they safe pt1

To address this question I will refer to published papers and Government advice on Bitter orange. The papers referred are not presented in any particular order and this post does not purport to be a complete comprehensive listing or review of the studies or their validity.

"A Review of the Human Clinical Studies Involving Citrus aurantium (Bitter Orange) Extract and its Primary Protoalkaloid p-Synephrine" (1) year 2012

Sidney J. Stohs, Harry G. Preuss, and Mohd Shara

The study was a review of previous studies by scientists who have been consultants to Nutratech, Inc a company that markets bitter orange products.

Some of the unpublished research reports reviewed in the study were provided by Nutratech, Inc. So you have to consider whether the authors have some bias in favor of showing Bitter Orange as safe and effective.

Where adverse effects have been reported previously by other studies the authors state these may have been other active ingredients in the formulations that caused the problems.

Quote...."The results involving both published and unpublished clinical studies indicate that p-Synephrine alone or in combination with caffeine does not appear to produce significant adverse cardiovascular effects or pose a risk to human health at doses commonly ingested orally."

Personally, I don't want any "adverse effects" to my cardiovascular system significant or otherwise from a supplement.

The authors assert that it is m-Synephrine (m-s) not p-Synephrine (p-s) that causes adverse effects and that Bitter Orange only contains p-Synephrine. They go on to state that other scientists are commonly mistaken about this.

The question of whether p-s or m-s Synephrine is addressed in a Technical Report entitled "Exactly which synephrine alkaloids does Citrus aurantium (bitter orange) contain?" link to report

This report acknowledges there was some confusion the composition and tested an over the counter weight loss product containing Bitter Orange. The findings were that the product tested contained both p-s and m-s.
  
Dr Stohs' has produced a youtube video proclaiming the benefits of Bitter Orange for weight loss.  In his video he states that the Canadian Government has relaxed the Guidelines for use of Synephrine, however this is not the case for weight loss or health products, see below quoted advice from Health Canada website as of April 2015.  

Canadian Government Health Website
"Bitter orange (Citrus aurantium) peel is used in traditional Chinese medicine for several conditions, including abdominal pain and constipation, and is used in food to make marmalade, but it is not authorized for the purpose of weight loss. Synephrine has not been approved for use in any health products to date. Health Canada has issued warnings about the potential risks of using Ephedra/ephedrine and bitter orange/synephrine for weight loss, including serious cardiovascular adverse reactions."

Whilst the Canadian Government has issued guidelines for approved medicinal uses the amounts up to 50g/day. 

Safety and efficacy of citrus aurantium for weight loss (2) year 2004

 

S Bent, A Padula, and J Neuhaus.

"The participants receiving the herbal mixture containing citrus aurantium lost an average of 1.4 kg in 6 weeks, dropping from 90.9 to 89.5 kg (a 1.5% change)…... Participants receiving the placebo lost an average of 0.9 kg, dropping from 83.6 to 82.7 kg (a 1.1% change). Participants who were in the no-placebo control group lost an average of 0.4 kg, dropping from 78.1 to 77.7 kg (a 0.5% change)."

 

The authors concluded.."There was no evidence that citrus aurantium is effective for weight loss. Information on safety was extremely limited".

Considering the small weight loss these could be due normal daily fluctuations in our weight.

Acute Myocardial Infarction Associated with Dietary Supplements Containing 1,3-Dimethylamylamine and Citrus aurantium (3) year 2014

Triston B. Smith, MD, Brian A. Staub, MD, [...], and Indu G. Poornima, MBBS

This paper describes a case and provides a cautionary tale about taking Bitter Orange and DMAA.
 

"In September 2012, a 22-year-old white man with no relevant personal or family medical history was transferred to our hospital. He had typical anginal chest pain (Universal Pain Assessment Tool score, 8/10), which had started while he coached basketball one day before admission."

"He did not use tobacco, alcohol, or illicit drugs. However, 3 weeks before presentation, he had begun taking daily oral doses of the dietary supplements...before undertaking physical activity."

Discussion 

".....the acute coronary syndrome was caused by the sympathomimetic supplements that he was ingesting before exercise. ....including caffeine, DMAA, and C. aurantium."

1,3-Dimethylamylamine (DMAA)

"Case reports linking dietary supplements with acute myocardial infarction have emerged in the last few years. In 2011, two United States soldiers (ages, 22 and 32 yr) died after sustaining heart attacks during fitness exercises. 1,3-Dimethylamylamine was found during postmortem toxicologic screening.".

"In February 2012, the U.S. Department of Defense removed all products containing DMAA from stores on military bases." 

"At least one case of cerebral hemorrhage linked to the recreational use of DMAA has been reported."

In March 2012, the New Zealand Health Ministry imposed a complete ban on DMAA.6 In February 2012, The Medicines and Healthcare Products Regulatory Agency of the United Kingdom warned several companies to stop selling products that contained DMAA...."

Citrus aurantium

"The Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure lists C. aurantium as a cause of resistant hypertension."

"The structural similarity suggests that C. aurantium would have pharmacologic actions similar to those of ephedrine and would evoke comparable physiologic responses."

"Some authors have postulated that because these formulations were polyherbal and polyalkaloidal, C. aurantium might have been unjustly imputed in the association with adverse events. Others have cited the traditional use of C. aurantium in Chinese medicine as justification of its safety in weight-loss products."

"We think that both of these assumptions should serve as poignant reminders of the ephedra debacle, because these same rationales were the chief arguments to validate ephedra's use."

Health assessment of sports and weight loss products containing synephrine and caffeine (4) year 2012

The Federal Institute for Risk Assessment (BfR), Germany

The BfR advise that quantities of synephrine should be limited to levels in conventional foods and no more than 6.7mg per day as supplement. They warn that the adverse from synephrine and other products in supplements reinforce each other.
  
It also considers them dangerous because the adverse effects may be magnified by exercise and that many people targeted are overweight. As a result BfR considered that a number of weight loss products on the market should be classified as unsafe.

Key point summary on bitter orange

• Bitter orange, synephrine has not been established to be effective in promoting weight loss in humans.
• Bitter orange in high doses may be unsafe and cause serious heart problems, there is many cases implicating bitter orange.
• Supplements containing other active ingredients and Bitter Orange have unpredictable interactions with other increasing and reinforcing adverse reactions.

Key point conclusion

It is better to stay away from weight loss supplements containing Bitter Orange. In fact it is better to stay away from any supplement until you have definitive evidence that it is safe.

Often we take bigger risks with our own health than we would that of loved ones. Before taking weight loss supplements consider if you would suggest that your adult child or spouse took supplements. 

Comments and discussion are welcome.