I know right off that some people will read this post and disagree heartily with what I am about to write. I love discussion - especially when it can be well supported by research - so if you have comments, please leave them!
I get asked a lot of questions about the best supplemental sources of Omega-3 fatty acids. Omega-3 fatty acids are essential fatty aids or EFAs. As the word essential implies, this group of fats are a requirement for normal health and cellular function. The body cannot make these fats itself, so it must – as with essential vitamins and minerals – obtain them from an outside source such as a food or a dietary supplement. Technically speaking, there are only two EFAs: the Omega-6 fatty acid Linoleic Acid (LA) and the Omega-3 fatty acid Alpha Linolenic Acid (ALA). From these, the body can derive the other four essential fatty acids: Gamma Linolenic Acid (GLA), Eicosapentaenoic Acid (EPA), Docosahexaenoic Acid (DHA), and Arachadonic Acid (AA). These four can also be ingested pre-formed.
Flax seed oil is an outstanding source of the Omega-3 fatty acids ALA. Other good sources are canola, pumpkin, walnut oils. The issue at hand is that most people are supplementing these things (versus using the food - like eating walnuts or pumpkin seeds) to obtain a specific health benefit. Virtually all the good research associated with health associated claims is directly related to EPA and DHA from fish oils. There is not substantial evidence that ALA alone from sources such as flax or canola has any of these effects, despite the fact that the body can create EPA and DHA from ALA.
Why? This may be because the ability to convert ALA to EPA and DHA can be impaired by a variety of factors including a diet high in the Omega-6 fatty acid Linoleic Acid (LA), trans-fats, and saturated fats, alcohol intake; deficiencies (even sub-clinical) of niacin (B3), vitamin B6, vitamin C, zinc or magnesium; diabetes and insulin resistance. Scientific studies report the human conversion of ALA to EPA and DHA to be between 0.2 (1) and 15 percent (2). That is incredibly inefficient. This blog recently discussed the new paper from the Journal of the American College of Cardiology that recommended 500mg per day of Omega 3 (specifically from EPA and DHA) for the prevention of heart disease (Omega 3 Updates, 27 Aug 2009). Assuming that you were doing a great job of converting your ALA, you would need to take over 3,300 mg (3.3 grams) of flax oil to get the equivalent of one 500mg fish oil capsule. If you are at the low end...well, you do the math.
Furthermore, ALA converts almost entirely to EPA (3) and minimally to DHA (which gives the greatest benefits for the brain). Therefore, for health benefits attributed to EPA and/or DHA, foods or products containing these preformed fatty acids should be the preferred source.
And I don't want to completely knock flax. The seeds are a great source of ALA, fiber, and lignan - which may have some of its own health benefits. Flax seeds or meal an excellent addition to muffins, pancakes, or other foods where they can nicely boost nutritional content. But if you want the health benefits of EPA and DHA, eat fatty fish or take fish oil.
References:
1) Pawlosky RJ, Hibbeln JR, Novotny JA, et al. Physiological compartmental analysis of alpha-linolenic acid metabolism in adult humans. J Lipid Res. 2001; 42: 1257–1265.
2) Emken EA, Adlof RO, Gulley RM. Dietary linoleic acid influences desaturation and acylation of deuterium-labeled linoleic and linolenic acids in young adult males. Biochim Biophys Acta. 1994; 1213: 277–288.
3) Mantzioris E, Cleland LG, Gibson RA, et al. Biochemical effects of a diet containing foods enriched with n-3 fatty acids. Am J Clin Nutr 2000;72:42-48.
04 September 2009
31 August 2009
Hoodia for Weight Loss
When I put out a call for ingredients that people wanted more information about I was not expecting to get questions on Hoodia. In the world of natural products for weight loss, ingredients come and go - there is always a "hot" trend" - and Hoodia really hit that status 3 or 4 years ago.
Nonetheless, I got more requests to talk about Hoodia than anything else, so here we go.
First, some history. Hoodia, primarily the species Hoodia gordonii, is a traditional plant of Southern Africa. The San people of the Kalahari Desert would eat this plant to ease thirst and hunger when they were traveling, and short on readily available food sources. Literature also suggests that the San found Hoodia to be helpful for indigestion and other mild GI complaints.
In the 1960s, the Council for Scientific and Industrial Research (CSIR) took an interest in Hoodia and other indigenous plants for their possible medicinal properties. CSIR later contracted with a British pharmaceutical company called Phytopharm LTD to continue the investigation of Hoodia as a drug for appetite suppression. Phytopharm isolated a compound called p57, which they felt was the active ingredient responsible for the appetite-suppressing qualities of the plant. They licensed this to pharmaceutical giant Pfizer in 1998. Pfizer dropped the product after early clinical trials for vague reasons. Reports/rumours later circulated that the levels of Hoodia required to suppress appetite in rats and dogs was extremely large and produced severe liver damage. It may have also caused kidney damage. (You can read about that here, but remember, most of this is not validated: Hoodia Report from Fatnews)
Take two. After the failed attempt with Pfizer, whatever the reasons, Phytopharm entered into a contract with Unilever. Unilever was researching p57 as an addition to its popular SlimFast line of diet products. After 4 years of research, Unilever followed Pfizer and dropped p57 in late 2008. The publicity following this split often quoted executives from Unilever as saying that "clinical study concluded that Hoodia could not meet Unilever’s safety and efficacy standards." (read more here: Hoodia Finds Life After Unilever)
But wait, you ask, Hasn't Hoodia been available as a dietary supplement for years?? Yes it has. Concurrent to all this negotiation over the patented p57 (this patent expires in 2017, by the way), the natural products industry (reeling from the loss of Ephedra in 2004) jumped all over Hoodia as a traditional weight loss ingredient - and this created another set of problems.
Hoodia has long been acknowledged by the Convention on International Trade in Endangered Species (CITES), as a fragile species. It is apparently slow growing and hard to harvest. When it began to boom in popularity two things happened: 1) you had a lot of plant poaching - literally people stealing the herb to sell - and 2) you had a lot of product showing up here in the US that probably was not Hoodia at all (read more about fake Hoodia here: Fake Hoodia Fears Easing as Market Stabilizes). Fortunately, for the past few years, this seems to be improving. Methods for farming Hoodia have improved as have methods for identifying the genuine ingredient.
So what is the good news? Those who have practiced traditional herbal medicine will tell you that when you take a plant that has had a long history of being used for "condition x", try to isolate a chemical out of it and then expect the same results, you may not get what you are looking for. There are many great examples of this such as hypericin from St John's Wort and lobeline from Lobelia inflata. The San people ate whole Hoodia, not p57. But you can't patent the plant...
So if you are going to use Hoodia as part of your weight management strategy, you are actually likely to be better off with the whole plant extracts that are present in dietary supplements and not the isolated p57 - at least until if/when research proves otherwise. Also if you are going to take Hoodia, take a certified product - for example Naturex's HoodiaPure® - or others with CITES certification.
In Health,
Dr. Jacques
Nonetheless, I got more requests to talk about Hoodia than anything else, so here we go.
First, some history. Hoodia, primarily the species Hoodia gordonii, is a traditional plant of Southern Africa. The San people of the Kalahari Desert would eat this plant to ease thirst and hunger when they were traveling, and short on readily available food sources. Literature also suggests that the San found Hoodia to be helpful for indigestion and other mild GI complaints.
In the 1960s, the Council for Scientific and Industrial Research (CSIR) took an interest in Hoodia and other indigenous plants for their possible medicinal properties. CSIR later contracted with a British pharmaceutical company called Phytopharm LTD to continue the investigation of Hoodia as a drug for appetite suppression. Phytopharm isolated a compound called p57, which they felt was the active ingredient responsible for the appetite-suppressing qualities of the plant. They licensed this to pharmaceutical giant Pfizer in 1998. Pfizer dropped the product after early clinical trials for vague reasons. Reports/rumours later circulated that the levels of Hoodia required to suppress appetite in rats and dogs was extremely large and produced severe liver damage. It may have also caused kidney damage. (You can read about that here, but remember, most of this is not validated: Hoodia Report from Fatnews)
Take two. After the failed attempt with Pfizer, whatever the reasons, Phytopharm entered into a contract with Unilever. Unilever was researching p57 as an addition to its popular SlimFast line of diet products. After 4 years of research, Unilever followed Pfizer and dropped p57 in late 2008. The publicity following this split often quoted executives from Unilever as saying that "clinical study concluded that Hoodia could not meet Unilever’s safety and efficacy standards." (read more here: Hoodia Finds Life After Unilever)
But wait, you ask, Hasn't Hoodia been available as a dietary supplement for years?? Yes it has. Concurrent to all this negotiation over the patented p57 (this patent expires in 2017, by the way), the natural products industry (reeling from the loss of Ephedra in 2004) jumped all over Hoodia as a traditional weight loss ingredient - and this created another set of problems.
Hoodia has long been acknowledged by the Convention on International Trade in Endangered Species (CITES), as a fragile species. It is apparently slow growing and hard to harvest. When it began to boom in popularity two things happened: 1) you had a lot of plant poaching - literally people stealing the herb to sell - and 2) you had a lot of product showing up here in the US that probably was not Hoodia at all (read more about fake Hoodia here: Fake Hoodia Fears Easing as Market Stabilizes). Fortunately, for the past few years, this seems to be improving. Methods for farming Hoodia have improved as have methods for identifying the genuine ingredient.
So what is the good news? Those who have practiced traditional herbal medicine will tell you that when you take a plant that has had a long history of being used for "condition x", try to isolate a chemical out of it and then expect the same results, you may not get what you are looking for. There are many great examples of this such as hypericin from St John's Wort and lobeline from Lobelia inflata. The San people ate whole Hoodia, not p57. But you can't patent the plant...
So if you are going to use Hoodia as part of your weight management strategy, you are actually likely to be better off with the whole plant extracts that are present in dietary supplements and not the isolated p57 - at least until if/when research proves otherwise. Also if you are going to take Hoodia, take a certified product - for example Naturex's HoodiaPure® - or others with CITES certification.
In Health,
Dr. Jacques
30 August 2009
CNN Review of Natural Cholesterol-lowering Substances
Often, natural products coverage in the mainstream media makes me want to cringe. They seem to go after or highlight the most sensational things they can find, which I believe contributes to consumer confusion about the safety and efficacy of natural products.
Sometimes, however, they do a good job, and I think these efforts should be encouraged and highlighted. There are a lot of people worried about their cholesterol - and with so many products from drugs to foods marketed at consumers, it can be hard to understand the choices.
While this article does not discuss all the options, it does highlight the currently available research on many of the more popular natural ingredients used in "heart health" products.
For those of you who are interested in this topic, here is the CNN article:
http://www.cnn.com/2009/HEALTH/08/20/cholesterol.lowering.supplements/
Sometimes, however, they do a good job, and I think these efforts should be encouraged and highlighted. There are a lot of people worried about their cholesterol - and with so many products from drugs to foods marketed at consumers, it can be hard to understand the choices.
While this article does not discuss all the options, it does highlight the currently available research on many of the more popular natural ingredients used in "heart health" products.
For those of you who are interested in this topic, here is the CNN article:
http://www.cnn.com/2009/HEALTH/08/20/cholesterol.lowering.supplements/
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