Glad to help, gents.
Seeing as it was a link to ultimatereef where this all started, I'm going to post a portion of my summation that I posted there approx 1 year ago when this topic reared its head, again.
Not to beat a dead horse, but even the research papers that the scientist posted had no real relevance to tropical fish feed, and/or tropical fish. Those studies involved cold-water fish (salmon) that are known to not be able to assimilate large amounts of carbohydrate of any kind, and a diet that consisted of massive amounts of plant matter. (as much as 50% of the diet)
Wombats comments on this forum were regarding lipid (fat) content from terrestrial based plant matter ..... period, end of story.
From one of his previous comments on this forum.
Terrestrial plant lipids are well known to cause heart and liver lesions in marine fish. The problem with feeding terrestrial plant oils (not just garlic but any terrestrial plant oil) to reef fish is problematic due the nature of the lipids the fish do not possess the enzymes to digest them correctly and this leads to fatty deposits and serious pathological changes in the heart and liver of fish that are fed these lipids. Although these are not instantly fatal they cause chronic change to these organs and long term deterioration in the health of the fish. Granted much of this his work is done on farmed fish, but it is a well known phenomena and here are some of the research papers that detail this problem.
He then went on to cite a number of research papers, involving not garlic powder, or the lipid content of any fish food product containing garlic powder, but papers where rapeseed oil, linseed oil, and olive oil, were fed to salmon. Also, in the papers cited they were using the plant extracts as a primary portion of the diet, or a VERY large percentage of a mixed diet (such as 50/50 with fish meal).
As I have stated repeatedly since joining this forum - the negative results found in those studies are not new to science, or aquaculture, and I have agreed on this point many a time over the years, on this forum & others. Very few fish that we keep in captivity do well on oils derived from terrestrial based plant matter - especially marine species. It doesn't matter if that oil comes from rapeseed, linseed, olives, corn, peanuts, or garlic.
Fish utilize lipids as a source of energy, and the main bulk of lipid content should always be derived from marine animal sources, not from terrestrial based plant matter. There is no argument about that, nor has there ever been - this has all been well documented for many years.
Is everyone clear on that?
The problem with Wombat's research, is he has never once tested commercial foods (certainly not the brand that I feed) for lipid content from garlic powder, and any potential health risks, because as previously stated once mixed in the formula that lipid source doesn't even register on the radar. We're not talking 50%, 10%, or even 2 or 3% - with regards to commercial foods, the "lipid" content derived from the garlic used in most formulas (garlic powder), would be almost nonexistent. Something along the lines of 0.0001% of the total lipid content in the food.
Therefore, using Wombat's conclusions, and studies cited, including his own research, there is zero concern for any of the negative health issues involved if one is feeding a diet that contains a very small inclusion rate of dry garlic powder. There is not a single shred of evidence that proves or even suggests otherwise.
No real lipid content from garlic, no problem.
There is an old saying among nutritionists; the difference between a nutrient, a drug, and a toxin, is typically the dosage.
Cheers!
Edited by RD., 10 September 2013 - 03:52 AM.