Garlic Myths & Realities
Garlic is the subject of a wealth of myths and misinformation, including fears of it’s long term effects. As an ingredient, there is real research into the benefits for general immune system health and parasite resistance.
Garlic is a key ingredient in quality foods. When the right amount is used, this single ingredient plays a major role in your fish’s long term health. It makes the food an attractant for fish. Yet more important is garlic’s anti-parasitic properties and strengthening of the immune system. We’ve been using garlic as a fish food supplement for over 20 years in both our commercial foods and farm feeds and the observed results over the years is a drastic drop in disease and parasite infestations to near zero. In our aquaculture facilities, since adding garlic to our ponds, vats or aquariums, we’ve not had a single case of “Florida Deep Well Disease” — caused by pathogenic bacteria Aeromonas sp. and Pseudomonas sp.
There are now many scientific studies on the effect of allicin complex (the active ingredient in garlic) in aquarium diets. These studies support the conclusion of allicin’s efficacy in increasing fish resistance to parasites. A 2006 study by A.M. Shalaby for the Central Laboratory for Aquaculture Research in Egypt found a 3% inclusion of garlic increased overall digestibility of protein, carbohydrates and fat in addition to lowering the total bacteria count within the intestines and muscles of the fish — as well as the water column of the aquarium. This research has been joined by similar findings from the aquaculture science departments around the world, including Australia, Israel, India and more.
Like any ingredient, balance is key. Recently, it has been suggested by some that garlic is harmful to aquarium life (due to it’s terrestrial oils and lipids). Garlic is indeed terrestrial, and we do advocate aquatic vegetation in aquarium diet formulas. Yet no aquatic plant has Allicin — for which there’s a wealth of research supporting it’s benefits in fish.
Much of this misconception is based on studies not about garlic specifically but heart and liver lesions on fish fed exclusively terrestrial plant diets. It’s also based on some industry-funded studies that use megadoses of processed purified Garlic oil that is far beyond even the most aggressive inclusion of garlic in consumer brand fish foods. Beyond this, in our opinion these results were not attributable to the allicin itself, but the high concentrations of oil fed to the subjects. Also not accounted for is the balance of other essential nutrients in the diet used.
THE “ALL OR NOTHING” FALLACY
“Hi, I’ve heard on some forums recently that garlic is actually poisonous to my fish. Is that true? I’m worried about using it in my aquarium.”
We’re regularly asked a variation on this theme about the trending “ingredient boogeymen” — whether it’s garlic, lipids, copper, vitamins, etc. Unfortunately, aquarium enthusiasts are susceptible to “panics” about their fish’s diet based on misinformation and questionable logic.
The common thread in these concerns is the “All-or-Nothing Fallacy”: the mistaken assumption that if a mega-dose is bad, it means the ingredient in any quantity is harmful and the best solution is it’s complete absence from your aquarium.
Virtually all biologically active substances are harmful in huge doses. Vitamin E is healthy, yet excess is toxic. A very large increase in aquarium salinity is deadly. This doesn’t mean salt is inherently “harmful” for marine fish — the very suggestion would be considered ridiculous. Yet this same logic is the basis for these “all or nothing” arguments. The key is inclusion in biologically appropriate amounts.
In the next article, we’ll be putting it all together and talking about how these nutritional principles are applied to the creation of commercially available tropical fish food.
BIBLIOGRAPHY & RECOMMENDED READING
SHALABY, A. M., KHATTAB, Y. A. and ABDEL RAHMAN, A. M. Effects of Garlic (Allium sativum) and chloramphenicol on growth performance, physiological parameters and survival of Nile tilapia (Oreochromis niloticus). J. Venom. Anim. Toxins incl. Trop. Dis. [online]. 2006, vol. 12, no. 2 [cited 2006-12-19], pp. 172-201.)
Ryad H. Khalil, Hanaa M. El-Hofy, Manal M. Yehya, Khalid M. Selim. “Some Biochemical and Immunological Changes Associated with Use of Garlic Extract (Allicin) in Combating Some Fish Pathogens”. AJVS 2014; 41(1): 1-
Fridman ,T. SinaiD. Zilberg. (2014) Efficacy of garlic based treatments against monogenean parasites infecting the guppy (Poecilia reticulata (Peters)). French Associates’ Institute for Agriculture and Biotechnology of Drylands, Ben Gurion University of the Negev, Be’er Sheva, Israel. Vetrinary Parasitology 16 June 2014, Vol.203(1):51–58.
Thane A. MilitzPaul C. SouthgateAlexander G. CartonKate S. Hutson. (2013) “Dietary supplementation of garlic (Allium sativum) to prevent monogenean infection in aquaculture”. Center for Sustainable Tropical Fisheries and Aquaculture, James Cook University, Townsville, Queensland, Australia. Aquaculture 15 September 2013, Vol.408:95–99
J.J. Guo, C.M. Kuo, Y.C. Chuang, J.W. Hong, R.L. Chou, T.I. Chen. (2012). “The effects of garlic-supplemented diets on antibacterial activity against Streptococcus iniae and on growth in orange-spotted grouper, Epinephelus coioides.” Aquaculture, Volumes 364–365: 33-38
Allah Dad Talpur, Mhd Ikhwanuddin. (2012) “Dietary effects of garlic (Allium sativum) on haemato-immunological parameters, survival, growth, and disease resistance against Vibrio harveyi infection in Asian sea bass, Lates calcarifer”. Aquaculture, Volumes 364–365, 5 October 2012: 6-12
Mohamed A.A. Abd El-Galil aShawky M. Aboelhadid. “Trials for the control of trichodinosis and gyrodactylosis in hatchery reared Oreochromis niloticus fries by using garlic”. Fish Department, Faculty of Veterinary Medicine, Sohag University, Sohag, Egypt; Parasitology Department, Faculty of Veterinary Medicine, Beni-Suef University, Beni-Suef, Egypt. Vetrinary Parasitology 30 April 2012, Vol.185(2):57–63
Debasis Sasmal, CH., Surendra Babu and T. Jawahar Abraham. “Effect of garlic (Allium sativum) extract on the growth and disease resistance of Carassius auratus”. Department of Fishery Pathology and Microbiology, Faculty of Fishery Sciences, West Bengal University of Animal and Fishery Sciences, Mohanpur, Nadia, India. Indian J. Fish., 52(2) : 207-214, Apr.-June, 2005