Garlic = Bad for fish liver?

"I wouldn't recommend long time use of garlic-been reading that it may be damaging to the fishes liver. Something to research."

This is a quote from a fellow 3reefer. I am just curious as to what other members might know about this instead of taking the original thread off topic anymore.

Is garlic really bad for fish livers?

 

If fish aren't eating, I think garlic is okay as an appetite stimulant short term. There is evidence it may cause issues in high doses, or perhaps with long term use. So, caution should probably be used.

These were freshwater studies. I believe there was some research in saltwater too now, which showed similar results. I don't have the specifics though.

Metabolic and histological studies on the effect of garlic administration on the carnivorous fish Chrysichthys auratus
Mohamed B. Al-Salahy, Abd Allah B. Mahmoud

Abstract

Chrysichthys auratus fish were orally administered with doses of garlic (Allium sativum) juice equivalent to 2g per kg body wt, as a single dose or the same dose every 48h for 5 and 11 days. The results showed a hypoglycaemia, hypolipidaemia, hypocholesterolaemia, hypotriglyceridaemia and drop in serum TFAA as well as promotion of lipogenesis and glycogenesis in white muscle in response to repeated doses of garlic. Such results may correlate with elevation of insulin release in the fish following garlic administration. Histological and biochemical studies confirmed liver glycogen depletion and liver histopathological changes including vacuolation, hypertrophy and degeneration of some hepatocytes, and dilatation and congestion of some blood vessels. Histopathological changes of the kidney were vacuolation and rupture of some renal tubules, and degeneration of the parietal cells of some Malpighian corpuscles. Garlic decreased the amount of collagenous fibres in both liver and kidney, and reduced carbohydrate content in the kidney. In spite of some cell degeneration in the liver and renal tubules, serum AST and ALT did not show any significant changes, while serum ALP was decreased. Generally, it could be concluded that garlic strongly affected carbohydrate metabolism in Chrysichthys auratus. Garlic may improve carbohydrate metabolism, probably lowering the dietary protein costs of the fish; the damage of garlic on both liver and kidney in this work may be attributed to the relative high dose of garlic used.



Some physiological studies on the effect of onion and garlic juices on the fish, Clarias lazera

M.B. Al-Salahy

Abstract
Fish, Clarias Lazera were orally administered onion (Allium cepa) or garlic (Allium sativum) juices. Contents of glucose, free amino acids, total lipids, triglycerides, cholesterol, albumin, total protein, urea, aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in serum as well as glycogen, free amino acids, total lipids, triglycerides and cholesterol contents in liver, white and red muscle were determined 5 h and 24 h after a single dose or after repeated doses (1 dose every 24 h for 5 days). Both onion and garlic treatments caused a temporary hypoglycemia as well as liver glycogen muscle depletion accompanied with a significant elevation in white muscle glycogen suggesting that dietary onion or garlic may enhance the process of glycogenesis in white muscle. Onion feeding caused hypolipidemia accompanied with significant decreases in liver content of total lipids in response to the repeated doses for 5 days and a severe rise in the lipid content of red muscle at all periods. Such results suggest that dietary onion may enhance the process of lipogenesis in red muscle of Clarias lazera. Probably, the main precursor of such lipogenesis in the red muscle was the serum fatty acids. Moreover, dietary onion led to hypocholesterolemia accompanied with a significant rise in cholesterol level of both liver and red muscle. On the other hand, dietary garlic significantly decreased serum free amino acids after 5 h and 5 days. Furthermore, significant elevations of liver free amino acids were dedected in the onion-treated fish group (24 h and 5 days) and in the garlic-treated fish group (5 h), probably due to oxidation of thiol components (sulfur attached to the proteins). This result was accompanied with either a marked increase in white muscle free amino acids at all periods of garlic fish group, or a noticeable drop in the onion group (repeated doses). Also, dietary onion and garlic treatment led to an elevation in hepatic ureagenesis in spite of the unchanged serum urea level. Significant decreases of both serum AST and ALT in garlic groups (all periods) and in onion groups (repeated doses) were observed. In liver, AST and ALT showed temporary rises after onion or garlic supplementation. In general, it could be concluded that both dietary onion and garlic have a transitory hypoglycemic action as well as a promoting effect on the process of glycogenesis in white muscle whereas dietary onion promotes lipogenesis in red muscle of fish. Also, dietary garlic may enhance the white muscle uptake of free amino acids which, in turn, may promote protein synthesis.

 

Ok, it has been awhile since I have been in biology or chemistry lol (like 13 - 14 years). Is there anyway you can break this down to layman terms?

 

If a fish has a wound or a disease process going on, feeding it garlic seems appropriate to me. Unless you are feeding food saturated daily in garlic long term I can not possibly see an issue, it's garlic for crying out loud.

I expect nothing less from m2434 than the real science, that's way I am fond of him/?.

The individual that posted that garlic may cause liver damage might provide links or research.

 

I have sent the OP a PM asking if they post on here where they found their research.

 

I have always been curious about fish and garlic because in the wild neither are introduced to each other.Also garlic is kinda harsh.

just my opinion.

 

Hmm.. well, basically, from looking at the articles, the take home message would be that it interferes with carbohydrate metabolism and leads to fatty liver disease. Basically, it interferes with metabolic processes involved in the use and storage of blood glucose and the fish become hyperglycemic, they can not store glycogen properly and therfore can't use energy from food efficiently. The excess isn't able to be stored properly and ends up in the liver which can result in liver disease.

 

So, would it be alright to say that using garlic in moderation would be alright. It would not be recommended to feed garlic every day, but maybe once every two weeks or so in order to keep the immune system up in species susceptible to ich and such.

 

I don't think any significant liver damage is going to happen overnight

One thing that's interesting though, re-reading this, is that the fish aren't able to utilizing the energy from food efficiently. So, perhaps eating more, doesn't necessarily mean that they are actually getting sufficient energy from the food they are eating. So, it's possible that it if it's acting as an appetite stimulant, it may be somewhat counterproductive as they aren't able to use the extra food. However, I don't see anything that shows it would be immediately harmful. And there is no info on lower doses, so, in moderation, it may be fine. I would sort of assume so, as people fish aren't dropping dead from garlic Whether or not there is a benefit though is more the question and as I said before, I'd be cautious about overdoing it...

 

I don't feed it at all right now, but I was thinking of buying stuff to soak my food in for my clowns. I don't think I will now lol. 8) Can you post a link to the article you are reading?