Sardines for fertility, a red herring?

Odd search phrase popped up in the Sciencebase logs today. Unfortunately, there isn’t an item in the archives that’s particularly relevant other than a story about a baseline analytical study that looked at arsenic, cadmium, lead and mercury content of tinned sardines using spectroscopy. I was intrigued, is there some advocacy (perhaps initiated by the fishing industry) to the idea that sardines can boost fertility. A PubMed search with surrounding terms: pilchards, fertility, sperm, sardines, brought up just one research paper: “Reproduction of the Spanish sardine, Sardinella aurita (Clupeiformes: Clupeidae) from the south-eastern area of Margarita Island, Venezuela”. Probably not entirely relevant.

The nutrient coenzyme Q10 (ubiquinone), which is found in beef, soy, mackerel, sardines, spinach, peanuts and vegetable oil is purportedly linked to increased sperm count and sperm motility although it is present mainly in the mitochondria and is linked to cellular energy from ATP. Research has suggested that it has a positive impact on seminal oxidative defence but doesn’t affect sperm number nor motility. So, maybe that’s a red herring (pardon the pun). A slightly more recent paper suggests it does have a positive effect, however.

There is a lot of spurious information on so-called “natural” fertility improving sites. Several of which mention sardines in a long list of foods that are supposed to be beneficial. Others simply say that it cannot hurt to eat healthily and cite the fact that sardines contain healthy fats (polyunsaturated omega-3 fatty acids: eicosapentaenoic acid, EPA, and docosahexaenoic acid, DHA) that might improve insulin sensitivity and reduce inflammation, which are “critical to fertility”. So, just generic and general advice there with no specific scientific support for sperm. There also wild claims that the omega-3 in sardines boost libido…

I wonder whether Oprah is a fan or they featured on Letterman or got a celebrity endorsement. That might explain the sudden rush of visitors to Sciencebase searching for “sardines for fertility”? Anyone know?

As an aside, is my photo of gutted trout a red herring too?

4 thoughts on “Sardines for fertility, a red herring?”

  1. I’m still trying to find out. I think it probably stays with you. It’s difficult to search for an answer to this because the web is littered with antivax carp about mercury in vaccines and about dental amalgams…

  2. So if not at 100% efficiency, how long approximately does it take to excrete mercury. And how much is left in the system?

  3. That’s a very good point and is the basis of why they recommend not eating oily fish more than once a week despite the omega-3 benefits. The amounts are tiny, mercury does accumulate, although it can be excreted (less than 100% efficiently).

    From Wiki: “The consumption of fish is by far the most significant source of ingestion-related mercury exposure in humans and animals, although plants and livestock also contain mercury due to bioaccumulation of mercury from soil, water and atmosphere, and due to biomagnification by ingesting other mercury-containing organisms.”

  4. I just saw your link on Facebook and I’ve got a question that maybe you can help answer. It’s not about sardines or herrings: It’s about mercury in fish.

    I understand that the mercury level in, for example, Sainsbury’s tuna is below whatever it considered an unsafe amount.

    But I also understand that mercury accumulates in the body, although I don’t know whether it is eventually excreted and if so, what the cycle is.

    So, if mecury does accumulate, when does a safe amount in a tin of tuna become unsafe?

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