By-products of the smoking process

Discussion in 'Food Safety' started by dyslexic nam, Aug 6, 2014.

  1. As I get older, I am becoming more health-aware.  Not rabidly so - more like a ‘research phase’ at the moment.   Thus I am wondering about the health implications of eating a lot of smoked products.  I only smoke fish (generally considered a healthy food), but I am wondering about the various things found in smoked foods that are viewed as harmful.  I have looked online, and there are three things that seem to be mentioned as potential negatives: phosphates, nitrates or nitrites, and “polycyclic aromatic hydrocarbons”.
    • Phosphates seem to be things a person may or may not add to the process, and thus are entirely controllable.  They also seem to be the least worrisome from a health perspective, but given that I don’t feel the need to use them I will just avoid them.
    • Nitrates or nitrites seem to be things created through the salting/smoking process itself, and thus unavoidable in smoked foods.  I have read on some sites that they ‘are added’ to smoked products, but most references indicate that they are a natural byproduct of the smoking process.
    • Polycyclic aromatic hydrocarbons seem to also be a byproduct of the smoking process, but apparently are somewhat controllable with the temperature of the overall process (ie. cold-smoking produces less PAH than hot smoking).   The kind of wood also seems to have some influence.  Don't know much about these, but some sources note them as the biggest health concern.
    I am wondering if the above info is accurate.  I know ‘everything in moderation’ is a pretty common sense rule, but when I smoke a load of fish there is very little that is moderate about my consumption.  I tend to dip into the fridge quite a bit and probably consume far more than what non-smokers would think of as a ‘moderate’ amount.

    Not trying to be a downer.  I plan to eat this stuff for a long time (and I feed it to my kids), so I just want to make sure I have accurate info, and am doing whatever is reasonable to make my “smoking-habit” as healthy as possible.

  2. forluvofsmoke

    forluvofsmoke Smoking Guru OTBS Member

    I had to wonder what some of your research entailed, as you did not post supporting links. Yes, off-site links are frowned upon here, unless they will aid in giving information which will assist others in understanding what the discussion is pertaining to. So, I did a bit of digging myself.

    Nitrites and Nitrates can be controlled and/or omitted, as they are not necessary for all smoked flesh foods. Granted, you would typically use a cure additive containing one or both for cold smoking of meats, for example, but for hot smoked processes, they are not necessary. The use of Phosphates as a preservative for the purpose of personal consumption would be, IMHO, taking it to the extreme. I did not find off-site info to support this that would not be giving away ads, so I chose not to post those links.

    Let's say you wish to cold smoke fish and are considering using a cure additive, which would contain one of the above. What if there were a proven method which does not use a cure? Would you consider it instead? Here's just one example:

    Regarding PAH, it seems they are somewhat controllable, based on the cooker temperature, with high heat being a secondary cause for their production during the cooking process, while the primary cause seems to be the heat source itself (incomplete burning of organic material, such as creating smoke with wood). If you desired to reduce PAH as much as possible, it would seem logical to not smoke the food, use reduced temperature cooking methods with indirect heat, and use a cooker which did not utilize a burning process to produce the necessary cooking heat.

    A quick search yielded these reports on PAH. In the report, it would appear that PAH are found widely in the majority of the globe's environment, provided it is an industrialized area which uses fossil fuels, or utilizes large amounts of burning processes (agriculture included). Also, note the emphasis on high-heat cooking processes...low & slow cooking will reduce this risk of generating PAH:

    As with many studies, there always seem to be some holes which one has to consider. I was recently told by a doctor that consumption of carcinogenic compounds can cause cancer, yes, but only in those individuals who have genetic defects which are more prone to result in cancer...either you're a potential cancer victim or you are not. Carcinogens will trigger cancerous growths, but they are not the actual cause for cancer. I've known heavy tobacco smokers who have lived far beyond the life expectancy and did not die of cancer...their last request may actually have been to light-up...yet others who had cancer at a much earlier age, and tobacco-related cancer did in fact kill them. That said, if you have family members who had cancer, you may have the very same genetics that could effect you in the same manner. What you do with this knowledge is entirely up to you. Myself, I have reduced my intake of carcinogens, the highest risk being tobacco which I have omitted, but I'm still going to enjoy my life while I'm able and willing. I'm not giving up smoked meats, period...I gotta draw the line somewhere. As you stated, moderation will be the key, but if you have access to something that you really enjoy, are you going to deny yourself that pleasure? Seek out the method for preparation of your food which best suits your desires, and, enjoy the pleasures of life.

  3. Thanks Eric - that is a great response. 

    So just to clarify one of your comments - nitrites and nitrates are additives, and not a naturally occurring by-product of the smoking process? 

    ("Nitrites and Nitrates can be controlled and/or omitted, as they are not necessary for all smoked flesh foods.")

    I have read that they are additives (wikipedia, your post, etc.) but some articles imply that they are a natural byproduct of the smoking process (, a Globe and Mail article, Daily Mail article, etc.).  I googled  "smoked fish nitrite" and of the top four hits, 2 mention nitrites as an additive, and 2 mention them as a byproduct of the smoking process.  Sometimes it is hard to know what is accurate.  The idea of nitrite-as-byproduct might simply be an oversimplification (ie. some people add them when smoking, therefore they are considered a byproduct of the process) but my concern is more about unavoidable carcinogens.  If nitrates and nitrites are things that I have to consciously add, then I am not concerned about them because I have only used salt and brown sugar as curing agents to date.  That may need to change when I start cold smoking (AMNPS is ordered), but it would be nice to know that nitrites and nitrates aren't in the food unless I intentionally put them there.

    Which only leaves PAH.  If this is the one unavoidable carcinogen in my smoked fish, then so be it.  Cold smoking with certain woods may help mitigate their production, and I will look into that, but some level of it may not be avoidable in the process.  One thing I will do, as a result of your post, is look into the idea of PAHs in the normal food I prepare.  If they are present in the fish that I fry or broil due to the high heat, there may be little incremental harm in replacing that with smoked fish.  

    Thanks again for the response.
  4. werdwolf

    werdwolf Master of the Pit OTBS Member

    Let's take a different aspect, as an environmental doctor, how bout the fish themselves being more of an issue than the above?

    Wild caught ocean fish seems to be the safest. Except tuna and grouper which have rather high mercury content. Fish from lakes can be contaminated.  There are recommendations on limiting your intake of fish from Lake Erie due to all the nasty stuff they take in.

    Farm raised fish have been proven to have altered fatty acid balance over wild caught, and that is one of the reasons doctors recommend fish.

    On that note, whenever I'm by the ocean on vacation I get grouper!
  5. I don't eat any lake fish - all the fish I eat are fresh-caught ocean goers (mackerel), freshwater fish (from spring-fed streams), wild pacific salmon, and some farmed Atlantic salmon (my favourite, but also the most expensive and thus the least frequently consumed).  I know that mercury can be an issue, but I suspect if it reasonable in the ones I consume.  Either way, it would still amount to eating mercury AND any smoke induced carcinogens, rather than just one or the other.

    As I said in the initial post, I am not trying to be disruptive - just trying to find out more since there seems to be some unclear or downright contradictory info out there.

  6. forluvofsmoke

    forluvofsmoke Smoking Guru OTBS Member

    I should have worded that a bit more bad. There are trace amounts of nitrates/nitrites in certain foods, and many would argue that they are directly related to either the way the food is grown (with chemical fertilizers, herbicides, pesticides, etc), or, by the surrounding environment and how water/air can carry these and other contaminants into/on the food during growth/harvest/storage...I would makes perfect sense. Organisms exposed to contaminants will contain some of the same (or some form of it's by-product if metabolized) when it is harvested. We can use certain additives to aid in preservation, and in doing so, we are increasing the loading effect it has on or our own much is too much will vary between individuals... at some point we suffer health problems as a result of these exposures...we know this. There also are some foods which these occur naturally, such as celery.

    How our food is produced has evolved from one family's needs to attempting to provide for hundreds from the same size of area. This is not easily accomplished without modernization of farming practices, no matter how much we would like to eat organic foods, for example. Combine with that how much our use of the environment has effected the food chain, from the air we breathe to the water we drink and the soil we walk on...everything around us reflects how we use the environment. All of the waste or by-products that have been released into the environment will eventually come back to us in our food, water or the air itself...everything that we consume to keep us alive, coincidentally, could be our demise. But to think that there are no contaminants in the general food chain would of course be foolish. It's a matter of finding the least contaminated sources if you wish to maintain yourself at peak health.

    On a related note, nitrites convert into nitrosamines (known carcinogens) after the curing process and application of heat to cook the meat (high heat cooking, charring or overcooking of the meat seem to dramatically increasing the risk), and also during digestion of the meats treated with nitrates (interaction with gastric acid), with one simple inhibitor for this being ascorbic acid (vitamin C), followed by erythorbic acid and vitamin E...these being added to the meat itself with the curing additives to inhibit nitrosamines prior to it's conversion from nitrites. So, there are ways to mitigate some of the risks in using nitrites for would seem fair to assume that adding them to foods suspected or known to be exposed to nitrites/nitrates would aid in reducing the health effects of consuming these foods. Maybe this would be something to focus on if it is of great concern for you. Finding a source for, and method for application of one of the above into your smoked fish...that would reduce one of the exposure risks, leaving PAH to be dealt with in another way.

    Hope that helps in your quest.

    Last edited: Aug 6, 2014
    dyslexic nam likes this.

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