Welcome to another feature series write up. In retrospect to my own / N=1 experience and research, I am going to compare which of these select two food(s), wins (or lose) in terms of their nutritional value. For those new to this concept initiative – welcome to the least visited channel on nutrition and fitness from (atypical) lens of accessibility.

Part 1 ~ Textured vegetable Proteins or Cans of Tuna

For this “debut” article, it is already difficult for me to spotlight if there is ever a win or lose.

Realistically, I would consider having both. Hence in this “Debut” article it is a straight coin toss.

In an itemised view:

1. For palatability, I’d favour Tuna. But the risk of accumulating mercury (and also some plastic) can be somewhat quicker than I’d realize, at least from what I gather in my research below.
2. For sustainability, TVP. But the obvious rubbery taste often requiring much more flavouring condiment to mask them.
   1. Then there’s the very high(!) oxalate content. And not to mention the psychological effects I derive from eating them for quite some time.

Before I get to explain the “why” ~ here is an overview on each food for  context.

Textured Vegetable Proteins.

Processed, dried and extruded to various shapes, flakes and nuggets also known as  “Soya Wadi”. The latter has a more “spongy” taste.

Generally derived from whole soy flour or actual SPI / protein isolate, they can also be a mix from other plant based “protein” sources. Allegedly ~  lentils, peas, cottonseed, gluten, oats and one that may pose letigimate concerns ~ fava beans.   

All it takes is boiling water to rehydrate or reconstitute which results in a volume approximately double their initial size. However, I personally would not eat them immediately as is. Because of its’ strange, funky or what I noted from my experience – “clay” or “rubber” like palate. Going through a second run-through with boiling water, and some acidic mediums (ACV / lemon) then squeezing the excess water out helps reduce, though not eliminate that “processed” taste.

The manufacturing / processing goes something like these. Firstly, soy flour is combined with sodium chloride, cut into shape and cooked simultaneously by cooker + extruder machine. Hexane may also be used here to separate the fat content. Then drying, colouring, flavouring and seasoning process before packaging.

As I wrote on this previously ~ I do give some respect to it no more than survival food. After all TVP stays dry for long periods of time. This article suggests anywhere between fifteen (15) to all the way twenty (20)! years of storage.

Tuna (canned).

Ranging anywhere from 4 pounds all the way to gargantuan 1,500 pounds! (Bluefin Tuna) ~ no wonder judging by weight alone they’d eat pretty much anything. Including (micro) plastics which some do potentially end up in the commercial cans*.

*Interestingly, there is reportedly more microplastics in brine/water canned version, than those canned in oil.

To recap, there are generally seven (7) species for “major commercial” consumption. In ascending order from small to biggest:

1. Skipjack
2. Albacore
3. Yellowfin
4. Bigeye
5. And Bluefin;
   • Southern, Pacific or (to the heaviest) ~ Atlantic.

For seafoods rating of mercury content – “1.0 mg mercury per kg” or 1.0 parts per million / ppm has been considered benchmark for  “High” category. Generally, larger species (Albacore, Wild Bluefin, Big Eye) have higher mercury. Canned skipjack tuna (small) has somewhere on average between 0.047~0400 PPMP. Wild bluefin tuna (Large) ranges from 0.057 – 3.030 ppm. 

Costing per serve and nutrition content wise, they are very good. Note we’re referring to canned, not steak version. Like TVP, they’re fat deficient thus from calorie needs standpoint obligates further condiments. Were I to rate entirely on “taste” tuna definitely wins.

Besides from its cost-friendly, complete source of protein, the only other benefit is its selenium, which to my small surprise ~ may actually be the only richest source there is coming from food protein source.

But here’s something about mercury. It takes a very LONG time for the body to get rid of. Other than its industrial use as bactericide and fungicide  in agriculture ~ everything else about it, is simply neurotoxic from head to toe.

Confusing safe-intake recommendations.

Methylmercury, the biologically active version, has a half life ranging from 39 to 70 days. And appears to build up commonly in the kidneys.

“Safe intake”, commonly referred to as PTWI or “provisional tolerable weekly intake”  appear to be different across institutions.

WHO reduced their 2003 PTWI limit from 3.3  microgram per/kg of body weight ~ down to 1.7 microgram per bodyweight per week, in their 2007 revision. In contrast, the 2004 Australian & New Zealand Food Safety standards (AUNZFS) paper suggests 3.3 micrograms per week.

In other words, WHO appears to recommend a lower limit compared to AUNZFS.

According to theconversation.com, (at least in Australia) “between” twenty-five to thirty-five (35!) cans (95g each) PER WEEK ~ is considered the maximum limit for  the most common canned Tuna intake (presumably between skipjack to yellowfin species). For pregnant mothers, these number is ideally halved (~ 12 cans per week).

Until there is a more in depth study + mercury analysis ~ I wouldn’t take the above as “safe” reference point.

Let’s run through the math. 25 cans x 95g = 2.4 kilograms per week. Divided by 7 = 340G per day. The authors seemed confident that hitting these numbers are “unlikely”. In my humble opinion ~ no ~ that range is actually more than likely,  especially if we’re favouring protein intake. Just one 425g Tuna already equates to around 350-375G edible yield already (minus excess water).

For me, I only eat Tuna infrequently as occasional 19:6 / 20:4 PSMF ~ 800kc days. Other than that, very few on occassion outside of these. 

For trivia, this is a case study on a fisherman who consumed 500g tuna steaks (specifically – Albacore and Yellowfin) everyday for years. His BML (Blood mercury level) obviously shot to a range between 38.70 all the way to 53 μg per litre. But after four months of stopping all tuna intake – readings went down to 14.18 μg per litre. For context, WHO set the 5 uML being the limit for safe plasma reading. His initial complaints was “pain” in both legs, and a case of paresthesia (needle-like/stinging-sensation).

(Slightly Lesser Evil) Winner: (coin toss).

Both have equal concerns. So much so as a result, it is a coin toss. 50:50. 

Nevertheless, my decision revolves around the following criteria.

1. Affordability. Obviously, the overarching theme of this concept initiative. How affordable is it? Is it sustainable?
2. Avoidability of toxins. How avoidable / unavoidable are the suspected ingredient, or toxin?
3. Recalling of personal experiences (between none, low / high) ~ Has anything stood out in terms of health effects in between these three intake levels?

Soy – Ubiqutuious and unavoidable.

Soy I would argue is everywhere.  It is already part of agriculture considering 70-90% of overall output appears dedicated towards feed/livestock, which is interesting.

No doubt TVP remains as most economical protein source there is. But effects I experienced, on top of its very processed, rubbery taste are still relevant to this day.  

Psychological “numbness” is what I can recall. I certainly do not feel at all “healthy” nor “nourished” in-the-head so to speak. Grey, dull, somewhat subdued. In other words, “staleness” ~ soon after eating.

Another strong reason for my concern is its oxalate content. Precisely whopping 638MG per 85g (presumably dry weight).

Tuna – Future unknowns.

Tuna no doubt wins for taste. But it is arguably the most potent source of Mercury.

There is however depending on how one views it, a flipside. Avoiding them might be easier. Besides from not eating blue-fin tuna, king mackerels, sharks/shark-fin-soups, we can also avoid use of (excessive) cosmetics, cleaners, and disinfectants.

However it’s worth noting some trace amount is still being used in various industries. In dentistry ~ they’re still present in some amount within amalgam fillings, and unfortunately has not been completely banned per-se here in Australia. In gold mining, mercury is used during the gold extraction & separation process, which consequents risk of mercury vapour. When inhaled ~ they’re obviously lethal, as indicated by several case studies here.

When toxicity arises, it might be worth reading about “chelation”. Essentially ~ it’s a therapy where the suspect minerals (usually Lead, Arsenic, Cadmium and Mercury) binds with chelating “agents” via oral supplementation. DMSA, Penicillamine Activated Charcoal (for those of you devout Ray Peat Forum readers) just as few examples ~  binds with these minerals in question, minimising their absorption by forming “complex” or simply inabsorble compunds. This is so they can be passed / excrete safely through either urine or faeces.

That, at least is only in theory.  The consequences however are probably a little too complex for lay reading.

Then, there’s very bold claim / fears on demand vs supply.

By 2048 ~ there will be extinction, or proclaimed “Collapse” or “Emptying” off all seafood.  This was initially raised in a 2006 paper by Worm et al.

The above stat was highlighted in an overfishing documentary “Seaspercy”.  I don’t really pay serious attention to Netflix®.  What do you expect after all, when you get supporters with the likes of James Cameron, Beyond Meat, Chan Zuckerburg Biohub and Vogt Foundation?

Thankfully, there’s been several debunk(s), alongside critics of the film. Worm & colleagues revised their stance two years later in a follow up 2009; admitting while there are still much more that can be improved in the fishing industry, both new research and the industry’s regulations suggests their prior “collapse” projection by 2048 ~ seems unlikely.

 

If there is anything I can take from reading the above Our World In Data (warning: very LONG article),  are the following:

• Pay attention to the Tuna catchment Zones.
  Some catchment zones are considered more more stable and sustainable in terms of population re-growth/Biomass point-of-view. Across the three regions (Pacific, Atlantic and Indian) Indian Ocean appears to be the least sustainable.  
• Fishing methodology matters.
  “Bottom Trawling” method (where netting occurs at the bottom most of ocean floor, dragging everything it takes) appears most unsustainable because it favours faster-than-ideal catchment, without much monitoring and/or in respect to ~ the current biomass / available fish population.
• The topic of “fish discards”.
  From each catchment, especially via the bottom trawling / dragging the net across the ocean floor ~ there could be potentially PRIOR batches of dead fishes ~ that were once previously discarded back to sea, yet only to be picked up (again). This compounds the difficulty at discriminating / filtering / separating those that are safe for human consumption vs those that are not.
• Proper monitoring of catchment.
  …By getting that “fine” balance of the amount to catch. Too little will not produce enough incomes for workers/fishers in the industry. Too high depletes natural biomass supply; before there is ever a chance to re-populate. 

Conclusion

Originally, I was writing this feature series with expectation it should be straightforward. Obviously, turning out quite the opposite.

On Tuna ~ apart from global food insecurity issue ~ to be honest I am not sure what advice to give, other than self- moderating my own intakes. However at least by being aware of the confusing discrepancy between WHO and Australian Food Standards recommendations certainly keeps me on the cautious side.

TVP, as much as it did allowed me to survive on $15 per week worth of food ~ was quite literally – a torture in disguise of humility.

I implore anyone before they virtue signal “eating the humble pie” ~ do consider tasting your own medicine, first.

I re-affirm once again that realistically from pragmatic perspective, I would acquire both foods – Tuna cans and TVP, in the worst of times.

Live-It-Forward,

AW.