What will cure/prevent type 2 diabetes is a low-carb, high-fat diet.
Sardines are a low-carb, high-fat food. Eating them replaces a big load of the carbs people usually consume, and just like that they reduce the amount of insulin they have to produce, reducing their insulin resistance and so on. Omega-3 fatty acids are just a slight benefit, probably, and not so much for the diabetes.
But "Just eat a can of sardines every now and then" is just a lucky guess. There are a lot of additional, more effective ways to reduce insulin sensitivity.
What other ways are you thinking of? Whole eggs, vegetables cooked in butter or oil, and fatty cuts of meat are probably the easiest for most people. But sardines are also easy because they're precooked.
Strength training, and good sleep to support the training, also help a great deal, but is not as easily managed as adding something relatively tasty and convenient to one's diet.
Eating a high quantity of diverse vegetables every day is a great idea but the practical effectiveness stumbles due to the difficulty of the habit change.
No, exercise actually doesn't work. Professor Noakes, (now) a proponent of the ketogenic diet, became a type 2 diabetic while running ultra marathons. Back then he was propagating a high-carb diet as ideal for athletes.
Sleep is essential, yes. Get screened for sleep apnoe if you have any reports of snoring. Sleep apnoe messes with insulin resistance.
The most effective way is fasting, at least 16 hours a day, called "intermittent fasting", and ideally a few days up to a few weeks regularly. Fasting absolutely demolishes insulin resistance.
I’ll have to read about Dr. Noakes. I recommend exercise because I see it lead to lower fasting numbers with similar diet, insulin dosage and sleep on my CGM. My understanding is that this happens because of a temporary increase in insulin action on the exhausted muscles, over the next day or 1.5 days in my case.
It does, but it doesn't seem to be enough in many cases. And it's not as effective as fasting for a few days.
I had to inject insulin for a few weeks recently, then I fasted for a few days and was able to quit Insulin totally. After a fast of about 2 weeks I had blood sugar levels in the lower normal range and you wouldn't know I ever had a problem. Interleaving periods of fasting and a low-carb diet with 16h-8h intermittent fasting I lost about 20 kg in 2 months.
Avocados, almonds, nuts, and other high fat vegetables are a heart healthy way to increase fat intake. And they are typically prepared with little salt or can be.
That's been debunked in the past few decades. Originally this idea came from very limited data on heart disease. Now the picture is almost the opposite. It's not a "fad".
Insulin resistance is a very basic physiological mechanism at the root of both obesity and various illnesses. There are scientifically proven ways to reduce that insulin resistance. And low-carb diets have been very successful in comparison studies...
Sardines are a household favorite for us. My kids love them.
The secret is, don't buy cheap ones. Look for brisling or any other small fish packed in olive oil. $3-5/can is a good sweet spot, although you can pay $9 for a can of imported Portuguese sardines no problem.
Speaking of Portugal, they do grilled fresh sardines. My 3 year old insisted on eating them daily when we were in Lisbon
> Speaking of Portugal, they do grilled fresh sardines
One of my Portuguese guilty pleasures, along with (ethically questionable, I know) octopus salad. Highly recommend trying this if you can get your hands on some fresh sardines.
Edit: grilled sardines are also a Japanese thing, so you might have luck finding them at an Asian market if your fishmonger doesn't have them.
As a portuguese I can tell you that sardine stocks are heavily controlled and regulated and there are years where the catchable tonnage is severely reduced. As the fish markets are centralized, meaning fishermen need to sell their catch in a government auction house, you cannot really do industrial fishing out of allowed stock quotas. Sardines quotas are the target of heavy diplomatic negotiations with EU.
South Africa has a pretty strong S. sagax stock, but it all gets canned or ground into fish meal. Eating fresh sardines just isn’t part of the culture — so sad.
Yes, kind of. That said, as far as I know anything that is more complex to digest like dark bread helps prevent type 2 diabetes.
(But maybe it's anyway better to talk to a real doctor or at least a food expert if that is any concern...)
Overfishing of sardines happen because most of it is ground up and used as feed in aquaculture (which is very inefficient). Instead, if you consume sardines directly, it will be a more sustainable enterprise.
They're incredibly intelligent, and there's a healthy debate around whether they're actually conscious[1]. I tend to question whether I should be eating something that might reasonably be aware, were it alive, that it's about to die.
They are certainly aware. At the simplest level, we know for a fact they respond to their environment. On accelerated time scales, it is also fairly obvious to see them compete with other plants and branches of themselves. We also know they communicate with other plants, warning them of the danger of insect predators, to which they respond by increasing the production of natural insecticides.
Though I can't prove it, I'm edging toward the belief they share resources with each other, including water and nutrients through the root system.
All these facts and ideas are easily undone by particularly defining "awareness" and so this is largely a terminological problem.
The discussion quickly becomes, "Define awareness." or ... more generally ... "Define consciousness," which we see with machines, insects, plants, even single celled organisms.
Here's what science does tell us repeatedly: Those things which humans as a species are convinced have no consciousness is decreasing. Most, even today, would not believe an octopus is conscious, but we now think they are. Dolphins. Birds, even fish now have scientific studies indicating they are self-aware.
So, yeah, justifying the eating of plants because they lack self-awareness isn't a valid argument in my book.
That doesn't absolve us of a mission to reduce suffering for the things we eat.
Plants can certainly suffer and it's trivial to identify.
Do really people not consider mammals--even mammals they have regular exposure to such as dogs and cats--to be conscious? I know people tend to have a superiority complex when it comes to other animals but I have a hard time believing that they don't consider them to be conscious.
Yes, there are vast numbers of them. I know doctors who do not believe the dog at the door wagging its tail when the person arrives to be experiencing emotions.
I believe the dog is happy and excited and eager to greet its friend of another species, but many, many people believe that dog is exhibiting purely mechanical behavior driven by instinct alone.
Octopuses are also cannibals, so your tentacled hero has questionable ethics sense also. If you eat an octopus you will probably be saving the live to dozens of baby octopuses (those score higher because cuteness card)
As usual when we apply "random ideology" we fall in an end road. From this point all are exceptions and excuses to fill the plot-holes, so the new guardians of the moral can keep asking for donations
FWIW, According to 2019 data from the International Diabetes Federation, Portugal is ranked 53rd (9.8%) out of 195 countries for prevalence of both type 1 and type 2 diabetes. Kiribati ranked 1st at 22.5% of the population between the ages of 20 and 79 having either type of diabetes and Benin ranked 195th at 1%.
Fresh grilled sardines on the beach in Malaga is one of my absolute favorite vacation memories. Baking sun, ice cold beer and fresh seafood is a powerful combination.
Sardines are fairly low in mercury. You might not want to eat them every day, but a few times a week shouldn't be a problem as long as you're not also eating other fish that are higher in mercury.
From Wikipedia [0]: "Canned sardines in supermarkets may actually be sprat (such as the brisling sardine) or round herrings.", and sprat [1] is a different fish, not a sardine [2]. Nobody in Russia or Nordic countries calls "sprat" "sardines" - this is one of the typical misnomers. Sprats are rich in omega-3s, but sardines are not.
Interesting, though I'd have to fry them up whole there. Otherwise the bones would get chopped up, suspending the disbelief and returning me to mere mortal size. (In that case they'd probably taste like small pieces of salmon bones instead of the entire skeleton of a big fish.)
Would it perhaps help to look backwards through a pair of binoculars while eating, so as to give the impression that the dish and its fishy contents are still small, thus maintaining the "giant" illusion?
This could be further aided by using a somewhat oversized plate.
Or perhaps use some particularly small eggs? (I think you'd be looking for some "Pullet eggs" in this case)
That's why I like to eat brussels sprouts! I feel like a giant eating whole heads of cabbage! I even got a tiny little grater so I can pretend to make slaw as a giant.
“Sardines will therefore have a protective element because they are rich in the aforementioned nutrients, whereas nutrients taken in isolation in the form of supplements won’t work to the same extent” : to me this reads as “we found a correlation but we are clueless about the root cause”.
True. The "root cause" could be that one improves one's diet:
- if you take "sardine" supplement pills and go on eating burgers and fries, do not expect a miracle with respect to type 2 pre-diabetes,
- if you eat sardines as part of a meal, I suspect that you are likely to *replace* parts of your current diet with the (fatty) fish, rather than keep your usual diet and add fish on top of it.
For instance, a funny paragraph from section 4 (Discussion) hints that the SG (Sardine Group) must have added less olive oil to the rest of their meals:
> Another possible limitation of the study to bear in mind is the use of canned sardines in olive oil, which, despite easing distribution and consumption, present differences in MUFA content as compared to fresh sardines. Although this may have modified the pattern of lipids consumed, the SG group decreased their overall MUFA consumption. This could be due to the fact that the use of olive oil added to meals did not occur when they consumed the canned sardines and, therefore, there are no differences in its consumption with respect to CG.
NB: I don't want to dismiss any part of the article, I only want to insist that it is hard to isolate causes because of this effect of "communicating vases".
> - if you take "sardine" supplement pills and go on eating burgers and fries, do not expect a miracle with respect to type 2 pre-diabetes,
The way I generally describe the result of switching from no intentional diet to any trendy/FOTM/recent diet is mostly just that a person begins to give a shit about what they're eating, which results in an array of positive benefits not directly related to that diet. Ketogenic diets are a good example. People go from not caring about what they eat, regularly eating fast food, sugary snacks/drinks, deep fried carbohydrates, etc. to spending a bunch of money on expensive butter and grass fed beef. They then lose weight. Sure, ketosis is a big deal, but in reality the biggest factor in a person's weight loss/health improvement is just replacing high calorie, high sugar, high carb, high fat food with no sugar, low/no carb, reasonable calorie food. (This is not an attack on the ketogenic diet. There is plenty of research for and against it. As with all diets, if you find positive outcomes while trying it, keep doing it! The goal is health).
I think the real test would be, what positive benefits _do exist_ when a person changes nothing else but includes a pack (tin? can? box?) of high quality sardines weekly. If nothing, I feel like it kind of just falls into the category of "being specific and intentional about dietary choices brings health benefits", which isn't necessarily new or ground breaking.
This is true, just adding sardines your diet will probably do nothing for most people. It’s more about the elimination of other things we eat as well. It wasn’t until I was eating only salmon for my fat and protein source that I was able to raise my HDL from 35 to 54!.
I credit this to totally eliminating the omega-6 fats. But this is just me because I’m a genetic freak with hyperlipidemia.
The value of reducing Omega-6 is over-hyped. The issue here is that when you eat a can of sardines, you tend to not eat them with a big load of carbohydrates, like white bread, rice, pasta, fries...
Totally eliminating omega-6 from your diet can't be healthy, can it? There are only two essential fatty acids for humans and one of them (linoleic acid) is omega-6.
Well, I exaggerated to make a point. Even salmon has long chain omega 6. I soul have said "eliminating plant based omega 6" and this is just for me and my genetics. People without certain FADS1 genetics can do fine with short chain omega 3 and 6.
Since supplements have been brought up, what's with the American's obsession over supplements? It's like people are just chomping them down like they're some sort of food stable like bread or rice (or maybe that's just what all the youtube videos want you to think). Its like every bodybuilder on youtube has their own brand of supplements now. Don't even get me started on pre-workout. "Don't feel like working out? Chug this powder!"
With bodybuilding most bodybuilders will agree that the only (legal) effective supplement for weightlifting is creatine, with vitamin D, fish oil, and multivitamins generally recognized as also useful for general health. But the most important “supplements” are anabolics which of course can’t be legally advertised. The problem is average Joe doesn’t know that, and bodybuilders need to make money (most make very little if any money from bodybuilding) so they do endorsements and marketing for health brands which are legal even if they may not be effective.
Preworkout is a bit different because it actually is marginally useful for workouts, and I think most actual bodybuilders take some form of it. But it’s super cheap to produce so most of the expense is on marketing. You can make homemade PWO with stimulants and “pump supplements” for super cheap if you buy the raw compounds
I’ve found exactly one supplement that had a major impact on my quality of life, and that’s magnesium. Something about magnesium supplements greatly reduced my daily anxiety, to the point that I was amazed because I’d always just imagined I was an “anxious person”.
In my case taking magnesium helps with insomnia and ADHD symptoms (although it's impossible to tell if the ADHD improved directly due the magnesium, or due to better sleep)
I'm not the person you asked, but the most important part isn't the dosage, it's the form.
Basically, make sure the magnesium tablet is anything but magnesium oxide - our digestive systems cannot absorb that. Just about any other form (there's like... six of them) will work. Magnesium oxide only helps with constipation, which is also important I guess but a completely different problem.
I take Magnesium Glycinate 400mg once a day. I feel super relaxed after taking it, although I have noticed an uptick in muscle twitches, which extra calcium seems to mitigate.
Certain segments of America tend to have poor diets. Especially the young, working class which happens to overlap with the bodybuilding class which makes whey protein a logical choice. Whey protein. It is very cheap; just add mix in a multivitamin and OTC stimulants like caffeine and you have a very marketable product with a 300% markup.
The YouTube body building demographic is in the same economic class so capitalizing on a product their audience already uses makes perfect sense.
Also, America is one of the few countries with consumer pharmaceutical advertising so marketing supplements is not out of the ordinary.
The sardines are a very high-fat food item that will satiate you and potentially replace a big load of carbohydrates. Which would affect the prediabetes.
While I can follow that line of thinking, we also shouldn't immediately be dismissive of the conclusions of a professor/researcher at a faculty of health sciences. At least not without a good reason to believe that we have more expertise on the subject than them.
On the other hand, there might also be a bit of Spanish cultural bias at work there (Spain is the second-largest consumer of fish after Japan). On the other other hand, it would fit into the mystery of the mediterranean diet.
I didn’t mean to dismiss their conclusions! It might be a pretty awesome discovery actually: eat delicious sardines and avoid getting diabetes? Count me in!
I just meant that, as is often the case, great discoveries are often made before we really understand them. For example, isn’t this what happened with antibiotics?
Ah, like that! Fair enough, thank you for elaborating (please consider adding a bit of extra context next time, it will go a long way to prevent such misunderstandings)
No, it simply repeats the commonly understood fact that it is better to have a diet rich in specific nutrients than to try to use supplements to make up the difference. Everything from dosage to bio-availability of supplements shows them to mostly be not worth the price of manufacture, let alone the price people pay at the till.
There are times, however, the high-dose vitamins Are the only thing that can replace a deficiency Quickly enough. Two of them that come to mind are zinc and biotin. So like everything else in nutrition, it depends, of deficiencies and genetics.
The trouble with observational cohort studies is that causality is very hard, if not impossible, to identify. Their main result is based on multivariate logistic regression. I like logistic regression as a technique, and it is very powerful, but if, for example, there is an unmeasured cofounding or causal variable that manifests itself as a linear combination of a number of measured but perhaps more acausal variables, it _will_ confidently give you the wrong result. </s>
These are very complex bio-chem processes, so there's probably no single "root cause", but a multivariable situation where certain combinations of nutrients in certain proportion causes these beneficial effects. Also nutrients in supplements often don't have the same bioavailability as in natural products, so it's possible that you take in the same amount of nutrients per label, but your body actually ends up absorbing only a small % of it. Supplements are not that strictly regulated, so many of them are fairly poor quality products making wild claims, counting just on marketing BS to sell.
My uncle used to come over and visit my family. He would play chess on our laptop (wasn't tech savvy but was amazing at chess) with a stack of sardines and a gallon of water. He'd then comment "haha your dog loves me! I wonder why?" as he tosses our dog another sardine. He was a funny and strange guy, but he loved those sardines!
He did tell me back in the 90s that processed carbohydrates were really bad for you, so I think he was ahead of the curve!
Probably, but sardines are way cheaper and a lot easier to store. Also they're at the bottom of the food chain and so less heavy metals, and there are a lot more of them in the ocean and are in abundance. I've been a long time sardine advocate for a fatty fish instead of tuna or salmon, nice to see I have some reasons now to support it.
If anyone in the US is new to sardines, of the choices available in US grocery stores, Matiz is by far the best. I recommend ordering online, where you’ll find other great choices like La Gondola, Angelo Parodi, Nuri/Pinhais, and Bela.
(If you’re in Europe, try Rödel sardines at least once in your life. They’re completely unavailable in North America.)
Gently mash them up with some of the olive oil that’s in the tin (usually not all of it, or you’ll mostly be eating olive oil). Use that as a spread on bread, toast, or crackers, or mix with something that doesn’t have a lot of flavor on its own, like farro or another mild grain.
>but their effect is usually caused by the synergy that exists between them
It's simple result from the fact that least available essential nutrient is the most important for health outcomes.
If you have a rain barrel full of holes, only fixing the lowest hole changes the water level. Fixing all other holes starts to have an effect after you have fixed the lowest one.
I have eaten 1 tin of Sardines everyday as my first meal for over 6 months. It takes the guess the work out of what to eat and the nutrition is off the charts, it basically replaces a handful of supplements. I've been using cronometer to track my diet and between the Sardines, a huge salad and a hunk of steak or liver, I only ever take the odd Magnesium supplement. Totally eliminated my need to buy expensive supplements. As it turns out, I find that 1500-1800 Kcal is more than enough everyday to leave me feeling stuffed and content and the Sardines alone keep me satiated for hours, what a superfood. Today's the last day to save $3 on a 6 pack of Sardines at Costco, I've bought about 6 cases over the last few weeks (180 + cans) to carry me for the next 6 months.
Anyone who wants to lose weight and get healthy, this is the food that will make a huge difference.
Fun fact about sardines: they used to be super popular in the US, until they were massively overfished on the west coast (Cannery Row is the classic example). They were gradually replaced over the 80s with milder fishes like tuna and tilapia.
>The fact that foods such as sardines - which are rich in taurine, omega 3, calcium and vitamin D - have a clear protective effect against the onset of diabetes does not mean that taking these supplements in isolation will have the same effect.
The only way i can understand this statement it that Rizzolo doubts that anything in the sardines are actually affecting type 2 diabetes. So perhaps the oily taste is suppressing apatite for 'sweet' and decreasing the patients sugar intake (decreasing them cheating on their diet).
Anyway a 152 patients study is not very conclusive, in larger studies there may not be any effect there at all.
You might be right but what I've read of nutrition is that taking supplements is thought to be quite different than eating a whole food. Taking Vitamin C tablets is different than eating an orange because of all the other things that are in an orange. Or what's in spinach or kale or blueberries or sardines. I think that's the point she's making.
> but only the intervention group added 200 grams of sardines to their diet every week (two cans of sardines in olive oil)
So they significantly changed the macro nutrient ratios of the intervention group, along with the addition of sardines. I would like to see an intervention versus a control group with matched macros, to see if the effect is due to more sardines, or to more fat and protein and fewer carbohydrates.
If anyone is wondering how to eat sardines, open a tin (I like the tins with them in tomato sauce) and just mash them onto some toast. No need for butter. It is a glorious lunch.
Some canned sardines are already de-boned, and for most bone-in canned sardines, you can just halve each one length-wise and pull out the spine in one piece. The bones are also totally edible themselves, albeit off-puttingly crunchy to some people.
If you're looking for a specific type of salmon my understanding is that wild Alaskan salmon has very low levels of mercury and the fisheries are healthy. I'm not sure where you are but it's widely available in the United States.
I hate the fact that the text compares percentage decrease of a group of “high risk” with a group of “very high risk” that makes the whole story ambiguous. I hate this, and always think how these clever people make these kind of mistakes writing result texts. Or do they?
I see it now, everyone going to their local mega grocery buying sardines packed in sunflower oil, Totally abolishing any of the positive effects of omega-3.
Yes... That's one of the things that concerns me also me about canned sardines. Even if it says "olive oil" I have a feeling that it's a pretty low quality one in most cases and definitely not EVOO (extra virgin olive oil) which is the good stuff.
Looking for any specific recommendations for brands, websites etc.
Though I haven't looked into it extensively, here in the US I've only seen olive oil and soybean oil on sardine ingredients labels. Might be different in other parts of the world but here soybean oil seems to be the oil of choice when cost cutting gets involved.
I think they're referring to sunflower oil's absence of Omega-3s. Per Wikipedia [1]:
> The ratios of omega−6 to omega−3 fatty acids in some common vegetable oils are: canola 2:1, hemp 2–3:1, soybean 7:1, olive 3–13:1, sunflower, flax 1:3, cottonseed (almost no omega−3), peanut (no omega−3), grapeseed oil and corn oil 46:1.
My understanding is that there's some Omega-6:Omega-3 ratio to shoot for, and most western diets are far more biased toward Omega-6, so adding some Omega-3 (sardines) along with a bunch of Omega-6 and no Omega-3 (sunflower oil) would actually work against that goal.
I don't think that's what they meant exactly, but rather that the amounts of omega-3 and 6 you consume should be in a specific ratio (or rather within a range of ratios), and the ratio in canned sardines is tilted towards the unhealthy side. There are other pairs of nutrients that follow this pattern as well. I highly recommend reading about them on Examine.com, but I suppose even Healthline will do.
I will add here to clarify my stance on food and health.
There is no healthy food, only food that is healthy for you, and that will be determined by your genetics. Wheat is not healthy for celiac and short chain PUFAs and bad for me.
But too much of any food or nutrient can override genetics as well.
This article seems to be akin to many others that promote carnivorous diets. "Drinking milk reduces X" or "eating [insert animal here] improves Y" might be true, but you don't need to consume the animal (and prolong the environmental impacts) to get them.
Wrong. There is a tremendous more amount of evidence that eating fish helps cardiovascular health. Unlike the “carnivore diet” where they just cherry pick RCTs.
And for those who say “you don’t have to eat the animal to get the health benefits”, please tell that to any Inuit or Saami people. They lived on his diet for generations and it’s affected their genome as a result.
Taurine, omega 3, calcium, and vitamin D, the nutrients discussed in the article are all available from sources other than fish. If you take someone who has a diet that's deficient in one or more those and give them sardines, then it's not surprising to see improvements. But it doesn't show that sardines/fish are the only way to get those benefits or that adding sardines/fish to a diet that isn't deficient in those nutrients would have any benefit.
The fact that Inuit and Saami people have been able to survive on primarily meat diets only demonstrates that it's possible to survive on those diets, not that they are ideal in any way or better than any other diet.
So those diets are better FOR THEM, not for everyone. But the same could hold true for you or me. I know it is true for me because I have Saami heritage and the diet cures my hyperlipidemia.
And Taurine, omega 3, calcium, and vitamin D are not the only thing in the fish. There is a synergy that humans could never find with logic.
> There is a synergy that humans could never find with logic.
Perhaps, but there is no science that demonstrates that.
It sounds like you are looking at this research and coming to stronger and more general conclusions than they claim. Again, most of it seems to be of the form "we took some people who were deficient in [some nutrient that is found in fish], gave them fish, and found that they did better than a control group who weren't given fish". Eg, the paper you link to shows that Greenland Inuits are genetically adapted to higher levels of PUFAs in their diet. It doesn't make any claims that those PUFAs have to come from fish. The paper that that one cites as showing that "fish oil supplementation is associated with increased concentrations of plasma insulin-like growth factor–1" (https://pubmed.ncbi.nlm.nih.gov/22337227/) does indeed show that association, but it doesn't show that non-fish oil sources of DHA (eg, algae-sourced DHA) don't also produce the same effect because they didn't test that.
That you've found a diet that cures your hyperlipidemia doesn't mean that that's the only diet that could achieve that or even that it's the best one.
Your previous comment:
> And for those who say “you don’t have to eat the animal to get the health benefits”, please tell that to any Inuit or Saami people. They lived on his diet for generations and it’s affected their genome as a result.
Actually sounds like an argument against a meat/fish heavy diet. If eating it for generations results in genetic changes that produce problems like hyperlipidemia, maybe it's not something that we should recommend or promote.
(An aside, as someone who's also of partial Sámi descent (Northern Sweden, represent!), I do want to point out that the Sámi diet was/is not strictly carnivore; it also traditionally includes a lot of flatbreads, berries, and foraged plants like mountain sorrel and wild celery).
I agree with you on the Saami diet, I was generalizing for the Sake of brevity in the comments. I am in no way any kind of carnivore or Paleo freak. I only have general guidelines and loose interpretations about what I should eat.
You’re right though, I have no scientific Evidence for synergy. But it is our arrogance to think we know everything that is in food And how it affects our bodies. This could never be tested scientifically.
But you’ve mistaken my argument as well. The genetic changes of the Inuit make them more susceptible to disease only when they are on a western diet. when they are on their ancestral diet they have no problems. Eating that much seafood makes them dependent on eating seafood. Do you understand that better?
Just like living in Africa change the color of people skin it actually makes them more dependent on getting sunlight. Does a sunlamp replace the sun? Hard to say.
Sardines are a low-carb, high-fat food. Eating them replaces a big load of the carbs people usually consume, and just like that they reduce the amount of insulin they have to produce, reducing their insulin resistance and so on. Omega-3 fatty acids are just a slight benefit, probably, and not so much for the diabetes.
But "Just eat a can of sardines every now and then" is just a lucky guess. There are a lot of additional, more effective ways to reduce insulin sensitivity.