Welcome to the second installment of my 3-installment blog post series on oysters. The first blog post explored the basics of oysters and talked about the magnificent nutrient profile found therein.
This second installment teaches you about the oyster health benefits and how to best eat them. The last final and installment, published after this blog post, talks about oysters, ecology, and sustainability.
Let's start with the oyster health benefits though;
So what oyster health benefits can you expect?
Let's look at an abbreviated list:
I've quickly touched upon this subject in the previous section.
Many people have low dopamine levels nowadays. Dopamine is essential for the higher brain functions that developed in humans during evolution.
Abstract thought for example - in which your brain can make simulations independent of space and time - is a typical human capacity. Complex planning, language use, and mathematics are other examples.
In today's world, high level thinking skills pay off more than ever. All the life pursuits that make you rich, from being a surgeon to stock broker to entrepreneur all depend on abstract thought.
Due to the high levels of zinc, magnesium, selenium, iron, and B-vitamins, oysters contain many precursors for building higher dopamine levels. If you can enhance your brain's dopamine levels, you can thus do much better financially and in terms of success.
(If you're interested, I've explained other methods by which you can increase your dopamine levels in great detail in my blog post about dopamine.)
Ready to boost your dopamine levels and become the Thinker?
Yes, oysters are the perfect testosterone booster. Why? Simple: many minerals such as zinc, magnesium, and selenium are prerequisites for building testosterone.
If you're deficient in these minerals, your testosterone levels wont'be as high as they'd otherwise be.
Both men and women need optimal testosterone levels for their overall health and well-being. Yes, women need that hormone tool.[217; 218]
The problem? Testosterone levels have been declining for decades.[214-216] That's very bad news, as you need testosterone for heart health, well being, strong bones, sexual performance, brain health, and much more.[219-228]
Fortunately, moreover, vitamin A, D, E, and K2 found in oysters may also boost testosterone.[211; 229-232]
Keep in mind that excessive testosterone levels are not conducive to overall health either. Lowered empathy and a higher propensity for aggression are possible side effects. You cannot accomplish such high testosterone levels with natural means though...
Now a topic related to sufficient (but not excessive) testosterone:
Oysters have been considered aphrodisiacs for millennia. The most probable reason for that finding is, again, the higher zinc content in shellfish.
Zinc stimulates fertility, as you already know. The earlier mechanisms of increasing testosterone also improves fertility - up to a certain point.
The overall fertility-boosting effects can simply be explained through a greater availability of high-quality nutrients. With nutritional deficiencies, you body is less likely to be ready for procreation.
In fact, a strong link has been found between diet and fertility.[233-235] Oysters are of course the pinnacle of healthy foods.
I've written a couple of blog posts on weight loss before.
One blog concerns the topics of how metabolic rate is the holy grail to long-term weight loss. Another blog argues that fast and junk food are addictive in the same way drugs are.
(Note: these blog posts will be published on the Alexfergus website soon but are unavailable right now!)
(Note 2: metabolic rate denotes the number of calories you're burning at rest. A low metabolic rate is what many people understand as having a "slow metabolism". Children, on the contrary, almost always have a high metabolic rate, meaning that they can eat anything they want without gaining fat).
How do oysters tie into that narrative?
Well, first of all, oysters contain lots of vitamins and minerals. These nutrients are highly absorbable compared to what you'd get from most plant foods. Vitamins and minerals are important for maintaining a high metabolic rate in turn.
In fact, zinc, iron, and magnesium are necessary for having a high metabolic rate.[248-254] Recall that most people are deficient in magnesium and zinc, and thus have lower metabolic rates than they'd otherwise have.
The result is that you'll gain body fat more easily.
The combination of both protein and carbohydrates in oysters is also very filling. Many proteins you buy in the supermarket, such as beef or chicken, don't contain any carbohydrates.
Additionally, the low number of calories of oysters allows you to consume tons of them without overeating. I don't think overeating on oysters is dangerous in the first place, because appetite is more prone to regulate itself naturally if you're eating natural foods.
The zinc found in oysters additionally increases wound healing potential.[258; 259] Without getting sufficient zinc in your diet, wound healing can be delayed.
What many people don't know is that zinc is also necessary for overall skin health. Skin cells, hair, nails, and joints all depend on zinc for their overall condition. The reason is that zinc is necessary for the formation of collagen.
That collagen is found in your skin and joints, for instance. Collagen is responsible for the elasticity of your skin.
The problem? Collagen production goes down with age, and is partially responsible for the appearance of wrinkles.
Zinc is not the only mechanism by which collagen synthesis is increased though. The proteins in oysters also contribute to skin conditions.[256; 257]
Oysters contain high levels of iron. You need iron to build a compound called "hemoglobin" in the blood.
Without sufficient iron, hemoglobin cannot be formed in adequate numbers, or is formed incorrectly.[259; 260] That hemoglobin is found in red blood cells.
Carrying oxygen is one of hemoglobin's main roles. If you have insufficient hemoglobin then your body cannot carry sufficient oxygen.
You probably don't need convincing that oxygen is important for your health. But just in case: oxygen is necessary for your mitochondria to work properly. Mitochondria are the "energy-producing factories" of the cell.
Food, light from your environment, and oxygen are the inputs of that mitochondria. If one of these three inputs is lacking, the end result is dramatic.
In fact, you can go without food or light for some time and your mitochondria will still function well. Why? Body fat can be broken down, and food can replace the input of light. But without oxygen your mitochondria stop functioning within minutes. The end result is death.
Better oxygenation moves you further away from death - towards better health and more energy.
Younger menstruating women and people who are really active are more at risk for low hemoglobin levels - or iron deficiency anemia. Read my blog post on iron to understand why.
Many minerals and trace minerals are actually necessary to build strong bones.
You probably know that calcium is a prerequisite, for example. But you may not know that minerals such as phosphorus and magnesium are also required for building strong bones.[261-263]
Even zinc, copper and manganese are necessary for bone health.[155; 264-268] Remember that many people are not ingesting the daily required minerals through a Standard American Diet.
Foods high in nutrients such as oysters can thus help out in that regard.
Anddd... we're back to the topic of minerals once again.
Copper, zinc, and iron all play a role in building a strong immune system.[269-274]
Vitamins are similar to minerals in that regard. B vitamins strengthen the immune system, for example. These vitamins are necessary to produce antibodies, which protect your body against invaders.
Anecdotally, many people that I know of who become sick several times a year are also usually not maximizing their vitamin and mineral intake through food. I know doing so is often expensive, you cannot go through life with mineral deficiencies and hope to do well.
"DHA", or "docosahexanoic acid" is a compound that's found in high qualities in fatty fish. That DHA Is necessary for optimal brain development.
While I don't believe that you need limitless quantities of DHA, many people do seem to be deficient in this fatty acid nowadays.[276; 277] The problem was worse 5 years ago.
In fact, it's the combination of the vitamins, minerals, and DHA that is responsible for the spectacular human brain development in the last few millions of years.
Humans (Homo sapiens) have denser brains that are more developed towards the prefrontal cortex than primates. That prefrontal cortex helps with impulse control, abstract thought, and planning. Humans also have a higher brain to lean muscle mass ratio than the primates we evolved from.
A higher-quality diet is partially responsible for your ancestors transition from primates to humans. Shellfish are one of the keys to that transition.
As a side note, I do not adhere to the thesis that all polyunsaturated fatty acids are bad for your health. If such fats were toxic, studies would have found increases instead of decreases in all cause mortality.[321-324]
All cause mortality is your general risk of dying, independent of circumstance, and aggregates all possible variables affecting that risk.
Of course, the fact that these fatty acids have benefits doesn't mean you'd have to binge on these foods either. There's no need to eat oysters every single day of the week.
And it's not just cognitive potential that's affected by these nutrients - well being is as well. Zinc, for example, protects against anxiety and depression.[279; 280] Magnesium accomplishes the same thing.
Many people are anxious nowadays because they've got excessive copper levels in comparison to zinc. Oysters have the perfect balance in that regard.
Oystercatcher birds: not quite as smart as humans yet, despite eating tons of oysters.
Vitamin K2 aids heart health, although evidence runs thin as of right now.[281-284]
The mechanism for vitamin K2 accomplishing that effect is reducing calcium stores in improper places of the body.
Calcium needs to be stored in your bones--not your arteries. That reduction in improper calcium stores reduces the risk of atherosclerosis - a condition in which your blood vessels constrict due to calcium deposits.
Remember that I estimated that 90%+ of people get too little vitamin K2 in their diets. Eating oysters a couple of times a week will be a major contribution to your vitamin K2 intake.
Want increased energy levels?
I'll sign you up.
A combination of vitamin B12, iron, and magnesium can all increase your energy levels.
Magnesium, for example, is essential for properly functioning of the mitochondria.[285-287] Iron and vitamin B12 are necessary for creation of hemoglobin, the oxygen-carrying compound in red blood cells which I've mentioned before.
A higher oxygen carrying capacity in your body leads to improved energy levels across the board.
Many animal foods, including oysters, contain phosphatidylserine. That compound lowers levels of stress hormones, such as cortisol, with almost 40%.[288; 289]
Higher nighttime cortisol levels are associated with lower sleep quality.[290; 291]
Zinc and magnesium, secondly, also help improve sleep quality and lower stress at the same time. Of course, you only get that benefit when you solve a deficiency in these minerals.
The vitamin A, C, zinc, and DHA found in oysters are all responsible for keeping your eyes healthy.
DHA is recycled quickly in the eye, and may deplete quicker when exposed to lots of blue light.[293; 294] Screens contribute to that process.
The more you're looking at screens, the more problematic for your health and the more nutrients you need to offset the problem.
So that's it, 12 different oyster health benefits. Let's move on to actually eating oysters:
Everyone knows how to eat an oyster, right?
Well, not so fast...
Let's begin with a problem many people face before they can eat oysters:
Oysters are impossible to open up without specialized tools. You cannot open such shellfish with your bare hands, for example. And a kitchen knife will likely break in the process.
Get an oyster shucking set:
These gloves protect you against cuts. Opening an oyster requires some force and dexterity, and you don't want to end up with a knife into your hand or wrist.
The knife is specialized towards cutting the adductor muscle contained in any oyster. That adductor muscle keeps the two halves of the oyster shell stuck together.
The adductor muscle is like a tight elastic band inside the two shells. Cut the adductor knife and the shells of the oyster open.
The process takes some practice, but in time you'll easily find the "hinge" at which the knife should be applied.
The easiest way to open an oyster is by laying the oyster flat on a kitchen table or another stable surface, and then fixating the oyster with one hand. With the other hand, insert the knife and find the hinge muscle that keeps the oyster together.
A twisting motion helps you separate the two parts of the shell. The two parts then come loose.
Ready to eat?
The next step is to move the pinpointed part of the knife along the bottom of the shell from all sides, so that the meat separates from the shell. Most civilized people (which I am not) then turn around the oyster, which improves presentation.
After that you can eat a raw oyster! Don't throw away the juices though, as these add to the taste and nutrient profile.
Prefer a video of that description?
Now you can enjoy the world-class nutrition.
(Almost) nothing as beautiful as raw oysters.
Raw oysters should be your preferred choice, if and only if you know you can trust the source you're buying them from and if you're in good health.
Remember that raw oysters can contain bacteria and viruses, and thus carry an inherent risk for some people.
Why eat raw oysters?
Nutrient content typically goes down when cooking animal foods.
While I couldn't find specific studies on oysters, cooking of fish reduces their vitamin content. Cooking also reduces the creatine content of meat - creatine is a well-known athletic and cognitive performance enhancer.
It can thus reasonably be expected that nutritional value in oysters also goes down with cooking.
As an upside, in many developed countries water quality is also tested before oysters are shipped. The FDA in the US mandates water testing, for example. The EU has similar legislation.
If you're eating oysters in a US restaurant, ask for the oyster tag. That tag shows when the oysters were pulled out of the water and is thus an indication of freshness. The fresher the oyster, the better.
Not all oysters are good to eat.
In New York City, where a billion oysters are planted as part of a restoration project, oysters live in polluted waters. Unless New York harbor becomes very clean again, don't think about consuming.
(The upside? 30 million oysters are currently restored in New York. In time that number will increase to 1 billion.)
Bottom line: as I had already said, ask any seller in a shop where the oysters are sourced from. Ask for a tag if necessary to gauge freshness.
And for the best health benefits, eat these beauties raw. Add some lemon for additional flavor...
It's best to buy raw oysters locally.
Only opt for very light cooking when using oysters. Steaming is probably best.
Heating oysters are the best option if you're less healthy. Many recipes can be found online to make oysters delicious, such as:
Or better yet: visit another websites for tons of additional oyster recipes.
Don't ask me about recipes though: I'm the worst cook on this planet...
Keep in mind that lower temperatures are generally best as an animal protein preparation method.
Both very long cooking and very high temperatures are often sub optimal because of nutrient depletion.
Canned oysters are almost always cooked, which is a downside. The upside is that they're really easy to use...
Canned oysters can be eaten at work, if you're in a traffic jam, on an airplane, and whenever you need a quick meal.
You get the idea.
Hoard canned oysters and pull a can out whenever you need one. The oysters are grown in South Korea and the cans are BPA-free.
Are canned oysters perfect? No, but they're a great tool in the toolbox.
Not necessarily, depending on when oysters were canned.
In fact, if they were canned almost immediately after harvesting, nutrient levels may be even higher than some fresh oysters.
The only reason canned oysters have lower levels of nutrients is the cooking process.
Many people still have a bias against frozen or canned foods. An yet, it has been demonstrated time and time again that frozen vegetables are sometimes even superior to their fresh counterparts.[299-302]
If prepared properly, canned oysters can thus be more nutrients than fresh ones (assuming the fresh oysters don't come directly out of the water, but have been laying around for a while).
Smoking is a disaster.
Smoking food also adds carcinogenic "polycyclic aromatic hydrocarbons".[298; 299] Avoid for obvious reasons - go for regular recipes or raw oysters.
Do smoked oysters taste good? Sure. But the same is true for meat that's barbecued under high heat - the smoke simply adds amazing flavor.
Is that strategy optimal?
Most of the time, very bad sauces such as "hot sauce" or other artificial ingredients are used in the smoking process as well. Such substances lead to sub-optimal health consequences.
Don't want to pay tons of money for oyster?
Try their little brother: mussels. Mussels are often far cheaper than oysters. In fact, here in the Netherlands I sometimes pay $4 - $5 for more than 4 pounds of these shellfish (if they're in season).
I also pay about $7 for a kilogram of mussel meat.
I'm sure you can get mussels at many places on this planet right now...
Mussels contain somewhat more protein than oysters in general, and fewer carbohydrates and fats. Vitamin and mineral content is somewhat lower for mussels overall.
Can you eat too many oysters?
If you're just relying on oysters you can end up with very high zinc levels, because oysters are the best zinc food in nature. For that reason I recommend not consuming high quantities of oysters more than 2-3 times a week.
But let's now talk about an elephant in the room. Whenever shellfish are discussed, the topic becomes:
First of all: is there such a thing as "shellfish allergy"?
The medical literature does accept that shellfish allergies exist. However, crustaceans are more likely to be allergenic than mollusks.[316; 317] Oysters are bivalve mollusks, and therefore less prone cause allergic reactions.
I also suspect that many false positives occur in relation to "shellfish allergies".
Many people also think they cannot digest red meat, even though insufficient stomach acid is responsible for that inability. Such people are not allergic to red meat but have a digestion problem.
So what if you do not tolerate oysters?
Becoming healthier overall and getting your immune system in sync can help then. So initially, you may need to avoid consuming oysters, start healing yourself, and then try re-introducing shellfish into your diet later on.
Disruptions to the 24-hour clock in your body - the "circadian rhythm" - can additionally increase the intensity of allergies.[318-320] Many people thus seem allergic to substances, while in reality they may not be.
Test before you give up oysters forever...
Lastly, let's move to a topic that keeps a few people up at night:
Should you eat shellfish?
Well, for most people the answer to that question depends on whether shellfish can feel pain.
Many vegetarians and vegans don't eat animal foods precisely because they don't want to hurt animals. Whether you think that reason is logically valid or not, let's assume for the sake of argument that eating animals that feel pain is unethical.
The latest studies show that shellfish, at a very basic level, do seem to adjust their behavior to certain stimuli that humans would find painful.[303; 304]
On the other hand, the argument is sometimes made that even fish don't have the neural structure developments to feel what humans would call "pain". Such pain responses are then often considered mere "reflexes".
That conclusion is almost certainly incorrect though, as there's a large learning component in that different marine animals try to avoid the painful stimulus next time.[306; 307]
But shellfish are not fish. And oysters are one very specific shellfish species, ones without a brain. The problem is that most shellfish research on pain is carried out with shrimp, lobsters, and crabs. Shrimp, crabs, and lobsters have brains, and probably feel pain--oysters probably do not.
From a philosophical perspective, moreover, it's really hard if not impossible to know for certain whether that certain expressed behavior can be linked to mental states that humans describe as "pain".
In fact, absolute certainty is impossible in that regard.
If you're completely skeptical, you can even hold the philosophical view that fellow humans than you don't even experience pain. Of course, you're playing the devil's advocate with that argument, but it cannot be logically debunked.
The way I read the research on shellfish and pain is that they're probably a safe alternative for vegetarians and vegans. The fact that oyster don't have a brain like other marine species do is crucial. My argument is largely based on intuition, however, in the absence of a possibility to establish certainty.
So is it possible to feel pain without a brain? Maybe. But in that case you could even claim that bacteria and viruses may feel pain, and that brushing them off your skin is equal to "killing animals". From a logic standpoint, the line needs to be drawn somewhere.
And if it helps you make a choice:
Oysters kill "others" as well sometimes. An oyster catcher bird bills can be trapped between the two shells of an oyster, for example. The oyster then hold that bird in place until the tide rises by which the bird then drowns.
Sure it's still self-defense, but oysters do kill. You need to (indirectly) kill animals too to survive. Nature is cruel, unfortunately.
And from an environmental perspective eating oysters is the best thing you can do: almost no oysters are sourced from wild deposits today. The more farmed oysters you eat, the more new ones that are produced. You're thus helping nature by eating them.
Capitalism at work...
I hope you're convinced that oysters are an incredible food with tons of health benefits. And, the food is also very easy to consume while you can also use it in more complex recipes.
Then, many people will probably have fewer issues with eating oysters than with land animals or fish, due to the nervous system of oysters.
Lastly, in the third installment of this blog post, I will consider how oysters can be mass-produced and supply the world with tons of cheap animal protein. Stay tuned for more to come!
This is a post by Bart Wolbers. Bart finished degrees in Physical Therapy (B), Philosophy (BA and MA), Philosophy of Science and Technology (MS - with distinction), and Clinical Health Science (MS), and is currently a health consultant at Alexfergus.com.
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