Boiling greens

LucH

show proof please

Throw your microwave away!
A study in the Lancet of 1989
"Aminoacid Isomerisation and Microwave Exposure"
G. Lubec, Chr. Wolf, B. Bartosch.
Microwaving of formula has transformed some trans amino acids into synthetic cis isomers. Synthetic isomers, whether trans or cis, are not biologically active. In addition, one of the amino acids, L-proline, has been converted to the D-isomer, known to be neurotoxic and nephrotoxic (kidney-toxic). It is already worrying that many babies are not breastfed [or not long enough fed]; now they are given fake milk made even more toxic by the passage in the microwave oven.

Source:
http://www.thelancet.com/journals/lancet/article/PIIS0140-6736(99)04101-X/abstract

Interesting links
http://veganbio.typepad.com/veg_anbio/2009/06/fours-à-microondes-un-choix-entre-sante-et-facilite.html
=> 10 raisons pour vous débarrasser de votre four à micro-ondes.
=> 10 reasons to get rid of your microwave oven

http://www.alterinfo.net/L-URSS-avait-interdit-les-micro-ondes-pour-leur-effet-mortel_a7784.html
=> L'URSS avait interdit le four à micro-ondes en 1976.
=> The USSR had forbidden the microwave in 1976.

http://www.cancersalves.com/articles/Microwave.html
=> The Hidden Hazards of Microwave Cooking. NEXUS Magazine, 1995.
Procès contre un hôpital en Oklahoma relatif à une femme tuée par une transfusion sanguine qui était réchauffée, comme de coutume, au four micro-ondes.
=> Lawsuit against a hospital in Oklahoma because of a woman killed by a blood transfusion that was heated, and as usual, in the microwave.

[7] Song K and Milner J A. "The influence of heating on the anticancer properties of garlic," Journal of Nutrition 2001;131(3S):1054S-57S
=> 60 ' dans le four micro-ondes suffit pour tuer les enzymes de l'ail.
In a study of garlic, as little as 60 seconds of microwave heating was enough to inactivate its allinase, garlic's principle active ingredient against cancer.

BioEclectic

@alfredoolivas said in Boiling greens:

@hwisdom doubt, show proof please

My word isn't proof at all but i recall reading about microwaves and nutrients a long time ago.

Personally my microwave sees limited use, am now even questioning heating water in it now that i've learned about water's other potential properties, structuring etc etc.

Edit: Luc's and hwisdom's info are pretty eye opening as well.

alfredoolivas

@hwisdom @luch @bioeclectic thanks guys

alfredoolivas

@Milk-Destroyer did you notice any benefits from the folate?

Corngold

@Milk-Destroyer

I am using an ai:

Overall nutrient loss from boiling is more dramatic for vitamins than minerals. Total nutrient losses after boiling kale can range from 87 to 95%, though this figure includes vitamins and other compounds, not minerals alone.

I asked for more on all the vitamins and research cited:

Here's a comprehensive breakdown of the vitamins affected by boiling kale, along with the research behind each finding:

Vitamin C (Ascorbic Acid)
This is the most severely affected vitamin. A study published in PMC using HPLC analysis found that boiling galega kale reduced total vitamin C content by 63%, with ascorbic acid (AA) specifically dropping by 38%, and dehydroascorbic acid (DHA) falling by 85%. A separate study confirmed similar results: Akdaş and Bakkalbaşı found that ascorbic acid decreased by 53.1% from boiling, compared to just 2.9% from steaming — making boiling the second-worst method after stir-frying (54.9%). The 2023 Journal of Food Processing and Preservation review by Khalid et al. explains that vitamin C loss is primarily driven by leaching, and is worsened by longer cooking times, higher temperatures, greater surface area exposed to water, and exposure to light and oxygen. nih + 2

Vitamin B1 (Thiamine)
A study in PMC measured vitamins in kale using HPLC and found that after blanching at 100°C for 20 minutes, only 86.9% of vitamin B1 was retained — meaning a loss of about 13%. A ScienceDirect study found that cooking kale prior to preservation reduced B-group vitamins by 29–75%, noting that vitamins B1 and B2 are essential for metabolism and nerve function, making their loss nutritionally significant. nihScienceDirect

Vitamin B3 (Niacin)
The same HPLC-based study found that vitamin B3 was more heavily affected than B1, with only 55.6% retained after blanching — a loss of roughly 44%. nih

Vitamin B2 (Riboflavin)
The ScienceDirect study specifically examined vitamins B1 and B2 in kale, finding that cooking before preservation caused reductions of 29–75% depending on method, with B2 (riboflavin) losses being notable — and epidemiological studies have linked low riboflavin diets to increased cardiovascular disease risk. ScienceDirect

Vitamin A / Beta-Carotene (fat-soluble)
Fat-soluble vitamins like A and K are better preserved through sautéing than boiling, as the presence of oil enhances their absorption — whereas water-based cooking does not provide this benefit. Total carotenoids (the precursors to vitamin A) degraded by 28.2% from stir-frying, and while boiling figures were not separately isolated, water-soluble phytochemicals were significantly reduced by boiling overall. pTaylor & Francis Online

Vitamin K (fat-soluble)
Vitamin K is among the more stable vitamins — even after cooking, kale still offers substantial amounts of it, as it is fat-soluble and therefore not as prone to leaching into boiling water. That said, some loss does occur with prolonged boiling. Well Wisp

Not the best format to read but here's a site on nutritional facts of kale:https://deltacalendar.com/nutrition/kale-analysis/

Looks like steaming or stir-frying are superior to boiling for nutrient absorption.

If you make southern greens with collards, kale and mustard greens, (garlic, peppers, onions, bacon, vinegar, brown sugar, hot pepper, etc) you will be eating more than one serving.

I feel like if you're eating fruit, meat, milk, and eggs you should be covered with any additional cooked greens.

Corngold

@hwisdom

What do you think of microwave defrosting? Any difference? I was thinking longer exposure might be worse than short and intense exposure. Maybe defrosting isn't as bad?

I also have leaned away from microwaving food.

LucH

@Corngold said:

What do you think of microwave defrosting? Any difference?

Hi,
I won't use microwave: Proteins are exploded.
Critical temp for Vit C is 60° C but is higher with steamed cooking. (no pressure).

Pressure cooking and amino acids
Effect of high pressure steam on the eating quality of meat proteins
High-pressure processing has potential for food preservation purposes because it can inactivate microorganisms and enzymes.
The spatial configuration of some enzymes is changed. Proteins are composed of amino acids connected by amide bonds. Due to high reactivity under pressure and heat the molecules are twisted and changed. They could be no longer recognized by our digestive enzymes.
Reference:
The use of high pressure to modify the functionality of food proteins
https://doi.org/10.1016/S0924-2244(97)01015-7
However some studies have shown to make it easier to digest meat but high pressure can affect protein conformation and can lead to protein denaturation, aggregation or gelation, depending on the protein system, the applied pressure, the temperature and the duration of the pressure treatment.

Steamed cooking with Vapok or "vitaliseur Marion" (Marion Kaplan):
The most respectful cooking method
Gentle steaming (95°C) is by far the ideal cooking method. It preserves nutrients (vitamins, enzymes, minerals) while eliminating natural toxins (excess fats, purines, bacteria) or artificial ones (mainly pesticides). It is a very quick cooking method that is very respectful of the integrity of the food.

sunsunsun

@LucH I agree, steaming is S-tier

Mossy

Interesting. So pressure cooking may not be the best? That is how I do a lot of my cooking. I know microwaving has been in the cross-hairs for quite some time. I quit using my microwave for about 10 years because of all the negative talk about it, but have started again about 2 1/2 years ago. It's a definite time saver. I read somewhere that microwaving vegetables actually retained the most nutrients (could it have been Peat that said this?). I'm not asserting this as if I know it to be true, but kind of thought dumping in response to this subject. As time allows, maybe I can provide better information, source, quotes, etc.

It's really tough to get the final answer on anything, but I respect and am open to arguments against modern cooking. In general, the modern world does tend to contaminate much that it touches. But, in the name of objectivity, one thing we know, the microwave and the pressure cooker have been around long enough for us to know that some people were able to eat food from them and not only survive, but live long lives.

Corngold

@Mossy said:

It's really tough to get the final answer on anything, but I respect and am open to arguments against modern cooking. In general, the modern world does tend to contaminate much that it touches. But, in the name of objectivity, one thing we know, the microwave and the pressure cooker have been around long enough for us to know that some people were able to eat food from them and not only survive, but live long lives.

Have you heard of food irradiation? Supposedly the majority of food in stores including produce, meat, etc., is "irradiated" before it is packaged.

https://www.iaea.org/newscenter/news/what-is-food-irradiation-and-why-is-it-important

I don't know what the risks are. It seems if large agencies defend it then it might be pretty bad. On the other hand not many people know or talk about it, and I don't know if it's still being done.

As for modern cooking, you're right because we "contaminate" so much, down to "bioengineered" food products.

My opinion is that if you find traditional recipes for greens or other foods, then that is best. As for nutrients, isn't it that nutrients from greens leach into the broth? So a hearty soup / stew should have a good amount of nutrients in the broth.

Had to ask a i for help:

Water-soluble nutrients (leach heavily into broth)

Vitamin C : 50–70% lost into the water (and further degraded by heat)
B vitamins (folate, B6, thiamine): 30–60% can leach out
Potassium and other minerals: 30–50% may pass into the broth

Fat-soluble nutrients (mostly stay in the greens)

Vitamins A, K, E: largely retained in the leaves since they don't dissolve in water
Beta-carotene: mostly stays put, and heat can actually improve its bioavailability

What this means practically
The broth itself becomes genuinely nutritious — think of it like a light vegetable stock. If you discard the water, you're throwing away a meaningful share of the water-soluble vitamins and minerals. Drinking or using the broth in soups, rice, or sauces is a simple way to recover those nutrients.
Factors that affect how much leaches out

Chopping: more cut surfaces = more leaching
Boil time: longer cooking = more loss
Water volume: more water = more dilution and loss
Temperature: a gentle simmer loses slightly less than a hard boil

The bottom line: roughly 30–60% of water-soluble nutrients end up in the broth depending on conditions. Fat-soluble nutrients stay mostly in the greens. If you want maximum retention, steaming or sautéing is more efficient — but if you're boiling, save and use the broth.

I don't think it's anything to worry too much about unless you're vegan or vegetarian. Those diets usually create vitamin / mineral deficiencies because they avoid dairy, meat, and fish.

@Mossy

LucH

@mossy
Talk with AI (Claude)
Context 1 (nutrition and health forum)
LucH says:
I won't use microwave: Proteins are exploded. (...)
Context 2:
LucH thinks:
Pressure cooking may become a problem for human metabolism as long you usually use this way. So it’s a question of frequency and quantity.
And saying it’s quicker and that we all know people who do so for their grand-ma who lives like a well-fit centenarian (nearly a 100 year-old well-fit body-shaped person)...
We have all heard of a 100 year-old smoker who’s fine. Nobody won’t refute / disprove that cigarette is bad for lungs ...

Demand for AI
Don’t comment what precedes.
The forumer cooks the weekend for the week. The menus are +/ balanced for macronutrients LPG and most nutrients. Eat home-made food, not much from manufactured origin.
Be positive, moderate in advice. Need to register in 2 or 3 times, like most people when it’s a thorough change. The key demand: How to adapt to optimize when you don’t have time or energy to prepare a meal after a workday.
Don’t ask for detailed menus. Of course, he / she doesn’t suffer from thyroid, adrenal glands, low-grade inflammation, immune reaction …

Claude says:
Blabla (not pertinent).
=> I summarize after 2x re-redirection.
So we suppose a lack of time and energy during the week. We accept short-time and easy cooking with potatoes, pasta and rice.
We use “meat cuts” that are allowed or +/ beneficial when cooked by pressure.

Here are suggestions for 3 “models”, for 2 days in the week.
Section 1 (for 2 days)
These share connective tissue and collagen — exactly what pressure cooking handles best. The result is tender, the cooking time is cut by half or more, and they reheat well during the week without drying out.
These are also generally less expensive cuts — an added practical advantage for batch cooking.

Examples:
Tough / thick cuts for pressure cooking — examples
Poultry
• Chicken thighs and drumsticks — ideal, stay moist
• Chicken whole legs — same
• Turkey thighs — less common but excellent
• Chicken wings — good for a richer result
Duck
• Duck legs — perfect for pressure cooking, fat renders well
• Duck confit-style preparation — works very well under pressure
• Duck thighs — same logic as poultry above
Rabbit
• Whole pieces or legs — underused but very well suited
• Stays tender, mild flavour, pairs with anything
Pork belly
• Shoulder — excellent
• Spare ribs — very good
• Cheeks — outstanding result
Beef / veal
• Shin, cheek, shoulder, short ribs
• Osso buco cuts — veal shin particularly good

Comment (LucH)
Moderate pork.
Duck breast and pork belly are specific cases
Duck breast (magret)
• Naturally tender — pressure cooking is too aggressive
• Best cooked pan-seared on weekend, medium doneness
• Reheats gently during the week without drying if sliced cold and warmed briefly in a covered pan with a little water. (Fine with musterd, if you like it so).
• 650g covers 3 days easily if portioned right
Pork belly
• Fatty and layered — pressure cooking actually works here
• Fat renders, meat stays moist, reheats very well
• Good candidate for the pressure cooker batch

So the distinction within this category
Cut / Method
Duck breast / Pan weekend, gentle reheat weekdays
Pork belly / Pressure cooker viable
Duck legs / Pressure cooker ideal
Chicken thighs / Pressure cooker ideal
NB: Roasted before pressure is best.

Section II (for 2 other days)
Pragmatic choices. What works well under pressure cooking
Legumes — best case for pressure cooking. Not 2 days in a row (anti-protease).
• Lentils, chickpeas, white beans, black beans
• Texture and digestibility actually improve
• Portion and freeze — grab one portion per weekday
Comment (LucH)
These two categories are where pressure cooking makes the most sense nutritionally and practically — long cooking times reduced problems. Need still to alternate.
What goes with it that's fast, real, and doesn't require weekend pre-cooking.
Eggs, tins, cheese — things that live in your kitchen permanently, no planning needed, combined with freshly cooked starch in 10 minutes total.

Third part — spontaneous weekday meals, no planning needed
Eggs + salad or tomato + a soup
• 5 minutes maximum
• Always available, no weekend prep required
Beans + pasta
• Pasta cooking = passive wait
• Beans from weekend batch or a tin — straight on top
Lentils + rice
• Both cookable during the week, passive
• Or lentils from weekend batch — even faster
Frozen mixed vegetables + wok + bacon
• 10 minutes, high heat, done
• Bacon adds fat and flavour instantly
• Frozen vegetables are nutritionally fine — underrated

Milk Destroyer

@alfredoolivas Perhaps, but I'm not certain. I actually was eating a lot more kale recently (maybe 150g a day) for a week and I did notice I had lost some weight (like 5lbs), but I was also walking in nature more at the time.

I'll try incorporating it more consistently and get back to you.