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| IF YOU SEE THIS SYMBOL ON YOUR FOOD...DO NOT BUY IT! |
All of these things we have been discussing the last few weeks, polyphenols, beta glucans, etc... more than likely derive much of their "magic" from the LIFE contained in these plant-based chemicals.
Endophytic microbes :
Endophytic organisms associated with plants are varied and complex. Endophytic microbes occupy a relatively privileged niche within plant and usually contribute to plant health. Some groups of endophytic microorganisms have been believed to be mutualists that protect plants against biotic stresses. Co-evolution may exist between endophytes and their host in resist to environmental stresses. During the last two decades endophytes have been targeted as valuable sources of new bioactive compounds.
We are now seeing that these endophytic microbes do more than protect the plant, they may also make compounds in that plant healthful to us, and without these endophytes present in our foods, we are just eating "paste".
Conventional farming practices (pesticide, fungicide, herbicide use) shown to reduce this endophytic life, as in this paper:
We obtained pesticide-free and organically cultivated (O) vegetables using water-soluble chitosan as a soil modifier and leaf surface spray (as an alternative natural insecticide) in order to investigate biofunctions induced or enhanced by such specialised cultivation practices. In addition, we purchased the same varieties of vegetables cultivated on an adjacent farm in the conventional manner (C) using pesticides and chemical fertilisers in order to examine the differences in biological activities and distribution of constituents responsible for such activities. The antioxidative activity shown by O vegetables was 120% times higher than that shown by C vegetables in the case of spinach and 20–50% higher in the case of Welsh onion, Chinese cabbage and qing-gen-cai. In comparison with C vegetables, the antimutagenic activity shown by O vegetables was higher against 4-nitroquinoline oxide (4NQO) in qing-gen-cai, Chinese cabbage and Welsh onion, against benzo[a]pyrene (BaP) in all five vegetables, against 2-amino-3-methylimidazo[4,5-f]quinoline (IQ) in qing-gen-cai, Chinese cabbage and green pepper and against 3-amino-1-methyl-5H-pyrido[4,3-b]indole acetate (Trp-P-2) in spinach only. Among all green vegetable juices tested for flavonoid composition, quercitrin, caffeic acid and baicalein in O vegetables were detected in concentrations 1.3–10.4 times higher than those found in C vegetables, suggesting the influence of different cultivation practices.
tl/dr? - This says: Veggies raised "un-organically" exhibit much less of the antioxidant properties we have come to see as healthy!
Pesticides/herbicide/fungicides kill these endophytes. But this is not good enough, for decades we have also been dropping nuclear bombs (literally) on our food, quite possibly making it useless as a healthy food source.
CONCLUSION
I've never been convinced that one must eat all organic food, or a food with an "organic" label, but this little green symbol of a healthy, plant-filled world is about as opposite from 'organic' as you can get! I have a feeling that possibly even "organic" foods can be irradiated and still be called "organic".
The vocal concerns about irradiated foods lie mainly in the dangers of the radiation itself. These concerns are probably unfounded. The elephant in the room is what this radiation does to our food...we are not meant to eat sterile foods.
Let's play a game...go out and see if we can find this symbol, and report here what it's on. I'm really curious.
Later,
Tim
But, please read more, from the FDA, and make up tour own mind.
From the FDA's website:
Food irradiation (the application of ionizing radiation to food) is a technology that improves the safety and extends the shelf life of foods by reducing or eliminating microorganisms and insects. Like pasteurizing milk and canning fruits and vegetables, irradiation can make food safer for the consumer.
The Food and Drug Administration (FDA) is responsible for regulating the sources of radiation that are used to irradiate food. FDA approves a source of radiation for use on foods only after it has determined that irradiating the food is safe.
Why Irradiate Food?
Irradiation can serve many purposes.- Prevention of Foodborne Illness – irradiation can be used to effectively eliminate organisms that cause foodborne illness, such as Salmonella and Escherichia coli (E. coli).
- Preservation – irradiation can be used to destroy or inactivate organisms that cause spoilage and decomposition and extend the shelf life of foods.
- Control of Insects – irradiation can be used to destroy insects in or on tropical fruits imported into the United States. Irradiation also decreases the need for other pest-control practices that may harm the fruit.
- Delay of Sprouting and Ripening – irradiation can be used to inhibit sprouting (e.g., potatoes) and delay ripening of fruit to increase longevity.
- Sterilization – irradiation can be used to
sterilize foods, which can then be stored for years without
refrigeration. Sterilized foods are useful in hospitals for patients
with severely impaired immune systems, such as patients with AIDS or
undergoing chemotherapy. Foods that are sterilized by irradiation are
exposed to substantially higher levels of treatment than those approved
for general use.
Debunking Irradiation Myths
Irradiation does not make foods
radioactive, compromise nutritional quality, or noticeably change the
taste, texture, or appearance of food. In fact, any changes made by
irradiation are so minimal that it is not easy to tell if a food has
been irradiated.
How Is Food Irradiated?
There are three sources of radiation approved for use on foods.- Gamma rays are emitted from radioactive forms of the element cobalt (Cobalt 60) or of the element cesium (Cesium 137).
Gamma radiation is used routinely to sterilize medical, dental and household products and is also used for the radiation treatment of cancer. - X-rays are produced by reflecting a high-energy stream of electrons off a target substance (usually one of the heavy metals) into food. X-rays are also widely used in medicine and industry to produce images of internal structures.
- Electron beam (or e-beam) is similar to X-rays and is a stream of high-energy electrons propelled from an electron accelerator
into food.
Did you know?
National
Aeronautics and Space Administration (NASA) astronauts eat meat that
has been sterilized by irradiation to avoid getting foodborne illnesses
when they fly in space.
Is Irradiated Food Safe to Eat?
FDA has evaluated the safety of irradiated food for more than thirty years and has found the process to be safe. The World Health Organization (WHO), the Centers for Disease Control and Prevention (CDC) and the U.S. Department of Agriculture (USDA) have also endorsed the safety of irradiated food.
What Foods Have Been Approved for Irradiation?
FDA has approved a variety of foods for irradiation in the United States including:- Beef and Pork
- Crustaceans (e.g., lobster, shrimp, and crab)
- Fresh Fruits and Vegetables
- Lettuce and Spinach
- Molluscan Shellfish (e.g., oysters, clams, mussels, and scallops)
- Poultry
- Seeds for Sprouting (e.g., for alfalfa sprouts)
- Shell Eggs
- Spices and Seasonings
How Will I Know if My Food Has Been Irradiated?
FDA
requires that irradiated foods bear the international symbol for
irradiation. Look for the Radura symbol along with the statement
"Treated with radiation" or "Treated by irradiation" on the food label.
Bulk foods, such as fruits and vegetables, are required to be
individually labeled or to have a label next to the sale container. FDA
does not require that individual ingredients in multi-ingredient foods
(e.g., spices) be labeled.
It is important to remember that irradiation
is not a replacement for proper food-handling practices by producers,
processors and consumers. Irradiated foods need to be stored, handled
and cooked in the same way as non-irradiated foods, because they could
still become contaminated with disease-causing organisms after
irradiation if the rules of basic food safety are not followed.
Hmmmm, Could organic food be irradiated and still be labelled organic? Could one of you expert researchers check this out?
ReplyDeleteI wouldn't be surprised. They keep f--king with those organic standards.
It never ends.
This is why I prefer to get food from my backyard or that of someone I can talk to face to face
EPA Says: "Irradiated food does not meet the U.S. Department of Agriculture's definition of organic. "
Deletehttp://www3.epa.gov/radtown/food-irradiation.html
I hope it stays that way!
I did a search to see what can be irradiated in Europe, and all sites are very obscure. Apparently the food has to be packaged before it can be irradiated and it should be mentioned on packaging. And it seems that everything we buy in a supermarket is irradiated, the full truck is just driven into the center and hey ho the whole shipment is irradiated, truck and all. These days every vegetable comes pre-packaged in cellophane, so it can be irradiated. It should say so in the package, so will have a look tomorrow.
ReplyDeleteHet voedingscentrum (the Dutch FDA) says it is not harmful for humans. Not many people give them credance as they are still sticking with outdated food guidelines. The problem is the director was a past Unilever employee (largest food manufacturer in Holland). So, of course, they espouce everything to the benefit of their sponsors.
Jo tB
Jo tB,
DeleteLook into who is credited with creating that cute little symbol (Radura).
Univeristy of Wageningen Holland!! Well wha'da know. The agricultural university that is in the pocket of Unilever. Not very surprising after all.....
DeleteIt was Wageningen who were going to confirm that food manufacturers had reduced fat, salt and sugar content when revamping their products. Yeah right. If the salt was reduced from 29 grams to 28 grams, then Wageningen gave the thumbs up.
Jo
PS: which Anon are you??
And it was Wageningen/Unilever that was behing another label called the "Tick" Vinkje. " I choose healthily" it also says around the edge. Any product that met their criteria of reduced fat, salt, or sugar could use the Tick. And the first product to get the Tick was skimmed milk!!! As if we didn't know that already. To most people it has been a joke, when you see what junk food products carry the Tick on the package.
Deletehttp://www.hetvinkje.nl/
Jo
Sorry, the anon was Barney. I forgot to type my name. I apologize.
DeleteBarney
Please tell me that Frikadellen get a tick!
DeleteAnd french fries covered in peanut butter.
Yes, your french fries have the "tick" , see below right.
Deletehttp://www.aviko.nl/producten/frites/frideaal/franse-frites
If the frikandel has it I will investigate for you.
Jo
In Finland and Sweden only spices can be iradiated.
ReplyDeleteHow strange. Is this just a concession for the ability to import spices? I'm glad to see that Finland and Sweden have set some limits!
DeleteCurrently, onions, potatoes, wheat, flour, whole wheat flour, and whole or ground spices and dehydrated seasonings are approved for irradiation and sale in Canada.
ReplyDeleteNicole
Wait. This is bull. What about canned food? Dehydrated food? Smoked food? Hell, cooked food? You telling us these Endophytes stay alive through all of these age-old techniques of making food safer to eat?
ReplyDeleteI think food irradiation has saved more lives than hurt.
Here is an interesting point of view against irradiation but unfortunately no links to studies.
DeleteThe article also points out the legal (Canadian) amount of irradiated food needed to have that label.
https://nowtoronto.com/lifestyle/ecoholic/how-we-can-tell-if-our-food-has-been-irradiated/
Nicole
And here is another article with sources:
Deletehttp://www.meghantelpner.com/blog/food-irradiation-5-things-you-need-to-know/
Nicole
Nice article you linked, Nicole. I liked this:
Delete""Irradiation is being embraced by the food industry as a way to mask filthy conditions in factory-style slaughterhouses and processing plants. Because it greatly extends the shelf life of food, irradiation is also being embraced by multinational corporations as a way to move food production operations to developing nations, a trend that has already financially imperilled multitudes of American farmers and ranchers.""
Anon - I would have said the same thing last year. Turns out that many microbes (fungal and bacterial) can withstand heat and extreme pressure, seemingly defying all laws of physics. Some can even withstand radiation.
DeleteI think this is a trend that I do not like one bit. From what I can tell, heavily irradiating life forms often alters DNA and causes irreparable harm. Endophytes are not on anyone's radar at the FDA. This is all a tactic to make food production cheaper, not healthier.
I'm not at all convinced that veggies and meat that is 'shelf-stable' is the healthiest thing one can eat.
The article you quoted may also explain why WHO accepts it. The poor and desperate have no choice.
DeleteAnd if irradiating life forms causes irreparable harm, I wonder about the consequences, especially long term for humans, when these microbes exchange DNA.
Nicole
And that's why milk started to be pasteurized - to sell contaminated milk. It's unhealthy whether you think it kills germs or not. I prefer raw healthy milk to pasteurized contaminated milk. It's all about $$$.
ReplyDeleteGina
Gina, I think you will find that milk is not only pasteurised but also homogenised as well. And homogenizing is even worse.
DeleteJo
Jo, I guess it might be a problem for people who rely on milk as a major source of nutrition. I probably shouldn't be consuming milk at all since I'm lactose intolerant (and it's not my gut bugs, it's genetic). I don't really care one way or the other but I use lactose free homogenized milk in my breakfast tea. I've tried a number of 'faux milks' and they don't taste good in my tea. I've been using lactose free homogenized milk in my morning cuppa for, oh, let's see now, since 1987. I'm still breathing. Just. ;)
DeleteThere's just too much hullaballoo about milk this way or that. It should not be a significant part of anyone's diet past age 2. Fermented dairy, fine. Liquid milk, not fine.
Gabriella,
DeleteGenetic lactose intolerance responds to eating live yogurt. It is in the literature. It just amounts to eating sub-symptomatic amounts of yogurt for three weeks. I have known people who have been lactose intolerant all their adult lives and were fixed in three weeks just by eating live yogurt.
Of course the cure requires functional biofilms that can facilitate the transformation of the beta-galactosidase genes from the yogurt lactobacilli to existing gut flora.
So I suppose if the yogurt cure doesn't work it may just indicate more profound dysbiosis. The genetic lactose intolerance myth is just commercial exploitation.
Art, bottom line: I can't be bothered. Milk isn't important. If I can get lactose free for my morning tea, that's enough. Supersour kefir is fine. There's limits to how much regular milk is tolerable. Doesn't concern me.
DeleteGabriella,
DeleteI am certainly not pushing milk consumption. There are many reasons to avoid it. I don't drink it myself, except cream in my morning polyphenolics/coffee.
I was just trying to explain that not making lactase does not determine lactose intolerance. Anyone can choose to be lactose tolerant with a healthy gut flora and access to bacteria that produce beta-galactosidase.
Almeida CC, Lorena SL, Pavan CR, Akasaka HM, Mesquita MA. 2012. Beneficial Effects of Long-Term Consumption of a Probiotic Combination of Lactobacillus casei Shirota and Bifidobacterium breve Yakult May Persist After Suspension of Therapy in Lactose-Intolerant Patients. Nutr Clin Pract., 27(2):247-51.
Radiation is naturally occurring throughout the universe so maybe it is organic after all.
ReplyDeleteI try to avoid buying those items but when you get into the produce department you don't have any clue as to what has been zapped. Example, purple sweet potatoes imported from ??? are more than likely radiated. Therefore you have to make sure they are coming from California. Lots of work trying to steer clear of the rays.
Yeah. I used to order Hawaiian Purple Sweet Potatoes direct online until I noticed the radura symbol on the box.
DeleteThere is a little twist in the paper comparing organic and traditional farming using polyphenolic antioxidant as a measure of wholesomeness.
ReplyDeleteThe organic plants were grown on chitin, a known elicitor of phytoalexins, plant antibiotics that are the major polyphenols produced by the plants. The conventional plants had few pests or pathogens, and hence lower levels of phytoalexins. In a parallel way, fungal beta 3,6 glucans are lauded as "immune system stimulants" because they stimulate inflammation.
As a plant scientist, I would use polyphenol levels as a measure of stressed, infested or infected plants. It has been known for decades that organic plants are not as perfect, i.e. disease free, as conventional plants. In an attempt to improve the appearance of organic plants, attempts have been made to increase phytoalexins using elicitors, such as chitin. It produces less healthy, but less infected plants, with higher polyphenolics, which have to be renamed as antioxidants instead of natural antibiotics.
"As a plant scientist, I would use polyphenol levels as a measure of stressed, infested or infected plants"
DeleteI guess my confusion now lies in why certain plants, ie. dark berries, would have 1000's times more polyphenols than similar berries of a different color.
Are flavanoids and vanillins in the same class?
That was an interesting twist on the chitosan growing medium! I missed that completely. I may have to give that a try next spring when I'm trying to start tomato plants. I've never seen it at Home Depot. Just vermiculite and perlite. Funny, but now that marijuana is legal here, a whole bunch of little stores have opened selling grow-lights and hydroponic stuff. I'll bet they have chitosan.
Yes, there is quite some research how to make soil ecosystem more resilient, some even from Wageningen, LOL
DeleteChitin Amendment Increases Soil Suppressiveness toward Plant Pathogens and Modulates the Actinobacterial and Oxalobacteraceal Communities in an Experimental Agricultural Field (2013)
"A long-term experiment on the effect of chitin addition to soil on the suppression of soilborne pathogens was set up and monitored for 8 years in an experimental field, Vredepeel, The Netherlands. Chitinous matter obtained from shrimps was added to soil top layers on two different occasions, and the suppressiveness of soil toward Verticillium dahliae, as well as plant-pathogenic nematodes, was assessed, in addition to analyses of the abundances and community structures of members of the soil microbiota. The data revealed that chitin amendment had raised the suppressiveness of soil, in particular toward Verticillium dahliae, 9 months after the (second) treatment, extending to 2 years following treatment. Moreover, major effects of the added chitin on the soil microbial communities were detected. First, shifts in both the abundances and structures of the chitin-treated soil microbial communities, both of total soil bacteria and fungi, were found. In addition, the abundances and structures of soil actinobacteria and the Oxalobacteraceae were affected by chitin. At the functional gene level, the abundance of specific (family-18 glycoside hydrolase) chitinase genes carried by the soil bacteria also revealed upshifts as a result of the added chitin. The effects of chitin noted for the Oxalobacteraceae were specifically related to significant upshifts in the abundances of the species Duganella violaceinigra and Massilia plicata. These effects of chitin persisted over the time of the experiment."
A key quote from the study above:
Delete"While the analysis of the unamended soil samples indicated that the community sizes did not change significantly over the seasons, the addition of chitin raised both microbial densities. Strikingly, the average bacterial densities under the chitin amendment were orders of magnitude higher than the fungal ones, and this effect persisted over time (up to 2 years)."
More bacteria, less fungi? What's not to like?
I am wondering what would be found if the polyphenol content in the plants was measured too. I am imagining these soil bacteria like guests in the restaurant, ordering in the plant kitchen: "more glycans and polyphenols, please, we are hungry."
This is a rough world. Eat mushrooms, people.
Gemma, LOL indeed. University Groningen is also involved, and they're big on ecology and paleo.
DeleteTim, We have huge greenhouse complexes, one in Westland near Rotterdam and the other near Lelystad where they are big on organic farming. Most of our tomatoes, cucumbers, and bell peppers are grown in both complexes. So I'll bet they would be hot on using Chitin.
Jo
From Wikipedia: Most recent studies point out that chitin is a good inducer of defense mechanisms in plants.[9] It has also been assessed as a fertilizer that can improve overall crop yields.[10] The EPA regulates chitin for agricultural use within the USA.[11] Chitosan is prepared from chitin by deacetylation.
DeleteAnd Chitosan can be used in agriculture as a seed treatment and biopesticide, helping plants to fight off fungal infections. (that would be of interest to greenhouse growers)
So maybe Chitosan is commercially available for amature gardners as well. Would be of interest to growing tomatoes.
Jo
General reference on polyphenols:
Deletehttp://ajcn.nutrition.org/content/79/5/727.full
Polyphenols are either not absorbed or are rapidly detoxed and secreted. This is the primary function of the liver detox system. More polyphenols just puts more stress on the detox system.
Any prebiotic fiber, including chitin, added to the soil will have the same impact of increasing microorganism numbers. The same thing happens in the gut.
Greenhouse growth or any conditions that reduce stress, reduce polyphenols. The highest levels are found in fungal infected, sick looking plants. Potato tubers rotting from late blight are loaded with polyphenolic phytoalexins. Unfortunately, the phytoalexins are also very teratogenic, causing lots of birth defects. Other phytoalexins are used as paint strippers in chemotherapy, and all the common drugs. I don't see why anyone is interested in ingesting a lot of organic chemicals, e.g. polyphenols, commonly found in the pharmaceutical industry?
Fungal walls are made of chitin, beta 3,6 glucan and mannan, so fungi don't tend to produce chitinases or live on chitin.
I thought it might be useful to put some of the beta glucan, polyphenol discussion into perspective by comparing plant and animal reactions to fungal wall glucan.
ReplyDeleteIn 1975, I published a series of papers on how plants recognize and respond to fungal pathogens. I applied hot water extracts of a fungus to plants and the plants turned vivid red and produced huge amounts of polyphenols (phytoalexins), which were hundreds of times higher than the lethal dose for the fungus. I purified the fungus wall chemical responsible for stimulating phytoalexins and determined the structure. It was a small beta 3,6 glucan, which was subsequently called the "glucan elicitor."
Subsequently, I was doing research purifying enzymes in Stockholm, when I attended a seminar on stimulation of melanin production in crayfish by fungal wall polysaccharides. Crayfish responded to my glucan elicitor by producing melanin as a defense.
My point is that plants respond to fungi or the glucan elicitor surrogate, by producing polyphenols. Invertebrates respond to the glucan elicitor by producing melanin. Both plants and animals respond to UV light damage by producing polyphenols/phytoalexins/melanin. Note that humans respond to UV by first producing the red skin of inflammation and subsequently producing the slower response of melanin accumulation. No pain/inflammation, no gain/tan. I expect if you could get the glucan elicitor to penetrate skin, it would cause pigmentation.
Humans respond to the glucan elicitor, aka fungal "beta 3,6, glucan", or sometimes just "beta glucan" with inflammation. It is interesting that plant polyphenols, aka "antioxidants" or "phytoalexins" also bind to fungal beta glucan, to make a polyphenol/glucan complex that is transported to the colon and metabolized by gut flora. Neither the glucan or the polyphenols are absorbed appreciably into the blood stream, but the small amount absorbed is quickly detoxed by liver enzymes.
Thus, if polyphenol/beta glucan complexes, e.g. blueberries and plant glucans (the other, 3,4 beta glucan, that doesn't stimulate inflammation) have a beneficial impact, it must take place in the gut and probably impacts gut flora. This would not be unlike most drugs (usually developed from phytoalexins) that have a physiological impact by selectively killing gut flora.
Interesting.
DeleteSome more complex action of beta glucans (source)
"The pharmacokinetics following intravenous administration of 3 different highly purified and previously characterized β-glucans were studied using carbohydrates covalently labeled with a fluorophore on the reducing terminus. The variations in molecular size, branching frequency and solution conformation were shown to have an impact on the elimination half-life, volume of distribution and clearance [27].
The low systemic blood level of β-glucans after ingestion does not reflect the full picture of the pharmacodynamics of β-glucans and does not rule out its in vivo effects.
Cheung-VKN et al. labeled β-glucans with fluorescein to track their oral uptake and processing in vivo. The orally administered β-glucans were taken up by macrophages via the Dectin-1 receptor and was subsequently transported to the spleen, lymph nodes, and bone marrow. Within the bone marrow, the macrophages degraded the large β-1,3-glucans into smaller soluble β-1,3-glucan fragments. These fragments were subsequently taken up via the complement receptor 3 (CR3) of marginated granulocytes. These granulocytes with CR3-bound β-glucan-fluorescein were shown to kill inactivated complement 3b (iC3b)-opsonized tumor cells after they were recruited to a site of complement activation such as tumor cells coated with monoclonal antibody [28] (Figure 2). It was also shown that intravenous administered soluble β-glucans can be delivered directly to the CR3 on circulating granulocytes.
Furthermore, Rice PJ et al. showed that soluble β-glucans such as laminarin and scleroglucan can be directly bound and internalized by intestinal epithelial cells and gut associated lymphoid tissue (GALT) cells [29]. Unlike macrophage, the internalization of soluble β-glucan by intestinal epithelial cells is not Dectin-1 dependent. However, the Dectin-1 and TLR-2 are accountable for uptake of soluble β-glucan by GALT cells. Another significant finding of this study is that the absorbed β-glucans can increase the resistance of mice to bacterial infection challenge.
How β-glucans mediate their effects after ingestion in human remained to be defined. In a phase I study for the assessment of safety and tolerability of a soluble form oral β-glucans [30]. β-glucans of different doses (100 mg/day, 200 mg/day or 400 mg/day) were given respectively for 4 consecutive days. No drug-related adverse events were observed. Repeated measurements of β-glucans in serum, however, revealed no systemic absorption of the agent following the oral administration. Nonetheless, the immunoglobulin A concentration in saliva increased significantly for the 400 mg/day arm, suggesting a systemic immune effect has been elicited. One limitation of this study is the low sensitivity of serum β-glucans determination.
In summary, based on mostly animal data, β-glucans enter the proximal small intestine rapidly and are captured by the macrophages after oral administration. The β-glucans are then internalized and fragmented into smaller sized β-glucans and are carried to the marrow and endothelial reticular system. The small β-glucans fragments are then released by the macrophages and taken up by the circulating granulocytes, monocytes and dendritic cells. The immune response will then be elicited. However, we should interpret this information with caution as most of the proposed mechanisms are based on in vitro and in vivo animal studies. Indeed, there is little to no evidence for these hypothesized mechanisms of action and pharmacokinetics occurred in human subjects at the moment."
BTW Laminarin and scleroglucan have 1,3 glucans with 1,6 branches, whereas the typical fungal wall glucan is 1,6 linked with 1,3 branches. Laminar and scleroglucan are inactive in plant elicitor assays and most of the animal systems. Note that dectin-1 does not bind them in some internalization assays in the paper.
DeleteIt is as if the investigators didn't know one beta glucan from another, just like every other molecular bigot. "Oh, they all look the same to me." "I didn't know that cellulose was also a beta glucan!"
What lessons can we learn from this?
DeleteCellulose is a string of 1,4 glucosidic bonds.
Oat beta glucans are a matrix of 1,3/1,4 glucosidic bonds
Fungal beta glucans are a matrix of 1,3/1,6 I believe.
This must be similar to the differences between amylose and amylopectin in starches.
There does not seem to be any bacterial fermentation or extraordinary health claims made about cellulose, other than it's water-binding capacity.
Any ideas which beta glucan "chitin" is most related to?
Tim,
DeleteI have found a lot of sources that indicate that cellulose s indeed fermented in the gut - not all, but a significant fraction, 30-50%. Here's an example
http://gut.bmj.com/content/25/8/805.full.pdf
In a nod to what Art has been saying, real plant cellulose ferments differently from purified cellulose.
I've seen no grand health claims though.
lol, from 1984. If you Google "cellulose fermentation NIH" the top hits are from the '40s and '70s. See the 1944 hit, Studies on Cellulose Fermentation
DeleteNo matter, just thought that was funny.
At any rate, maybe cellulose fermentation is not so mysterious. If you pile garden waste in a compost pile, it is mainly cellulose, and is readily fermented into wonderful garden soil. Is it possible that the main cellulose degraders, then, are not the bacteria thought to be "probiotoc" but just run-of-the-mill gut bacteria from the ever-present bacteroides and firmicute families?
These bacteria are in every single human, bar none. They are rarely credited with much more than turning undigested plant matter into turds. Surely some SCFA or gasses are produced, but it takes some special foods, to get the special bacteria excited.
Cellulose, in its simple chain of 1,4 bonds must be easy to ferment, and the byproducts are few. Unlike the matrix of 1,3/1,6 bonds in mushroom fiber, or 1,3/1,4 bonds in cereal bran.
Remember back to the RS discussions. These starch granules are so tightly packed and have so few loose ends, that it takes several species of bacteria to ferment them. One breaks it in half, another eats from the ends, another from the middle, and all sorts of by-products and new food sources are created to sustain an ecosystem that does not exist in the absence of these complex fiber types.
This cellulose as a beta-glucan explains how the Primal "big ass salad" promotes good bowel movements, but worsening health when all other fibers (RS/beta glucans/inulin) is strictly avoided or simply lacking from the salad bar.
And look, Wilbur! This backs up Art's observation that "It is as if the investigators didn't know one beta glucan from another, just like every other molecular bigot. "Oh, they all look the same to me." "I didn't know that cellulose was also a beta glucan!"
DeleteFrom the paper you linked"
"For example, in the work of Van Soest's group in which healthy volunteers were fed controlled diets with the addition of cellulose from either cabbage, bran, or a purified cellulose, average cellulose digestibility was 74% on the control diet..."
So here, in 1984, they were lumping bran with cellulose, and accidentally feeding a highly fermentable type of beta glucan along with the rest.
Last one, I promise. I was enjoying reading the 1984 paper. A search of the document does not reveal the term 'beta-glucan'. But when they discussed the bran of cereal grain, which they considered "cellulose", the found:
Delete"Bran is about 3% lignin, while most fruit and vegetables contain only one-tenth of this amount."
Just a minute beta glucan fans, cellulose is not digested in the gut because it is crystalline. It is the most abundant macromolecule on earth and is extruded through the cytoplasmic membrane as it is made in a flotilla of cellulose synthese enzymes and crystallizes into wall fibers. I worked with a group of biochemist at the Swedish Forest Products Research Laboratories on the enzymes involved in cellulose degradation. Cellulose and lignin go through the gut untouched.
ReplyDelete"Some are more equal than others"
Deletehttp://www.ncbi.nlm.nih.gov/pmc/articles/PMC3669169/
Interestingly the only human colonic bacterium so far shown to be able to degrade crystalline cellulose is another species of Ruminococcus, R. champanellensis. It has been proposed that subjects whose colonic microbiota are capable of degrading this type of cellulose are characterized by possession of this species.20,21 It is intriguing, but probably not coincidental, that the same family of Gram-positive bacteria (Ruminococcaceae) includes potential primary degraders of two very different substrates, lignocellulose and resistant starch.
Ha! You found one of my favorite papers, and I completely missed that about cellulose. I guess my eyes were filled with the wonders of RS.
DeleteAs described, we often lose sight of a very important concept:
"The current tendency toward wholly sequence-based descriptions of microbial communities provides little definitive information on the functional roles of the multitude of different phylotypes that make up the community. "
"The cellulose-degrading microbial community of the human gut varies according to the presence or absence of methanogens" (2010)
Deletehttp://www.ncbi.nlm.nih.gov/pubmed/20662929
Cellulose-degrading microorganisms involved in the breakdown of plant cell wall material in the human gut remain rather unexplored despite their role in intestinal fermentation. Microcrystalline cellulose-degrading bacteria were previously identified in faeces of methane-excreting individuals, whereas these microorganisms were undetectable in faecal samples from non-methane excretors. This suggested that the structure and activity of the cellulose-degrading community differ in methane- and non-methane-excreting individuals. The purpose of this study was to characterize in depth this cellulose-degrading community in individuals of both CH(4) statuses using both culture-dependent and molecular methods. A new real-time PCR analysis was developed to enumerate microcrystalline cellulose-degrading ruminococci and used to confirm the predominance of these hydrolytic ruminococci in methane excretors. Culture-dependent methods using cell wall spinach (CWS) residue revealed the presence of CWS-degrading microorganisms in all individuals. Characterization of CWS-degrading isolates further showed that the main cellulose-degrading bacteria belong essentially to Bacteroidetes in non-methane-excreting subjects, while they are predominantly represented by Firmicutes in methane-excreting individuals. This taxonomic diversity was associated with functional diversity: the ability to degrade different types of cellulose and to produce H(2) from fermentation differed depending on the species. The structure of the cellulolytic community was shown to vary depending on the presence of methanogens in the human gut.
Gemma - This is fascinating! But why would a professor, who studied all of this not realize that human gut bacteria can actually ferment cellulose? If he is wrong on this, could he be wrong about other things? I have flip-flopped all week about the dangers/benefits of polyphenols and beta-glucans.
DeleteThank you for helping us see the forest through the trees!
Bruno,
DeleteYour personal attack is rather harsh. You are really discouraging anyone with knowledge about the subject from commenting. All opinions are not equal on topics of science. Most concepts are flawed, but that does not mean that all science is flawed or that the current concepts are useless.
I think that you will find that there are bacterial cellulose degraders and they are very effective in ruminants, but have little or no impact on cellulose ingested by humans. Modern techniques permit the detection of "hydrolytic ruminococci" in humans, but that doesn't mean that they have any impact on cellulose, since they actually degrade RS.
To clarify my main points on polyphenols and beta glucans:
That studies on the benefits of beta glucans are weak and do not fully assess potential hazards.
Just because glucans and polyphenols are produced by plants, does not mean that they are safe.
Glucans and polyphenols are immense classifications of molecules with vastly different properties, and each molecule has numerous different interactions/side effects with human systems. These are very non-specific biologically active molecules (as are most drugs.) Fortunately, most of these molecules pass through our gut or are quickly detoxified by the gut and liver. Most of the impact is as antibiotics that alter gut flora populations.
Sorry, Prof Ayers. Maybe is my English. I thought you were describing yourself above with "molecular bigot" comment. My professors always say they miss alot when looking simple at chemistry. When we look at the chemistry of polyphenols and beta-glucans, we see things that appear bad for humans. But when people eat them for millions of years, it turns out OK.
DeleteBut I think my flip-flopping is over, I must disagree that natural polyphenols found in blueberries and beta-glucans as in oats are harmful. Maybe it is NOT having them on regular basis is harmful to health of gut ecosystem and overall health?
Sorry for harshness. No offense meant.
Bruno,
DeleteThe polyphenols in each plant species are unique. Polyphenols from one species have different properties from all others. The only thing that they have in common, is that they are polyphenols and by definition test positive in the antioxidant tests. They are in plants because they provide defenses against pathogens, i.e. as antibiotics, not because of their chemical properties as antioxidants.
I never indicated that plant beta glucans, e.g. oats, were toxic. I merely said that plant beta 3,4 glucans are different from fungal 3,6 glucans.
Polyphenols and plant glucans will normally be safe to eat, because host detox systems and barriers provide protection. Healthy people with healthy gut bacteria need not worry.
The problem comes with people who have compromised gut and gut microbiota. A leaky gut and dysbiosis, means that the major barrier to the toxicity of polyphenols and fungal 3,6 glucans (not those in oats) is breached.
People with food intolerances have damaged gut microbiota and may not safely interact with polyphenols. After all, the polyphenols are not safe for human cells, but rather are rendered safe by functional host barriers.
These sick people are immunocompromised and are the same group that succumb to food poisoning. Increasing numbers of immunocompromised people with gut dysbiosis are responsible for the impression that food is less safe. Billions of exposures to potential poisoning agents occur each year, and yet only hundreds of thousands of cases result from the compromised people. Why are these rare (<one in a thousand) individuals affected?
High amounts of blueberries and oat beta glucans have not been eaten prior to modern times. Certainly this was also true of Metformin.
Interesting thoughts here. I will be curious to see if the oat-blueberry-fiber combo helps, or hurts, people with gut problems.
DeleteI wonder, was the diet we evolved on low in fiber and polyphenols, or high? My gut feeling says 'high'. Most heirloom fruits and veggies are much more colorful and less sweet. Ancient grains would have been eaten with bran intact.
Hopefully the combo of mega-dosed beta-glucans, polyphenols, and fiber proves helpful to those who have "tried everything".
I've been "drinking the Kool-aid" for about 10 days now, just to make sure it was not going to cause issues, and I must say that it it very, very filling and also leads to very good bowel movements. No purple/red diarrhea, no constipation. I hope to hear reports from the hard cases, good or bad.
"High amounts of blueberries and oat beta glucans have not been eaten prior to modern times."
DeleteI think this is not true, and these and other statements sound unnecessarily alarmistic.
Concerning blueberries, people might start thinking that they are dangerous or what. On the contrary. Blueberries (and other colorful berries) are normally available in nature for half a year. There is plenty of time to pick berries for immediate consumption and for winter storage, which is what people used to do for eons. Old books, and nowadays also open minded physicians recommend that everybody eats at least 5kg of blueberries in summer, for their health benefits. Not only diabetics, of course.
Fungal glucans: I am repeating myself here, but people have been consuming mushrooms for ages. Some mushrooms are considered medicinal, have various medical effects. Fermented foods also contains yeasts. In general, I see no reason to scare people from eating fungi, mushrooms and yeasts.
Metformin: we talked, dissected (and corrected, LOL) a patent talking metformin + food combo for diabetics, that is, not very healthy people. Metformin is a plant alkaloid, derived from french lilac (Galega officinalis, used for diabetes since Middle Ages if not before). In short, sick people (and animals) have been using nature's pharmacy long before Big Pharma was around. In fact, people picked many herbal ideas by observing animals: what they do, which plants they chew or eat when sick or wounded. Ignorant animals, should we say?
I very much hope that Art isn't chased away by comments, because I think the combination of amateur scientists, along with professionals, has amazing potential.
ReplyDeleteThis is especially true if both sides are willing to acknowledge the others' strengths -- professionals have a wealth of knowledge learned over the years, and the amateur has a less insular bias and, often, more motivation to find a solution.
In the blogosphere, the open-minded professional is the rarer breed, and so I'd hate to lose Art's contributions (and any other pros I'm not aware of).