Saturday, 13 February 2010

The problem with "Wholegrain" cereals etc.

As I mentioned in Carbohydrates: Dogs' Doodads or Spawn of Satan?, some breakfast cereals turn into blood glucose faster than table sugar (half glucose bonded with half fructose) even though they're "Wholegrain" cereals.

A whole (i.e. intact) grain consists of a protective outer shell (a.k.a. bran) and innards consisting of starchy/proteiny endosperm and nutritious germ. See Cereal germ.

To turn a grain into a breakfast cereal, it's ground into dust, mixed with water to form a paste and the paste is extruded through holes into whatever shape the manufacturer desires. Technically-speaking, everything that was in the whole grain is in the finished product. However, the form & function have completely changed. Here are a couple of analogies.

1) I want to sell my car. I take it to a scrap-yard and have it shredded into tiny pieces. All of the tiny pieces are put in a skip, which is delivered to my driveway. I place a sign on the skip stating "Whole Mazda MX-5 for sale. Enquire within. £5,000 O.N.O.". What would you offer for my "Whole Car"?

2) An insane person gives me £5,000 (in £50 notes) for my "Whole Car". As I'm on a roll, I take the notes and put them through a cross-cut shredder which turns them into thousands of 2mm x 2mm pieces. I empty the pieces into an attaché case. Who will accept my attaché case full of "Whole £50 notes" as payment for their second-hand car? Any more insane people out there?

Turning grains into dust does four things.

1) It exposes the starchy endosperm.

2) It vastly increases the surface area of the grain resulting in much faster digestion & absorption as blood glucose. Surface area is inversely proportional to particle size. If 3mm grains are reduced to 0.1mm particles, the surface area is increased by a factor of 30. How effective is chewing? Interestingly, once the particle size has fallen below a certain value, reducing it further makes no further difference. See The Effect of Particle Size of Whole-Grain Flour on Plasma Glucose, Insulin, Glucagon and Thyroid-Stimulating Hormone in Humans. Therefore, "wholegrain" bread is just as bad as white bread in terms of its glucose & insulin response.

3) It makes the finished product much more likely to stick to your teeth, resulting in the rapid formation of tartar that damages your teeth and gums.

4) It makes the finished product more energy-dense.

Rolled grains are grains that have been steamed (to cook and make them soft), then put through what's effectively a mangle. They're still intact, if somewhat flat. Puffed grains are grains that have been heated to make the water within boil. As steam takes up a much larger volume than water, the grains are inflated to a much larger size. They're still intact, if somewhat funky-looking!

Don't be conned by breakfast cereal labels. If they look like "O"s or Brillo pads or brake pads, they're not intact grains.

Oats are O.K. even when turned into oatmeal, probably due to their high beta-glucan content, which forms a wallpaper paste-like goo when wet. See Particle size of wheat, maize, and oat test meals: effects on plasma glucose and insulin responses and on the rate of starch digestion in vitro.

See also Anthony Colpo's The Wholegrain Scam.

16 comments:

gallier2 said...

Accorded, breakfast cereals are bad and such, but I think your analogies are not good. The purpose of the food is to be shredded in pieces by the digestive system, so your car analogy would be not that bad if the purpose of the car was not to drive with, but to be recycled. Every piece melted and reassembled, for the buyer it would make no difference between a new and a shredded car.
I'm with you to say that cereals are bad.

Nigel Kinbrum said...

Hi gallier2.

Chewing is very inefficient at breaking food into tiny pieces. Eat a load of sweetcorn and see how many kernels make it intact when they reappear at the far end of your GI tract! If large things like sweetcorn kernels are poorly chewed/unchewed, what about small things like grains?

Flour contains tiny particles, the size of which could never be achieved by using our molars.

Thanks for your comment. Nige.

gallier2 said...

Sorry for not being clear in my message (it's not my mother laguage).
The whole digestive system, from the teeth to the colon is there to shred every piece of food to the smallest possible entity it can ake use of (amino acids, triglycerides, glucose, fructose, galactose, minerals). In that regard it would even be a "good thing" for the processed cereals to be reduced to its components, as it would simplify the absorbtion of nutrients. Isn't it all what cooking is about?
The problem with the extruded cereals is that anti-nutrients get also easier access and the "denaturated proteins" contained within can break havoc where these kind of proteins never occured before.
To go back to the car analogy, the purpose of the car was to be recycled, so a shredded version might be more interesting because you can use a magnet to filter out the steel parts, but the plastic parts are worthless because they are mixed from different sorts and tainted with the motor oil and cooling fluid giving hazardous waste.

Nigel Kinbrum said...

Hi again gallier2. Your English is much better than my French!

Yes, I agree that the purpose of digestion is to extract everything worth extracting from food. The problem with the excessively-rapid digestion & absorption of starchy carbohydrate is its effect on blood glucose (BG) and insulin. Please see Blood Glucose, Insulin & Diabetes. High-GL carbs cause instability in BG & insulin levels which causes sluggishness at first and over-eating later-on.

I do agree that there's a problem with un-neutralised anti-nutrients in refined wholegrains (phytate etc). I don't think that denatured proteins are a problem as all proteins get denatured by HCl & pepsin in the stomach anyway.

I guess that my car analogy wasn't the best, but it seemed like a good idea at the time!

Nige.

Anonymous said...

so are you saying at the end that rolled oats and puffed oats are or are not still in a meaningful whole form? or that they are just as bad as the rest of the completely processed "whole grain" cereals. I wasn't quite clear if you put that in there as added clarification or to say that they are exceptions.

Nigel Kinbrum said...

Hi Anonymous.

Rolled & puffed grains are still whole. If I wasn't on a low-carb diet, I'd eat them.

Nige.

Rahim Samuel said...

I live in the "health" food section of the grocery store (when I actually go to a grocery store), and I realized that a lot of those "healthy" whole grain cereals have just as much of a high sugar and carb count as the kids cereals.

Rahim Samuel
Publisher, Wellnessbymanymeans.com

Nigel Kinbrum said...

Hi Rahim.

Supermarkets sell plain rolled wheat & oats for making muesli & porridge and you should also be able to buy plain puffed corn, wheat & rice without any added sugar.

As grains are naturally high in carbohydrate, the carb content of breakfast cereals is always going to be high! This is fine for active people. See Everyone is Different.

Nige.

lightcan said...

Hi Nige,

At the moment, I'm totally confused about cereals. I don't remember everything I've read and there is a big noisy mess in my head. I got to the point where I believed that they were bad for you. Don't eat them. It's not that simple in real life. Refined flour is bad as it doesn't contain any nutrients (besides the carbs issue and maybe LDL size, no science for the latter though). Whole grains and nuts are bad as they contain phytic acid and lectins. Gluten is always bad. Sourdough fermentation or special soaking (Stephan) is best for eliminating phytic acid. Should I give my kids only GF foods? Am I going OTT? If they're physically active and do not seem to have coeliac, obviously insulin sensitive, not getting too much omega 6, then sourdough rye bread is OK? I know, I should take some notes, organise my ideas and take a deep breath.

BTW, unrelated, Nige, do you think it's a good idea to 'try' some antidepressants? My GP says I should but I'm reluctant. (Lexapro 5mg, then 10 mg) Your opinion is appreciated.

Nigel Kinbrum said...

Hi lightcan.

Before I answer all of your questions, I have one very important question for you. Have you sorted out your low FT3 problem?

W.r.t. gluten: It's only bad for people that it's bad for. I know that's a bit of a circular argument, but the majority of the population don't have a problem with gluten. People with Coeliac Disease, Dermatitis Herpetiformis, Sjögren's Syndrome & Cerebellar Ataxia benefit from avoiding gluten. Do your kids have any of the above, or stomach bloating from eating gluten? Sourdough breads have neutralised the anti-nutrients.

Cheers, Nige.

lightcan said...

My son has a bit of stomach bloating (he's 5 and sometimes his belly looks too round, although he's not fat, but not in the morning before eating) and a bit of a rash near his nose for the last 2 weeks, that looks like eczema, also his skin is very sensitive. He has an aunt that had coeliac disease and died of oesophageal cancer. My husband had asthma as a child, but he was bottlefed, however to me it looks like I should be careful. I eliminated cow's milk for a while and gave him only goats but didn't make any difference to his rashes (a few years ago) So only sourdough bread and occasionally desserts made with normal flour.
I hear you and I answered on dr. A's blog. What do doctors want? To medicate you. I was prescribed anti depressants, I should think about contraception, I'm sure they want to put me on statins. My GP called today to say I should repeat bloods to see what happened to my lipids. I asked for a referral to see an endo. She's not listening. So, no, nothing has been done regarding low T3. Dr. Harris thinks maybe on low carb one's T3 is lower and it's not something to worry about. So much speculation. Do you go on his forum?
I've started at last with 5k D3 from iherb and vit K2. I'm curious about my gums.

Nigel Kinbrum said...

Hi lightcan.

If your son has a bloated tum, try him on non-gluten carbohydrates i.e. everything except wheat/spelt, rye & barley. Oats contain avenin, a relatively harmless form of gluten so see how he gets on with that. My ex-G/F's son has eczema and he avoids gluten to keep his skin clear. She has DH & SS so she also avoids gluten.

As for you, I did say that until your FT3 is in the Reference Range (the middle of it preferably), your health problems (sky-high cholesterol, hair loss, feeling cold & sluggish, depression etc) won't go away.

I do read Kurt G Harris' blog. Low FT3 when in caloric deficit may be normal but you aren't in caloric deficit. Your weight hasn't significantly gone down or up so your FT3 should be in the RR, not way below the bottom of it. Do a deal with your GP. Tell her that you're willing to do things her way (take anti-depressants, statins etc) if and only if she gets your FT3 into the middle of the RR and it doesn't make any difference. This has gone on for way too long. Why are you curious about your gums?

I'm having an inguinal hernia operation today so I won't be around later to answer any questions. Hopefully, I'll be back tomorrow.

Nige.

lightcan said...

Thank you again for your suggestions. It's good to have somebody to talk to.
I hope your operation goes well.

I had serious gum disease with gum recession about 3 years ago. I'm seeing the hygienist every 4 months now for cleaning. I'm trying to preserve my bone tissue.

Nigel Kinbrum said...

Hi lightcan.

Thanks. I'm back again. The Vitamin K2 should help your bones. As for your gums, the only things off the top of my head that I can think of that adversely affect gums are Vitamin C deficiency and Co-enzyme Q10 deficiency.

Nige.

plastic surgery marketing guide said...

Eating more whole grains isn't just a new fad though, eating more whole grains can help with weight management, reduce the risk of coronary heart disease, reduce constipation, and eating grains fortified with folate.

Nigel Kinbrum said...

Hi plastic surgery marketing guide,

As my post points out, most "whole grain" cereals don't contain whole (i.e intact) grains.

Why is eating grains so important? There's nothing in grains that you can't get from other foods.