the fallacy of dietary fibres & increasing digestive time

[Guest guest]

Hi everyone,

I'm re-posting this message because I wanted to ensure the subject

line was corrected. Bee

> Robin wrote: Hi Bee, What is your recommended level of fiber for

>people? I wasmade to understand that while bad bacteria and Candida

>thrive on sugars and starches and things moving through the colon

>slowly, goodbacteria thrive on fiber and and things moving through

>the colon quickly..

The term " dietary fibre " describes a group of complex carbohydrates,

usually plant-derived, that resist digestion by mammalian enzymes.

Common sources of dietary fibre include the plant cell walls of

vegetables, fruits and cereals and the outer protective layer of

seeds. Dietary fibre is a diverse group of substances, which includes

cellulose and other complex carbohydrates.

The main factor to note here is " dietary fibre " " resist digestion by

mammalian enzymes. " It does not make sense to me that foods which

resist digestion are a good thing. Maybe these foods are only good

for herbivores like cows who have 5 stomachs to totally break down

these foods? I'll provide more information on fibre and bowel

transit time further down in this message.

Candida does thrive on sugars and starches, but does it thrive

on " things moving through the colon slowly? " What " things? " Candida

does not feed off of protein or fat so even if proteins or fats were

moving slowly candida would not feed off of them.

I don't know where the idea came from that " good bacteria thrive on

fiber? " That doesn't make sense either. If that were true the

Eskimos and other peoples who only eat protein and fats would not

have any " good bacteria " in their guts.

I question the idea that it is healthier to make food move quickly

through the digestive system. Why? The body needs times to absorb

important nutrients. This assumption would mean that it takes " too

much time " for proteins and fats to move through the digestive

system, and that somehow causes problems. I don't believe that is

true.

I went on a total high protein and high fat diet for a few weeks and

did not find transit time was increased. I also did not find a lack

of bulky stools. When I've consumed higher amounts of grains and raw

vegetables high in fibre I found they had a tendency to irritate and

upset my bowels. But when I was on a total protein and fat diet my

stomach and bowels were fine - no gas, no bloating, no cramps, etc.,

and no abnormal stools.

This led me to believe that the whole idea of eating plent of fibre

to increase bowel transit time was totally false, probably

perpetrated by the food industry. It didn't make sense that foods

which " resist digestion by mammalian enzymes " would take less time

than proteins or fats which do not resist digestion. I tried to find

out exactly how long it takes to digest meats and fats as opposed to

fibres, but I couldn't find anything specific. All I could find were

normal digestive times: 1) 2-4 hours in the stomach, 2) 5-6 hours in

the small intestine, and 3) 12-24 hours in the large colon = total

time about 20 - 30 hours. Most people have regular stools once a

day, so this makes sense. I don't think that if I ate a large salad

first and then had meat and fats that the bowel would move faster for

the salad and slower for the meats and fats. That wouldn't be

physically possible anyway.

Following are some excerpts from an article by Barry Groves

called " CLIMB DOWN FROM THE BRAN WAGON " at:

http://www.second-opinions.co.uk/bran_and_cancer.html

I will be posting the entire article in the files as well.

" The claims made for fibre are based on its rapid transit through the

gut and, because of this property, bran has been a popular way to

manage irritable bowel syndrome (IBS) for since the early 1970s. So,

is it effective? The answer appears to be no.

A number of placebo controlled studies of bran in IBS have not shown

any convincing effect of the fibre on overall symptom patterns.

Results of a study from St Bartholomew's Hospital in London, showed

clearly that fifty-five percent were made worse compared to only ten

percent made better. (7) All symptoms of IBS were exacerbated (made

worse) by wheat bran, with bowel disturbance most often adversely

affected, followed by distension and pain.

The authors conclude: 'The results of this study suggest that the use

of bran in IBS should be reconsidered. The study also raises the

possibility that excessive consumption of bran in the community may

actually be creating patients with IBS by exacerbating mild, non-

complaining cases.'

Some patients found that the added bran in their food induced or

exacerbated uncomfortable symptoms of flatulence, distension and

abdominal pain. In these cases, reduction in the amount of bran eaten

was recommended.

The late Yudkin, Professor Emeritus of Nutrition and Dietetics

at London University, pointed out that 'perhaps one reason for the

wide acceptance of the suggestion that fibre is an important, if not

essential, dietary component is that it had the enthusiastic support

of commercial interests.' He was writing in particular about the high-

bran products, All Bran and Branslim. (5)

It had been shown in the mid-1980s that dietary fibre increased the

risk of colon cancers. (10) In 1990 The British Nutrition Foundation

admitted that the hypotheses that IBS, diverticulosis and colo-rectal

cancer are caused by a deficiency of fibre had not been

substantiated, neither have those that fibre might protect against

diabetes, obesity and CHD. (11)

The Seventh King's Fund Forum on Cancer of The Colon and Rectum

agreed: 'The Forum commented that cereal fibre does not offer

protection against cancer'. (12)

Dr M Inoue, et al published in 1995 an investigation of cancers at

several colorectal subsites: ascending, transverse, descending,

sigmoid, and rectum, within a Japanese hospital environment. They

concluded that loose or soft faeces are a significant risk factor for

cancer at these sites. (13) And bran loosens and softens faeces -

that's why it is recommended.

The following year Drs HS Wasan and RA Goodlad of the Imperial Cancer

Research Fund showed that bran can increase the risk of colorectal

cancers. (14) 'Many carbohydrates', they say, 'can stimulate

epithelial-cell proliferation throughout the gastrointestinal tract.

They conclude: 'Until individual constituents of fibre have been

shown to have, at the very least, a non-detrimental effect in

prospective human trials, we urge that restraint should be shown in

adding fibre supplements to foods, and that unsubstantiated health

claims be restricted. . . . Specific dietary fibre supplements,

embraced as nutriceuticals or functional foods, are an unknown and

potentially damaging way to influence modern dietary habits of the

general population.'

This study spawned several critical letters. It comes as no surprise

that half were from people connected with the breakfast cereal

industry. (15) "

Other adverse effects from fibre:

Tests into the supposed benefits of increasing dietary intake of

fibre soon showed that there could be other harmful side-effects:

•Because it is indigestible, bran ferments in the gut and can

induce

or exacerbate flatulence, distension and abdominal pain. (19)

•Although it is supposed to travel through the gut at a faster

rate,

it does not always do so and it has been shown to cause blockages.

(20)

•All the nutrients in food are absorbed through the gut wall and

this

takes time. It should be obvious, therefore, that if the food travels

through faster, less will be absorbed. And, indeed, this is the case.

Fibre is found to inhibit the absorption of zinc, (21) iron, calcium,

phosphorus, magnesium, energy, proteins, fats and vitamins A, D, E

and K. (22)

•Phytate associated with cereal fibre (bran) also binds with

calcium,

iron, (23) and zinc, (24) causing malabsorption. For example,

subjects absorbed more iron from white bread than from wholemeal

bread even though their intakes of iron were fifty percent higher

with the wholemeal bread. (25) Also, while white bread must have

added calcium, the law does not require it of wholemeal bread.

•Bran fibre has also been shown to cause faecal losses, (26) and

negative balances of calcium, (27) iron, zinc, phosphorus, (28)

nitrogen, fats, fatty acids and sterols thus depleting the body of

these materials. (29) (A negative balance is where more is lost from

the body than is absorbed, i.e. the body's stores are depleted.)

The findings, particularly in sub-paragraphs c. to e. above are a

cause for concern in several sections of the population who are at

considerable risk from eating too much fibre - and bran fibre in

particular:

•Post-menopausal women stand a 1 in 2 chance of suffering from

osteoporosis (brittle bone disease) and 1 in 5 of them will die as a

direct result. (30) That is twice as many as many fractures as there

were in the 1950s. (31) Osteoporosis is caused by a number of things,

but it is basically a calcium deficiency which is at the heart of the

disease. Very few surveys have concentrated on intake of any nutrient

other than calcium and more research is needed on this subject.

However, as the eating of bran both inhibits the absorption of

calcium from food and depletes the body of the calcium it has, is it

coincidence that the incidence of osteoporosis has increased by about

ten percent a year for the past two decades?

In England alone, a fifth of all orthopaedic beds are now occupied by

patients with broken hips and the direct hospital costs alone

amounted to more than £160,000,000 a year over a decade ago. (32)

That figure did not include other breakages, personal costs and, of

course, the pain and hardship brought on by the disease. Broken bones

also require zinc for their repair, and zinc is another mineral whose

absorption is adversely affected by cereal fibre.

•Calcium also plays an important role in the processes that keep

normal body cells normal. Imbalances in these processes can have such

adverse consequences as acute disruption leading to rapid cell death,

and start other processes which lead to the deregulation we call

cancer. Recent studies have shown that increases in dietary calcium

may protect against cancer of the colon. (33) From this must follow

that if calcium is not available because of the amount of bran in the

diet, the risk of such cancer may be enhanced.

•Patients with Alzheimer's disease (senile dementia) have been

found

to have abnormal amounts of aluminium in their brains. Tests on the

people of Guam and parts of New Guinea and Japan, who get the disease

at a much younger age, have linked it too with a lack of calcium. It

is suggested that the lack of calcium causes a hormonal imbalance

which allows the aluminium to penetrate the brain. (34)

•Infants can suffer a similar brain damage if fed soya based baby

milk. (35) Soya based milk has a high phytate content which, as we

have seen, inhibits the absorption of some minerals. (36) It is

believed that a zinc deficiency so caused enhances the uptake and

deposition of aluminium in the milk.

•Depression, anorexia, (37) low birth weight, (38) slow growth,

(39)

mental retardation, (40) and amenorrhoea are also associated with

deficiencies of zinc and the first five of these are also associated

with a deficiency of iron (see sub-paragraph g. below).

•Vitamin deficiency diseases such as rickets are also increasing.

Such diseases are common in communities where a nutrient poor, fibre

rich diet is consumed, and rickets was so common in this country

early in the century, that it was called the 'English disease'. All

such diseases in this country should have been relegated to the past

but now they are on the increase again. (41) Studies of UK Asians, in

which the incidence of rickets is high, cite as the cause the Asians'

low-calcium, high-cereal diet. (42)

•If there is a large intake of 'anti-nutrients' such as phytate,

dietary fibre and tannins, which impair the absorption of iron, (43)

and a low intake of flesh foods (another result of the diet-heart

recommendations), there is a real risk of iron deficiency anaemia.

And sub-optimal iron nutriture is already found in UK, USA, Canada

and South Africa. (44)

•Lastly, there is an apparent relation between dietary fibre and

reproductive function in the female. It affects the onset of

menstruation and retards uterine growth. (45) Later it is associated

with menstrual dysfunction. (46)

The best in health,

Bee