Re: Tomato Question .... allergies, autoimmune disease and hygeine

[Guest guest]

Youske;

Some researchers suggest that the increased incidence of allergies

and autoimmune diseases in Western societies is due to greatly

improved hygeine, and especially the eradication of worms. This

eradication of worm parasites has tipped the balance of the immune

system, causing more inflammatory T cells (especially Th17 cells) to

be produced. This article from the New York Times does a pretty good

job of explaining it all ...

_______________________

Babies know: Dirt is good for you

By JANE E. BRODY

The New York Times - Published: February 1, 2009

Ask mothers why babies are constantly picking things up from the

floor or ground and putting them in their mouths, and chances are

they'll say that it's instinctive — that's how babies explore the

world. But why the mouth, when sight, hearing, touch and even scent

are far better at identifying things?

When my young sons were exploring the streets of Brooklyn, I couldn't

help wondering how good crushed rock or dried dog droppings could

taste when delicious mashed potatoes were routinely rejected.

Since all instinctive behaviors have an evolutionary advantage or

they would not have been retained for millions of years, chances are

that this one too has helped us survive as a species. And, indeed,

accumulating evidence strongly suggests that eating dirt is good for

you.

In studies of what is called the hygiene hypothesis, researchers are

concluding that organisms like the millions of bacteria, viruses and

especially worms that enter the body along with " dirt " spur the

development of a healthy immune system. Several studies suggest that

worms may help to redirect an immune system that has gone awry and

resulted in autoimmune disorders, allergies and asthma.

These studies, along with epidemiological observations, seem to

explain why immune system disorders like multiple sclerosis, Type 1

diabetes, inflammatory bowel disease, asthma and allergies have risen

significantly in the United States and other developed countries.

" What a child is doing when he puts things in his mouth is allowing

his immune response to explore his environment, " writes Ruebush,

a microbiology and immunology instructor, in her new book, " Why Dirt

Is Good. " " Not only does this allow for 'practice' of immune

responses, which will be necessary for protection, but it also plays

a critical role in teaching the immature immune response what is best

ignored. "

One leading researcher, Dr. V. Weinstock, the director of

gastroenterology and hepatology at Tufts Medical Center in Boston,

said that the immune system at birth " is like an unprogrammed

computer. It needs instruction. "

He said that public health measures like cleaning up contaminated

water and food have saved the lives of countless children, but

they " also eliminated exposure to many organisms that are probably

good for us. "

" Children raised in an ultra-clean environment, " he added, " are not

being exposed to organisms that help them develop appropriate immune

regulatory circuits. "

Helpful worms

Studies Weinstock has conducted with Dr. Elliott, a

gastroenterologist and immunologist at the University of Iowa,

indicate that intestinal worms, which have been all but eliminated in

developed countries, are " likely to be the biggest player " in

regulating the immune system to respond appropriately, Elliott said.

He added that bacterial and viral infections seem to influence the

immune system in the same way, but not as forcefully.

Most worms are harmless, especially in well-nourished people,

Weinstock said.

" There are very few diseases that people get from worms, " he

said. " Humans have adapted to the presence of most of them. "

In studies in mice, Weinstock and Elliott have used worms to both

prevent and reverse autoimmune disease. Elliott said that in

Argentina, researchers found that patients with multiple sclerosis

who were infected with the human whipworm had milder cases and fewer

flare-ups of their disease over a period of four and a half years.

At the University of Wisconsin in Madison, Dr. Fleming, a

neurologist, is testing whether the pig whipworm can temper the

effects of multiple sclerosis.

In Gambia, the eradication of worms in some villages led to

children's having increased skin reactions to allergens, Elliott

said. And pig whipworms, which reside only briefly in the human

intestinal tract, have had " good effects " in treating the

inflammatory bowel diseases Crohn's disease and ulcerative colitis,

he said.

How may worms affect the immune system? Elliott explained that immune

regulation is now known to be more complex than scientists thought

when the hygiene hypothesis was first introduced by a British

epidemiologist, Dr. P. Strachan, in 1989.

Strachan noted an association between large family size and reduced

rates of asthma and allergies. Immunologists now recognize a four-

point response system of helper T cells: Th 1, Th 2, Th 17 and

regulatory T cells. Th 1 inhibits Th 2 and Th 17; Th 2 inhibits Th 1

and Th 17; and regulatory T cells inhibit all three, Elliott said.

" A lot of inflammatory diseases — multiple sclerosis, Crohn's

disease, ulcerative colitis and asthma — are due to the activity of

Th 17, " he explained. " If you infect mice with worms, Th 17 drops

dramatically, and the activity of regulatory T cells is augmented. "

Are we too clean?

In answer to the question, " Are we too clean? " Elliott

said: " Dirtiness comes with a price. But cleanliness comes with a

price, too. We're not proposing a return to the germ-filled

environment of the 1850s. But if we properly understand how organisms

in the environment protect us, maybe we can give a vaccine or mimic

their effects with some innocuous stimulus. "

Ruebush, the " Why Dirt Is Good " author, does not suggest a return to

filth either. But she correctly points out that bacteria are

everywhere: on us, in us and all around us. Most of these micro-

organisms cause no problem, and many, like the ones that normally

live in the digestive tract and produce life-sustaining nutrients,

are essential to good health.

" The typical human probably harbors some 90 trillion microbes, " she

writes. " The very fact that you have so many microbes of so many

different kinds is what keeps you healthy most of the time. "

Ruebush deplores the current fetish for the hundreds of antibacterial

products that convey a false sense of security and may actually

foster the development of antibiotic-resistant, disease-causing

bacteria. Plain soap and water are all that are needed to become

clean, she noted.

" I certainly recommend washing your hands after using the bathroom,

before eating, after changing a diaper, before and after handling

food, " and whenever they're visibly soiled, she writes. When no

running water is available and cleaning hands is essential, she

suggests an alcohol-based hand sanitizer.

Weinstock goes even further. " Children should be allowed to go

barefoot in the dirt, play in the dirt, and not have to wash their

hands when they come in to eat, " he said. He and Elliott pointed out

that children who grow up on farms and are frequently exposed to

worms and other organisms from farm animals are much less likely to

develop allergies and autoimmune diseases.

Also helpful, he said, is to " let kids have two dogs and a cat, "

which will expose them to intestinal worms that can promote a healthy

immune system.

_______________________

The section of the article on Th17 cells is particularly intersting

to me, since a lot of the newly discovered Crohn's disease and

ulcerative colitis susceptibility genes seem to be involved in Th17

cell production. These genes would likely remain silent in a worm-

parasitized population, but would come into play in an environment

that is worm-free, and could explain the massive increase in

incidence of IBD in Western societies in recent years.

Best regards,

Dave

(father of (23); PSC 07/03; UC 08/03)

> I wonder I'm more sensitive than most as my body seems susceptible

to allergies (I have many environmental allergies - pollen, mold,

dust mites, etc).  Allergies are immune response (attacking foreign

substance that the immune system falsely recognize as harmful) which

causes inflammation.  PSC is an auto-immune disease (attacking our

own body part (cells) that the immune system falsely recognize as

harmful) causing inflammation, so I wonder if there's some connection

here.