From what I have read, lecithin has been used medically since before I was born to dissolve gallstones and in more recent times a cure for MS. The brain being mostly lecithin and the blood flows on a lecithin highway, etc., etc. I see it as an important supplement to the normal diet. Those with a natural diet would not need it.

Like dissolves like and the body must be able to take up the plant lecithin and use it possible to make human lecithin, either way, it is cheap and is used allot in commerical cooking, because with out lecithin, many foods could not be sold. I can safely state most people are lecithin deficient because commerical food used the lecithin as bait for their junk foods on purpose.

MH

Lipids come in 3 forms: (1) fats, (2) phospholipids, and (3) steroids (sometimes referred to as waxes).
You might want to look through this page to get an idea of the differences:
http://www.mansfield.ohio-state.edu/~sabedon/campbl05.htm#lipids
Oils come under the category of "fat."
Cholesterol is a steroid.
And lecithin is a phospholipid.
One thing about lecithin is that it is an emulsifier. One side of it can mix with fat, the other side can mix with water. So it can bind together things that normally will not mix together.
Eating lecithin is not the exact same as eating an oil and it doesn't have all the same effects. Eating oil makes the body secrete bile, makes the liver and gallbladder pump. Eating lecithin helps the body absorb fat and fat soluble vitamins. Eating lecithin helps the body create bile, and bile can dissolve oils and cholesterol (and the body produces most of its own cholesterol - so you have it even if you never eat it).

Here's some more reading, if you're interested (you can skip over some of the chemistry diagrams and still get something out of it):

http://www.mothernature.com/Library/Bookshelf/Books/23/46.cfm
http://www.mansfield.ohio-state.edu/~sabedon/biol1030.htm
http://biology.clc.uc.edu/Courses/bio104/lipids.htm
http://www.1001herbs.com/lecithin/
http://www.thehealthierlife.co.uk/article/2892/gallstones.html
http://www.doctoryourself.com/lecithin.html
http://alternative-medicine-and-health.com/conditions/gallprobs.htm
http://www.mothernature.com/Library/Bookshelf/Books/23/92.cfm
http://www.cockatoo.com/lecithin/index.htm
http://web.indstate.edu/thcme/mwking/lipids.html
http://web.indstate.edu/thcme/mwking/cholesterol.html (bottom reads):
----------------------------
Clinical Significance of Bile Acid Synthesis

Bile acids perform four physiologically significant functions:

1. their synthesis and subsequent excretion in the feces represent the only significant mechanism for the elimination of excess cholesterol.

2. bile acids and phospholipids solubilize cholesterol in the bile, thereby preventing the precipitation of cholesterol in the gallbladder. (LECITHIN IS A PHOSPHOLIPID)

3. they facilitate the digestion of dietary triacylglycerols by acting as emulsifying agents that render fats accessible to pancreatic lipases.

4. they facilitate the intestinal absorption of fat-soluble vitamins.

it is because it restores dead liver cells that are there because u were deficient in lecithin in the first place, very good to do after a liver flush!