In order to illustrate, I am gathering links to various threads that have discussed the ways diet and healthy habits relate to acne. And the various ways that various nutrients help. Because there's so much to it, it's impossible to remember it all. Will always be in progress.

And please, note that each and every individual study will always have some condition they didn't control for. That doesn't mean they necessarily should be discounted. That means you should look into more studies and use your brain to put two and two together.

-----------------------------------------------------------------------------------------------------
Diet effects acne in so many ways: digestion, allergies and intolerances, liver function, adrenal function, hormone balance, SHBG levels, Insulin resistance, inflammation, cell function and turnover, sebum quality, nutrient deficiencies, body fat, etc, etc. And most of those overlap and are also affected by environment and lifestyle habits like stress management, sleep and exercise.

Start with the pinned Studies thread:
http://www.acne.org/messageboard/Clinical-...-A-t215374.html

Then try NdRomeo's excellent summary of research:
http://www.acne.org/messageboard/forums.html...t

And LiliVGs excellent
Big Picture http://www.acne.org/messageboard/Bigger-Pi...it-t182474.html
and her first post in her Taurine/Fructose thread: http://www.acne.org/messageboard/Fructose-...ri-t178851.html

And we all know there's thousands of insulin resistance/blood sugar threads. (Exercise, however, does more for insulin resistance than diet.) In addition, there are several studies in the studies thread relating insulin to acne. Stimulates Androgen and IGF1 production. Androgens stimulate oil production, IGF1 causes hyperkeratinization and hyperproliferation of skin cells. And note how high GI foods relate to inflammation.
http://www.acne.org/messageboard/Glucose-I...Acn-t43208.html
http://www.acne.org/messageboard/Fat-Diet-...;hl=cholesterol
http://www.acne.org/messageboard/Fats-Insu...;hl=cholesterol
http://www.acne.org/messageboard/Rethinkin...ol-t196482.html
http://www.acne.org/messageboard/forums.html...t

And zinc threads.
And Gluten
And dairy.
And Omega 3.
And IBS, Leaky Gut syndrome and other digestion problems leading to food intolerances leading to inflammation and elevated androgen leading to acne.

Dietary Fats
High Fat diet can lower SHBG levels: http://www.ncbi.nlm.nih.gov/pubmed/3558725?dopt=Abstract
But there's been several studies on low fat and low carb helping hormone issues, partially by improving SHBG levels. See more on SHBG levels

And Cholesterol can lower testosterone. Looking for a thread.
And fat can help prevent blood sugar spikes within a meal, lowering the GI effect of the meal, but that doesn't mean the meal needs to be high fat, it just needs to include fat.

Omega 3s and Omega 3/6 ratio
Omega 3 is anti-inflammatory and improves insulin resistance. Lots of threads, not found yet. But more below under Nutrients and deficiencies.
Affects Melatonin http://www.ncbi.nlm.nih.gov/pubmed/1871617...Pubmed_RVDocSum
EFAs important for zinc absoption: http://www.ncbi.nlm.nih.gov/pubmed/6253772?dopt=Abstract
GLA, the omega 6 that's anti-inflammatory and good for hormone balance. See under Nutrients.

Inflammation:
http://www.acne.org/messageboard/Inflammat...ml&hl=sleep
Study finding high protein diet might lead to inflammation:
http://www.acne.org/messageboard/Study-Inf...ro-t206146.html
Inflammation a role in insulin resistance and many, many of our modern diseases. See how sleep has a role in inflammation. Which affects adrenals, which affects hormones.
High Fructose Corn Syrup
http://www.acne.org/messageboard/Fructose-...;hl=cholesterol
Innactivity leads to Inflammation: http://www.acne.org/messageboard/Inactivit...nf-t158893.html - also insulin resistance.

Stress/poor sleep habits can lead to adrenal fatigue adrenal fatigue? Notice it also has a role in estrogen dominance. Poorly functioning adrenals can use up nutrients.
http://www.acne.org/messageboard/Adrenal-f...on-t189260.html
http://www.acne.org/messageboard/Adrenal-g...in-t170228.html
Dr Lam http://www.drlam.com/articles/adrenal_fatigue.asp?page=4
Vitamin C; Vitamin B12; Vitamin B5 and its derivative pantethine; Vitamin E; adrenal glandular from various sources; herbs such as licorice, ashawanda, ginseng, maca (Peruvian ginseng); pro-hormones such as DHEA and pregnenolone; and steroids are good for Adrenal fatigue. Sugar, Caffeine, stress, poor sleep are bad.

You need sleep for healthy adrenals.
http://www.acne.org/messageboard/Circadian...ml&hl
http://www.acne.org/messageboard/Sleep-t215896.html
http://www.acne.org/messageboard/Skin-Isn-...ar-t184301.html
Omega 3 EFAs can effect melatonin which helps you sleep. See EFAs

Allergies, Intolerances and Histamine- causes inflammation in addition to possibly directly leading to a pimple. It's not just rashes, hives and asthma attacks.
Relationship between elevated androgens and elevated histamine: http://www.acne.org/messageboard/Androgens...ml
IgE vs IgG anti-body responses: http://www.acne.org/messageboard/IgE-vs-Ig...le-t200416.html
Different responses besides histamines involved in reactions and how to mediate them:
http://www.acne.org/messageboard/Immune-Re...se-t196132.html
Somewhere in a sweetjade thread there's reference to a study in which levels of Linoleic acid affect ROS levels which are involved in some types of reactions in food hypersensitivities. So more linoleic acid can reduce some reactions.

Experiments with prescription anti-histamines:
Zantac T: http://www.acne.org/messageboard/Theory-t70386.html
Alavert experiment: http://www.acne.org/messageboard/allergy-a...on-t152543.html
Natural anti-histamins: Vitamin C, sodium, and some flavanols/oids whatever the collective term is.

Allergies and Intolerances can lead to/and be caused or worsened by:
IBS, Leaky Gut and other digestion issues (which lead to inflammation, hormone imbalance)
http://www.acne.org/messageboard/ACNE-DIET...mp;hl=leaky+gut
http://www.acne.org/messageboard/forums.html...t

Binge eating causes blood sugar spikes stimulating hormones. Also causes inflammation.
http://www.acne.org/messageboard/Binge-eat...ml&hl
http://www.acne.org/messageboard/forums.html...t

Hyperkeritinization & Sebum quality
Hyperkeritinization is when dead skin cells are blocked from leaving the follicle by an excess of keratin, a natural protein found in the skin. This results in an increased adherence/bonding of dead skin cells together that block hair follicles causing keratosis pilaris or oil ducts causing acne. This tendency is genetics. One of the ways we are predisposed to acne.
http://www.acne.org/messageboard/Linoleic-...;hl=cholesterol
I've just read in a sweetjade thread reference to a study in which levels of Linoleic acid affect ROS levels which are involved in some types of reactions in food hypersensitivities. So more linoleic acid can reduce some reactions.

Hyperproliferation of skin cells
Taurine http://www.acne.org/messageboard/Fructose-...ri-t178851.html which your body can't make without sufficient sulfur containing amino acids.
Vitamin D http://www.acne.org/messageboard/Good-resu...ar-t188139.html
IGF-1 - hormone triggered by insulin which leads to hyperproliferation of skin cells.

IGF-1 Insulin Growth Factor - stimulated by high blood sugar/insulin, in Dairy, stimulates hyperkeratinization.

Hormone Imbalance:
Testosterone and DHT
DHT inhibitors and receptor blockers: Zinc, Green tea, beta sitosterol-in all plant oils, good sources include avocados, pumpkin seeds and olive oil. It's the main magic ingredient in well known herbals like Saw Palmetto, Pygeum, nettle.
5-alpha-reductase -enzyme that converts testosterone to DHT. There are two types. Type 1 more involved in DHT that binds to oil follicles. And type 2 effects DHT that binds to hair follicles.
http://www.acne.org/messageboard/Hormonal-...s-Spir-f51.html
EGCG can decrease DHT, but other substances in green tea can increase DHT
http://www.acne.org/messageboard/Green-tea...in-t189363.html
Phyto-Androgens, foods with plant androgen hormones: http://www.acne.org/messageboard/Phyto-And...;hl=cholesterol
Spearmint/peppermint tea

Estrogen dominance
PMS issues and irregular cycle may be indicators of estrogen dominance. It's about a possible excess of estrogen relative to a possible deficiency of progesterone. And acne and other symptoms occur with the monthly fluctuation of progesterone. And you can be estrogen dominant and have excess testosterone or DHT at the same time.
- see adrenal threads above
- DIM, Broccoli pill threads- contain all kinds of great info, not just about DIM
http://www.acne.org/messageboard/female-ma...pp-t185775.html
http://www.acne.org/messageboard/science-D...ge-t189051.html
http://www.anapsid.org/cnd/hormones/estrogen.html
http://www.acne.org/messageboard/DIM-appea...cn-t189473.html
More info on estrogen dominance that can lead to so many health problems like fibroids, breast and endometrial cancer...


Progesterone

-Phyto Estrogens - from soy, flax seed, can help or hurt. Avoid if you have hypothyroid
Dangers of soyhttp://www.acne.org/messageboard/forums.html...t
Peppermint Tea

GLA - the anti-inflammatory omega 6 that's also helps with hormone balance.
Omega 3

SHBG levels Sex hormone binding globulin synthesized in the liver. Binds to androgens so they can't bind to receptors in follicles where they stimulate oil production. Low GI diet increases SHBG levels. High levels of insulin in body, from insulin resistance for example, is linked to low SHBG levels.
http://www.acne.org/messageboard/Sex-hormo...;hl=SHBG+levels
http://www.acne.org/messageboard/fat-high-...;hl=SHBG+levels PCOS diet is also low fat and low carb which results in improved SHBG
http://www.acne.org/messageboard/forums.html...t
More on SHBG to be looked into, including the conditions low levels can cause:
http://www.digitalnaturopath.com/cond/C655233.html

Liver function (and one of those functions is to remove excess hormones from circulation)
http://www.acne.org/messageboard/Fructose-...rkeratinization -HFCS over taxes liver.
Bile http://www.acne.org/messageboard/Fiber-And...54#entry2655754

Prostaglandins (& GLA)
http://www.acne.org/messageboard/Ingredien...ne-t209192.html

Arachidonic acid



Nutrients & deficiencies:

Zinc - antibiotic, anti-inflammatory, anti-androgenic (enhances SHBG binding), 5-alpha reductase inhibitor, needed for converting Vitamin A into 13-cisi retinoic acid
http://www.acne.org/messageboard/forums.html...t
http://www.acne.org/messageboard/Zinc-rese...lk-t154999.html

Magnesium
http://www.acne.org/messageboard/Magnesium-heal-t183604.html

Taurine - Non-essential, but very important nutrient that requires B vitamins, sulfur containing aminos, zinc, D etc to manufacture.
http://www.acne.org/messageboard/Fructose-...ri-t178851.html

B vitamins
B6 is Anti-androgenic and involved in fat metabolism to improve sebum quality. But you need to take in the form of a complex.

EFAs, omega 3/6 ratio, GLA--the 'good' omega 6
http://www.acne.org/messageboard/Linoleic-...ai-t170647.html
EFA levels effect melatonin production which affects sleep and is an anti-oxident
http://www.ncbi.nlm.nih.gov/pubmed/1871617...Pubmed_RVDocSum

http://www.acne.org/messageboard/Omega-3-6...id-t141574.html

C - http://www.acne.org/messageboard/Adrenal-g...in-t170228.html

D http://www.acne.org/messageboard/Study-Vit...es-t213767.html
Sie's research http://www.acne.org/messageboard/Good-resu...ar-t188139.html

E
http://www.acne.org/messageboard/Finally-1...52#entry2298152

Fiber:
http://www.acne.org/messageboard/Glucomannan-t192949.html

Resveratrol

Hydrochloric Acid affects nutrient absoption, and of course, complete digestion (stimulate with cayenne)
http://www.acne.org/messageboard/Skin-Dise...ydr-t72702.html
http://wholehealthsource.blogspot.com/2009...d-nutrient.html

Sulfur/sulfur amino acids - anti-inflammatory, needed to make Taurine, plant sources good for the liver, components such as I3C helps remove bad estrogens.
http://www.acne.org/messageboard/Sulfur-t76078.html

High Fructose Corn Syrup - Coca cola and almost all bottled drinks
Fructose intake at current levels in the U.S. cause gastrointestinal distress/malabsoption. http://www.ncbi.nlm.nih.gov/pubmed/16183355

Dairy, esp from Cows
IGF-I
Iodine,
Lactose intolerance
Common Allergen

Wheat/gluten


List of several nutrients and their sources:
http://www.acne.org/messageboard/forums.html...t

Body fat, which affects hormone balance, inflammation...And another way a diet or exercise change can improve, or possibly worsen acne.

General discussions on variety of causes
http://www.acne.org/messageboard/Real-Cause-t215657.html

Things that can deplete or inhibit absorption of nutrients:

Sugars
Depletes/inhibits Chromium, copper, calcium and magnesium, E
Fructose intake at current levels in the U.S. cause gastrointestinal distress/malabsoption.
http://www.ncbi.nlm.nih.gov/pubmed/16183355"

20ways sugar harms your health http://articles.mercola.com/sites/articles...s-part-two.aspx

Phytates: in grains
Inhibit Zinc and other metals

Gluten

Oxalates in almonds, chard, cocoa, rhubarb and spinach
Can Inhibit absorption of magnesium, iodine, calcium (but some studies on calcium in spinach show the effect is negligible.)

Phosphorus - it's what keeps us from vomiting from the massive amounts of sugar in Coke.
Depletes zinc, magnesium and calcium.

'How I cleared my skin' threads.

Success Compilation Thread, Links to threads of people who have become clear
http://www.acne.org/messageboard/Success-C...ea-t172158.html

Holistically Clear Skin club
http://www.acne.org/messageboard/Holistica...20&start=20

Healthoid's
http://www.acne.org/messageboard/Cure-Acne-t200048.html

NdRomeo's
http://www.acne.org/messageboard/Finally-1...52#entry2298152

I don't have one, but you can visit my log. http://www.acne.org/messageboard/clear-ski...di-t143913.html

Pretty good compilation of how diet affects acne. Doesn't leave much out.
http://www.acne.org/messageboard/Bigger-Pi...it-t182474.html

The OFFICIAL Diet-Acne Link Articles Thread
http://www.acne.org/messageboard/OFFICIAL-...ink-t77931.html

Raise a hand if U don't GET Diet-Acne connection, Questions, Break down, Discusssion, etc
http://www.acne.org/messageboard/Raise-han...;hl=SHBG+levels

http://www.acne.org/messageboard/SILENT-Co...rkeratinization

http://www.acne.org/messageboard/Acne-and-...ar-t208435.html

http://www.acne.org/messageboard/Glucose-Intolerance-and-Acn-t43208.html ://http://www.acne.org/messageboard/Gl...cn-t43208.html ://http://www.acne.org/messageboard/Gl...cn-t43208.html

Rethinking Cholesterol
http://www.acne.org/messageboard/Rethinkin...;hl=cholesterol

What happens when you drink a coke
http://www.healthbolt.net/2006/12/08/what-...coke-right-now/

http://www.acne.org/messageboard/Acne-figh...=prostaglandins

http://www.acne.org/messageboard/forums.html...t

http://www.acne.org/messageboard/HORMONAL-...=prostaglandins

http://www.acne.org/messageboard/TRUTH-ACC...=prostaglandins

Types of acne and how they form:
http://www.best-treatment-for-acne.com/cause-of-acne.html

I just came across this thread and I hope that it gets pinned because it's so replete with information regarding diet, nutrition and the link to acne. So BUMP me up baby!!!!

I agree entirely, very useful post thanks