Phytosterols:  These are polycyclic alcohols which occur in plants ("phyto-" is a prefix meaning "plant").  Evidence suggests that phytosterols may play a significant role in regulating blood cholesterol.  Their Table 2 data come from the USDA food composition tables.

Tocopherols:  These are isomeric fat-soluble alcohols which include Vitamin E (alpha-tocopherol).  Their antioxidant property helps to keep cooking oils from becoming rancid.  Their Table 2 data come from the USDA food composition tables.

Tocotrienols:  These compounds are closely related to tocopherols and have Vitamin E activity.  Their Table 2 data (except for rice bran oil) come from the Seed Oil Fatty Acids (SOFA) database.  The SOFA database can be most easily searched by inserting a single word (e.g. corn, safflower, etc.) into the Freetext block of the search form and leaving the rest of the search form blank.

Polyphenols:  These are loosely defined as aromatic alcohols with 1 or more hydroxy group (strictly speaking, phenols with 1 hydroxy group should not be called polyphenols).  They, like tocopherols and tocotrienols, function as antioxidants and help keep cooking oils from becoming rancid.  Their Table 2 data come from an online research journal article (Asia Pacific J Clin Nutr (1996) 5: 105-107).

Vitamin K:  A fat-soluble cyclic ketone that promotes blood clotting; also called phylloquinone.  The Table 2 data for Vitamin K come from the USDA food composition tables.

Squalene:  A metabolic precursor of cholesterol which has exhibited anti-cancer properties in animal studies.  The Table 2 data for squalene (except for rice bran oil) come from an abstract of an article in the European Journal of Cancer Prevention 12(1):67-75, Feb 2003.  Seed oils contain only minimal amounts of squalene, and there is no convenient data source to which to link to such data.

1) All of the Table 2 data presumably refer to refined oils although none of the data sources explicitly say so.  Unrefined oils are much richer in minor components than refined oils.

2) Commercial cooking oils have standards for peroxide content (i.e. degree of rancidity).  However, these standards are often not strict enough for highly sensitive individuals such as myself.

3) The ingredients listed in Table 2 are generally regarded as having a positive effect on health.  The refining process attempts to remove whatever ingredients are known to have negative effects.

1) The most plausible explanation for the symptoms shown in Table 3 is that I am sensitive to peroxides which arise via the oxidation of oils during manufacturing.  The strongest evidence for this is that corn oil, peanut oil and canola oil do not cause me symptoms when they are produced via expeller pressing, but cause headaches when they are manufactured via the conventional high-temperature process.  Few people experience noticeable symptoms from ingesting cheap cooking oils but that does not mean that the oils are high quality.  If they were high quality, there would be no reason for health-food stores to offer the expeller-pressed oils as an alternative.

3) The oils obtained by low-temperature manufacturing were expeller pressed, except for grapeseed oil, which must be solvent extracted.