• lipids are divided into three major classes: triglycerides, phospholipids (lecithin), and cholesterol
• lipids are vital component of nutrition and perform necesary functions: basic component of cell membrane, cell metabolism, enzyme reactions, synthesis and utilization of sterol hormones and hormone-like prostaglandins, carrier for fat soluble vitamins A, D, E and K, memory and nervous system function
• all fats and oils are a combination of saturated and unsaturated fatty acids; fats are classified by the fatty acid structure of the major constitiuent oil
• pesticides, which are very fat soluble, tend to be concentrated in oil products; therefore it is a good idea to buy organic oils whenever possible. Oils especially high in pesticide residue: soy, corn, cottonseed, canola
• store oils in refrigerator, tightly capped away from light
• buy oils in small quantities and use before they become rancid

Saturated fats:
• solid at room temperature (butter, lard)
• derived from animal products
• fatty acid chain contains no double bonds (that is: all the bonds are “saturated” by hydrogen atoms)

Polyunsaturated fats:
• liquid at room temperature
• derived from plant sources
• fatty acid chain contain two or more double bonds; therefore are more easily oxidized by light, heat and air (that is: the double bond is attacked by oxygen) to become rancid
• lowers total serum cholesterol by lowering both HDL and LDL
• they are implicated in some types of cancer, especially breast
• high in essential fatty acids

Monounsaturated fats:
• liquid at room temperature
• derived from plant sources
• fatty acid chain contains only one double bond; therefore are more resistant to oxidation
• lowers total serum cholesterol by lowering LDL and leaving HDL levels unchanged

Fiber
• complex of cellulose, non-cellulose polysaccharides and lignans
• protects against: diverticulosis, diverticulitis, colon cancer, hemorrhoids, varicose veins, appendicitis, irritible bowel syndrome, ulcerative colitis, Crohn’s disease, kidney and gallstones, obesity, diabetes mellitus, gout, cerebrovascular disease, hypertension, pulmonary embolism, ischemic heart disease, dental caries, dermatological conditions, autoimmune diseases

Cellulose
function:
• smooth function of large bowel: absorb water, increase size of stool, decrease transit time, help prevent constipation
• important source of short chain fatty acids via bacterial degradation
sources:
• whole wheat flour, bran
• plant cell wall constituent: cabbage, young peas, green beans, wax beans,
broccoli, brussels sprouts, cucumber skins, peppers, carrots, apples

Hemi-cellulose:
function:
• increase fecal weight
• important source of short chain fatty acids via bacterial degradation
• binds bile acids
sources:
• oatbran, cereals, whole grains, brussel sprouts, mustard greens, beetroot

Algal polysaccharides:
function:
• laxative
• delays gastric emptying time
• heavy metal chelation
sources:
• algin
• seaweeds: agar, arame, hijiki, kelp, kombu, etc.
• carrageenan is considered suspect: it has been associated with food sensitivities, colon cancer, birth defects

Mucilage:
function:
• decrease fat absorption
• lower cholesterol levels
• coat gut and delay glucose absorption to smooth sugar surges for diabetics
• delays gastric emptying time
• heavy metal chelation
sources:
• psyllium seeds, guar
• legumes: dried beans, chickpeas

Pectin:
function:
• decrease fat absorption
• lower cholesterol levels
• coat gut and delay glucose absorption to smooth sugar surges for diabetics
• delays gastric emptying time
• heavy metal chelation
sources:
• squash, apples, citrus rinds, cauliflower, green beans, cabbage, dried peas, carrots, strawberries, potatoes

Lignin:
function:
• binds with bile acids to lower cholesterol
• reduces digestibility of other fibers
• helps speed food through the gut
• antioxidant
• anticarcinogenic
sources:
• wheat, bran, older vegetables, apples, cabbage, strawberries, eggplant, pears, green beans, radishes