Lipids - Health Issues & Lipids

Vocabulary flashcards to review key lipids concepts from the lecture notes.

Lipids

A diverse group of fat-like substances (fats, oils, and related compounds) that are insoluble in water; provide 9 kcal/g, supply essential fatty acids, aid absorption of fat-soluble vitamins, add palatability, promote satiety, and serve as stored energy and structural components.

Essential fatty acids

Fatty acids that must be obtained from the diet because the body cannot synthesize them; include linoleic (n-6) and alpha-linolenic (n-3) acids.

Linoleic acid (n-6)

An essential omega-6 fatty acid important for skin integrity, cholesterol regulation, growth, and production of prostaglandins.

Alpha-linolenic acid (ALA) (n-3)

An essential omega-3 fatty acid that serves as a precursor to EPA and DHA; important for brain development, immune function, and cardiovascular health.

EPA

Eicosapentaenoic acid; long-chain omega-3 fatty acid derived from ALA; contributes to heart health and anti-inflammatory effects.

DHA

Docosahexaenoic acid; long-chain omega-3 fatty acid derived from ALA; essential for brain and neural development and cardiovascular health.

Omega-3 fatty acids

Polyunsaturated fats with the first double bond at the third carbon from the methyl end (includes ALA, EPA, DHA); associated with cardiovascular benefits.

Omega-6 fatty acids

Polyunsaturated fats with the first double bond at the sixth carbon from the methyl end (includes linoleic acid); important for skin integrity and inflammation regulation.

Saturated fats

Fats with no double bonds; usually solid at room temperature; mainly from animal sources; associated with increased LDL cholesterol and atherosclerosis risk.

Monounsaturated fats

Fats with one double bond; typically liquid at room temperature; examples include olive oil and canola oil; can lower LDL when replacing saturated fats.

Polyunsaturated fats

Fats with two or more double bonds; include omega-3 and omega-6 fatty acids; essential fatty acids fall into this category.

Trans fatty acids

Unsaturated fats that have been hydrogenated to become more saturated and solid; raise LDL and lower HDL; associated with higher cardiovascular risk.

Cis fatty acids

Naturally occurring unsaturated fats with hydrogens on the same side of the double bond; generally healthier than trans fats.

Triglycerides

The main storage form of fat in the body; glycerol backbone with three fatty acids; can be monoglyceride or diglyceride if fewer fatty acids are attached.

Lipoproteins

Complexes of lipids wrapped in water-soluble proteins that transport lipids in the bloodstream (e.g., chylomicrons, VLDL, IDL, LDL, HDL).

LDL

Low-density lipoprotein; transports cholesterol from liver to tissues; high levels promote atherosclerosis.

HDL

High-density lipoprotein; returns cholesterol from tissues to the liver for excretion; protective against cardiovascular disease.

Chylomicrons

Lipoproteins formed in intestinal mucosa to transport dietary triglycerides via the lymphatic system into circulation.

Essential fatty acid deficiency

Deficiency due to inadequate intake of EFAs; symptoms include dry/scaly skin, liver abnormalities, poor wound healing, growth failure in infants, impaired hearing and vision.

AMDR for fat

Acceptable Macronutrient Distribution Range for fat: 20–35% of total daily calories.

Cholesterol

A sterol, not a fat or triglyceride; synthesized in the liver; essential for cell membranes and precursor to bile acids and steroid hormones; found in animal foods; dietary guidelines focus on fat quality, not a strict mg/day target.

Phospholipids

Lipids with glycerol backbone, two fatty acids, and a phosphate group; major components of cell membranes; lecithin is a common phospholipid that helps lipid transport.

Lecithin

A major phospholipid in lipoproteins; facilitates transport of lipids and formation of cell membranes.

Hydrogenation

Chemical process that adds hydrogen to unsaturated fats to make them more saturated; partial hydrogenation creates trans fats.

Hidden fat

Fat present in foods not obviously fatty (e.g., milk, eggs, cheese, nuts, bakery items, processed foods).

Visible fat

Fat that can be seen in foods (e.g., butter, margarine, oil, fatty meats).

Fat replacers

Substitutes used to mimic the functional properties of fat with fewer calories; include carbohydrate-based thickeners and protein-based products.

Olestra

Fat substitute that is not absorbed and provides 0 kcal/g; may interfere with absorption of fat-soluble vitamins.

Simplesse

Fat replacer made from milk or egg proteins; used as microparticulation to mimic fat texture with fewer calories.

Carrageenan

Fat replacer thickener derived from seaweed used to modify texture in foods.

Bile acids

Emulsifiers produced by the liver that aid fat digestion in the small intestine; release is stimulated by cholecystokinin (CCK).

Pancreatic lipase

Digestive enzyme from the pancreas that digests triglycerides in the small intestine.

MCT oil

Medium-chain triglycerides; fats with shorter chain length that are more water-soluble and absorbed directly into the portal blood; often used in intestinal diseases.

Atherosclerosis

Hardening and narrowing of arteries due to buildup of lipids and fibrous material; increases risk of heart attack and stroke.