HWS 410: Role of Fats & Lipids in Health & Disease

Types of fatty acids

- saturated: single bonds (animal fat, butter)

- monounsaturated: one double bond (avocado, olive oil)

- Polyunsaturated: more than one double bond (plant oil, omega 3/6)

When someone eats a lot of saturated fats, membranes are not as....

permeable which decreases the health of cells and eventually organs

Trans fat

synthetic fat

- we don't have enzymes to break this down

- hydrogens are across each other

Functions of Essential Fats

part of cell membrane

- omega-3 important in brain function, found in myelin

- essential in the form of 18 carbon which needs to be metabolized into 20 carbon (eicosanoids)

Eicosanoids

20 carbons

- regulate inflammation

- blood coagulation

- allergic reactions

Eicosanoids - different chemicals/functions

- prostaglandins (PGEs): regulate inflammation

- thromboxanes (TXAs): regulate blood clotting

- Leukotrienes (LTs): regulate allergic reactions (asthma, hay fever)

Omega-6 Fatty Acid

found in vegetable oils

- eicosanoid: arachidonic acid is pro-inflammatory

Omega-3 Fatty Acid

primarily from fish oil (also found in flaxseed, canola, soybean oils)

- ecosanoid: EPA is anti-inflammatory (produces DHA)

Farm raised fish is a good or bad sources omega-3?

bad source

Omega-6 eicosanoids; archidonic acid

increases blood clotting, allergic responses, and inflammatory responses (free radicals)

Omega-3 eicosanoids; EPA

decreases blood clotting, allergic reactions, and inflammatory responses (free radicals)

Importance of balancing omega 6 with omega 3

omega 6 is abundant in American diet, omega 3 is limited; imbalance is unhealthy

Large amounts of omega 6...

consumes all the necessary enzymes to produce EPA (anti-inflammatory omega 3)

- too much omega 6 negates the anti-inflammatory effect of plant based omega 3 which is why foods containing EPA are needed

Inflammation and free radical generation

Injury -> pain, activation of WBC, release of arachidonic acid -> production of inflammatory substances (leukotrienes and prostaglandins) -> recruitment and stimulation of neutrophils -> production of free radicals -> if enough antioxidants are present, free radicals are neutralized -> if there are not enough antioxidants it leads to oxidative stress

What would reduce a response from WBC during inflammation and free radical generation?

omega 3

What would reduce/stop oxidative stress during inflammation and free radical generation?

antioxidants

Omega-6, free radicals, and LDL oxidation

oxidized LDL no longer recognized by LDL receptor

- when LDL is oxidized, it cannot bind to the receptor because the shape has changed causing LDL to remain in the blood and raising blood cholesterol

Omega 3 decreases cell multiplication

prevents obesity, inhibits cancer, prevents angiogenesis

Functions of cholesterol

- essential component of cell membrane

- produced by the liver

- found only in animal products

- forms important hormones (estrogen, testosterone, vitamin D)

- precursor to bile acids

HDL

high-density lipoprotein; healthy cholesterol

LDL

low protein lipoprotein; lethal cholesterol, easily oxidized

How to increase HDL

exercise, B3 or niacin, fish (omega 3), purple skinned fruits

Resveratrol

comes from fruits like grapes and berries; reduces inflammation, antioxidant

Alcohol/wine and heart health

does not lower heart disease; shrinks brain, increases oxidative stress, kills neurons (and are unable to regenerate)

Heart disease

covers a number of diseases which affect the heart, including coronary artery disease, heart failure, and angina; #1 killer in US

Risk factors of Heart disease

age, gender, hyperlipidemia (LDL, VLDL), hypertension, diabetes (AGEs, endothelial dysfunction), obesity, genetic predisposition, stress, lifestyle (lack of physical activity, smoking)

Homocysteine

- amino acid that can accumulate when there is a deficiency of folate, B12, B6

- easily oxidized amino acid that can cause injury to lining of blood vessels and oxidation of LDL

Are women at risk of heart disease?

yes, only after menopause because estrogen prevents heart disease (after menopause estrogen levels decrease)