More Facts on Fats Lipids and Health

The Fats Saturated Unsaturated Hydrogenated Trans fats triglycerides containing saturated fatty acids Unsaturated Contain unsaturated fatty acids Double bond usually has cis conformation Hydrogenated Addition of hydrogens to unsaturated fats to make them more solid at room temperature Trans fats Contain unsaturated fatty acids in trans conformation

Lipids & Cholesterol Lipids are hydrophobic Blood contains water Lipids are conjugated with proteins in order to be transported in blood Lipid + protein = lipoprotein 3 types of lipoproteins: High-density lipoproteins (HDL) aka good cholesterol Carry cholesterol from the rest of the body to the liver Low-density lipoproteins (LDL) aka bad cholesterol Carry cholesterol from liver to the rest of the body Very low-density lipoproteins (VLDL) - this one is an ugly one Carry triglycerides from liver to adipose tissue Excess cholesterol can be detected by measuring the amount of lipoproteins present in the blood

Atherosclerosis "Hardening of the arteries" Slow process that may start in childhood Over time, walls of arteries become damaged - Fatty tissues release compounds that promote healing through plaque build-up

Plaque Fatty substance made up of cholesterol, fat and calcium Builds up over damaged area, but causes the artery to become narrowed Narrowed tube = higher pressure (think of putting your thumb over end of hose) Higher pressure sometimes causes more damage to the artery walls

Risk Factors Atherosclerosis may start when certain factors damage the inner layers of the arteries. These factors include: Smoking High amounts of certain fats and cholesterol in the blood High blood pressure High amounts of sugar in the blood due to insulin resistance or diabetes

So… Arteries that are blocked cannot provide the heart with needed oxygen/nutrients Lack of oxygen leads to death of tissue Also can cause embolism- chunk of plaque breaks off and enters bloodstream Clot enters major artery going to heart leads to heart attack; to brain = stroke

Bypass Surgery Surgeons take a segment of a healthy blood vessel from another part of the body and make a detour around the blocked part of the coronary artery.

LDL (aka "Bad" Cholesterol) Transports ~ 75% of cholesterol to cells If LDL is oxidized, (combines with free-radicals), LDL is modified penetrates and damages the walls of arteries- causes inflammatory response Body's response can promote further damage: WBC's and other inflamm. factors gather and form a plaque Damage to endothelium Increase risk for blood clots Reduces levels of nitric oxide (needed for relaxation of vessels)

HDL (aka "Good" Cholesterol) Removes cholesterol from walls of arteries and returns it to the liver Prevents oxidation of LDL (has antioxidant properties) Reduces narrowing of vessels, and risk of heart attack High levels of HDL are beneficial to health Fish oils, omega-3, 6 fatty acids

Role of Omega-3 & Omega-6 Fats? High in whole grains, fresh fruits and vegetables, fish, olive oil, garlic (0mega-3) and meat (omega-6) reduce inflammation and help prevent risk factors associated with chronic diseases such as heart disease, cancer, and arthritis important for cognitive (brain memory and performance) and behavioral function Balance of omega-3 and omega-6 needed

Omega 6 Omega 3

Triglycerides (good? Bad?) Are now becoming known as a major problem for the heart Interaction between HDL and TG- shows a decrease in HDL as TG levels rise (relationship is under study) Imbalance of HDL/TG associated with obesity, insulin resistance, and diabetes Also may lead to blood clots and inflammatory responses