Note

Lecture March 2011 Lipids continued

Fats Why are lipids important from a nutritional perspective ? Blood free fatty acids-if elevated concentration then greater risk of type II diabetes Blood triglycerides – if elevated concentration then greater risk of heart disease Blood cholesterol- if elevated concentration then greater risk of heart disease

Lipoproteins -lipids are insoluble in water -need protein and phospholipid coat to be transported around in body blood (water a problem)

Lipoproteins continued -good cholesterol-high density lipoprotein cholesterol -bad cholesterol –low density lipoprotein cholesterol -very low density lipoprotein- carry mostly triglyceride in fasting state -chylomicrons-carry triglyceride only post- prandially

Atherosclerosis- how does it work ? LDL- pumps cholesterol into arterial wall HDL- pumps cholesterol out of arterial wall Triglycerides make the LDL more aggressive in pumping cholesterol into the arterial wall

Eating lipids -it’s a good news/bad news story Saturated fats raise concentrations of blood triglycerides, free fatty acids and cholesterol and bad cholesterol and chylomicrons and very low density lipoproteins and lower good cholesterol

Eating lipids -it’s a good news/bad news story Monounsaturated fats lower concentrations of blood triglycerides and cholesterol and bad cholesterol and chylomicrons and very low density lipoproteins and free fatty acids and maybe raise good cholesterol

Eating lipids -it’s a good news/bad news story Polyunsaturated fats lower concentrations of blood triglycerides and cholesterol and bad cholesterol and very low density lipoproteins and chylomicrons and free fatty acids and raise good cholesterol Trans fatty acids elevate blood cholesterol levels and bad cholesterol and lower good cholesterol

Eating lipids -it’s a good news/bad news story Keep lipids to 30 % or less of total dietary energy intake -this means 600 kcal of fat per day for a 2000 kcal diet-why? Keep saturated fatty acids to less than 10 % or less of total dietary energy intake- why? To accomplish these fat goals follow Canada’s food guide

Fats in foods and other sources Saturated fat foods -meats (especially red meats and pork) -fried foods -dairy products

Fats in foods and other sources Monounsaturated fat foods Omega 9 –oleic acid is the major fatty acid of interest nutritionally at this point in time -olives -olive oil -canola oil

Fats in foods and other sources Polyunsaturated foods -corn -corn oil -most plant products -deep sea or cold water fish-why? -arctic char -salmon

Fats in foods and other sources Omega 3 -alpha-linolenic acid (ALA) -flax seed oil -canola seed oil -black currant seed oil -humans make eicosapentaenoic acid and docosahexaenoic acid from alpha-linolenic acid -eicosapentaenoic acid-fish and algae -docosahexaenoic acid- fish and algae -oil blends containing fungal oil

Concept of functional foods versus a nutraceutical -a functional food is a food that contains one or more molecules that do not have a traditional nutrient role but yet confer a therapeutic advantage -a therapeutic advantage means preventing or partially preventing or curing or partially curing a disease -eg flax bread fish garlic (not used for lipid composition to date)

-a nutraceutical is a concentrate of one or more molecules of a plant or animal -these one or more molecules may not have a traditional nutrient role but yet confer a therapeutic advantage -eg fish oil canola oil allicin (not a lipid) –allicin found in garlic

Thus the lipids can be found in food, a functional food or a nutraceutical

When we get to diseases we will talk more about lipids and their role in specific diseases -arthritis -heart disease (atherosclerosis) -stroke -type I diabetes -type II diabetes -cancer