next up we're going to take a look at the unsaturated fatty acids so we've got our mono as well as our polyunsaturated and referring back to the presentation from earlier unsaturated just means there's a point of a double bond so either one or many so let's take a look here at the first group which are the monounsaturated monounsaturated fats are also known as heart healthy fats these are very healthy for us and you can go ahead and glance through some of those food sources there and some of the reasons why these foods are often recommended is due to these monounsaturated fats uh some of the health benefits that you'll want to take note of monounsaturated fats have been associated with lower LDL cholesterol levels LDL is the bad stuff or the lousy stuff monos are also associated with lower overall triglyceride levels in the body as well as lower total cholesterol levels so they really have that he heart healthy cardiovascular benefit to them an interesting fact about these is that even if someone doesn't change anything else in their diet but they increase their intake of these it will improve their cardiovascular system Health uh sometimes I get asked about these oils so I just thought I'd throw in a consumer tip for you I get asked about is canola better than Olive is Olive better than canola well canola actually has less saturated fat to it so remember that glycerol with the Three fatty acids canola has more unsaturated than Olive uh canola oil also has Omega-3s which we'll get into next on the other hand olive oil has a higher percentage of these monounsaturated fats and it also contains antioxidants so they both have their Pros my recommendation would be to have both on hand and mix it up one day cook with Canola one day cook with olive or cook a little bit with both include both of them in the dish that you're creating to get the the best benefits from these oils oldfashioned peanut butter just means it hasn't been processed so literally we're just taking the peanuts we're grinding them down and we're using the peanut butter in that way so next up we have the polyunsaturated fatty acids these can be neutral for us or heart healthy uh going back to the neutral comment here they can be neutral if we're eating an appropriate amount of them if we start overdoing it on the neutral versions then it can affect our overall health which we'll get into here shortly so a bit of background on these under the umbrella term of polyunsaturated fatty acids we have two big categories they are Omega 6 and omega3 they are known collectively as essential fatty acids or efas so if you remember back to our first chapter essential means that we can't make it or enough of it in our body and we have physical symptoms without the nutrient so with these essential fats both omega-6 and omega-3 we've got to get them through our diet we're not going to be able to make them in our bodies and we're going to start having some physical symptoms without them so Omega 6 we see listed here as linolic acid linolic acid is the most predominant of the omega-6 fatty acids so therefore it's almost used as a term equivalent to omega-6 fatty acids on the diagram on the right here we have a picture of what this looks like uh just an FYI for you if you're curious about what these notations mean the c18 colon 2 uh all this means is there's 18 carbons so carbons 18 and then there's two double bonds so the number after the colon is the number of double bonds so just FYI there with the Omega-3s the most predominant minant one is called alpha linolenic acid sometimes it's abbreviated as ala and here is what it looks like so same uh system with the notations there's 18 carbons and then three double bonds so I trust all of you have heard of Omega-3s and if I asked you a food source you'd probably holler fish at me and you're very correct fish is a great food source of these we'll learn some other food sources of Omega-3s as well as these Omega sixes but I do want to make the fact or the point here that both are essential to us we have to get them through the diet and we really want a good balance of the two so let's go ahead here and get into the topic further I've got an FYI slide here just to if you haven't had chemistry or or organic chemistry to some extent uh just so that you understand why they're named omega-3 Omega 6 or even Omega 9 we're basically looking at the structure of that fatty acid the fatty acids have an Omega end which is a methyl end we have a carbon and three hydrogens they also have an alpha or an acidic end where we have the oxygen double bond so when we name these we're actually looking at the methyl end the Omega end here and we're counting carbons to see when that first double bond takes place and wherever that is that is how we name them so omega-3 with ala that first double bond is on carbon number three so we're going to name that molecule omega3 same for lenic acid Omega 6 the six carbon has that double bond so just if you are interested where these naming uh configurations come from so in looking at the food sources Omega 6 these are the ones that we consider neutral for our health if we get them in a very very high amount they can have some health detriments and then Omega-3s we know that these are the healthy oils for us so the recommended balance of these in our diets is about 3:1 ratio so for example uh out of all of the polyunsaturated oils that we consume we should have about 75% coming from Omega 6es and about 25% coming from Omega-3s so that's our classic 3:1 ratio the actual intake in America is about 95% of our polyunsaturated fats are from Omega 6 and only about 5% are coming from those Omega-3s so that's where we see some of the potential for uh for health implications Health considerations which we'll get into a couple of tips I wanted to share with you with Chia seeds and flax seeds these are fantastic sources of Omega-3s uh chia seeds you can just consume those as is you can add them to cereals you can add them to other products such as baked goods flax seeds to get the Omega-3s out we have to grind them so ground FL FL seed would be a better choice or uh if you are doing your own grinding let's say you have a coffee grinder then you can purchase whole flax seeds and then grind them in a coffee grinder and then add them to your baked goods or add them to your cereals that kind of thing uh sometimes it's recommended to purchase the ones that are that are whole flax seeds and then grind them on your own because you're uh limiting the rancidity so if we purchase flax seeds that are already ground at the store then some of those flax seeds may already be a little bit may already have some rancidity from that oil being exposed to oxygen and whatnot uh if you consume them fairly quickly though if you go through a package of ground flax seeds in several weeks then you're you're probably fine on that we just wouldn't want that ground flax seed to sit out on the counter for months and months and months because after that it's going to start losing its benefits and losing its taste uh fortified Foods we do see these added to foods for example some of the cereals out there breakfast cereals have omega-3s added also there's an egg brand Eggland's Best if you've seen those in the stores they feed the hens a feed that has omega-3 fatty acids in them so their eggs particularly that yolk will actually have a bit of Omega-3s in them so you're going to get some in through eggs even though eggs aren't a traditional source of these so why is balance key with these well this is a little bit of a heavy topic so I've included some more words on this slide just so that you guys are on the same page with knowing learning what you need to know about this in our bodies these essential fats both omega-6 and Omega-3s are precursors to what we call ioso so in essence they're making compounds called ioso uh ioso are compounds like prostaglandins or lucot triin thromboxanes you probably learned learned some of these in chemistry or in physiology they're also outlined in your book so if you want the correct spelling you can check that section out these substances are very very valuable for regulating our body function and you see my first point here here are some of the main body functions inflammation in particular so the omega-6 fatty acids particularly that linolic acid the one that's the most predominant makes a compound in our bodies called Aria acid and you see that listed here in the left hand side of the figure this is a particular ioso precursor that then leads to the formation of compounds that regulate immunity blood claing so on and so forth on the other hand omega-3 fatty acids particularly ala is very helpful to making fatty acids in our body that are called EPA and DHA and these are also precursors to ooids EPA and DHA you've probably heard these terms if you take fish oil supplements you've probably seen those on the nutrition facts panel EPA and DHA are very very healthy compounds that when we talk about the benefits of omega3 we're really talking about the benefits of those those particular fatty acids uh a couple of points here before we talk about the the health outcomes if you will on the slide here's the same not so 182 means 18 carbons two double bonds for lenic and then Alpha linolenic you see there's even more double Bonds in these molecules so just as a recap the omega3 Omega 6s make certain fatty acids in our bodies that are precursors to these ioso so here's the problem with some of these ioso the ones that are made from Omega-3s are very healthy for us they're and anti-inflammatory and you can read through this figure kind of walk your way down we've talked about food sources here's ala EPA DHA and then anti-inflammatory agents on the other hand omega-6 fats tend to be the ones that lead to Pro inflammatory compounds this arachadonic acid uh if we get too much of it in we create compounds that can create inflammation as well as damage DNA uh proliferate aging there's even some studies that suggest too much arachidonic acid can increase the risk of cancers arthritis heart disease is another one so this is why that ratio of them is so so valuable we don't want to have a lot of this pro-inflammatory stuff going on if we don't have enough anti-inflammatory stuff to balance it out so just food for thought a lot of our oils are coming from Omega sixs are there things in your diet that you could do to increase a bit more of these omega-3s so I wanted to include just a slide and a few comments from me about the benefits of Omega-3s in the chapter of carbohydrates I spent some time on fiber and its unique Health properties in this chapter my favorite topic is Omega-3s just due to their potential benefit on health so I'll read you a couple of key Health outcomes that we find with high intakes of Omega-3s we find that that EPA and the DHA those two oils have very beneficial effects on brain development so particularly in embryo as well as a child's young years so developing the brain fully they also have a fantastic effect on our blood they help thin the blood which makes it less likely to clot uh they also decrease inflammation in the body systemic inflammation other benefits noted by your book they can lower blood pressure they decrease your bad cholesterol they improve your sleep they actually improve circadian rhythms that help you to sleep and a couple of other benefits they enhance the immune system and they help decrease tumor development so we're not going to get into the mechanisms of all the wise of that in this class but bottom line super healthy compounds for us the visuals I've chosen to include on the left are the amounts of Omega-3s in certain fish so you can see mackerel is great salmon is a good one as well most of us pretty low including just one or two servings of fish per week can actually get you the the Omega-3s that are recommended for health if you're not a fish person there are some other Alternatives uh this is where the walnuts and the different seeds can come into play so here's flax seeds uh these are not ground yet so we would have to grind them to have it more of a powder to get the benefits chia seeds you don't need to grind them they're already uh they're able to be the oil is able to be liberated as is from that chia seed and a final note on Omega-3s the Alaskan Eskimos actually brought our attention to Omega-3s way back in the' 40s and the 50s uh Alaskan Eskimos eat a lot of fat because they're eating a lot of fish so 50% of their diet is coming from fat but it's all healthy fat right we know this now so we were looking at their diets as well as their health outcomes and seeing that this is a population that really doesn't suffer with heart disease no problems with blood pressure no problems with clog arteries so what's in their diet that's making such a difference and we found that it's this compound uh in to summarize it the Ala the alphin lenic acid the the precursor then to the EPA and the DHA in our bodies all right so that is the last section I believe here on our fatty acid so we've covered triglycerides we've covered the main fatty acids which were saturated trans monounsaturated and then these polyunsaturated so we're ready to move on to our second main category of lipids which are phospholipids our third one is steril which will be on the next slide so we're not going to spend too much time on these two because they're not a huge dietary source they certainly have benefits in the body that 95 to 98% of what we eat in the form of lipids comes from triglycerides so with phospholipids if we take a look at our structure here some of it is quite similar to that of a triglyceride we have a glycerol backbone and now we have two fatty acids so instead of three we've got two the main difference that we see is we have another group on top of that glycerol we have a phosphate group for all of them and then potentially another group depending on what that phospholipid is so this one this example on the figure is actually leathan I've got that on the slide this is a very predominant phospholipid so the choline is specific to leathan if we look at our end product here we have this large uh Circle if you will that they've highlighted where we've got our glycerol we've got the choline and the phosphate group this is the section that helps make that compound soluble in water so it's able to be transported in water whereas the fatty acids are going to be the opposite they're the ones repelling water or not soluble in water so phospholipids as a whole are unique and that they're soluble both in fat and water and that's going to lead us to some of the key functions of these these molecules so number one function uh they are great carriers we'll talk here in a few minutes about kyom microns and lipoproteins those are molecules that help to transport fat in our bodies and we need some kind of a compound that's soluble both in water our bloodstream as well as fat to be able to transport and get these fats to our tissues so lipoproteins and carriers are a big function a second function to note is this wonderful cell membrane all of our cell membranes have a beautiful phospholipid uh bilayer and this allows for that cushioning the support the fluidity to our cells and then a third function to note is phospholipids are fantastic emulsifiers so what is an emulsifier an emulsifier is something that allow ows both fat and water soluble compounds to be together in solution so I'm going I'm going to give you a few examples of these in a food form just so you can visualize it a very common emulsifier is leathan so that's why included this one on our figure lethan is found in egg yolk and egg yolk is something that we add to a lot of foods to help the fat components stay in solution with the water soluble components so a great example example would be adding egg yolk to mayonnaise so when we're creating mayonnaise or when the food companies are creating mayonnaise they have water they have vinegar and they also are having oil so what can keep that together in solution it's an emulsifier leian that's found in egg yolk so we have egg yolk added it's then the mo the food then is processed to where those two the fat and the water soluble components stay in solution uh this is a reason why we bake with eggs we add egg yolks to a lot of baked products to allow for things to disperse and be in solution uh a final example that comes to my mind is salad dressings have you ever seen salad dressings that will separate out where you've got the fat on the top and the water um water soluble components on the bottom and you're to mix it up right they say mix this up prior to using some of the salad dressings out there already premixed you don't really have to do too much to them and that is because they've got additives added to those foods that are emulsifiers it can be lethin that that's been uh isolated out from the egg yolk or it can be an artificial emulsifier uh check out the ingredient list on your salad dressings next time you have one out and I guarantee you some of those ingredients are just emulsifiers they're meant to keep the salad dressing in solution so that it doesn't separate out on you food sources of phosph well egg yolk I've mentioned that one a few times there really aren't that many other than that there wheat germ is one that's a plant-based one soybeans or another and those are really the top uh the top sources in our diet and as I alluded to earlier majority of what we eat is in that triglyceride form so we're not really taking in a lot of these an interesting tidbit regarding phospholipids our body makes quite a few of them for us uh including leathan it's one that's created in our bodies so certainly we can get it through food but more importantly for this uh is keeping in mind its various functions in the body so again lipoproteins and carriers cell membranes and emulsifiers then my final slide for this segment is on stero so steril are going to be our third class of lipids they look completely different than those fatty acids and triglycerides there is no glycerol and there are no fatty acids it's a ring-like structure filled with hydrogen and carbons it's a very dense molecule due to the structure of these molecules cholesterol being the most predominant stero they're able to do a wide array of functions in our bodies so I'll outline a few and you've probably heard of these in in previous classes as well sterols primarily cholesterol help to make hormones like estrogen and testosterone so the sex based hormones in our bodies cholesterol also helps to make bile another nutrition related one is vitamin D we all have heard that we make Vitamin D from Sunshine the precursor to that is actually a cholesterol that's found under our skin so when the UV light hits our skin it gets a Cascade of steps going to make vitamin D for us in our bodies food sources well we don't really see we do find cherol and food but we really don't see this being a huge contributor to our diets unless we're eating a a lot of animal products so cholesterol in general is mainly found in is only found in animal products primarily in liver and in brains so in organs so if you are a big fan of beef liver when you eat beef liver you're taking in quite a bit of cholesterol and the reason for that is any mammal is going to be making cholesterol in their liver so if we're consuming the liver of a mamal that's that's why we we take in so much the brain central nervous system requires a lot of fat FS for proper development so for eating brains of an animal we're going to get in a lot of cholesterol as well uh something to note with stero they're not essential in the diet because our bodies do make them so our livers can actually make as much cholesterol as we need from other fats so if we have someone who's a vegan who's not consuming any animal products then that's okay their bodies will be able to synthesize cholesterol just fine so animal sources tend to be the biggest s es of cholesterol there are some uh there are some plant-based steril out there as well which we'll talk about towards the latter part of this presentation they're not a huge component of our diets as we we generally don't consume them to such levels that they would be my final Point here I wanted to reinforce this the dietary cholesterol that we eat let's say that we're eating animal products uh liver or the muscles of animals eggs cheese whatever it might be we're going to get in some dietary cholesterol however that doesn't really lead to an increase in blood cholesterol levels that's a common misconception that if you eat too much cholesterol you're going to have high blood cholesterol um we do find in about 10% of people that can be true so there's always that caveat but 90% of us can eat a good amount of cholesterol and not have it affect our blood cholesterol levels now one of the reasons for that is the body takes some of this dietary cholesterol and starts synthesizing estrogen testosterone vitamin D cortisol and some of those other functions and our B's also sense if we're taking in a lot of cholesterol in the diet they're going to tell the body's going to tell the LI to not make as much so it has that uh kind of balancing effect on its own the biggest contributors to blood cherol levels as I hope you've taken away already are saturated fats and trans fats all right thank you for listening next up we're going to get into more of the digestion absorption and transport of these unique molecules in the body