Aside from carbohydrates, fats have been blamed for making us fat.
And certainly, maybe that's an easy thing to correlate.
Fat makes us fat. But if we talk about them as lipids,
maybe it'll be a different story. Just like carbs, fat has gotten a bad
rap. Lipids are an essential part of our diet
we need fat and as i go through the next series of slides remember about what you
eat and think about what it means how is the quality of lipid I consume going to
dictate the quality of my own body withins Lipids.
And just remember, as I said, we need fats, its our storage form of energy, it
helps us digest our foods, its important in breaking, digesting, the essential
the, its, stop So just remember, too, we need fat.
As I mentioned, it's important for our storage of energy, we need it to digest
fat soluble vitamins, and just make our taste, food taste good.
And not all fat is bad. It's the excess fat intake, just like the
excess sugar intake, that's causing the problem.
So let's talk a little bit about different types of lipids, among the
categories of lipids, how we name them and how we identify them.
The simplest form of lipid is the free fatty acid.
These hydrocarbon chains range from 4 to 24 carbons in length with a methyl group
at one end, and a carboxyl group at the other.
The carboxyl end is termed alpha, the methyl end termed omega.
And this technique is useful in naming fatty acids are grouped by degree of
saturation. A saturated fatty acid has no double
bond. All of its carbons are bonded to
hydrogen. Mono-unsaturated fatty acids have one
double bond in their chain. They're sometimes abbreviated as MUFA, or
MUFA, Folic acid as imaged here is found in olive oil and it's an Omega-9 fatty
acid. Omega-9 fatty acids are not considered
essential. Fats because we can make them in the
body, and of course, saturated fats are also not essential.
This omega designation comes from the naming of fats, and it's based on where
that first double bond is. the double bond here is signified with a
red color. If you are unable to see that you can see
the lack of hydrogens in the slight change in shape of the structure.
The simplified image to the right points out the 9 carbon and it's the simplest
counting over, counting over one, two, three, four, five, six, seven, eight,
nine. Nine carbons Omega-9 fatty acid we will
do the same thing for omega threes and omega sixes polyunsaturated fatty acids
have multiple double box in our chain and are abbreviated PUFA,
or PUFA. The malonic acid illustrated here is
found in corn and corn oil and is an essentiall fatty acid.
Essential fatty acids are essential as I mentioned because we can't make them. We
lack the specific saturated enzyme required to make a double bond anywhere
before Carbon 9. So this makes the Omega-3's and 6's
essential, and you'll see potentially marketing campaigns, so you talk about
increasing them in a subsequent lecture. You're going to hear a little bit more
about the healthful benefits of eating more omega-3 fatty acid based foods or
sources of omegO Fatty acids. These dietary sources may vary.
Omega-6's are more abundant in what we consider a western diet, typically we do
consume Omega-6's than 3s, but Mediterranean and fish-based diets will
have more Omega-3's. Again, you'll learn more about that in
the subsequent lecture for this week. The saturation of a fatty acid will
affect it's structure, quality in food, stability and affect in the body.
The more saturated the fat is, the more saturated the food containing that fat
too, the more solid it will be. So think about lard versus butter, versus
margarine, versus olive oil. At room temperature, these will all have
different consistencies. This occurs, put simply, because the
double bonds in saturated fatty acids create a kink in the structure.
These lipids then stack less tightly, resulting in a.
More liquid form. In regard to stability, less saturated
fatty acids are more susceptible to oxidation and they will be more likely to
become rancid. Foods that they're in will be more likely
to Become rancid. We can protect foods higher in
unsaturated fat by adding more antioxidants or preservatives, a natural
one would be vitamin E, as well as keeping these foods cool and reducing
their exposure to air and light. Another way we could actually change the
structure of some of these. Highly unsaturated fatty acid sources.
we've done this to produce a spreadable plant-based product, margarine.
And this semi-solid fat is created through the process of hydrogenation.
In this process, unfortunately, trans-fat synthesis does occur.
And while there are some trans-fats in nature, they're primarily a product of
food processing. In order to create a plant based fat with
this butter consistency the manufacturer removes double bonds of some of the fatty
acids via hydrogenation which. Addition of hydrogen under pressure.
As this product liquif, solidifies, as this product solidifies, we're going to
make some more saturated fat, not all saturated, but we're also going to alter
the structure of some of the unsaturated. Fats.
And if you hadn't had a lot of chemistry or else you put this in a simple terms,
we go from a trans-is to a trans-bond. And here, I've shown images of this, you
can see the difference. So, in the sis form, the carbons go down
to both sides of that bond. In the trans form, become
transcontinental. Trans goes from one side to the other.
And so that's what's happening on these transfats.
Again they are somewhat in nature but really our bodies don't process those
well, and like saturated fat they come with significant pulse concerns if we
over consume trans fats. Fatty acids are also identified by
length. We can elongate short chain essential
fatty acids to longer ones, though it is not a highly efficient process in humans.
We can also desaturate them as the chain link that and only after the ninth carbon
in a short chain acid that you can get from plant or long chain. Omega-3 fatty
acids also come in the shorter or longer chain versions.
This current version is not, efficient, and when we talk about Omega-3 fatty
acids, in health, and if you go to the next lecture, think about the benefits
coming primarily from EPA or DHA. So, if you want to improve outcomes, you
likely want to consume foods, or supplements, with EPA and DHA in it.
And those would be the animal based To form.
You can obtain lineolinic and linolaic Omega-3 and Omega-6 from newer sects of
foods, including veggies, grains, meats, seafood, eggs and milk.
Here is a figure illustrating the types of fat found in your food.
So, take a minute just to compare. So they are lipids, again your going to
find it in the fat portion especially when you are talking about animal foods,
there in the fat of fish or the oil portion of the plant.
And we can compare some of the sources, so lets say we do want to get more omega
three A real abundant source in the oil category would be coconut oil.
An abundant source in some of the animal products would actually be fish.we will
talk about that one in the next slide, but right now looking at the types of
fats you could cook with if you do want to change the profile of your, Profile of
your body. My, one might be canola oil.
Now some people don't like consuming canola oil, it is a processed food.
Another one that's going to give you the biggest bang for your buck is flaxseed
oil. Now flax seed oil, is not something you
can cook with, however. That's why I did not list it first, of
these here, that you can cook with. Normal oils again, is the highest source,
but flax seed oil is a great thing we could add as a salad dressing, or as a
topping later, as opposed to, a cooking oil.
As far as animal based sources go, seafood, especially fish are great
sources of essential fatty acids, Omega-3, especially EPA and DHA And just
like we are what we eat, our animals are what they eat, the livestock that we
choose to consume. And a corn fed cow is going to have a
different fatty acid profile than a grass fed cow.
Same goes for the chicken producing eggs the eggs, not only the chicken will
differ, the meat from the chicken will differ, but the eggs will differ.
Here's a chart illustrating the fatty acid profiles of feed stuffs.
Now, if you are a vegetarian, maybe you don't really want to think about the idea
of eating animals, but maybe you do eat eggs or cheese.
And certainly, the health of an animal. Just like the health of a person is
dictated by what he eats. Alright.
So the next type of fat is the Triglycerides, the lipid Tryglyceride.
Here we see fatty acids in our triglyceride.
It is the storage form of fat and the fat we're going to find in our food.
So it's what's in our fat cells and the fat of our fish, once digest the glycerol
component will be metabolized like a carbohydrate.
And to synthesis the triglyceride if you're going to make fat to store, we do
require a series of condensation reactions that combine a hydrogen.
From the glycerol, to a hydroxyl from a fatty acid.
Making a bond, and water. We now have a compound that can be
stored. It also is important for the taste and
texture of our food. Can then later.
Well, after being sorted, could be used as energy.
It's going to bring in those essential fatty acids.
And it's also important for cell signaling and gene transcription by
releasing those 3 fatty acids. So when we think about function
triglycerides, really encompasses the function of fatty acids that it's
bringing in. Another important lipid is the
phospholipid, so again when we think fat, fat's not, is just fat.
There's a lot of different types of lipids that are in our bodies.
So here, we see what is a cell membrane, it's an illustration and we are going to
make our, stop. Start.
So here we see the illustration of a cell membrane, with its phospholipid
components, including the fatty acids associated with that phospholipid.
And this is where "we are what we eat" comes into play.
Depending on what type fat is in that phospholipid, that will determine what
type of fat what you utilize in the body. All right, so the next category of lipid
is the Lipoprotein and Sterols, including Cholesterol.
There are numerous types of Lipoproteins, all of which have different jobs to do.
the Chylomicron and VLDL we won't focus on.
We will come back to Chylomicrons when we talk about digestion.
Mostly, we're going to talk about LDL and HDL.
Now one thing to clarify, when we talk about good or bad cholesterol,
cholesterol is cholesterol. It's all the same thing.
really when we talk about good or bad cholesterol, we talk about the LDL and
HDL, which are lipoproteins, low density and high density, and we can remember
which one's good or bad by L, standing for lethal, and H standing for healthy.
All right. , So the job of LDL lipoprotein is to
carry those cholestrol molecules from the liver to the cell.
And in doing so, we do at times see deposition of cholestrol and plaque
buildup in the cardiovascular system. On the other hand the job of HDL
lipoprotein is to take this cholesterol from the cells to the liver and it can
along the way clean up the cardiovascular tract preventing plaque buildup and
blockages. See if you go to the doctor, and you may
not only hear a reports of your LDL level, but also the ratio of LDL to HDL.
Improving HDL cholesterol and reducing LDL cholesterol has been shown to be
beneficial in cardiovascular disease. So again let's not blame the lipid
blaming the cholesterol for causing all of these problems.
It's simply the excess intake leading to the excess deposition of the problem.
And you can go to the following link here to see this illustration and learn more
about the progression of cardiovascular disease.
but to give you a basic summary what we're seeing here.
Is that, in this cardiovascular tract in the arteries, we don't have normal blood
flow. And when excess cholesterol and other
components of the blood build up on the arterial walls, it can restrict the blood
flow. When we get the point where this blood
flow is completely restricted or completely blocked, that is when we see
heart attacks. Risk of stroke.
What you eat, how much fat you eat, fiber, how many antioxidants you consume,
how varied your diet is, this can all dictate whether or not you will have more
or less buildup in your cardiovascular system.
Certainly there are genetic components to cholesterol level, and some people can
eat as healthy as ever and still have high cholesterol.
Speaker: But, even if you do have genetic predisposition to high cholesterol,
eating healthy is still key to managing the condition.
So, just in short, we do know that certain foods are going to be better for
maintaining a heart healthy diet, and the Congludo Monounsaturated fatty acids over
saturated ones, improving the Omega-3 intake.
Increasing omega 3s versus all other fatty acids, including Omega-6's 6s.
Consuming more fiber. Talked a little about that in the
carbohydrate lecture. Also, B vitamins to help keep the body
healthy. Antioxidants to help keep the
cardiovascular system strong. And as well as some soy proteins relative
to other proteins. to help balance our body.
We would then like to avoid saturated fats trans fats which are laid to
saturated fats and their effects and excessive cholesterol intake, again you
do use cholesterol all you need cholesterol in your body but your body
meets plenty of it so you don't need to eat it All right.
So I hope you've learned a little bit about fats.
Oops, nope I meant lipids in the diet.