LipidsPBHL 211

Darine Hachem, MS, LD

Outline

• Functions of lipids in our body

•Types of lipids

•Sources of lipids

•Recommendation of fat intake

• Fat association with heart diseases

Role of fat in our body

Provide energy (9Kcal/g fat)

Stored in adipose tissues

• No limit for fat storage

• Fat cells expand in size, and then new adipose cells are formed to store further fat

Acts as an Insulator

Protects the body from shocks

Part of cell membranes

Slow digestion and provides satiety

Transports fat-soluble vitamins (A, D, E, K)

High Fat Food Sources

Healthy Fats??

What are the different types of fats that we consume?

1. Saturated fatty acids

2. Unsaturated fatty acidsoMUFA

oPUFA

3. Trans fatty acids

4. Cholesterol

Saturated Fatty Acids

Unsaturated Fatty Acids

Monounsaturated Fatty Acids

(MUFA)

Polyunsaturated Fatty Acids

(PUFA: ω-3 and ω-6)

Structure No double bond One double bond Two or more double bonds

Source Mainly Animal sourcesTropical Oils

PlantsNuts

PlantsNutsSeafood

Food Sources Butter, dairy products, meat, chicken Coconut oil and Palm oil

Olive oilAvocadoSesamePeanutCanola oil

WalnutsSalmon Flaxseeds

Structure at Room Temperature

Solid at room temperature Liquid at room temperature

Liquid at roomtemperature

Stability Stable Not very stable Not very stable

Health benefits of MUFA

Monounsaturated fats help in improving blood cholesterol levels

Can decrease heart disease risk

http://www.eatright.org/resource/food/nutrition/dietary-guidelines-and-myplate/choose-healthy-fats

Essential fatty acids:

✓ Not synthesized in the body

✓ Structural part of cell membranes

✓ Major part of lipids in brains and nervous system

✓ Essential for normal growth in infants and children

✓ Transformed into hormone-like substances: (blood clot formation, blood pressure, immune inflammation responses…)

Health benefits of ω-3 fatty acids

✓ Lower blood cholesterol

✓ Lower triglycerides

✓ Decrease risk of blood clot formation

✓ Reduce blood pressure

✓ Improve blood vessel function and delay the build up of plaque in coronary arteries

Decreasing the risk for heart attacks & stroke

https://www.heartfoundation.org.au

Where do we get our ω-3 sources from?

Sources of (ω-3) fatty acids:

1. Seafood2. Plant sources

Seafood

(Fatty fish)Salmon

Tuna

Sardines

Plants:

Walnuts

Flaxseeds

Chia seeds

Canola oil

Soybean oil

Oil and Shelf life

Unsaturated fatty acids:

Have a short shelf life

Become rancid

(double bonds in MUFAs and PUFAs react with

atmospheric oxygen)

HOWEVER!

How can unsaturated fatty acids become more stable for use in the food industry?

Hydrogenation

Hydrogenation:

Chemical process by which hydrogen atoms are added to unsaturated fatty acids (liquid oils)

Upon Hydrogenation fats become:✓more saturated

✓more solid (semi-solid structure)

✓more stable- has a longer shelf life

Hydrogenation

HOWEVER!!

A new type of unsaturated fatty acids are produced:

“TRANS FATTY ACIDS”

Increase the risk for heart diseases by:

↑ LDL and ↓ HDL cholesterol in blood

High Trans Fat Food Choices

High Trans Fat Food Choices

Sources of Trans Fats

The process of hydrogenation used by the food industry:

oCakes, cookies, pie crusts and crackers made from partially hydrogenated vegetable oil

oChips

oPackaged or microwave popcorn

oFried food:

French fries, doughnuts and fried chicken (deep frying)

Can contain trans fat from the oil used in the cooking process

oCreamer and margarine

Cholesterol

Not an essential fat:

Synthesized in the liver of humans

Liver produces ~ 800 to 1500 mg cholesterol/day

Total blood cholesterol should be less than 200 mg/dl

Which foods are rich in cholesterol?

Cholesterol is found in animal products only

Cholesterol-rich foods:

➢ Eggs

➢ Shellfish

➢ Red meats, liver

➢ Dairy products

LDL v/s HDL Cholesterol

LDL-Cholesterol:

Transports cholesterol from

the liver to tissues

Bad cholesterol

Associated withheart disease

HDL-Cholesterol:

Transports cholesterol from tissues back to

the liver

Good cholesterol

Protective role

V/S

Factors that Increase

HDL-cholesterol

ExerciseEstrogen (women)

Weight loss (if obese)

HDL goal >60 mg/dl

Factors that IncreaseLDL-cholesterol

Saturated fat intake

Trans fat intake

Smoking

Obesity

Sedentary lifestyle

LDL goal< 80 mg/dl

Fats and Cardiovascular Diseases

Prevalence of CVDs Globally

CVDs are the number 1 cause of death globally

http://www.who.int/mediacentre/factsheets/fs317/en/

Over 75% of CVD deaths occur in:low- and middle-income countries

How can we prevent heart diseases?

Most cardiovascular diseases can be preventedby addressing behavioral risk factors:

1. Tobacco use

2. Unhealthy diet and obesity

3. Physical inactivity (sedentary lifestyle)

4. Harmful use of alcohol

Using population-wide strategies

http://www.who.int/mediacentre/factsheets/fs317/en/

Individual-Level Management

Risk Factors for CVDs

1. High Blood Cholesterol Levels

2. Smoking

3. Hypertension (high blood pressure)

Other Risk Factors include:

Obesity

Physical Inactivity

Diabetes

Atherosclerosis (cont’d)ATHEROSCLEROSIS

Narrowing/ Hardening of arteries (Atherosclerosis)

Blood Flow Blocked

Heart AttackStroke

Dietary Recommendations

Dietary Recommendations

❖ Excess fat consumption can lead to:Obesity, CVD, and some types of cancer

Total fat intake: 30% of Total daily calories10% of each of SFA, MUFA and PUFA

Dietary cholesterol: ~ 300 mg/day from the diet

Trans fat: should be limited

Dietary Recommendations

AVOID:

Frying your food Even healthy oils can become unhealthy upon

heating

Prolonged consumption of burnt oils can lead to atherosclerosis

Eating processed/ packaged food High in sodium, saturated fat, sugars, and trans fats

CHOOSE:

Healthy alternatives to frying: Baking

Broiling

Grilling

Using oil sprays

Eat fish twice a week

Heart Health & Diet

Lifestyle Changes:

1. Follow a healthy diet

2. Maintain a healthy weight

3. Perform regular physical activity

4. Quit smoking

5. Manage stress

http://www.eatright.org/resource/health/wellness/heart-and-cardiovascular-health/heart-health-and-diet

A Heart-Healthy Diet:

1. Follow a healthy eating pattern across the lifespan

2. Focus on variety and nutrient density

3. Control your meal and snack portion sizes

4. Limit calories from added sugar and saturated fat

5. Reduce sodium intake

6. Choose healthier food and beverages

7. Support healthy eating patterns for all

(With reference to the 2015 Dietary Guidelines for Americans)

http://www.eatright.org/resource/health/wellness/heart-and-cardiovascular-health/heart-health-and-diet

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