Rose Johnson
7/19/15
Introduction
 Dietary fats are highly maligned nutrients
 Healthy fats are important to long term health
Goals & Objectives
 Increase awareness of the role of healthy dietary fats
 Understand fats in the blood
 Learn the difference between LDL/HDL/Triglycerides
 Describe categories of fats
 Learn the sources of good dietary fats
 Understand relationships between dietary fats and
chronic disease
 Identify categories of unhealthy fats
Role of Dietary Fats
 The body needs some fat from food.
 Dietary fats:
 Provides a major source of energy
 Helps the body absorb some vitamins and minerals.
 Helps to build cell membranes

Vital exterior of each cell, and the sheaths surrounding
nerves.
Other Roles for Dietary Fats
 Blood clotting
 Muscle movement
 Inflammatory response
A Few Words About Cholesterol
 The mix of fats and carbohydrates in the blood is the
biggest factor on levels of cholesterol and not the
amount of cholesterol eaten from food.
 While it is important to limit dietary cholesterol
particularly for diabetics, it is not as big a problem as
problematic as once believed.
 Cholesterol is used by the body in the following ways:
 Estrogen/Testosterone
 Vitamin D
 Other compounds
A Few Words About Cholesterol
 LDL cholesterol in the blood stream is what is used to
determine health risk.
Fats in the Blood
 Low Density Lipoproteins (LDL) - Bad
 Carry cholesterol from the liver to other parts of the
body
 Excess LDL forms plaque on arterial walls
 High Density Lipoproteins (HDL) - Good
 Scavenge cholesterol from the blood and LDL and
arterial walls and carries it back to the liver for disposal
 Triglycerides
 Is from fat eaten from food and transports fats to cells
 Fats are important for health but too much is unhealthy
Categories of Dietary Fats
 Good fats
 Monounsaturated fats
 Polyunsaturated fats
 Bad fats
 Include industrial-made trans fats.
 Saturated fats fall somewhere in the middle
Good Fats
 Sources:
 Vegetables, nuts, seeds, and fish.
 Healthy fats are liquid at room temperature, not solid.
 Two categories of good/beneficial fats:
 Monosaturated
 Polyunsaturated
Good Fats: Monounsaturated
 Sources:
 Olive oil, peanut oil, canola oil, avocados, and most
nuts, as well as high-oleic safflower and sunflower oils.
Good Fats: Polyunsaturated
 Two main types of polyunsaturated fats:
 Omega-3 fatty acids
 Omega-6 fatty acids
Good Fats: Polyunsaturated
 Omega-3 fatty acids:
 May help prevent heart disease/stroke
 Helps reduce blood pressure, raises HDL, & lowers
triglycerides
 Good Sources of omega-3 fatty acids:
 Fatty fish (salmon/mackerel,/sardines)
 Flaxseeds, walnuts, canola oil, and
soybean oil.
Good Fats: Polyunsaturated
 Omega-6 fatty acids:
 Helps to protect against heart disease.
 Good Sources of omega-6 fatty acids:
 Foods rich in linoleic acid
 Vegetable oils such as un-hydrogenated safflower,
soybean, sunflower, walnut, and corn oils.
Bad Fats: Hydrogenated Oils
 Diets rich in bad fats are linked to:
 Increases in bad cholesterol (LDL) levels
 Reduces good cholesterol (HDL) levels
 Contribute to inflammation related to:




Heart disease
Stroke
Diabetes/diabetes risk factors
Other chronic conditions
Bad Fats: Hydrogenated Oils
 Trans-Fats
 Listed as Partially Hydrogenated Oil (PHO)
on food labels
 By-product of a process called hydrogenation


Turns healthy oils into solids
Prevent rancidity.
 Healthy oils become unhealthy when processed through
hydrogenation
Bad Fats: Hydrogenated Oils
 Research from multiple studies show that:
 Trans fats can harm health in even small amounts
 For every 2% of calories from trans fat consumed daily,
the risk of heart disease rises by 23%.
Bad Fats: Hydrogenated Oils
 Permeate the food supply:
 Commercial cookies and pastries to fast-food
French fries
 In our snack foods
 Raw PHOs are abundant in supermarkets

Think:
 Shortening & conventional margarine products
In Between: Saturated Fats
 Solid at room temperature — think cooled bacon
grease.
 Common sources:
 Red meat, whole milk and other whole-milk dairy foods,
cheese, coconut oil, and many commercially prepared
baked goods and other foods.
In Between: Saturated Fats
 Diets rich in saturated fats can:
 Drive up total cholesterol
 Increase more harmful LDL cholesterol, which prompts
blockages to form in arteries in the heart and elsewhere
in the body.
 Some health experts recommend limiting saturated fat
to under 10% of calories daily
In Between: Saturated Fats
 Exceptions


Tropical Oils
 Palm oil
 Coconut oil
Have been found to lower bad cholesterol levels (LDL)
Dietary Fat & Disease
 Heart Disease
 Recent study of persons following a Mediterranean diet
with extra-virgin olive oil or nuts, both rich sources of
unsaturated fat, reduced the incidence of major
cardiovascular events amongst patients with diabetes or
other risk factors over a 4.8-year follow-up
Dietary Fat & Disease
 Other outcome from the study:

low-fat diets are losing credibility, and that incorporating
healthy fats – such as those included in the Mediterranean
diet – can improve heart health
Dietary Fat & Disease
 Mediterranean diets including the following guidelines
were considered effective:

High intake of olive oil, nuts, vegetables, fruits, and mainly
whole grain cereals
– Moderate intake of fish and poultry
– Low intake of dairy products, red meat, processed meats,
and sweets
– Wine in moderation, consumed with meals
Dietary Fat & Disease
 Breast cancer
 Currently no clear evidence links any specific type of fat
with cancer incidence
 Colon cancer
 Recent & better studies contradict past studies and
revealed no significant association between fats and
colon cancer
Dietary Fat & Disease
 Prostate Cancer
 Connection between prostate cancer and dietary fats is
unclear
 More research is needed to determine any connections
between fats and prostate cancer
Dietary Fat & Disease
 Other chronic conditions
 Preliminary findings do not offer sufficient evidence to
suggest modifying dietary fat recommendations for
conditions such as:





Depression
Osteoporosis
Age-related memory loss
Cognitive decline
Macular degeneration
http://www.hsph.harvard.edu/nutritionsource/dietary-fat-and-disease/
Causes for Confusion
 Guidance related to intake of dietary fats can be
confusing with some bodies research conflicting with
others making it difficult to make good decisions
about fats.
 Let’s examine a couple examples.
http://www.health.harvard.edu/staying-healthy/the-truth-about-fats-bad-and-good
Causes for Confusion
 One meta-analysis of 21 studies said that there was not
enough evidence to conclude that saturated fat
increases the risk of heart disease, but that replacing
saturated fat with polyunsaturated fat may indeed
reduce risk of heart disease.
http://www.health.harvard.edu/staying-healthy/the-truth-about-fats-bad-and-good
Causes for Confusion
 Two other major studies narrowed the prescription
slightly, concluding that replacing saturated fat with
polyunsaturated fats like vegetable oils or high-fiber
carbohydrates is the best bet for reducing the risk of
heart disease, but replacing saturated fat with highly
processed carbohydrates could do the opposite.
http://www.health.harvard.edu/staying-healthy/the-truth-about-fats-bad-and-good
Conclusion
 Where Do We Go From Here?
 Focus on choosing foods with healthy fats
 Keep portion sizes moderate
 Don’t fixate on fat percentages
http://www.hsph.harvard.edu/nutritionsource/healthy-fats/#tropical-oils
References:
Harvard School of Public Health
The Truth About Fats: The Good, The Bad, and The In-Between
http://www.health.harvard.edu/staying-healthy/the-truth-about-fatsbad-and-good
Dietary Fat and Disease
http://www.hsph.harvard.edu/nutritionsource/dietary-fat-and-disease/
Cholesterol
http://www.hsph.harvard.edu/nutritionsource/cholesterol/
Fats and Cholesterol
http://www.hsph.harvard.edu/nutritionsource/fats-and-cholesterol-1/