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

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.

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.

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.

Conclusion Where Do We Go From Here? Focus on choosing foods with healthy fats Keep portion sizes moderate Don’t fixate on fat percentages

References: Harvard School of Public Health The Truth About Fats: The Good, The Bad, and The In-Between bad-and-good Dietary Fat and Disease Cholesterol Fats and Cholesterol