Fats: Fact and Fiction

Gretchen Gruender MS, RD, CD

Seattle Cancer Care Alliance

Pouring over the fats

• Dietary fat and cancer • Role of fats in our body• Types of fat• Sources of fat in food• Cooking with fat

Cancer Survivors

Increased risk for lingering effects:– Body composition changes

• Weight gain, weight loss, changes in body composition

– Accelerated bone loss / Osteoporosis– Diabetes– Congestive heart failure– Changes in bowel function– Taste and smell changes– Hot flashes– Neuropathies– Hyperlipidemia

Where can the quantity and quality of fat make a difference?

Women’s Intervention Nutrition Study (WINS):

Study ResultsDoes a low fat diet prevent breast cancer (BC)

recurrence?• 2437 women with early stage resected BC• 48 to 79 years old• Randomized to one of two groups:

– Low fat diet (~15% total calories) - ~33 gm total fat• 8 individual counseling sessions with Registered

Dietitian (RD), then every 3 month contact with RD, monthly and quarterly group classes

– Control – ~51 gm total fat• 1 individual counseling session, then every 3

month contact with RD• Median follow-up of 5 years

Chlebowski, J Nat’l Cancer Inst 98, 2006

Women’s Intervention Nutrition Study (WINS):

Study Results

24% reduction in breast cancer recurrence in the

low fat diet group compared to the control

group

Nutrition and Lifestyle Studies

Prostate cancer intensive nutrition & lifestyle change study:

• almost vegan diet – very low meat intake– high fruit and vegetable intake

• reduced fat • lifestyle interventions: yoga, exercise, meditation

and support groups

After one year, participants had no need for conventional therapies– lower PSA’s – greater quality of life– less in vitro prostate cancer cell growth

Dean Ornish, 2005

Role of Fat in our BodyFAT• is a nutrient• is a source of energy• adds taste and texture

to foods• makes us feel full

longer• helps absorb fat-

soluble vitamins (A, D, E, K)

• Regulates immune function, inflammation and cell membrane integrity

Types of Fat

Polyunsaturated fats (PUFA)

Monounsaturated fats (MUFA)

Saturated fats

Trans fats

Foods Have a Mixture of Fats

0% 20% 40% 60% 80% 100%

HardMargarine

Butter

Olive Oil

Corn Oil

PUFA

MUFA

SFA

TFA/Other

Types of Fat

Polyunsaturated fats• Essential because our bodies need but

cannot make

• Polyunsaturated fatty acids: 2 types– Omega-6: linoleic acid (LA)

•AA (Arachadonic acid)- eicosanoids– Omega-3: alpha-linolenic acid (ALA)

•DHA/EPA (docosapentaenoic acid/eicosapentaenoic acid)

Essential Fatty Acids

The ratio of omega-6 to omega-3 is more important than the absolute amount of omega-3.

Was 1:1 or 2:1 Now 15:1 or 20:1

Essential Fatty Acids

Role of omega-3 fatty acids in chronic disease

• Cancer• Cardiovascular disease• Rheumatoid arthritis• Diabetes• More…

Fats in FoodOmega-3• ALA: flaxseed oils, walnuts, hemp and

chia seeds, legumes, green leafy vegetables, canola, soybean, black current seed oil, algae

• EPA and DHA: oily cold-water fish such as herring, tuna, sardines, anchovies and salmon, grass-fed meats/poultry and eggs

• ALA has to be converted in our bodies to EPA/DHA

Fats in Food

Conversion of ALA to DHA and EPA is inefficient and is reduced with:

• High intake of omega 6 fatty acids• Alcohol• Trans fat

It is estimated that only 2-5% of ALA is converted to EPA/DHA.

Fats in Food

Omega-6• LA: corn, soy, sunflower and

safflower oils, processed foods and grains

• AA: beef, pork and poultry

Fats in FoodMonounsatura

ted Fats Examples:Olive oil canola oilPeanutsAlmondsCashewsHazelnutspecans

Fats in FoodSaturated Fats

Examples: butter, cakes and pastries, chocolate bars, coconut, coffee creamer, meat, poultry, dairy products, coconut oil

Fats in Food

Trans Fats• Made by hydrogenating

vegetable oils• More dangerous than

saturated fats in the body– Increases inflammation– Inhibits the conversion

of ALA to DHA– Makes membranes more

rigid– Interferes with

intercellular communication

– Increases LDL cholesterol

– Increases insulin resistance

Fats in Food

Trans Fats• Most found in processed foods

– French fries, potato chips, donuts, cookies, crackers, cereals, shortening, muffins, pizza crusts, buns, cakes, fish sticks

Read labels!!!!!A product can say trans-fat free and still have hydrogenated oils.

Fats in Food

What’s next?• Fully hydrogenated fat• Inter-esterified fats• Genetically modified seed oils• Tropical oils• Partially hydrogenated with low

Trans Fats

How do we damage fats?

Refine, oxidize, heat

Refining grains, nuts and seed oils• Creates a colorless, flavorless oil• Destroys/removes micronutrients• >180 degrees C – fatty acids are

oxidized • >240 degrees C – trans fat is formed

Preparation of oils

How are oils extracted from the nut/seed?

• Cold pressing: mechanical process - maximum temperature of 172 degrees

• Heat pressing: mechanical process – temperatures between 208-280 degrees. Oil from this method will be treated with a solvent, and may go through degumming, refining, neutralizing, bleaching, hydrogenating, or deodorizing.

Cooking with Fats

• If possible, choose oils that have not been refined, expeller pressed or extracted with solvents

• Best options: unrefined and/or cold pressed

• Avoid exposing oils to heat, light and air

Cooking with Fats

• Do not exceed the smoke point of an oil

• PUFA’s are not tolerant of high temperatures

• Better choices for cooking at high heat include peanut, sunflower and canola oil

• Avoid cooking with cold pressed oils and reserve for vinaigrettes

Cooking with Fats

• Purchase nuts and seeds raw and in a shell if possible

• Store in a cool, dark place

Best choices for fish:– Wild salmon, cod, sardines, small

tuna or halibut

20 – 35% of total Calories from fat

2000-Calorie diet = 44 – 78 grams of fat

or 11 – 19 ½ teaspoons

1500-Calorie diet = 33 – 58 grams of fat

or 8 ¼ – 14 ½ teaspoons

How much is enough?

Ways to decrease your overall fat intake:

• Use higher fat foods as “condiments”– Grate cheese on vegetables– Add a handful of granola to fruit– Add a small handful of nuts to a salad

• Most fruits, vegetables, grains and legumes have very small amounts of fat – enjoy an abundance of these foods.

• Decrease the amount of meat that you eat

• Take the skin off chicken and turkey

Ways to decrease your overall fat intake:

continued…• Before sautéing, warm your pan slightly

before adding vegetable oil – the oil will disperse in the pan quicker if it is warm which may result in using less oil

• Minimize eating processed foods such as crackers, cakes and microwavable meals as they are generally higher in fat than whole foods.

• Eat real cheese but eat it in small amounts, not at every meal, not daily

Ways to decrease your overall fat intake:

continued…• Use low fat or nonfat dairy, or eat smaller

amounts of whole fat dairy• If you buy large quantities of nuts or

vegetables oils (like olive oil), put a small amount in a separate container to use daily. Studies show we serve 22% more volume of food when we dispense food from a larger container.

• Practice mindful eating – don’t buy a bid bag of nuts and eat them in the car while you are driving to work, talking on the phone, etc.

Cooking with Fats

Recipe: Triple A Salad

Smell and Taste

Questions?