Post on 23-Dec-2015
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?