Category Archives: Monounsaturated Fat

Saturated Fat Leads To Higher LDL, Lower Energy Expenditure, Than Monounsaturated Fat

High_Fat_Foods2This new study found that replacing saturated fat (palmitate) with monounsaturated fat (oleate) resulted in lower LDL, and a lower LDL:HDL ratio:

Dietary Intake Of Palmitate And Oleate Has Broad Impact On Systemic And Tissue Lipid Profiles In Humans, American Journal of Clinical Nutrition, March 2014

It was a crossover trail of 15 adults. They ate a high–palmitic acid (HPA) diet for 3 weeks then switched to a low–palmitic acid and high–oleic acid (HOA) diet.

“HOA lowered the ratio of serum low-density lipoprotein to high-density lipoprotein (LDL:HDL) in men and women. … These results suggest that replacing dietary PA with OA reduces the blood LDL concentration.”

Palmitic acid (PA) is a saturated fatty acid found abundantly in meats, cheeses, butter, and other dairy products.  (16:00)

Oleic acid (OA) is a monounsaturated omega-9 fatty acid. Good sources are oils of safflower, olive, canola, sesame, pecan, almond, sunflower, peanut, and avocado. It is also found in animal fats including fats of pork, poultry, and beef. (18:1 cis-9)

I looked up Dr. Lawrence Kien (University of Vermont), the lead author on this study, and found the following related research he had published:

Substituting Dietary Monounsaturated Fat For Saturated Fat Is Associated With Increased Daily Physical Activity And Resting Energy Expenditure And With Changes In Mood, American Journal of Clinical Nutrition, April 2013

Design: With the use of a balanced design, 2 cohorts of 18 and 14 young adults were enrolled in separate randomized, double-masked, crossover trials that compared a 3-wk high–palmitic acid diet (HPA; similar to the Western diet fat composition) to a low–palmitic acid and high–oleic acid diet (HOA; similar to the Mediterranean diet fat composition). All foods were provided by the investigators, and the palmitic acid (PA):oleic acid (OA) ratio was manipulated by adding different oil blends to the same foods. In both cohorts, we assessed physical activity (monitored continuously by using accelerometry) and resting energy expenditure (REE). To gain insight into a possible mood disturbance that might explain changes in physical activity, the Profile of Mood States (POMS) was administered in cohort 2.

Results: Physical activity was higher during the HOA than during the HPA in 15 of 17 subjects in cohort 1 (P = 0.008) (mean: 12% higher; P = 0.003) and in 12 of 12 subjects in the second, confirmatory cohort (P = 0.005) (mean: 15% higher; P = 0.003). When the HOA was compared with the HPA, REE measured during the fed state was 3% higher for cohort 1 (P < 0.01), and REE was 4.5% higher in the fasted state for cohort 2 (P = 0.04). POMS testing showed that the anger-hostility score was significantly higher during the HPA (P = 0.007).

Conclusions: The replacement of dietary PA with OA was associated with increased physical activity and REE and less anger. Besides presumed effects on mitochondrial function (increased REE), the dietary PA:OA ratio appears to affect behavior.

Kien found that a diet high in saturated fat not only lowered the drive to be physically active, but also “appeared to affect behavior.” Replacing saturated fat with monounsaturated fat increased physical activity, increased the amount of energy used at rest (burned more calories at rest), and resulted in a lower anger-hostility score.

What foods to eat?

Using PA and OA lipid numbers (which I’ve included in parentheses above) and NutritionData, I determined that one ounce (2 tablespoons) of:

Butter has 6.1 grams palmitic, 4.7 grams oleic
Olive oil has 3.2 grams palmitic, 20 grams oleic (4 grams sat fat total)
Cheddar cheese has 2.7 grams palmitic, 2.2 grams oleic (6 grams sat fat total)
Sesame oil has 2.5 grams palmitic, 11.0 grams oleic
Almond oil has 1.8 grams palmitic, 19.4 oleic
Beef chuck has 0.4 grams palmitic, 0.9 oleic (2 grams sat fat in a 3 oz. serving)
Safflower oil has 1.2 grams palmitic, 21 grams oleic
Canola oil has 1.2 grams palmitic, 16.7 grams oleic
Almonds (23 whole kernels) has 0.8 grams palmitic, 8.6 grams oleic

It’s evident that eating more olive oil to increase monounsaturated fat has a down side … it comes with a hefty amount of saturated fat.  Olive oil has more saturated fat than a large egg, and more saturated fat than a 3 ounce serving of beef.

I think a better way of lowering the saturated fat:monounsaturated fat ratio is to get your fat from whole food sources. Note that almonds, 23 of them!, provide 8.6 grams monounsaturated fat, along with several other vitamins and minerals, and 3.4 grams of fiber.  Oil would be pressed to achieve that.