Dietary Fats and Oils: Dietary Fats and Oils: Relation to Blood CholesterolRelation to Blood Cholesterol

Frank M. Sacks, MDProfessor, Nutrition Department, Harvard School of Public Health;

Professor of Medicine, Harvard Medical SchoolSenior Physician, Brigham & Women’s Hospital

LDL-cholesterolLDL-cholesterol

• The “bad” cholesterol• Goes into the arterial wall• Causes atherosclerosis• Lowering blood LDL-cholesterol by diet or by most

drugs reverses atherosclerosis, prevents heart attacks• In trials of dietary polyunsaturated fats, the decrease

in LDL-cholesterol matches the decrease in heart disease.

Types of fatty acids

Saturated Monounsaturated (Oleic acid)

Linolenic acid Linoleic

acid

Methyl group

Acid group

Polyunsaturated (Essential fatty acids)

N-6N-3

Based on Mensink & Katan 2003. Figure from Micha & Mozaffarian, Lipids 2010

Effects of Dietary Fats on LDL-Cholesterol

=0.032*

=-0.009*

=-0.019*

Poly-unsaturated

Mono- unsaturated

Saturated

percentage of calories vs. carbohydrate

Change inLDL-C

(mmol/L)

Change inLDL-C

(mmol/L)

=0.052*

=0.048*

=0.039*

=-0.004

16:0 (palmitic)

14:0 (myristic)

12:0 (lauric)

18:0 (stearic)

Effects of Individual Saturated Fatty Acids on LDL cholesterol

percentage of calories vs. carbohydrate

LDL cholesterol

Figure from Micha & Mozaffarian, Lipids 2010. Based on Mensink & Katan 2003.

Palm oil and Lard Increase LDL-Cholesterol Compared to Olive Oil: 3 weeks each oil, 17% energy

Palm

Olive

Lard

Tholstrup T. AJCN 2011

18-carbon fatty acids

Stearic acid Oleic acid

Linolenic acid Linoleic

acid

Methyl group

Acid group

Oleic acid trans

Meta-analysis of 60 controlled trials on dietary fats and blood lipids: effect of replacing

carbohydrate with cis- or trans-fat

Mensink..Katan. Am J Clin Nutr 2003;77:1146

The OmniHeart Study Diets: The OmniHeart Study Diets: Lower Carbohydrate Modifications of Lower Carbohydrate Modifications of

DASH DietDASH Diet

Emphasize:Fruits, Vegetables; High-protein foods including beans, whole grains, nuts, low-fat dairy, fish and poultry; Unsaturated Cooking Oils

Reduced in:Carbohydrates, Saturated Fats, Red Meat, Sweets, and Sugar-containing Beverages.

Higher unsaturated fat, higher protein lowered BP and improved lipid risk factors more than the original high-carbohydrate DASH diet.

OmniHeart: LDL-cholesterol (mg/dL)OmniHeart: LDL-cholesterol (mg/dL)All diets low in saturated fat, All diets low in saturated fat, healthful DASH-type dietary healthful DASH-type dietary

patternspatternsMean Change from

Baseline in Each Diet

BaselineHigh

CARB (DASH)

High PROT

High UNSAT

FAT

All 129 -12 -14 -13

LDL-C > 130 157 -20 -24 -22

LDL-C < 130 105 -4 -6 -5

Appel L, Sacks F, et al. JAMA 2007

Dietary Fats, Oils to Lower LDL-cholesterol and Prevent Heart Disease

• Best Choice:– Polyunsaturated vegetable oils

• Peanut, Soybean, Corn, Rapeseed, sesame

• Next Best– Monounsaturated vegetable oils

• Olive* (more benefits when polyphenols high)• High-oleic sunflower, safflower

• Unhealthful Choices:– Trans unsaturated oils– Animal fats, high in saturated fatty acids– Palm oil