Key statements about fatty acids
fatty acid expert roundtaBle
key statements aBout fatty acids
• Cardiovascular disease (CVD) remains a leading cause of death and disability.
• Clinical guidelines and pharmaceutical development have focused on the reduction of LDL
cholesterol (LDL-C) as a main goal for reducing CVD, but other lipoproteins, including HDL
cholesterol (HDL-C), triglycerides, and LDL-particle size may also be important.
• Saturated fatty acid consumption (grams or percent calories) increases LDL-C and HDL-C,
but tends to lower triglycerides.
• When substituted isocalorically for carbohydrate, any of the three classes of fatty acids
(i.e., poly, mono, saturated) results in increases in HDL-C and decreases in serum triglycerides levels.
• Dietary guidelines from the American Heart Association and other agencies recommend that
<1%, with the remainder from monounsaturated and polyunsaturated fats.
total fat account for <25-35% of total daily caloric intake; saturated fat, <7%; and trans fat,
• A 2005 estimate of the average American diet found that trans fatty acid intake contributed
2.5% of total calories.
• Changes in carbohydrate intake must be taken into account when considering the effect
of changes in fatty acid metabolism in human physiology.
considerations for replacing trans fats when a solid fat
is required for food functionality and staBility
• Trans fatty acids increase LDL-C and decrease HDL-C levels.
• Public health officials and policy makers are recommending that trans fatty acids
to be eliminated from the American diet.
• Efforts to reduce or eliminate trans fatty acids in baked goods forces manufacturers
to make one of several changes in food manufacturing:
1. Substituting saturated fat such as palm oil for trans fat
2. Substituting interesterified fat for trans fat
3. Substituting carbohydrate for trans fat
• Each choice adds additional complexity to “improving” our manufactured food supply.
• Finding a suitable fat with desirable functionality, taste and shelf life similar to a hydrogenated
fat presents a challenge for food manufacturers. Solid fats (saturated fatty acids) are more readily
adaptable for food preparation processes.
• If half of trans fatty acids are replaced by polyunsaturated fat or monounsaturated fat, and half
replaced with saturated fatty acids, it is expected that the saturated fat component in the diet will
increase approximately 1 to 1.5% of total fat calories (composed of primarily palmitic and/or stearic acid).
The overall public health goal in regard to trans fatty acids is to prevent adverse health effects
associated with exposure to them. The preferred option would be to replace them with unsaturated
fatty acids, or when necessary for structural or functionality purposes, a natural or modified saturate.
A further consideration is that “healthier” baked goods with no trans fats should be consumed in the
context of an overall diet containing fruit, vegetables, dairy products and grains.
fat replacement options for food manufacturers
An example of replacing trans fatty acids with saturated fatty acids required for functionality might be
formulated as follows:
Medium Muffin With Trans Fat No Trans Fat
Total Fat 10.3g 10.3g
Trans Fat 0.7g 0g
Saturated Fat 1.5g 2.2g
Monounsaturated Fat 2.4g 2.4g
Polyunsaturated Fat 5.7g 5.7g
Currently available technology offers two major options:
1. Replace partially hydrogenated fatty acids with a saturated fatty acid that is mostly palmitic acid
from natural fat(s).
2. Replace partially hydrogenated fat with a specifically designed, interesterified fat containing more
saturated fatty acids made up mostly of stearic acid.
The pros and cons of each of these choices are outlined in the table below.
Issue Palmitic Acid Option Interesterified Stearic Trans Fatty Acid
Naturally occurring Fully hydrogenated Partially hydrogenated
saturated fatty acid
Fatty acid is placed Fatty acid is placed
Fatty acid is placed randomly at the 1,2 randomly at the 1,2
at the 1,3 position on and 3 position on the and 3 position on the
triglyceride molecule triglyceride molecule triglyceride molecule
Neutral to increase in Neutral to increase Increases LDL
Effects on LDL LDL depending on level in LDL depending depending on level
of intake on level of intake of intake
Neutral to moderate Neutral to decrease
Effects on HDL Decrease in HDL
increase in HDL in HDL at high intakes
Issue Palmitic Acid Option Interesterified Stearic Trans Fatty Acid
Effects on Relatively neutral to Tends to increase
Increases ratio (typically)
LDL: HDL ratio slight decrease in ratio ratio at high levels
One study found increase
One study found One study found
in postprandial glucose
Effect on postprandial increase in postprandial increase in postprandial
(under the curve) more
glucose (area under glucose (under the glucose(under the curve)
than palmitic acid, but
the curve) curve), but less than more than palmitic acid
less than interesterified
stearic acid and trans fat and trans fat
When combined with Increased fibrinogen,
Effect of high levels on myristic and lauric but at lower levels
inflammatory markers acids has similar than stearic acid
effect as carbohydrates and control group
Effect on myocardial
Neutral effect Increases risk of MI Neutral effect compared
infarction risk through
compared to control compared to control to control
a third option for food manufacturers—increase carBohydrate
A third option for replacing trans fatty acids (still within FDA guidelines for <0.5g TFA/serving) would
be to reduce them to less than 0.5g without replacing the fat. Therefore, the carbohydrate and protein
levels would not change, but they would represent a greater percentage of the total energy in the
An example for a hypothetical muffin follows:
Medium Muffin With Trans Fat No Trans Fat*
Total Fat 10.3g 10g
Trans Fat 0.7g 0.4g
Saturated Fat 1.5g 1.5g
Monounsaturated Fat 2.4g 2.4g
Polyunsaturated Fat 5.7g 5.7g
*Based on FDA labeling that states less than 0.5 g can be defined as “no trans fat”
key consensus statements
• Where possible, the selection of oils or fats to replace trans fatty acids should favor polyunsaturated
or monounsaturated fatty acids.
• Where a solid fat is required for product taste and functionality, the only saturated fatty options
currently available to replace trans fatty acids are palm oil or interesterified stearic acid.
• Replacing trans fats with either palmitic acid or interesterified stearic acid is expected to reduce
cardiovascular risk factors.
• How future changes, including the introduction of fats from genetically modified crops and the
availability of interesterified diets richer in stearic acid, will alter fatty acid consumption of
consumers, and hence, cardiovascular risk, remains unclear.
• Consumption of a variety of fats—including polyunsaturated (both omega-3 and omega-6),
monounsaturated, and saturated fatty acids—is preferable to over-reliance on any one fatty acid.
• A one-to-one exchange of saturated fatty acids for trans fatty acids is expected to raise the former
to a level consistent with reduced cardiovascular risk (assuming no other shift in macronutrient
composition or total amount of fats in the average diet).
• Before any policies are made related to trans fatty acids and potential replacement fats, further
interventional and observational studies should be completed to fully understand the tradeoffs
inherent in the solution.
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• Baer DJ, et al. Dietary fatty acids affect plasma markers of inflammation in healthy men fed
controlled diets: a randomized crossover study1–3. Am J Clin Nutr 2004;79:969 –73.
- LMP diet, 8% of energy enrichment with saturated fatty acids as the sum of lauric (L), myristic
(M), and palmitic (P) acids (ratio of L to M to P of 0.3:1.4:8.3); stearic acid (STE) diet, 8% of
energy enrichment with stearic acid; trans fatty acid (TFA) diet, 8% of energy enrichment in
TFAs (spectrum of trans 18:1 positional isomers similar to that in the US food supply).
- Inflammatory Marker Data: In both stearic acid enriched diet and stearic acid/trans fat
enriched diet fibrinogen increased. In stearic acid only, was 4.4% higher than control
carbohydrate group. Consumption of the diet enriched in stearic acid resulted in higher
concentrations of fibrinogen than did consumption of all other diets except the TFA/STE diet.
Concentrations of plasma markers of inflammation after 5 wk of consumption of each diet:
diet mean (g/l)
CHO (control) 2.74
TFA + STE 2.75
• van der Bom JG, de Maat MP, Bots ML, et al. Elevated plasma fibrinogen: cause or consequence
of cardiovascular disease? Arterioscler Thromb Vasc Biol 1998;18:621–5.
- Myocardial Infarction Risk: A rise in fibrinogen of 1 g/L was associated with a 45% increased
risk (odds ratio adjusted for age, sex, and smoking, 1.45; 95% CI, 1.12 to 1.88). Lowering
fibrinogen levels is not associated with a lower risk of myocardial infarction.
• Sundram K, Karupaiah T, Hayes KC. Stearic acid-rich interesterified fat and trans-rich fat raise the LDL/
HDL ratio and plasma glucose relative to palm olein in humans. Nutrition & Metabolism 2007, 4:3.
- One test fat rotation was based on palm olein (POL) and provided 12.0 percent of energy (%en)
as palmitic acid (16:0); a second contained trans-rich partially hydrogenated soybean oil
(PHSO) and provided 3.2 %en as trans fatty acids plus 6.5 %en as 16:0, while the third used an
interesterified fat (IE) and provided 12.5 %en as stearic acid (18:0).
- Effects on LDL: Dietary fat also affected absolute change in LDL-C, with the concentration after
the PHSO being 7% greater than POL (P < 0.05). The IE diet effect was intermediate and not
significantly different from either POL or PHSO.
- Effects on HDL: After adjusting for multiple comparisons between dietary treatments, plasma
HDL-C was significantly lower (p < 0.001) both during the PHSO (-8%) and IE (-9%) diet
treatments compared to POL.
- Effects on LDL:HDL ratio: The LDL-C/HDL-C ratio was similarly increased by the PHSO and IE
diets, with differences being about 15% greater than the POL diet (P < 0.001).
- Glucose Data: After four weeks on each test fat, the rise was 3% for POL, 9% for PHSO, and 22% for IE.
• Judd JT, et al. Dietary cis and trans Monounsaturated and Saturated FA and Plasma Lipids and
Lipoproteins in Men. Lipids 2002;37:123-131.
- The six diets were planned to vary by 8 en% as follows: diet CHO, 8.5 en% reduction in fat
(approximately equivalent to 8 en% reduction in FA) replaced by digestible carbohydrate; diet
OL, 8 en% enrichment in oleic acid; diet LMP, 8 en% enrichment with saturated FA as the sum
of lauric (L), myristic (M), and palmitic acids (P) (LMP) with the ratio of L/M/P of 0.3:1.4:8.3; diet
STE, 8 en% enrichment with stearic acid; diet TFA: 8 en% enrichment in TFA with a spectrum
of trans 18:1 positional isomers similar to that in the U.S. food supply; and diet TFA|STE, a
combined enrichment with 4 en% TFA and 4 en% STE.
- Dietary fatty acid levels prior to enrichment were targeted at levels within the range of typical
U.S. diets with the exception that saturated FA were to be about 10 en% with STE excluded.
Otherwise, the diets before enrichment were targeted to have 2.5 en% STE, 4 en% linoleic acid,
10 en% OL, 10 en% LMP FA, and 2.5 en% other FA.
Plasma Lipid, Lipoprotein Cholesterol, and Apolipoprotein Concentrations and Ratios of Total and LDL
Cholesterol to HDL Cholesterol of 50 Adult Men After 5 wk Consumption of Each Dieta
expressed as mg/dl
Medium Muffin CHO OL TFA TFA/STE STE LMP
Triglycerides 91b,c 78a 91b,c 94b, c 101c 86a,b
Total Cholesterol 184a,b 179a 195d 194d 175b 193c,d
LDL 119a,b 115a 131e 129d,e 121b,c 125c,d
HDL 47b 48c 45a,b 46a,b 45a 51d
Diets labeled with different roman superscripts are significantly different at P < 0.01.
TC/HDL (ratio) 4.1b 3.9a 4.5d 4.4c,d 4.3c 4.0a,b