Artificial trans fats: considering the issues

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• Artificial trans fatsconsidering the issues

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Evidence for the ill effects of trans fats

• Trans fats have adverse effects on blood lipids
  and lipoproteins
• Epidemiological studies show a relationship
  between trans fat intake and coronary heart
  disease

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Impact of trans fats on plasma lipids results of
a meta-analysis
Plt0.05 Plt0.01 Plt0.001.
Source Mensink et al. Am J Clin Nutr.
2003771146-1155.
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Effects of dietary fats on plasma lipids
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Increasing trans fats have increasing impact on
LDLHDL
Trans fatty acids Saturated fatty acids
Source Ascherio et al. New Engl J Med.
19993401994-1998.
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2 increase in energy from trans fats results in
23 increase in CHD risk
Source Mozaffarian et al. New Engl J Med.
20063541601-1613.
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Potential physiological effects of trans fats

• Impact on hepatocyte metabolism of lipoproteins
  and effects on plasma cholesteryl ester transfer
  protein (CETP) likely cause changes in plasma
  lipids
• Altered fatty acid metabolism
• Altered inflammatory response of adipocytes
• NO-dependent endothelial dysfunction
• Increased sICAM-1 and sVCAM-1 seen with trans
  fat intake
• Modulation of monocytes and macrophages
• Increased inflammatory mediators (IL-6, TNF-a)

Source Mozaffarian et al. New Engl J Med.
20063541601-1613.
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Cis and trans double bonds
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Trans fat from vegetablebut not ruminantsource
associated with increased risk of CHD
Source Willett et al. Lancet. 1993341581-585
Ascherio et al. Circulation. 19948994-101.
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Is there a difference between industrial and
natural trans fats

• Two recent studies have given mixed results
• Motard-Bélanger et al
• Essentially no difference
• TRANSFACT
• Only industrial trans fats reduce HDL cholesterol
• Absolute impact on CVD risk factors not clear

Source Motard-Bélanger et al. Am J Clin Nutr.
200887593-599. Chardigny et al. Am J Clin Nutr.
200887558-566.
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Recent study compared impact of ruminant and
industrial trans fats
Percent trans fats in study diets
Source Motard-Bélanger et al. Am J Clin Nutr.
200887593-599.
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Industrial trans fat and high trans fat ruminant
diets had significant impact on plasma lipids







Source Motard-Bélanger et al. Am J Clin Nutr.
200887593-599.
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Essentially no difference between industrial and
ruminant trans fats

• Diets high in trans fat have a significant
  deleterious affect on plasma lipid CVD risk
  factors
• Gram for gram, no difference between industrial
  and ruminant trans fats
• However, impossible to achieve this level of
  trans fats in a normal diet
• Butter fortified with trans fats to achieve this
  level in study
• Concluded that current intake of ruminant trans
  fats in population not likely to have significant
  impact on CVD risk factors

Source Motard-Bélanger et al. Am J Clin Nutr.
200887593-599.
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TRANSFACT

• Randomised double-blind, controlled, crossover
  study
• Patients consumed 11-12 g/day TFA from industrial
  or natural sources
• 5 of daily energy
• 40 patients completed study
• 19 male
• 21 female
• Serum lipids and lipoproteins monitored

Source Chardigny et al. Am J Clin Nutr.
200887558-566.
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TRANSFACT changes in HDL and LDL
Significant decrease in HDL (P0.012) and LDL
(P0.001) in women, but not in men, with trans
fat from industrial vs. natural sources.
LDL cholesterol
HDL cholesterol
120
80
100
60
80
Concentration (mg/dL)
Concentration (mg/dL)
60
40
40
20
20
0
0
Male
Female
Male
Female
Baseline
Industrial
Natural
Source Chardigny et al. Am J Clin Nutr.
200887558-566.
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TRANSFACT Conclusions

• Trans fatty acids from natural and industrial
  sources have different effects on cardiovascular
  risk factors in women
• Absolute impact on CVD risk factors not clear
• HDL lowering is specific to industrially derived
  trans fats

Source Chardigny et al. Am J Clin Nutr.
200887558-566.
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Grams trans fats in a high trans fat menu
around the world
Numbers in parentheses are trans fats in each
menu item.
Source Stender et al. Food Nutr Res. 2008 52.
doi 10.3402/fnr.v52i0.1651.
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Trans fat intake decreasing but remains well
above recommended levels
Source Harnack et al. J Am Diet Assoc.
20031031160-1166.
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Predicted impact of removing industrial trans
fats from US diet
Reduced by half (2.1?1.1)
Near elimination (2.1?0.1)
0
-3
-5
-6
-10
Proportion of CHD events
preventable in the US ()
-10
-12
-15
-20
-19
-22
-25
Based on totalHDL cholesterol (dietary trials)
Based on replacement with carbohydrates
(prospective studies)
Based on additional replacement with cis fatty
acids (prospective studies)
Source Mozaffarian et al. New Engl J Med.
20063541601-1613.
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Impact of reducing trans fat intake in Denmark
Trans fat intake
CHD Mortality Curves
Source Stender et al. Food Nutr Res. 2008 52.
doi 10.3402/fnr.v52i0.1651 .
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Alternatives to partially hydrogenated fat
Source Eckel et al. Circulation.
20071152231-2246.
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Alternatives to partially hydrogenated fat
(contd)
Source Eckel et al. Circulation.
20071152231-2246.
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Some alternatives to trans fats should be
approached with caution

• Industrial trans fats were originally introduced
  as an alternative to saturated fats
• We know the result
• Do we know that alternatives to trans fats are
  safe?
• Interesterified fats are present in many products
  today
• Little known about health effects
• Robinson et al (2009) recently reported on acute
  metabolic changes with chemically and
  enzymatically interesterified stearic acid rich
  spread
• 85 increase in TAG with CIE vs NIE in obese
  subjects
• Increased stearic acid with CIE and EIE vs NIE

TAGtriacylglycerol CIEchemically
interesterified EIEenzymatically
interesterified NIEnon-interesterified.
Source Robinson et al. Lipids. 20094417-26.
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Professional societies have taken stances on
trans fat consumption

• Foods containing industrially derived TFA should
  be minimized....TFA replacement strategies
  should not result in a higher TFA and SFA

ADA (American Dietetic Association)

• A recent meta-analysisfound that a 2 increase
  in energy intake from trans fatty acids was
  associated with a 23 increase in the incidence
  of coronary heart disease
• Recommends limiting trans fat consumption to lt1
  total energy/day

AHA (American Heart Association)

• There is a positive linear trend between trans
  fatty acid intake and total and LDL cholesterol
  concentration, and therefore increased risk of
  CHD, thus suggesting a Tolerable Upper Intake
  Level (UL) of zero

IOM (Institute of Medicine)
FDA (Food and Drug Administraation)

• Food manufacturers are allowed to list amounts of
  trans fat with less than 0.5 grams (1/2 g) as 0g
  (zero) on the Nutrition Facts panel

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FDA rounding rule allows for significant trans
fats

• Total trans fats of lt0.5g/serving can be listed
  on Nutrition Facts panel as 0g trans fat
• Allows for up to 0.49g trans fat per serving
• Serving size definition is often quite small
• Results in consumption of 2?3 or more servings at
  a time
• Individual can consume up to 1.5g trans fat and
  believe they have consumed 0g

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Example 1. Kelloggs Rice Krispies Treats Cereal

• Actual trans fat 0.444g/serving
• Serving size ¾ cup

U.S. Department of Agriculture, Agricultural
Research Service. 2008. USDA National Nutrient
Database for Standard Reference, Release 21.
Nutrient Data Laboratory Home Page,
http//www.ars.usda.gov/ba/bhnrc/ndl
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Example 2. Malt-O-Meal Cinnamon Toasters

• Actual trans fat 0.324g/serving
• Serving size ¾ cup

U.S. Department of Agriculture, Agricultural
Research Service. 2008. USDA National Nutrient
Database for Standard Reference, Release 21.
Nutrient Data Laboratory Home Page,
http//www.ars.usda.gov/ba/bhnrc/ndl
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Example 3 Pillsbury Buttermilk Biscuit
Refrigerated Dough

• Actual trans fat 0.350g/serving
• Serving size 3 biscuits (64 g)

U.S. Department of Agriculture, Agricultural
Research Service. 2008. USDA National Nutrient
Database for Standard Reference, Release 21.
Nutrient Data Laboratory Home Page,
http//www.ars.usda.gov/ba/bhnrc/ndl
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Example 4 Crème-Filled Sponge Cake
Actual trans fat 0.459g/serving
U.S. Department of Agriculture, Agricultural
Research Service. 2008. USDA National Nutrient
Database for Standard Reference, Release 21.
Nutrient Data Laboratory Home Page,
http//www.ars.usda.gov/ba/bhnrc/ndl
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Conclusions

• Trans fats have negative impact on cardiovascular
  markers and CHD
• Evidence that industrial trans fats have worse
  impact than ruminant trans fats
• Reducing trans fats could significantly impact
  CHD
• Demonstrated in Danish experience
• Pros and cons to trans fat alternatives
• Professional societies and FDA recommend limiting
  trans fats in diet to lt1 total energy
• But zero isnt necessarily zero on trans fat
  labels

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