Dietary fatty acid targets: how can they be achieved? what should be achieved?

Transcription

1 Dietary fatty acid targets: how can they be achieved? what should be achieved? Feed for Health 1 st International Workshop (COST action) Milano, March 16-17, 2009 Dr. Peter L. Zock Lead Scientist Cardiovascular Health, Unilever

2 Unilever the Vitality Mission Theme of this meeting: Food for Health 1

3 Scope of this presentation Dietary fatty acids and health: heart disease Effects of the major classes of fatty acids Saturated (SAFA), Monounsaturated (MUFA), Polyunsaturated (PUFA), and Trans (TFA) fatty acids Different types of TFA: Industrial vs. Ruminant Not in detail: specific saturated fatty acids, CLA, specific omega-3 vs. omega-6 fatty acids

4 Background - Different Dietary Fatty Acids - Blood Lipids and Heart Disease - Approaches for Nutrition Research

5 Chemical structure of major dietary fatty acids CH3 C12:0 lauric acid COOH SATURATED CH3 C14:0 myristic acid COOH SAFA CH3 CH3 C16:0 palmitic acid COOH COOH C18:0 stearic acid COOH CH3 TRANS- MONOUNSATURATED CH3 trans-c18:1n-9 elaidic acid trans-c18:1n-7 vaccenic acid COOH TFA CIS MONOUNSATURATED CH3 cis-c18:1n-9 oleic acid COOH MUFA POLYUNSATURATED cis,cis-c18:2n-6 linoleic acid COOH PUFA CH3

6 Chemical structure of different polyunsaturated fatty acids (PUFA) first double bond in omega-3 (n-3) or omega-6 (n-6) position CH3 6 Linoleic acid (LA, C18:2n-6) COOH Plant oils g/day CH3 CH3 CH COOH Alpha-linolenic acid (ALNA, C18:3n-3) Eicosapentaenoic acid (EPA, C20:5n-3) Docosahexaenoic acid (DHA, C22:6n-3) Peter Zock COOH COOH Plant oils, nuts, meat 1-2 g/day Fatty fish g/day

7 The Good and the Bad fats

8 Importance of blood lipids as risk factors of CHD: summary LDL: the bad cholesterol 1% up 1-2% increase in risk HDL: the good cholesterol 1% up 3% decrease in risk Total/HDL ratio: strongest risk predictor 1 % up 1.5-3% increase in risk (Triglycerides probably also important!)

9 Strengths and limitations of various types of biomedical research approaches Type Strength Limitation Biomarker trials Randomized Validity of marker Epidemiology Hard end points Confounding Clinical trials In vitro, animals Hard end points; Duration, patients randomized Mechanism, Insight Extrapolation Adapted from a slide by Martijn Katan

10 Major types of dietary fatty acids: SAFA vs MUFA vs PUFA vs TFA

11 Iso-energetic (iso-caloric) replacement There There is no is no such such thing thing as a as placebo a placebo for dietary for fats or dietary other energy-yielding fats or other nutrients energy-yielding nutrients % of energy as Protein Carb 15 SAFA MUFA PUFA 50 Daily energy intake ~2400 kcal (10MJ)

12 Effects on LDL and HDL cholesterol of replacing carbohydrates with fatty acids mmol/l change per 1% energy LDL HDL SAFA MUFA PUFA TRANS Source: Mensink, Zock, Kester, Katan. Am J Clin Nutr 2003;77:

13 Effect on Total/HDL cholesterol of replacing carbohydrates with different fatty acids Unit change per 1% energy Total to HDL cholesterol ratio SAFA MUFA PUFA TRANS Source: Mensink, Zock, Kester, Katan. Am J Clin Nutr 2003;77:

14 Effect on Total/HDL cholesterol of replacing saturates with carbohydrates or other fatty acids Unit change per 1% energy Total to HDL cholesterol ratio MUFA PUFA CARB TRANS Source: Mensink, Zock, Kester, Katan. Am J Clin Nutr 2003;77:

15 Effect on CHD risk of replacing saturates with other fats or carbohydrates: the Nurses Health Study Change in CHD risk (%) % -46% -13% +83% MUFA PUFA CARB TRANS per 5 en% per 5 en% per 5 en% per 2 en% Source: Hu et al, NEJM 1997;337:1491

16 A pooled analysis of 11 cohort studies involving > 340,000 subjects shows that: Replacing SAFA with PUFA is most beneficial Quality of fat is more important than quantity % change in risk * MUFA PUFA CARB MUFA PUFA CARB Events * Deaths Source: Jakobsen et al, Am J Clin Nutr 2009;89: published ahead of print February 11 *

17 Clinical trials from the ies: replacing SAFA with PUFA lowers both cholesterol and Heart disease % Difference heart disease Low-fats diets DART MRC LOW FAT High-polyunsaturated fat diets MRC SOY OIL DAYTON LEREN TURPEINEN % Cholesterol difference Source: Sacks F, J Cardiovasc Risk 1994; Am J Med 2002

18 Major types of dietary fatty acids: Summary of evidence for benefical effects on heart health REPLACEMENT AVAILABLE EVIDENCE SAFA PUFA: SAFA MUFA: SAFA Carbohydrate: TFA Anything: convincing probable/possible not supportive convincing

19 Different types of Trans fatty acids: Industrial vs Ruminant sources

20 Industrial vs Ruminant TFA is not the same as elaidic acid vs vaccenic acid Vaccenic acid Elaidic acid

21 A large part of total TFA intake is from ruminant sources Intake in Europe in the mid 90-ies Based on TRANSFAIR, Hulshof Eur J Clin Nutr 1999;53:143

22 Association of ruminant TFA with CHD in epidemiological studies Relative risk of coronary heart disease Ruminant TFA ATBC Study Case-control study Nurses Health Study, 8 y follow-up Zutphen Cohort Study Intake of ruminant t TFA (g/day) Weggemans et al 2004 Eur J Lipid Sci Technol 106:390-97

23 Association of ruminant or industrial TFA with CHD in the same epidemiological studies Relative risk of coronary heart disease Ruminant TFA (closed symbols) ATBC Study Case-control study Nurses Health Study, 8 y follow-up Zutphen Cohort Study Industrial TFA (open symbols) Absolute trans-fatty acids intake (g/day) Weggemans et al 2004 Eur J Lipid Sci Technol 106:390-97

24 TransFact: both industrial and ruminant TFA have adverse effects on the blood lipid risk profile % change in blood cholesterol on high-industrial vs high-dairy TFA diets HDL LDL Total Men Women All subjects 19 men and 21 women, cross-over design, 5% of energy industrial vs ruminant TFA, diets for 3 weeks Chardigny, Am J Clin Nutr 2008

25 TFA from Industrial and Ruminant sources: evidence for differences in health effects? Ruminant TFA not associated with CHD in epidemiology - but may be due to low intake levels and ranges Similar adverse effects on blood cholesterol in controlled diet studies (both human and animal) No good biochemical explanation how ruminant and industrial TFA could have differential effects Given the available evidence, it is prudent to assume that both industrial and ruminant TFA are detrimental to health (until proven otherwise)

26 Intake of natural TFA in Denmark Median intake: 1.7 gram per day or 0.7% of total calories Jakobsen, EJCN 2006

27 SAFA intake in Europe is too high SAFA recommendation: less then 10% of energy intake SAFA (recommendation <10 en%) men women Country en% en% UK NL France Belgium Sweden Finland Denmark Norway Bulgaria Data from National dietary surveys

28 Trans Fatty Acids: Conclusions There is strong evidence that TFA have adverse health effects No clear evidence that natural TFA differ in health effects from industrial TFA Changes in industrial processing and food policy led to large reductions in TFA intake TFA is not a major public health issue anymore - SAFA is more important

29 Dietary Fatty Acid Targets: How can they be achieved? Reduce saturated fat content Replace preferably with polyunsaturated fat Avoid increase in trans fatty acids Focus on type rather than on amount of fat

30 And to end this talk Biofortifiction or biomodulation of foods can offer effective and sustainable ways for improving population health THANK YOU!