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DIETARY FAT AND HEART HEALTH

This section outlines the research regarding the effect that dietary fat has on various heart-related health parameters. 

 

While dietary fat might have a bad reputation, not all fats can be necessarily considered harmful. Dietary fats can be categorised as “unsaturated” and “saturated”, as they are below.

There are 3 kinds of unsaturated fat: trans-fat, mono-unsaturated and poly-unsaturated.

 

If dietary fats were categorised as “good” or “bad” it might be as follows.

 

GOOD

Poly-unsaturated fat (e-h)

 

BAD

Trans fat (a-b)

 

POSSIBLY FINE IN MODERATION

Mono-unsaturated fat (c-d)

 

CONTROVERSIAL

Saturated fat  (i-o)

 

 

 

RESEARCH FINDINGS

UNSATURATED FATS

TRANS FAT

a. Increasing trans-fat intake has been associated with increased trans fatty acids, total cholesterol and LDL levels in blood

b. Increasing trans-fat intake has been associated with increased risk of heart disease

 

Trans-fat is universally accepted as being bad for health, and has been associated with physiological indicators of heart-related health-problems (a), as well as increased risk of heart disease (b).

 

 

MONO-UNSATURATED FAT

c. Mono-unsaturated fat intake has been associated with decreased total cholesterol and LDL levels in the blood 

d. Mono-unsaturated fat intake has been positively associated with incidence of CHD, as well as not associated

 

Mono-unsaturated fat might be considered one of the “good” fats because, like polyunsaturated fat, it has been associated with reduced total cholesterol and LDL levels in the blood (c). However, it has also been positively associated with the incidence of CHD, though some studies report no association (d).

 

 

POLY-UNSATURATED FAT

e. Poly-unsaturated fat intake has been associated with reduced total cholesterol and LDL levels in blood 

f. Poly-unsaturated fat intake has been positively associated with the incidence of CHD

g. Fish oil consumption has been associated with reduced risk of CHD mortality

h. Fish oil consumption has been associated with no change in CHD mortality risk

 

Poly-unsaturated fat intake is largely considered “good” as it has been associated with reduced total cholesterol and LDL levels (e), the incidence of CHD (f). Fish oil (which contains high amounts of polyunsaturated fat) has been associated with reduced risk of CHD mortality (g), although it has also been associated with no change in CHD mortality risk (h).

 

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SATURATED FATS

i. Increasing saturated-fat intake has been associated with increased trans fatty acids, total cholesterol and LDL levels in blood

j. The different effect in different types of saturated fat. Auric, myristic, and palmitic acids have all been associated with increased cholesterol levels in blood

k. Stearic acid has been associated with no change in blood cholesterol levels

l. Increasing saturated-fat intake has been associated with an increased risk of cardiovascular disease

m. Reports of no association between saturated fat intake and all-cause mortality

 

Saturated fat can definitely be considered “controversial”. It has long been considered a contributor to heart disease. However, a number of well-established researchers are strongly contending this view.

 

As saturated fat consumption is associated with increased trans-fatty acid, total cholesterol and LDL levels in the blood (i), and increased risk of cardiovascular disease (l), as well reported as having no association with all-cause mortality (m), both sides of the argument have research studies to support their viewpoint. 

 

SATURATE FAT V POLY-UNSATURATED FAT

n. Substituting saturated fat with polyunsaturated fat has been associated with reduced incidence and/or risk of cardiac events

o. Substituting saturated fat with polyunsaturated fat has been associated with reduced cholesterol levels in the blood

 

A number of studies report the possibility of health benefits from reducing saturated fat and increased poly-unsaturated fat. This research is used by the AHA to support the position that dietary fat should be predominantly poly-unsaturated fat and that saturated fat intake should be kept to a minimum. 

 

 

REFERENCES

Dietary fat intake and CV disease

 

UNSATURATED FATS

TRANS-FAT

a. Increasing trans-fat intake has been associated with increased trans fatty acids, total cholesterol and LDL levels in the blood

  • Ascherio A, Katan MB, Zock PL, Stampfer MJ, Willett WC. 1999. Trans fatty acids and coronary heart disease. N Engl J Med 340:1994–1998. 

  • Clarke R, Frost C, Collins R, Appleby P, Peto R. 1997. Dietary lipids and blood cholesterol: Quantitative meta-analysis of metabolic ward studies. Br Med J 314:112–117. 

  • Hegsted DM, Ausman LM, Johnson JA, Dallal GE. 1993. Dietary fat and serum lipids: An evaluation of the experimental data. Am J Clin Nutr 57:875–883. 

  • Howell WH, McNamara DJ, Tosca MA, Smith BT, Gaines JA. 1997. Plasma lipid and lipoprotein responses to dietary fat and cholesterol: A meta-analysis. Am J Clin Nutr 65:1747–1764. 

 

b. Increasing trans-fat intake has been associated with increased risk of heart disease

  • Ascherio A, Hennekens CH, Buring JE, Master C, Stampfer MJ, Willett WC. 1994. Trans-fatty acids intake and risk of myocardial infarction. Circulation 89:94– 101. 

  • Hu FB, Stampfer MJ, Manson JE, Rimm E, Colditz GA, Rosner BA, Hennekens CH, Willett WC. 1997. Dietary fat intake and the risk of coronary heart disease in women. N Engl J Med 337:1491–1499. 

  • Pietinen P, Ascherio A, Korhonen P, Hartman AM, Willett WC, Albanes D, Virtamo J. 1997. Intake of fatty acids and risk of coronary heart disease in a cohort of Finnish men. The Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study. Am J Epidemiol 145:876–887. 

  • Willett WC, Stampfer MJ, Mason JE, Colditz GA, Speizer FE, Rosner BA, Sampson LA, Hennekens CH. 1993. Intake of trans fatty acids and risk of coronary heart disease among women. Lancet 341:581–585.

 

MONO-UNSATURATED FAT

c. Mono-unsaturated fat intake has been associated with decreased total cholesterol and LDL levels in the blood 

  • Gardner CD, Kraemer HC. 1995. Monounsaturated versus polyunsaturated dietary fat and serum lipids. A meta-analysis. Arterioscler Thromb Vasc Biol 15:1917– 1927.

 

d. Mono-unsaturated fat intake has been positively associated with incidence of CHD, as well as not associated

  • Hu FB, Stampfer MJ, Manson JE, Rimm E, Colditz GA, Rosner BA, Hennekens CH, Willett WC. 1997. Dietary fat intake and the risk of coronary heart disease in women. N Engl J Med 337:1491–1499. 

  • Kromhout D, de Lezenne Coulander C. 1984. Diet, prevalence and 10-year mortal- ity from coronary heart disease in 871 middle-aged men. Am J Epidemiol 119:733–741. 

  • Pietinen P, Ascherio A, Korhonen P, Hartman AM, Willett WC, Albanes D, Virtamo J. 1997. Intake of fatty acids and risk of coronary heart disease in a cohort of Finnish men. The Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study. Am J Epidemiol 145:876–887. 

 

 

POLY-UNSATURATED FAT

e. Poly-unsaturated fat has been associated with reduced total cholesterol and LDL levels in the blood 

  • Gardner CD, Kraemer HC. 1995. Monounsaturated versus polyunsaturated dietary fat and serum lipids. A meta-analysis. Arterioscler Thromb Vasc Biol 15:1917– 1927.

  • Arntzenius AC, Kromhout D, Barth JD, Reiber JHC, Bruschke AVG, Buis B, van Gent CM, Kempen-Voogd N, Strikwerda S, van der Velde EA. 1985. Diet, lipoproteins, and the progression of coronary atherosclerosis. The Leiden Intervention Trial. N Engl J Med 312:805–811. 

  • Becker N, Illingworth R, Alaupovic P, Connor WE, Sundberg EE. 1983. Effects of saturated, monounsaturated, and ω-6 polyunsaturated fatty acids on plasma lipids, lipoproteins, and apoproteins in humans. Am J Clin Nutr 37:355–360. 

  • Sonnenberg LM, Quatromoni PA, Gagnon DR, Cupples LA, Franz MM, Ordovas JM, Wilson PWF, Schaefer EJ, Millen BE. 1996. Diet and plasma lipids in women. II. Macronutrients and plasma triglycerides, high-density lipoprotein, and the ratio of total to high-density lipoprotein cholesterol in women: The Framingham Nutrition Studies. J Clin Epidemiol 49:665–672. 

  • Mensink RP. Effects of Saturated Fatty Acids on Serum Lipids and Lipoproteins: A Systematic Review and Regression Analysis. Geneva, Switzerland: World Health Organization; 2016.

 

f. Poly-unsaturated fat intake has been inversely associated with the incidence of CHD

  • Arntzenius AC, Kromhout D, Barth JD, Reiber JHC, Bruschke AVG, Buis B, van Gent CM, Kempen-Voogd N, Strikwerda S, van der Velde EA. 1985. Diet, lipo- proteins, and the progression of coronary atherosclerosis. The Leiden Inter- vention Trial. N Engl J Med 312:805–811. 

  • Gartside PS, Glueck CJ. 1993. Relationship of dietary intake to hospital admission for coronary heart and vascular disease: The NHANES II National Probability Study. J Am Coll Nutr 6:676–684

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g. Fish oil consumption has been associated with reduced risk of CHD mortality 

  • Daviglus ML, Stamler J, Orencia AJ, Dyer AR, Liu K, Greenland P, Walsh MK, Morris D, Shekelle RB. 1997. Fish consumption and the 30-year risk of fatal myocardial infarction. N Engl J Med 336:1046–1053. 

  • Dolecek TA. 1992. Epidemiological evidence of relationships between dietary poly- unsaturated fatty acids and mortality in the Multiple Risk Factor Intervention Trial. Proc Soc Exp Med Biol 200:177–182. 

  • Kromhout D, Bosschieter EB, de Lezenne Coulander C. 1985. The inverse relation between fish consumption and 20-year mortality from coronary heart disease. N Engl J Med 312:1205–1209. 

  • Kromhout D, Feskens EJM, Bowles CH. 1995. The protective effect of a small amount of fish on coronary heart disease mortality in an elderly population. Int J Epidemiol 24:340–345. 

 

 

h. Fish oil consumption has been associated with no change in CHD mortality risk

  • Albert CM, Hennekens CH, O’Donnell CJ, Ajani UA, Carey VJ, Willett WC, Ruskin JN, Manson JE. 1998. Fish consumption and risk of sudden cardiac death. J Am Med Assoc 279:23–28. 

  • Ascherio A, Rimm EB, Stampfer MJ, Giovannucci EL, Willett WC. 1995. Dietary intake of marine n-3 fatty acids, fish intake, and the risk of coronary disease among men. N Engl J Med 332:977–982. 

 

 

SATURATED FAT

i. Increasing saturated-fat intake has been associated with increased trans fatty acids, total cholesterol and LDL levels in the blood

  • Clarke R, Frost C, Collins R, Appleby P, Peto R. 1997. Dietary lipids and blood cholesterol: Quantitative meta-analysis of metabolic ward studies. Br Med J 314:112–117. 

  • Hegsted DM, Ausman LM, Johnson JA, Dallal GE. 1993. Dietary fat and serum lipids: An evaluation of the experimental data. Am J Clin Nutr 57:875–883. 

  • Kasim SE, Martino S, Kim P-N, Khilnani S, Boomer A, Depper J, Reading BA, Heilbrun LK. 1993. Dietary and anthropometric determinants of plasma lipoproteins during a long-term low-fat diet in healthy women. Am J Clin Nutr 57:146–153. 

  • Krauss RM, Dreon DM. 1995. Low-density-lipoprotein subclasses and response to a low-fat diet in healthy men. Am J Clin Nutr 62:478S–487S. 

  • Mensink RP, Katan MB. 1992. Effect of dietary fatty acids on serum lipids and lipoproteins. A meta-analysis of 27 trials. Arterioscler Thromb 12:911–919. 

 

j. Auric, myristic, and palmitic acids have all been associated with increased cholesterol levels in blood

  • Mensink RP, Temme EH, Hornstra G. 1994. Dietary saturated and trans fatty acids and lipoprotein metabolism. Ann Med 26:461–464. 

 

k. Stearic acid has been associated with no change in blood cholesterol levels

  • Bonanome A, Grundy SM. 1988. Effect of dietary stearic acid on plasma choles- terol and lipoprotein levels. N Engl J Med 318:1244–1248. 

  • Denke MA. 1994. Effects of cocoa butter on serum lipids in humans: Historical highlights. Am J Clin Nutr 60:1014S–1016S. 

  • Yu S, Derr J, Etherton TD, Kris-Etherton PM. 1995. Plasma cholesterol-predictive equations demonstrate that stearic acid is neutral and monounsaturated fatty acids are hypocholesterolemic. Am J Clin Nutr 61:1129–1139. 

 

l. Increasing saturated-fat intake has been associated with increased risk of cardiovascular disease

  • Hooper L, Martin N, Abdelhamid A,et al. Reduction in saturated fat intake for cardiovascular disease. Cochrane Database Syst Rev 2015: CD011737. 

  • de Oliveira Otto MC, Mozaffarian D, Kromhout D, et al. Dietary intake of saturated fat by food source and incident cardiovascular disease: the Multi-Ethnic Study of Atherosclerosis. Am J Clin Nutr 2012; 96: 397–404.

 

m. There are reports of no association between saturated fat intake and all-cause mortality

  • Siri-Tarino PW, Sun Q, Hu FB, et al. Meta-analysis of prospective cohort studies evaluating the association of saturated fat with cardiovascular disease. Am J Clin Nutr 2010;91:535–46. 

  • Hooper L, Summerbell CD, Thompson R, et al. Reduced or modified dietary fat for preventing cardiovascular disease. Cochrane Database Syst Rev 2012;(5):CD002137. 

  • Hooper L, Summerbell CD, Thompson R, et al. Reduced or modified dietary fat for preventing cardiovascular disease. Cochrane Database Syst Rev 2011;(7): CD002137. 

  • Skeaff CM, Miller J. Dietary fat and coronary heart disease: summary of evidence from prospective cohort and randomised controlled trials. Ann Nutr Metab 2009;55:173–201. 

  • Jakobsen MU, O’Reilly EJ, Heitmann BL, et al. Major types of dietary fat and risk of coronary heart disease: a pooled analysis of 11 cohort studies. Am J Clin Nutr 2009;89:1425–32. 

  • De Souza RJ, Mente A, Maroleanu A, et al. Intake of saturated and trans unsaturated fatty acids and risk of all cause mortality, cardiovascular disease, and type 2 diabetes: systematic review and meta-analysis of observational studies. BMJ 2015;351:h3978. 

  • Praagman J, Beulens JW, Alssema M, et al. The association between dietary saturated fatty acids and ischemic heart disease depends on the type and source of fatty acid in the European Prospective Investigation into Cancer and Nutrition-Netherlands cohort. Am J Clin Nutr 2016;103:356–65. 

  • Mente A, De Koning L, Shannon HS, et al. A systematic review of the evidence
    supporting a causal link between dietary factors and coronary heart disease. Arch
    Intern Med 2009;169:659–69. 

  • Chowdhury R, Warnakula S, Kunutsor S, et al. Association of dietary, circulating,
    and supplement fatty acids with coronary risk: a systematic review and
    meta-analysis. Ann Intern Med 2014;160:398–406. 

  • Puaschitz NG, Strand E, Norekval TM, et al. Dietary intake of saturated fat is not
    associated with risk of coronary events or mortality in patients with established
    coronary artery disease. J Nutr 2015;145:299–305. 

  • Schoenaker DA, Toeller M, Chaturvedi N, et al. Dietary saturated fat and fibre and
    risk of cardiovascular disease and all-cause mortality among type 1 diabetic patients: the EURODIAB Prospective Complications Study. Diabetologia 2012;55:2132–41.

 

 

Saturated fat v poly-unsaturated fat

n. Substituting saturated fat with polyunsaturated fat has been associated with reduced incidence and/or risk of cardiac events

  • Farvid MS, Ding M, Pan A, Sun Q, Chiuve SE, Steffen LM, Willett WC, Hu FB. Dietary linoleic acid and risk of coronary heart disease: a system- atic review and meta-analysis of prospective cohort studies. Circulation. 2014;130:1568–1578. doi: 10.1161/CIRCULATIONAHA.114.010236. 

  • Jakobsen MU, O’Reilly EJ, Heitmann BL, Pereira MA, Bälter K, Fraser GE, Goldbourt U, Hallmans G, Knekt P, Liu S, Pietinen P, Spiegelman D, Stevens J, Virtamo J, Willett WC, Ascherio A. Major types of di- etary fat and risk of coronary heart disease: a pooled analysis of 11 cohort studies. Am J Clin Nutr. 2009;89:1425–1432. doi: 10.3945/ ajcn.2008.27124. 

  • Li Y, Hruby A, Bernstein AM, Ley SH, Wang DD, Chiuve SE, Sampson L, Rexrode KM, Rimm EB, Willett WC, Hu FB. Saturated fats compared with unsaturated fats and sources of carbohydrates in relation to risk of coronary heart disease: a prospective cohort study. J Am Coll Cardiol. 2015;66:1538–1548. doi: 10.1016/j.jacc.2015.07.055. 

  • Dayton S, Pearce ML, Hashimoto S, Dixon WJ, Tomiyasu U. A controlled clinical trial of a diet high in unsaturated fat in preventing complications of atherosclerosis. Circulation. 1969;40(suppl II):II-1–II-63. 

  • Leren P. The Oslo Diet-Heart Study: eleven-year report. Circulation. 1970;42:935–942. 

  • 22. Controlled trial of soya-bean oil in myocardial infarction. Lancet. 1968;2:693–699. 

  • Turpeinen O, Karvonen MJ, Pekkarinen M, Miettinen M, Elosuo R, Paavilainen E. Dietary prevention of coronary heart disease: the Finnish Mental Hospital Study. Int J Epidemiol. 1979;8:99–118. 

  • Miettinen M, Turpeinen O, Karvonen MJ, Pekkarinen M, Paavilainen E, Elosuo R. Dietary prevention of coronary heart disease in women: the Finnish Mental Hospital Study. Int J Epidemiol. 1983;12:17–25. 

  • Miettinen M, Turpeinen O, Karvonen MJ, Elosuo R, Paavilainen E. Effect of cholesterol-lowering diet on mortality from coronary heart disease and other causes: a twelve-year clinical trial in men and women. Lancet. 1972;2:835–838. 

  • Watts GF, Lewis B, Brunt JN, Lewis ES, Coltart DJ, Smith LD, Mann JI, Swan AV. Effects on coronary artery disease of lipid-lowering diet, or diet plus cholestyramine, in the St Thomas’ Atherosclerosis Regression Study (STARS). Lancet. 1992;339:563–569. 

  • Mozaffarian D, Micha R, Wallace S. Effects on coronary heart disease of increasing polyunsaturated fat in place of saturated fat: a systematic review and meta-analysis of randomized controlled trials. PLoS Med. 2010;7:e1000252. doi: 10.1371/journal.pmed.1000252. 

  • Chowdhury R, Warnakula S, Kunutsor S, Crowe F, Ward HA, Johnson L, Franco OH, Butterworth AS, Forouhi NG, Thompson SG, Khaw KT, Mozaf- farian D, Danesh J, Di

  • Angelantonio E. Association of dietary, circulating, and supplement fatty acids with coronary risk: a systematic review and meta-analysis [published correction appears in Arch Intern Med. 2014;160:658]. Ann Intern Med. 2014;160:398–406. doi: 10.7326/M13-1788. 

  • Hooper L, Martin N, Abdelhamid A, Davey Smith G. Reduction in saturated fat intake for cardiovascular disease. Cochrane Database Syst Rev. 2015:CD011737. doi: 10.1002/14651858.CD011737

 

o. Substituting saturated fat with polyunsaturated fat has been associated with reduced cholesterol levels in the blood

  • Bronte-Stewart B, Antonis A, Eales L, Brock JF. Effects of feeding different fats on serum-cholesterol level. Lancet. 1956;270:521–526. 

  • Keys A, Anderson JT, Grande F. Prediction of serum-cholesterol responses of man to changes in fats in the diet. Lancet. 1957;273:959–966. 

  • Ahrens EH Jr, Insull W Jr, Blomstrand R, Hirsch J, Tsaltas TT, Peterson ML. The influence of dietary fats on serum-lipid levels in man. Lancet. 1957;272:943–953. 

  • Malmros H, Wigand G. The effect on serum-cholesterol of diets contain- ing different fats. Lancet. 1957;273:1–7.

  • Dayton S, Pearce ML, Hashimoto S, Dixon WJ, Tomiyasu U. A controlled clinical trial of a diet high in unsaturated fat in preventing complications of atherosclerosis. Circulation. 1969;40(suppl II):II-1–II-63. 

  • Leren P. The Oslo Diet-Heart Study: eleven-year report. Circulation. 1970;42:935–942. 

  • Controlled trial of soya-bean oil in myocardial infarction. Lancet. 1968;2:693–699. 

  • Turpeinen O, Karvonen MJ, Pekkarinen M, Miettinen M, Elosuo R, Paavilainen E. Dietary prevention of coronary heart disease: the Finnish Mental Hospital Study. Int J Epidemiol. 1979;8:99–118. 

  • Miettinen M, Turpeinen O, Karvonen MJ, Pekkarinen M, Paavilainen E, Elosuo R. Dietary prevention of coronary heart disease in women: the Finnish Mental Hospital Study. Int J Epidemiol. 1983;12:17–25. 

  • Miettinen M, Turpeinen O, Karvonen MJ, Elosuo R, Paavilainen E. Effect of cholesterol-lowering diet on mortality from coronary heart-disease and other causes: a twelve-year clinical trial in men and women. Lancet. 1972;2:835–838. 

  • Watts GF, Lewis B, Brunt JN, Lewis ES, Coltart DJ, Smith LD, Mann JI, Swan AV. Effects on coronary artery disease of lipid-lowering diet, or diet plus cholestyramine, in the St Thomas’ Atherosclerosis Regression Study (STARS). Lancet. 1992;339:563–569. 

  • Houtsmuller AJ, van Hal-Ferwerda J, Zahn KJ, Henkes HE. Favorable influ- ences of linoleic acid on the progression of diabetic micro- and macroan- giopathy in adult onset diabetes mellitus. Prog Lipid Res. 1981;20:377– 386.

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