Commentary to USDA Report of the Dietary Guidelines, ESC/EAS Guidelines for the management of dyslipidaemias and European Guidelines on cardiovascular disease prevention in clinical practice1-3

Overview of scientific recommendations

The last 15 years have seen a sharp drop in death rates from coronary heart disease in many countries of the developed world, the United States of America and several European countries in particular. Despite these welcome advances, coronary heart disease is still a major cause of death, illness and disability in population worldwide which justifies focusing upon preventive medicine.

It is common knowledge that eating habits influence the development of risk factors for coronary heart disease, i.e. overweight, diabetes, hypertension and dyslipidemia.

The current international dietary recommendations particularly emphasize the following items1-3

  • a calorie balanced diet for maintenance of normal weight and weight reduction in overweight persons, respectively,
  • a diet which is nutrient dense
  • an healthy eating pattern, e.g. traditional mediterranean diet (figure 1).

 

healthydiet_a

figure 1

 

Detailed recommendations9-16 

Maintenance of normal body weight or weight reduction in overweight persons

  • Overweight is a substantial risk factor for the development of hyperlipidemia, hypertension, diabetes mellitus and gout.
  • Coronary heart disease and stroke are more common in people who are overweight.
  • Overweight predisposes to breast and colon cancer.
  • Overweight may induce gallstones and cause degeneration of the joint.

Abundant consumption of plant based foods or carbohydrate rich sources with a high content of fibre (approximately 30g/day)

  • It is recommended to consume daily of at least 200g fruits (2-3 portions) and 200g vegetables (2-3 portions).
  • Dietary pattern high in fruits, vegetables, whole grain products, legumes and nuts have been associated with a decreased risk of CHD.
  • A high-carbohydrate, high fibre diet is rich in vitamins, antioxidants, minerals, micronutrients and low in saturated fatty acids.
  • A high fibre intake reduces LDL-cholesterol levels (figure 2).
  • Fibre promotes satiety and prevents diseases of the digestive system.
  • Higher intakes of refined carbohydrates (e.g. white bread) and sugars may lead to increased calorie consumption and may have unfavourable effects on HDL-cholesterol and triglyceride levels.
  • High intake of saturated and so called trans fatty acids is the main factor responsible for a nutrition-induced rise of LDL-cholesterol levels. Conversely, decreased intake of saturated and trans fatty acids results in a substantial lowering of LDL- and total  cholesterol levels (figure 2).

Lower intake of saturated fatty acids and trans fatty acids (up to 10% of total energy intake) and their replacement by mono- and polyunsaturated fatty acids.
Reduction of trans fatty acids lower than 1% of total energy intake

Saturated fatty acids and trans fatty acids
  • High intake of saturated and so called trans fatty acids is the main factor responsible for a nutrition-induced rise of LDL-cholesterol levels. Conversely, decreased intake of saturated and trans fatty acids results in a substantial lowering of LDL- and total  cholesterol levels (figure 2).

healthydietfigure 2

Monounsaturated fatty acids
  • Replacement of saturated fatty acids by monounsaturated fatty acids results in a decrease of total and LDL-cholesterol levels.
  • Replacement of saturated fatty acids or carbohydrates by monounsaturated acids results in a favourable effect of HDL-cholestol.
  • Higher intake of monounsaturated fatty acids may protect LDL-cholesterol against oxidation.
  • Main sources for monounsaturated acids are rapeseed and olive oil.

Polyunsaturated fatty acids
  • Replacement of saturated fatty acids by polyunsaturated fatty acids results in decreased LDL-cholesterol levels.
  • An increased consumption of omega-3 fatty acids may reduce coronary morbidity and mortality, lower triglyceride levels, reduce platelet aggregation and have anti-arrhythmic effects.

Considerations concerning total fat intake

The recommended total fat intake ranges between
25 and 35% of total energy intake. Whether there is a higher total fat intake acceptable, depends primarily upon fat quality and a calorie balanced diet.

  • It is recommended to reduce the consumption of saturated fatty acids (less than 10% of total energy intake) and their replacement by mono- and polyunsaturated fatty acids as well as reduction of trans fatty acids to less than 1% of total energy intake. These are the prior measures for influencing the blood lipid levels (total cholesterol, LDL-cholesterol) in a positive way despite of an increased total fat intake.

Limited intake of dietary cholesterol (less than 300 mg/day)

  • A high intake of dietary cholesterol results in increased levels of total and LDL-cholesterol. However, this effect is on average less pronounced than the effect observed with high intakes of saturated and trans fatty acids. However, there is a high genetically determined variability concerning the influence of dietary cholesterol intake to LDL-cholesterol levels.

Limited salt intake (less than 5g per day)

  • Reducing salt intake is associated with systolic and diastolic blood pressure reduction.
  • This recommendation for alcohol intake considers all-cause mortality based on results of scientific studies.
  • Several studies have shown that a moderate consumption of alcohol does not increase but rather tend to decrease the risk of coronary heart.
  • However, alcohol intake may exacerbate high blood pressure and high triglyceride levels and may contribute to the development of certain cancers (e.g. oral-, pharyngeal-, laryngeal- or esophagus cancer), overweight, cardiovascular diseases, alcohol dependency and hepatic diseases.

Limited alcohol intake, if consumed: men no more than 20 g alcohol per day; women no more than 10 g alcohol per day

  • This recommendation for alcohol intake considers all-cause mortality based on results of scientific studies.
  • Several studies have shown that a moderate consumption of alcohol does not increase but rather tend to decrease the risk of coronary heart.
  • However, alcohol intake may exacerbate high blood pressure and high triglyceride levels and may contribute to the development of certain cancers (e.g. oral-, pharyngeal-, laryngeal- or esophagus cancer), overweight, cardiovascular diseases, alcohol dependency and hepatic diseases.

Adequate fluid consumption (at least 1.5 litres per day)

  • An adequate intake of fluids is essential for the regulation of the body temperature, for blood flow, for the digestion and transport of food, for kidney function and for the excretion of break-down products.
  • Calorie-free or low-calorie drinks are particularly recommendable.

Source

[1]   USDA Report of the Dietary Guidelines Advisory Committee on the Dietary Guidelines for Americans, 2010. January  11, 2011.

[2]   Catapano AL, Reiner Z, De Backer G et al. ESC/EAS Guidelines for the management of dyslipidaemias The Task Force for the mnagement of dyslipidaemias of the European Society of Cardiology (ESC) and the European Atherosclerosis Society (EAS). Atherosclerosis 2011;217:3-46.

[3]   Perk J, De Backer G, Gohlke H et al.: European Guidelines on cardiovascular disease prevention in clinical practice (version 2012). The Fifth Joint Task Force of the European Society of Cardiology and Other Societies on Cardiovascular Disease Prevention in Clinical Practice. European Heart Journal 2012;33,1635–1701.

[4]   Sofi F, Abbate R, Gensini GF, Casini A. Accruing evidence on benefits of adherence to the Mediterranean diet on health: an updated systematic review and meta-analysis. Am J Clin Nutr. 2010;92:1189-96.

[5]   Trichopoulou A, Costacou T, Bamia C, et al. Adherence to a Mediterranean diet and survival in a Greek population. N Engl J Med. 2003;348:2599-608.

[6]   Knoops KT, de Groot LC, Kromhout D et al. Mediterranean diet, lifestyle factors, and 10-year mortality in elderly European men and women: the HALE project. JAMA. 2004;292:1433-9.

[7]   de Lorgeril M, Salen P, Martin JL et al. Mediterranean diet, traditional risk factors, and the rate of cardiovascular complications after myocardial infarction: final report of the Lyon Diet Heart Study. Circulation. 1999;99:779-85.

[8]   Barzi F, Woodward M, Marfisi RM, et al. Mediterranean diet and all-causes mortality after myocardial infarction: results from the GISSI-Prevenzione trial. Eur J Clin Nutr. 2003;57:604-11.

[9]   Hooper L, Griffiths E, Abrahams B et al.: Dietetic guidelines: diet in secondary prevention of cardiovascular disease. J Hum Nutr Diet 2004;17:337-49.

[10] Mead A, Atkinson G, Albin D et al. Dietetic guidelines on food and nutrition in the secondary prevention of cardiovascular disease – evidence from systematic reviews of randomized controlled trials (second update, January 2006). J Hum Nutr Diet. 2006;19:401-19.

[11] International Task Force for Prevention of Coronary Heart Disease und International Atherosclerosis Society: Handbuch Prävention der koronaren Herzkrankheit. Thomson Reuters 2009.

[12] International Task Force for Prevention of Coronary Heart Disease and International Atherosclerosis Society: Prävention der koronaren Herzkrankheit. Bruckmeier Verlag, Grünwald 2003.

[13] International Task Force for Prevention of Coronary Heart Disease: Coronary Heart Disease: Reducing the Risk. The scientific background for primary and secondary prevention of coronary heart disease. A worldwide view. Nutr Metab Cardiovasc Dis 1998;8:205-71.

[14] Krauss RM, Eckel RH, Howard B et al.: Revision 2000: A Statement for Healthcare Professionals from the Nutrition Committee of the American Heart Association. Circulation 2000;102:2284-99.

[15] World Health Organisation: Diet, nutrition and the prevention of chronic disease. Report of a Joint WHO/FAO Expert Consultation. WHO Technical Report Series 916, Genf, 2003.

[16] Working Party I: Final report. Public Health Nutrition 2001;4:275-292.

[17] Fletcher B, Berra K, Ades P, et al. Managing abnormal blood lipids: a collaborative approach. Circulation. 2005;112:3184-209.