Mediterranean Diet and Prevention of Heart Diseases - Literature review Example

The first law of dietetics seems to be: if it tastes good, it’s bad for you” – Issac Asimov 1920 – 92: attributed (Susan Ratcliffe, 2001) Introduction. Mediterranean Diet (henceforth referred to as Med-Diet), although a misnomer (Simopoulos, 2001), is defined variously by different authors in the scientific literature. However, all of them agree on the aspect that Med-Diet is commonly seen in Crete, Greece, particularly in the early 1960s (Walter C Willett et al., 1995; Anonymous, 2013c). In addition, Med-Diet may be followed in Southern Italy (Walter C Willett et al., 1995), Southern France (Anonymous, 2013c), and Southern European Countries (Covas, Maria-Isabel, 2007). Typically Med-Diet involves an emphasis on fruits, vegetables, nuts, grains, olive oil (as opposed to butter), and a glass or two of red wine (Simopoulos, 2001; Martins e Silva and Saldanha, 2007; Nadtochiy and Redman, 2011). Variations exist, which are followed in other parts of Italy, France, Lebanon, Morocco, Portugal, Spain, Syria, Tunisia, Turkey and elsewhere in the Mediterranean countries. Traditional Med-Diet may involve low levels of dairy products, meat (fish, Chicken, Sea food) and zero to four eggs per week (Walter C Willett et al., 1995; Anonymous, 2013c). Ancestral origin of the Med-diet has been discussed by at least one author, who also suggested that metabolism of people, may have evolved to work optimally on such a diet rather than on current diet (Covas, Maria-Isabel, 2007). Heart disease (HD) is defined at www.medterms.com (Anonymous, 2013b) as any disorder that affects heart, with common errors of using HD as synonymous for coronary heart disease (CHD) having been mentioned. Nevertheless, HD encompasses a number of heart related ailments including cardiovascular disease (CVD). It is now well established that many fish and amphibians can repair and regenerate damaged heart tissue while the same cannot be said to be true with regard to humans (Anonymous, 2009). Perhaps it is this incapability of human heart to repair itself results in heart disease. Before taking the discussion any further, it would be prudent to look into the factors that contribute to heart disease. Heart Disease in humans, per se, is multi-factorial in nature (Rayo Llerean et al., 1998) and can be considered a life style disease. HD is seen in both developing countries and the developed nations. Alcohol, Tobacco, high blood pressure and high cholesterol are the major risk factors for this disease (Majid Ezzati et al., 2002). Margene A Wagstaffs’ (1992) detailed analysis suggests a complex relationship between dietary factors and coronary heart disease (CHD). Walker and Reamy (2009) advise that physicians should emphasise diets which are rich in plant products and limit the patients’ fat intake. Furthermore, they also suggest one or two dietary interventions every 3 - 6 months for CVD risk. Since historical times humans have realized clearly that a link exists between the food taken in and diseases, including those of heart. Consequently, modifications in diet are made as per the disease observed. This is markedly pronounced in the Ebers papyrus believed to have been written around 1550BC. In reality, this Ebers papyrus is a copy of an original document dating from the 1st Egyptian dynasty (circa 3400BC) (Cyril P Bryan, 1930). Similarly, diet exerts its influence on human heart, with MedDiet standing out for several health benefit reasons (Sánchez-Muniz, 2012), an aspect that is widely touched upon by various authors in the scientific literature, and also forms the topic of discussion in the present document. Diet and the heart disease. The lower mortality rate in Southern European Countries in comparison to that observed in Northern European countries or the USA is perhaps an indicator of Med-dietary influence on HD (Trichopoulou et al., 2003; Covas, Maria-Isabel, 2007). Whayne and Maulik (2012) say that cardiovascular health starts with good nutrition. While these statements are interesting with available evidence strongly pointing to diet, the readers of this document must keep in mind that dietary factors alone may not fully explain the excellent health of Mediterranean people (Lawrence H Kushi et al., 1995). Dietary influence on onset of heart disease. “Prevention is better than cure” – A 17th century proverb. Degirolamo and Rudel (2010) explored in coronary heart disease (CHD), one type of heart disease, replacement of dietary saturated fatty acids (SFA) with higher intakes of monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA) in animal models. Their results suggest that MUFA from either animal fat or vegetable oils is not cardio-protective. On the contrary, Chrysohoou et al., (2010) found that a greater adherence to the Med-Diet seems to preserve left ventriolic systolic function at hospitalization and seems to be associated with better long-term prognosis of patients who have had an acute coronary syndrome (ACS). Whereas, Walker and Reamy (2009) say that the popular Med-Diet is more useful in patient oriented setting, in comparison to other commercial diets; consumption of whole olive might also confer similar health benefits as olive oil, one of the main ingredients of Med-Diet (Waterman and Lockwood 2007). Similarly, Trichopoulou et al., (2005) found in a study involving 74,607 men and women, aged 60 or more, modified Med-Diet applicable across Europe was associated with increased survival among older people. These observations concur with an earlier study of Trichopoulou et al., (2003) in 22,043 adults in Greece, wherein a greater reduction in total mortality was observed. Nevertheless, the precise mechanisms of how dietary modifications alter the risk of cardio vascular disease remain uncertain (Rajaram 2003; Hingorani, 2004). Cristina Andres-Lacueva et al., (2006) found in a study of 52 patients of wine consumers that resveratrol metabolites are good biomarkers to study the effects of moderate wine consumption. This gains prominence given the observation that wine is a part of MedDiet. Therefore it is natural to expect a negative correlation between wine consumption and cardiovascular disease. Continuing the discussion in similar lines, Rayo Llerana et al., (1998) conclude that alcohols’ negative effects outweigh the beneficial effects for coronary artery disease. Hence, the authors continue, alcohol consumption may not be prescribed for prophylaxis for the general population. As already mentioned, consuming one or two glasses of red wine is part of MedDiet. Contrary to what have been mentioned in the above passage, the very observation of lower mortality in people following Med-Diet may in-part be a supporting fact that Med-Diet prevents HD to a certain extent. Gardner et al., (2011) conducted a survey in a population of 69 + 10 years of age wherein they found Med-Diet to be associated with decreased risk of vascular events. Similar results were found in a study of 41078 individuals (29 – 69 years) by Buckland et al (2009). Dai et al., (2010) found that a Med-Diet pattern is associated with higher heart rate variability (HRV). A reduced HRV is considered one risk factor for coronary artery disease (CAD). Perhaps, some beneficiary effect must be attributed to ethanol present in red wine (Rayo Llerena et al., 1998). Needless-to-say, the list is endless in this direction. All this is summarized as table I. Table I. Summary and comparison of various studies demonstrating the use of Med-Diet in heart disease Sl. # Study # of patients Diet Comparing Diet Remarks 1 Serge Renaud et al., 1995 605 Cretan Med-diet Usual prescribed diet/prudent diet When adopted to a Western population Cretan Med-Diet protects against Coronary Heart Disease (CHD) 2 Maria Annunziata Carluccio et al., 1999 -- Med-Diet -- The protective component in diets against heart disease may be Oleic acid 3 Michel de Lorgeril et al., 1999 423 Med-Diet Western-type Diet Final report of the popular Lyon Diet Heart study. The authors propose that cardioprotective diet to be included to decrease cardiovascular morbidity and mortality 4 Penny Kris-Etherton et al., 2001 -- Med-Diet American Heart Association (AHA) step I and II diets Suggest more funding for nutrition-based research 5 Robertsson & Smaha, 2001 -- Med-Diet -- -- 6 Frank B Hu & Walter C Willett, 2002 -- -- -- Clubbed with avoidance of smoking diets similar to Med-Diet prevents Cardiovascular Disease (CVD) in Western patients 7 Trichopoulou et al., 2003 22,043 Traditional Med-Diet -- Found significant association between reduction in total mortality and traditional Med-Diet 8 Trichopoulou et al., 2005 74,607 Modified Med-Diet -- In older people, modified med-diet and survival are associated 9 Katherine Esposito and Dario Giugliano, 2005 -- -- -- This study/paper is essentially a discussion linking unhealthy diets to metabolic and cardiovascular diseases 10 Dalziel et al., 2006 605 Med-Diet Prudent Western Diet A cost-utility analysis wherein Med-diet was found to be highly cost-effective in patients with previous myocardial infarction 11 Sofi et al., 2008 1,574,299 Med-Diet -- Meta-analysis of prospective cohort studies wherein improved health status is associated with adherence to Med-Diet 12 Jun Dai et al., 2008 345 Med-Diet -- Med-Diet reduced cardiovascular risk via reduced inflammation 13 Buckland et al., 2009 41,078 Med-Diet -- Association of Med-Diet with a reduced coronary heart disease (CHD) risk 14 Chrysohoou et al., 2010 1000 Med-Diet -- Better prognosis of patients who have had acute coronary syndrome (ACS) is associated with Med-Diet 15 Dai et al., 2010 276 Food Frequency Questionnaire (FFQ) A higher heart rate variability (HRV) is associated with Med-Diet, whence a reduction is a risk factor for Coronary Artery Disease 16 JÖnsson et al., 2010 44 Paleolithic Diet Med-Diet Per calorie, a paleolithic diet is more satiating 17 Gardner et al., 2011 2568 Med-Diet -- A decrease in the risk of vascular events is associated with Med-Diet 18 SchrÖder, et al., 2011 7146 Med-Diet FFQ Describe the development of a shorter screening method for rapid estimation of adherence to the Mediterranean diet Legend: ACS: Acute coronary syndrome; AHA: American Heart Association; CHD: Chronic/Coronary Heart Disease (as appropriate); CVD: cardiovascular disease; FFQ: Food Frequency Questionnaire; HRV: Heart rate variability; Med-Diet: Mediterranean Diet; Other abbreviations carry their usual disease. For specific references, see the list of references at the end of the article. Med-Diet during Heart disease. Ancient Egyptians attributed heart ailments to drinking warm water and bad food. Thus during heart ailments diet based treatments were involved. One such remedy includes milk, honey and water. If this didn’t cure the disease, then a stronger mixture of Onions, Sweet Beer and Date-meal or a remedy to heal the heart for certain Figs – 1/8th; Fresh lead-earth – 1/16th; cake – 1/32nd and water 5/6th, was recommended (Cyril P Bryan, 1930). Renaud et al., (1995) conducted a comparative study of Med-Diet with the usual prescribed/prudent diet commonly prescribed to coronary patients in 605 individuals recovering from myocardial infarction. They found that a Cretan Med-Diet adapted to a Western population protected them against coronary heart disease. This finding is consistent with the higher life expectancy observed in people having Med-Diet. Robertson and Smaha (2001) in their editorial in circulation raise the issue of effective methods of intervention in cardiovascular disease condition. They also mention that we live in an age wherein dietary advice comes in many forms. This confuses the consumer as to what is best, as all these advices are mostly based on sound science. However, for the formulation of appropriate dietary guidelines, identification of appropriate active compounds of Med-Diet is crucial. Given the fact that human studies are difficult owing to ethical and practical reasons, dietary formulations may be based on animal model studies, meta-analysis of earlier reports and Food frequency questionnaires (FFQ) based on patient responses (Visioli et al., 2005). Despite this, American heart association (AHA) issued an advisory stating that a Med-Diet has notable effects on CVD (Robertson & Smaha, 2001). Med-Diet after recovery from Heart disease. Dalziel et al., (2006) assessed the performance of Med-Diet in patients after a first acute myocardial infarction (AMI) and found that in such scenarios Med-Diet is highly cost-effective. However, they also caution the policy/decision makers about applying their results to other settings. Conclusion. While what has been described above speaks highly of the Med-Diet, one must keep in mind that the traditional Med-Diet has its negative points in the sense that it may not contribute to heart disease but may contribute to other diseases, which of course is beyond the scope of this article. As already mentioned, traditional Med-Diet was in vogue in the early 1960s, and is high in nitrate rich vegetables (Anonymous, 2013a). Whereas dietary nitrate has beneficial vascular effects in humans (Nadtochiy & Redman, 2011; Lidder & Webb, 2013), positive and negative associations with dietary nitrate and cancer have been reported (Anonymous, 2013). Plausible mechanisms of nitric oxide induced cancer have been hypothesized earlier with partial scientific evidence available for the same (Kane et al., 1997; Poduri, 2003). Based on these observations, it is only prudent to expect that in future more information will be revealed with regard to the negative effects. At present lack of long-term studies on the effects of dietary nitrate is a major limitation. The currently available diets are modified Med-Diets, and whether the same statements can be said with regard to modified diets currently available is an open-ended question. Although some information is available with regard to modified diets, more work needs to be done. Perhaps the scientific community is being naïve by attributing too much emphasis on Med-Diet alone in a situation best described as life-style disease. At this stage one must keep in mind that diet is one aspect of life style. To conclude, perhaps, the greater life expectancy observed in Mediterranean regions may be because of other factors, viz., genetic composition of the individuals, environment and life styles involved (Krebs, 2009). Data source. Because discussing all the factors leading to heart disease is beyond the scope, this article reviews heart disease with reference to diet, in general, and Med-Diet, in particular. For this purpose, PubMed (with full text option), Google Scholar, and Academic OneFile Infotrac databases served as the sources for a review of literature. Key words used were ‘Mediterrranean Diet’, ‘Heart Disease’, without any time limit. Subsequently, to narrow down the huge number of articles that showed up, we restricted the search to those articles with free full text option. The articles were selected and reviewed for their suitability to the present purpose. Only those found appropriate for the present article were included in the reference list. List of Abbreviations used: ACS – Acute Coronary Syndrome; AHA – American Heart Association; AMI – Acute Myocardial Infarction; BC – Before Christ; CAD – Coronary Artery Disease; CHD – Coronary Heart Disease; CVD – Coronary Vascular Disease; HD – Heart Disease; HRV – Heart Rate Variability; Med-Diet – Mediterranean Diet; MUFA – Monounsaturated Fatty Acids; PUFA – Polyunsaturated Fatty Acids; SFA – Saturated Fatty Acids; USA – United states of America; Other abbreviations carry their usual significance. References. Anonymous. (2009) “Last Author”. Nature; 461.7260: 9. Acadmic OneFile. Web. 3 Mar 2013 Anonymous. (2013a) “Vascular effects of dietary nitrate (as found in green leafy vegetables and beetroot) via nitrate-nitrite-nitric oxide pathway”. British Journal of Clinical Pharmacology; 75.3: 677+. Academic OneFile. Web. 7 March 2013. Anonymous. (2013b) Heart Disease. www.medterms.com (accessed 04/03/2013) Anonymous. (2013c) Mediterranean Diet. www.medterms.com (accessed 04/03/2013) Chrysohoou C, Panagiotakos DB, Aggelopulos P, et al. (2010) The Mediterranean diet contributes to the prevention of left ventricular sustolic function and to the long term favourable prognosis of patients who have had an acute coronary event. Am J Clin Nutr; 92 (1): 47 – 54. Covas, Maria-Isabel. (2007) “Benefits of Mediterranean diet on cardiovascular disease”. Future Cardiology; 3.6: 575+. Academic OneFile Web. 3 Mar 2013. Cristina Andres-Lacueva, Ramon Estruch, Walter Jaegar, et al. (2006) Diagnostic performance of urinary resveratrol metabolites as a biomarker of moderate wine consumption. Clinical Chemistry, 52.7: 1373+ Academic OneFile. Web. 10 Mar 2013. Cyril P Bryan. (1930) The Papyrus Ebers (translated from German Version). The Garden City Press Ltd., Letchworth, Herts, UK. Dai J, Lampert R, Wilson PW et al. (2010) Mediterranean dietary pattern is associated with improved cardiac autonomic function among middle-aged men: a twin study. Circ Cardiovasc Qual Outcomes 3 (4): 366 – 373. Dalziel K, Segal L, de Lorgeril M. (2006) A mediterrranean diet is cost-effective in patients with previous myocardial infarction. J Nutr; 136 (7): 1879 – 85; Degirolamo C, Rudel LL. (2010) Dietary monounsaturated fatty acids appear not to provide cardioprotection. Curr Atheroscler Rep; 12 (6): 391 – 6. Frank B Hu and Walter C Willett. (2002) Optimal diets for prevention of coronary heart disease. JAMA; 288: 2569 – 2578. Gardner H, Wright CB, Gu Y et al. (2011) Mediterranean-style diet and risk of ischemic stroke, myocardial infarction, and vascular death: the northern manhattan study. Am J Clin Nutr; 94 (6): 1458 – 64. Genevieve Buckland, Gonzalez CA, Agudo A et al. (2009) Adherence to the Mediterranean diet and risk of coronary heart disease in the spanish EPIC cohort study. Am J Epidemiol; 170 (12): 1518 – 1529. Hingorani AD. (2004) Diet, the endothelium and atherosclerosis. Clin Sci (Lond); 106 (5): 1447 – 8. JÖnsson T, Granfeldt Y, Erlanson-Albertsson C et al. (2010) A paleolithic diet is more satiating per calorie than a Mediterranean like diet in individuals with ischemic heart disease. Nutr Metab (Lond); 7:85. Jun Dai, Andrew H Miller, J Douglas Bremner et al. (2008) Adherence to the Mediterranean diet is inversely associated with circulating interleukin-6 among middle-aged men: A twin study. Circulation; 117: 169 – 175. Kane JM, Shears LL, Hiewholzer C et al. (1997) Chronic hepatitis C virus infection in humans: induction of hepatic nitric oxide synthase and proposed mechanisms for carcinogenesis. J Surg Res, 69: 321+ Katherine Esposito and Dario Giugliano. (2005) Diet and inflammation: a link to metabolic and cardiovascular diseases. European Heart Journal; 27: 15 – 20. Krebs JR. (2009) The gourmet ape: evolution and human food preferences. Am J Clin Nutr; 90 (3): 707S – 711S. Lawrence H Kushi, Elizabeth Blenart and Walter C Willett. (1995) “Meat, Wine, Fats, and Oils”. American Journal of Clinical Nutrition; 1416S+. Academic OneFile. Web. 12 Mar 2013. Lidder s and Webb AJ. (2013) Vascular effects of dietary nitrate (as found in green leafy vegetables and beet root) via the nitrate-nitrite-nitric oxide pathway. Br J Clin Pharmacol, 75 (3): 677 – 696. Majid Ezzati, Stephen Vander Hoorn, Alan D Lopez, et al. (2002) Selected major risk factors and global and regional burden of disease (Articles). The Lancet; 360.9343: 1347+. Academic OneFile. Web. 3 Mar 2013. Maria, Annunziata Carluccio, Marika Massaro cosima Bonfrate et al. (1999) Oleic acid inhibits endothelial activation – a direct vascular antiantherogenic mechanism of a nutritional component in the mediterranean diet. Arterioscler Throm Vas Biol; 19: 220 – 228 Martins e Silva J and Saldanha C. (2007) Diet, atherosclerosis, and atherothrombotic events. Rev Port Cardiol, 26 (3): 277 – 94. Michel de Lorgeril, Patricia Salem, Jean-Louis Martin et al. (1999) Mediterranean diet traditional risk factors, and the rate of cardiovascular complications after myocardial infarction – final report of the lyon diet heart study. Circulation; 99: 779 – 785. Nadtochiy SM, Redman EK. (2011) Mediterranean diet and cardioprotection: the role of nitrite, polyunsaturated fatty acids and phenols. Nutrition; 27 (7 – 8): 733 – 44. Penny Kris-Etherton , Robert H Eckel, Barbara V Howard, Sachiko St. Jeor, Terry L Bazzare. (2001) Lyon Diet Heart study: Benefits of Mediterranean style, national cholesterol education program/American Heart Association step I dietary pattern on cardiovascular disease. Circulation; 103: 1823 – 1825. Poduri C D. (2003) Hepatitis C virus (HCV) – A review molecular biology of the virus, immunodiagnostics, genomic heterogeneity and the role of virus in hepatocellular carcinoma. Indian Journal of Experimental Biology; 41: 549 – 562. Rajaram S. (2003) The effect of vegetarian diet, plant foods, and phytochemicals on homeostasis and thrombosis. Am J Clin Nutr; 78 (3 Suppl): 552S – 558S. Rayo Llerena I, Marin Huerta E. (1998) Wine and Heart. Rev Esp Cardiol; 51 (6): 435 – 49. Robertson RM, Smaha L. (2001) Can a Mediterranean-style diet reduce heart disease? Circulation; 103 (13): 1821 – 2. Sánchez-Muniz FJ. (2012) Dietary fibre and Cardiovascular health. Nutr Hosp; 27 (1): 31 – 45. SchrÖder H, Fito M, Estruch R et al. (2011) A short screener is valid for assessing Mediterranean diet adherence among older Spanish men and women. J Nutr; 141 (6): 1140 – 5. Serge Renaud, Michel de Lorgeris, Jacques Delaye et al. (1995) Cretan Mediterranean diet for prevention of coronary heart disease. Am J Clin Nutr; 61 (Suppl): 1360S – 7S Simopoulos AP. (2001) The Mediterranean diets: what is so special about the diet of Greece? The Scientific evidence. J Nutr; 131 (11 Suppl): 3065S – 73S. Sofi F, Cesari F, Abbate R et al. (2008) Adherence to Mediterranean diet and health status: meta-analysis. BMJ; 337: a1344 Susan Ratcliffe (Ed). (2001) Oxford Dictionary of Quotations and Proverbs. Oxford University Press, New Delhi; pp: 79. Trichopoulou A, Costacou T, Bamia C, Trichopoulos D. (2003) Adherence to a Mediterranean diet and survival in a Greek population. N Engl J Med; 348 (26): 2599 – 2608. Trichopoulou A, Orfanos P, Norat T et al. (2005) Modified mediterranean diet and survival: EPIC-elderly prospective cohort study. BMJ; 330 (7498):991 Visioli F, Bogani P, Grande S, Galli C. (2005) Mediterranean food and health building human evidence. J Physiol Pharmacol; 56 suppl1: 37 – 49. Wagstaff, Alargene A. (1992) “The Lancet, Vol 338, Oct – Dec, 1991”. Journal of the American Dietetic Association; 92.6: 766+. Academic OneFile. Web. 3 Mar 2013. Walker C, Reamy BV. (2009) Diets for cardiovascular disease prevention: what is the evidence? American Family Physician; 79 (7): 541 – 2. Walter C Willett, Frank Sacks, Antonia Trichopoulou, Greg Drescher, et al. (1995) Mediterranean diet pyramid: a cultural model for healthy eating. American Journal of Clinical Nutrition; 61 (suppl): 1402S – 6S. Waterman E, Lockwood B. (2007) Active components and clinical applications of olive oil. Altern Med Rev; 12 (4):331 – 42. Whayne TF Jr, Maulik N. (2012) Nutrition and Healthy heart with an exercise boost. Canadian Journal of Physiology and Pharmacology; 90 (8): 967 – 76. Read More