Fried food consumption and ischemic heart disease. A systematic literature review Giuseppe Lippi, Camilla Mattiuzzi, Gianfranco Cervellin PII: DOI: Reference:
S0167-5273(15)00911-0 doi: 10.1016/j.ijcard.2015.04.178 IJCA 20384
To appear in:
International Journal of Cardiology
Received date: Revised date: Accepted date:
3 March 2015 20 April 2015 21 April 2015
Please cite this article as: Lippi Giuseppe, Mattiuzzi Camilla, Cervellin Gianfranco, Fried food consumption and ischemic heart disease. A systematic literature review, International Journal of Cardiology (2015), doi: 10.1016/j.ijcard.2015.04.178
This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
ACCEPTED MANUSCRIPT Fried food consumption and ischemic heart disease. A systematic literature review.
T
Giuseppe Lippi1, Camilla Mattiuzzi2, Gianfranco Cervellin3
SC R
IP
1. Laboratory of Clinical Chemistry and Hematology, Academic Hospital of Parma, Parma, Italy. 2. Service of Clinical Governance, General Hospital of Trento, Trento, Italy. 3. Emergency Department, Academic Hospital of Parma, Parma, Italy.
Word count: 1086 words + 1 table.
NU
Type of Article: Letter to the editor.
MA
Keywords: Ischemic heart disease; Acute coronary syndrome; Coronary Heart Disease; Acute Myocardial Infarction; Fried food.
AC
CE P
TE
D
Author for correspondence: Prof. Giuseppe Lippi U.O. Diagnostica Ematochimica, Azienda Ospedaliero-Universitaria di Parma, Via Gramsci, 14, 43126 - Parma, Italy Tel. 0039-0521-703050 Tel. 0039-0521-703791 E-mail:
[email protected],
[email protected]
ACCEPTED MANUSCRIPT Several lines of evidence convincingly attest that the so-called Mediterranean diet exerts a number of beneficial effects on the cardiovascular risk [1,2]. A typical
T
Mediterranean diet entails large quantities of fruits and vegetables, balanced by low
IP
intake of meat, carbohydrate-enriched products and fried foods [3]. The consumption of
SC R
fried food is conventionally considered unhealthy due to the fact that frying impairs the chemical properties of food or oil, increases the overall content of trans fats and decreases that of unsaturated fats [4]. This evidence has generated the widespread
NU
perception that consumption of this type of food should be limited to prevent the onset
MA
of cardiovascular events. Therefore, we carried out a systematic review of published clinical studies that investigated whether an association may exists between large consumption of fried food and the risk of ischemic heart disease (IHD).
TE
D
An electronic search was conducted in Medline (with PubMed interface), Scopus and ISI Web of Science using the keywords “fried” AND “food” AND “myocardial
CE P
infarction” OR “coronary heart disease” OR “coronary artery disease” OR “acute coronary syndrome” OR “ischemic heart disease” in “Title/Abstract/Keywords”, with
AC
no language or date restriction. All articles identified according to the search criteria were systematically reviewed by two authors (G.L. and C.M.). The references of selected articles were also hand-searched to identify other pertinent documents. A total number of 41 documents were identified after elimination of replicates, and 36 items (16 review articles, 16 articles with no specific data on fried food intake or IHD, 3 letters or commentaries) were excluded after accurate reading of title, abstract or full text. Therefore, 6 studies (2 prospective and 4 case-control) were finally selected for this systematic literature review (Table 1) [5-10]. Inter-rater agreement was absolute (kappa statistics, 1.00). Kabagambe et al performed a case-control study including 485 survivors of a first acute myocardial infarction (121 women and 364 men; mean age 57±10 years) and
ACCEPTED MANUSCRIPT 508 controls (137 women and 371 men; mean age 58±11 years) matched by age, gender and area of residence [5]. The total intake of fried food was found to be similar between
T
patients with acute myocardial infarction and controls (7.11 versus 6.76 serving per day;
IP
p>0.05).
SC R
Iqbal et al carried out a large case-control trial including 5,761 patients with acute myocardial infarction and 10,646 matched control subjects (data on gender prevalence and age were unavailable in the full text of the manuscript) free from angina,
NU
diabetes, hypertension or hypercholesterolemia [6]. Compared to subjects in the lowest
MA
quartile of fried food intake, those in the highest quartile were found to have a marginally but significantly higher risk of acute myocardial infarction (OR, 1.13; 95% CI, 1.02-1.25).
TE
D
Panwar et al carried out a case-control study including 165 patients with coronary heart disease (13 women and 152 men; mean age 43±6 years) and 199
CE P
matched controls (24 women and 175 men; mean age 43±6 years) [7]. Compared to controls, patients with coronary heart disease reported a greater intake of both deep fried
AC
food (15±25 versus 1±5 g/day; p<0.01) and shallow fried food (24±60 versus 3±17 g/day; p<0.01).
Guallar-Castillón et al performed a prospective trial including 40,757 adults (gender prevalence was not specified) aged 29-69 years and free of coronary heart disease at baseline, who were followed up for a median period of 11 years [8]. Overall, 606 coronary heart disease events were recorded on follow up (rate of coronary heart disease: 1.5%). In the fully adjusted Cox proportional hazards analysis, no association was found between consumption of total fried food and coronary heart disease. In particular, the risk of subjects in the highest quartile of fried food intake was nonsignificantly different from that of subjects in the lowest quartile (HR, 1.08; 95% CI, 0.82-1.43). Interestingly, no association with coronary heart disease was also found
ACCEPTED MANUSCRIPT across specific risk models limited to intake of fried fish (HR, 1.13; 95% CI, 0.89-1.44), fried meat (HR, 1.09; 95% CI, 0.82-1.43), fried potatoes (HR, 0.90; 95% CI, 0.70-1.15)
T
and fried eggs (HR, 0.87; 95% CI, 0.68-1.13).
IP
Guo et al published a case-control study including 1,312 cases of first acute
SC R
myocardial infarction (346 women and 966 men; mean age 60±14 years) and 2,235 matched control subjects (641 women and 1594 men; mean age 59±11 years) free of angina, diabetes, hypertension and stroke [9]. The weekly frequency of fried food intake
NU
was found to be marginally but significantly higher in patients with acute myocardial
MA
infarction than in controls (1.3±2.1 versus 1.1±1.8 week intake; p=0.025). More recently, Cahill et al carried out a prospective trial including 70,842 women aged 30-55 years recruited from the Nurses' Health Study and 40,789 men aged
TE
D
40-75 years participating to the Health Professionals Follow-Up Study [10]. All study subjects were free of diabetes, cardiovascular disease or cancer at baseline, and were
CE P
followed up for 14-16 years. A total number of 5,778 incident coronary artery disease events were recorded on follow up (rate of coronary artery disease: 5.2%). In the fully
AC
adjusted Cox proportional hazards analysis, the risk of coronary artery disease was found to be similar between subjects consuming total fried food ≥7 times per week and those reporting an intake of <1 time per week (OR, 1.08; 95% CI, 0.95-1.24). Neither the habits of total fried food consumption at home (OR, 1.11; 95% CI, 0.99-1.24) or away from home (OR, 1.05; 95% CI, 0.89-1.25) were found to be significantly associated with an increased risk of coronary artery disease. Interestingly, the unadjusted risk of coronary artery disease was found to be significant in patients consuming larger amounts of total fried food (OR, 2.00; 95% CI 1.77-2.26), but this association almost completely disappeared after adjustment for demographic data, body mass index, hypertension and dyslipidemia.
ACCEPTED MANUSCRIPT The evidence provided by our systematic literature review attests that the association between large intake of fried food and IHD remains elusive. In the two large
T
prospective trials, the adjusted risk attributable to large fried food consumption was
IP
found to be non-significantly different from that of subjects consuming lower amount of
SC R
these nutrients [8,10]. In three out of the four case-control trials [6,7,9], a higher consumption of fried food was reported in subjects with IHD than in controls, whereas no association was found the remaining [5] (Table 1). Even assuming that an
NU
association may exist between large intake of fried foods and IHD, the overall risk
MA
emerging from the current literature data is very modest, globally lower than 13% [510]. A major limitation of the selected studies is that a differentiation between the different types of fried foods was frequently unavailable, so that it cannot be definitely
TE
D
established whether a certain type of fried aliments may be more atherogenic than another.
CE P
In conclusion, the current epidemiological data does not support that notion that large consumption of fried food should be avoided in primary prevention of IHD.
AC
Indeed, a major issue that emerged from this systematic literature review is that the quality rather than the quantity of fried food may have a larger impact on the cardiovascular risk. Moreover, the biological effects of fried food may be strongly dependent upon the combination with other type of foods (e.g., those enriched in antioxidants may partially neutralize the unhealthy effects trans fats originating from frying). Accordingly, the overall impact of fried foods may be different between subjects consuming a Western diet and those regularly following a Mediterranean diet.
Conflicts of interests The authors declare that no conflict of interest exists.
ACCEPTED MANUSCRIPT References 1. Catalano D, Trovato GM, Pace P, Martines GF, Trovato FM. Mediterranean diet
T
and physical activity: an intervention study. Does olive oil exercise the body
IP
through the mind? Int J Cardiol 2013;168:4408-9.
SC R
2. Siniorakis E, Arvanitakis S, Zarreas E, et al. Mediterranean diet: natural salicylates and other secrets of the pyramid. Int J Cardiol 2013;166:538-9. 3. García-López M, Toledo E, Beunza JJ, et al. Mediterranean diet and heart rate: the
NU
PREDIMED randomised trial. Int J Cardiol 2014;171:299-301.
MA
4. Leitzmann MF, Kurth T. Fried foods and the risk of coronary heart disease. BMJ 2012;344:d8274.
5. Kabagambe EK, Baylin A, Siles X, Campos H. Individual saturated fatty acids and
TE
D
nonfatal acute myocardial infarction in Costa Rica. Eur J Clin Nutr 2003;57:144757.
CE P
6. Iqbal R, Anand S, Ounpuu S, et al; INTERHEART Study Investigators. Dietary patterns and the risk of acute myocardial infarction in 52 countries: results of the
AC
INTERHEART study. Circulation 2008;118:1929-37. 7. Panwar RB, Gupta R, Gupta BK, et al. Atherothrombotic risk factors & premature coronary heart disease in India: a case-control study. Indian J Med Res 2011;134:26-32. 8. Guallar-Castillón P, Rodríguez-Artalejo F, Lopez-Garcia E, et al. Consumption of fried foods and risk of coronary heart disease: Spanish cohort of the European Prospective Investigation into Cancer and Nutrition study. BMJ 2012;344:e363. 9. Guo J, Li W, Wang Y, et al; INTERHEART China study investigators. Influence of dietary patterns on the risk of acute myocardial infarction in China population: the INTERHEART China study. Chin Med J (Engl) 2013;126:464-70.
ACCEPTED MANUSCRIPT 10. Cahill LE, Pan A, Chiuve SE, et al. Fried-food consumption and risk of type 2 diabetes and coronary artery disease: a prospective study in 2 cohorts of US women
AC
CE P
TE
D
MA
NU
SC R
IP
T
and men. Am J Clin Nutr 2014;100:667-75.
ACCEPTED MANUSCRIPT Table 1. Description of prospective and case-control trials investigating the association between large intake of fried food and ischemic heart disease.
Panwar et al, 2011
Casecontrol
Acute myocardial infarction
Total intake of fried foods similar between cases and controls.
Casecontrol
5,761 patients with acute myocardial infarction and 10,646 matched controls
Acute myocardial infarction
Casecontrol
165 patients with coronary heart disease (13 women and 152 men; mean age 43±6 years) and 199 controls (24 women and 175 men; mean age 43±6 years)
IP
[5]
Marginally but significantly increased risk of acute myocardial infarction (OR, 1.13; 95% CI, 1.02-1.25)
[6]
Coronary heart disease
Total intake of fried food higher in cases than in controls.
[7]
Incident coronary heart disease
No association between large consumption of fried food and coronary heart disease (HR, 1.08; 95% CI, 0.821.43)
[8]
40,757 subjects aged 2969 years, followed up for 11 years
Casecontrol
1,312 patients with acute myocardial infarction (346 women and 966 men; mean age 60±14 years) and 2,235 controls (641 women and 1594 men; mean age 59±11 years)
Acute myocardial infarction
Total intake of fried food higher in cases than in controls.
[9]
111,631 subjects (70,842 women and 40,789 men, age 30-75 years), followed up for 14-16 years
Incident coronary artery disease
No association between large consumption of fried food and coronary heart disease (OR, 1.08; 95% CI, 0.951.24)
[10]
TE
CE P
Cahill et al, 2014
Reference
Prospective
Prospective
AC
Guo et al, 2013
T
Results
D
GuallarCastillón et al, 2012
Endpoint
485 survivors of acute myocardial infarction (121 women and 364 men; mean age 57±10 years) and 508 controls (137 women and 371 men; mean age 58±11 years)
SC R
Iqbal et al, 2008
Study population
NU
Kabagambe et al, 2003
Study design
MA
Authors
HR, hazard ratio; OR, odds ratio.