Consuming an egg a day-and more generally, foods that do contain cholesterol-does not increase the risk of stroke. Nor in individuals predisposed to hypercholesterolemia. That is the conclusion reached by a study from the University of Eastern Finland, recently published in ‘The American Journal of Clinical Nutrition. (1)
Eggs and cholesterol in the diet, scientific uncertainty
Eggs have long been blamed for exposing consumers to an increased risk of stroke because of their cholesterol content (200 mg/100 g of food). This belief was based on a scientific literature that has, however, come to contradictory conclusions in recent years. Indeed, while some studies have associated high dietary cholesterol intake with an increased risk of stroke, other research has conversely associated the consumption of eggs (high in cholesterol) with a reduction in the incidence of cardiovascular disease.(2)
A group of researchers at the University of Eastern Finland therefore conducted a randomized clinical trial, with the aim of testing whether a moderately high intake of cholesterol-or consumption of one egg a day-could actually increase the risk of stroke. Having regard to both the general population and individuals carrying the APOE4 phenotype. Namely, an inherited variant that causes a greater effect of dietary cholesterol on serum cholesterol, which affects one-third of the Finnish population.
Eggs and cholesterol, the Finnish study
The study examined the dietary habits of 1,950 men aged 42 to 60 years-without a baseline diagnosis of cardiovascular disease-included in the 1984-1989 Kuopio Ischemic Heart Disease Risk Factor Study (KIHD) at the University of Eastern Finland. Data on the APOE phenotype, available for 1,015 individuals in the group, showed a 32 percent prevalence of this genetic variant.
During a 21-year follow-up, 217 individuals were diagnosed with stroke. However, the study found that neither dietary cholesterol nor egg consumption was associated with the event, even in APOE4 carriers. Compared with an estimated average daily intake of cholesterol of 520 mg, about one-fourth contributed by eggs.
Eggs and health, tentative conclusions
The results of the Finnish study, according to the researchers, suggest that moderate cholesterol intake or daily egg consumption may not come to be associated with stroke risk. Not even in people genetically predisposed to a greater effect of dietary cholesterol on blood cholesterol levels.
Thus finds support for the assumption behind the reform introduced in the ‘Food Information Regulation,’ which expressly prohibits the indication–on labels and advertisements–of any reference to cholesterol content in food. Precisely because there is no science-proven correlation between its intake and blood cholesterol concentration. (3)
Green light to eggs then, in the context of a varied and balanced diet. Without neglecting the daily protein requirements at every stage of life, to which eggs can contribute significantly, thanks to a high biological value protein content of 12.2 g/100 g (26 percent of energy value), as well as modest costs compared to other protein sources. (4) Rather, organic eggs that come from free-range hens without antibiotics are to be favored. Most importantly, that they come from farms where sexing (i.e., the killing of male chicks) is banned.
Marta Strinati and Dario Dongo
Notes
(1) Anna M Abdollahi, Heli E K Virtanen, Sari Voutilainen, Sudhir Kurl, Tomi-Pekka Tuomainen, Jukka T Salonen, Jyrki K Virtanen.‘Egg consumption, cholesterol intake, and risk of incident stroke in men: the Kuopio Ischaemic Heart Disease Risk Factor Study‘. The American Journal of Clinical Nutrition, 2019; DOI: 10.1093/ajcn/nqz066
(2) On the effects of egg consumption, the scientific literature comes to divergent conclusions. See, for example, the following recent studies.
Nicholas R Fuller, Amanda Sainsbury, Ian D Caterson, Gareth Denyer, Mackenzie Fong, James Gerofi, Chloris Leung, Namson S Lau, Kathryn H Williams, Andrzej S Januszewski, Alicia J Jenkins, Tania P Markovic. ‘Effect of a high-egg diet on cardiometabolic risk factors in people with type 2 diabetes: the Diabetes and Egg (DIABEGG) Study-randomized weight-loss and follow-up phase‘. The American Journal of Clinical Nutrition, 2018; DOI: 10.1093/ajcn/nqy048
Victor W. Zhong, Linda Van Horn, Marilyn C. Cornelis, John T. Wilkins, Hongyan Ning, Mercedes R. Carnethon, Philip Greenland, Robert J. Mentz, Katherine L. Tucker, Lihui Zhao, Arnita F. Norwood, Donald M. Lloyd-Jones, Norrina B. Allen.‘Associations of Dietary Cholesterol or Egg Consumption With Incident Cardiovascular Disease and Mortality‘. JAMA, 2019; 321 (11): 1081 DOI: 10.1001/jama.2019.1572
Chenxi Qin, Jun Lv, Yu Guo, Zheng Bian, Jiahui Si, Ling Yang, Yiping Chen, Yonglin Zhou, Hao Zhang, Jianjun Liu, Junshi Chen, Zhengming Chen, Canqing Yu, Liming Li On Behalf of the China Kadoorie Biobank Collaborative Group. ‘Associations of egg consumption with cardiovascular disease in a cohort study of 0.5 million Chinese adults‘. Heart, 2018 DOI: 10.1136/heartjnl-2017-312651
(3) See reg. EU 1169/11, Article 30 and Annexes XIII, XIV. In contrast, the European Commission has recently taken an interest in trans fatty acids, with reg. EU 2019/649. See previous article https://www.greatitalianfoodtrade.it/sicurezza/acidi-trans-grassi-negli-alimenti-nuovi-limiti-ue
(4) See CREA (formerly INRAN) entity nutrition table, http://nut.entecra.it/646/tabelle_di_composizione_degli_alimenti.html?idalimento=180010&quant=100
Professional journalist since January 1995, he has worked for newspapers (Il Messaggero, Paese Sera, La Stampa) and periodicals (NumeroUno, Il Salvagente). She is the author of journalistic surveys on food, she has published the book "Reading labels to know what we eat".
Dario Dongo, lawyer and journalist, PhD in international food law, founder of WIISE (FARE - GIFT - Food Times) and Égalité.
