{"id":2930,"date":"2021-02-18T10:04:11","date_gmt":"2021-02-18T08:04:11","guid":{"rendered":"https:\/\/suprastratum.com\/?p=2930"},"modified":"2022-03-06T13:19:48","modified_gmt":"2022-03-06T11:19:48","slug":"eggs-and-health","status":"publish","type":"post","link":"https:\/\/suprastratum.com\/en\/2021\/02\/18\/eggs-and-health\/","title":{"rendered":"ABBA AND HEALTH"},"content":{"rendered":"

Do eggs harm or benefit health? How many can we safely eat?<\/p>\n


\nIn general, there is confusion as to whether eggs can be considered part of a healthy diet or whether they can actually be bad for our health.<\/p>\n

This comes mainly from the fact that until a few years ago the recommendations were negative, as the egg is a source of cholesterol. Over the years, however, it has been found that not all sources of cholesterol have the same effect on cholesterol levels.<\/p>\n

It seems that finally the cholesterol has a relatively modest effect on total and LDL cholesterol<\/a>, while egg phospholipids have the ability to increase HDL-c and may have positive effects on total cholesterol<\/a>, things we will deal with later.<\/p>\n

However, a recent survey<\/a> found that eating even half an egg a day can increase the chances of mortality.<\/p>\n

So who is right? Most people who have neither the time, nor access to scientific articles, nor the necessary foundation to understand who is right and who is wrong are understandably unable to attend this debate.<\/p>\n

So, we will try to list the results of major studies to clarify whether or not eggs are ultimately a risk to our health.<\/p>\n

So let's start with one relatively old meta-analysis<\/a> which used 8 articles.<\/p>\n

\n
\"Eggs,<\/a>
Source: Rong Y, Chen L, Zhu T, Song Y, Yu M, Shan Z, Sands A, Hu FB, Liu L. Egg consumption and risk of coronary heart disease and stroke: dose-response meta-analysis of prospective cohort studies. BMJ. 2013 Jan 7;346:e8539. doi: 10.1136\/bmj.e8539. PMID: 23295181; PMCID: PMC3538567.<\/a><\/figcaption><\/figure>\n<\/div>\n

Here, no significant association was found between egg consumption and the risk of coronary heart disease or stroke, but data on more than one egg per day were limited.<\/p>\n

Also of note, among diabetic participants, higher consumption was associated with an increased risk of coronary heart disease but a lower risk of bleeding stroke.<\/p>\n

Go ahead in an investigation<\/a> which was done by studying and comparing food groups.<\/p>\n

\n
\"Eggs,<\/a>
Source: Bechthold A, Boeing H, Schwedhelm C, Hoffmann G, Kn\u00fcppel S, Iqbal K, De Henauw S, Michels N, Devleesschauwer B, Schlesinger S, Schwingshackl L. Food groups and risk of coronary heart disease, stroke and heart failure: a systematic review and dose-response meta-analysis of prospective studies. Crit Rev Food Sci Nutr. 2019;59(7):1071-1090. doi: 10.1080\/10408398.2017.1392288. epub 2017 Nov 7. PMID: 29039970.<\/a><\/figcaption><\/figure>\n<\/div>\n

Again, no association was found between egg intake and risk of coronary heart disease or stroke (with an intake of 75g\/day considered high), but an association was found between egg intake and risk of heart failure (with an intake of 140g\/day considered high).<\/p>\n

So what we have here is a limit of just under 2 eggs per day<\/span>.<\/p>\n

This survey<\/a> used data from 3 large international studies from 50 countries with a total of about 177000 people.<\/p>\n

\n
\"Eggs,<\/a>
Source: Dehghan M, Mente A, Rangarajan S, Mohan V, Lear S, Swaminathan S, Wielgosz A, Seron P, Avezum A, Lopez-Jaramillo P, Turbide G, Chifamba J, AlHabib KF, Mohammadifard N, Szuba A, Khatib R, Altuntas Y, Liu X, Iqbal R, Rosengren A, Yusuf R, Smuts M, Yusufali A, Li N, Diaz R, Yusoff K, Kaur M, Soman B, Ismail N, Gupta R, Dans A, Sheridan P, Teo K, Anand SS, Yusuf S. Association of egg intake with blood lipids, cardiovascular disease, and mortality in 177,000 people in 50 countries. Am J Clin Nutr. 2020 Apr 1;111(4):795-803. doi: 10.1093\/ajcn\/nqz348. PMID: 31965140; PMCID: PMC7138651.<\/a><\/figcaption><\/figure>\n<\/div>\n

As you can deduce from the graph, this study found no significant associations between egg intake and blood lipids, mortality or major cardiovascular events, when it comes to eating one egg a day<\/span>.<\/p>\n

We go to this meta-analysis<\/a>, which used 7 studies for stroke and 7 for coronary heart disease.<\/p>\n

\n
\"Eggs,<\/a>
Source: Alexander DD, Miller PE, Vargas AJ, Weed DL, Cohen SS. Meta-analysis of Egg Consumption and Risk of Coronary Heart Disease and Stroke. J Am Coll Nutr. 2016 Nov-Dec;35(8):704-716. doi: 10.1080\/07315724.2016.1152928. epub 2016 Oct 6. PMID: 27710205.<\/a><\/figcaption><\/figure>\n<\/div>\n

Here we found that high egg intake versus low egg intake (less than 2 eggs per week) was not associated with coronary heart disease risk, but instead was associated with a reduction in stroke risk.<\/p>\n

Again, however, the high egg intake threshold was judged to be about 1 egg per day<\/span>.<\/p>\n

Go ahead in this 2019 study<\/a> which included a total of 21 articles.<\/p>\n

\n
\"Eggs,<\/a>
Source: Marventano S, Godos J, Tieri M, Ghelfi F, Titta L, Lafranconi A, Gambera A, Alonzo E, Sciacca S, Buscemi S, Ray S, Del Rio D, Galvano F, Grosso G. Egg consumption and human health: an umbrella review of observational studies. Int J Food Sci Nutr. 2020 May;71(3):325-331. doi: 10.1080\/09637486.2019.1648388. epub 2019 Aug 5. PMID: 31379223.<\/a><\/figcaption><\/figure>\n<\/div>\n

Here there was no meaningful association between egg consumption and a wide range of health outcomes, including cancer, cardiovascular and metabolic disorders. In contrast, evidence was found for possible beneficial effects of egg consumption on the risk of stroke.<\/p>\n

Unfortunately, the recruitment limits are not mentioned here.<\/p>\n

But let's move on to this investigation<\/a> which included data from 39 studies and about 2 million people.<\/p>\n

\n
\"Eggs,<\/a>
Source: Godos J, Micek A, Brzostek T, Toledo E, Iacoviello L, Astrup A, Franco OH, Galvano F, Martinez-Gonzalez MA, Grosso G. Egg consumption and cardiovascular risk: a dose-response meta-analysis of prospective cohort studies. Eur J Nutr. 2020 Aug 31. doi: 10.1007\/s00394-020-02345-7. Epub ahead of print PMID: 32865658.<\/a><\/figcaption><\/figure>\n<\/div>\n

Here we start to see contradictory results.<\/p>\n

On the one hand, it was found that there were consistent results on the association between moderate egg consumption (four eggs per week compared to no consumption) and lower risk of cardiovascular disease.<\/p>\n

On the other hand, while overall there were no strong associations with increased or decreased risk of cardiovascular outcomes after moderate egg consumption (i.e. one egg per day compared to no intake), there was an association with the risk of heart failure.<\/p>\n

This was found to be higher especially from studies from the US and the male population.<\/p>\n

Which makes things even more complicated, as we understand that there are health outcomes in this particular survey that vary by region.<\/p>\n

\n
\"Eggs,<\/a>
Source: Godos J, Micek A, Brzostek T, Toledo E, Iacoviello L, Astrup A, Franco OH, Galvano F, Martinez-Gonzalez MA, Grosso G. Egg consumption and cardiovascular risk: a dose-response meta-analysis of prospective cohort studies. Eur J Nutr. 2020 Aug 31. doi: 10.1007\/s00394-020-02345-7. Epub ahead of print PMID: 32865658.<\/a><\/figcaption><\/figure>\n<\/div>\n

As we can see in the table above, in the case of four eggs per week, egg consumption may be associated with favourable outcomes in the US but unfavourable in Europe (or with unfavourable outcomes in both regions as in the case of heart failure and consumption of one egg per day), while in Asia it seems that egg consumption is always associated with favourable outcomes.<\/p>\n

And anyway, again we see that we are talking about relatively moderate egg consumption (up to 1 egg per day<\/span>) and not excessive.<\/p>\n

So let's focus our attention on China by going to another huge survey that lasted 4 years and included almost half a million people there.<\/p>\n

\n
\"Eggs,<\/a>
Source: Qin C, Lv J, Guo Y, Bian Z, Si J, Yang L, Chen Y, Zhou Y, Zhang H, Liu J, Chen J, Chen Z, Yu C, Li L; China Kadoorie Biobank Collaborative Group. Associations of egg consumption with cardiovascular disease in a cohort study of 0.5 million Chinese adults. Heart. 2018 Nov;104(21):1756-1763. doi: 10.1136\/heartjnl-2017-312651. Epub 2018 May 21 PMID: 29785957; PMCID: PMC6241631.<\/a><\/figcaption><\/figure>\n<\/div>\n

Here, more frequent consumption of eggs was associated with a lower risk of cardiovascular disease, ischaemic heart disease, major coronary events, haemorrhagic stroke and ischaemic stroke in non-diabetics.<\/p>\n

But again, frequent consumption of eggs was considered something less than 6 eggs per week<\/span>.<\/p>\n

And finally we will refer to in a 2018 survey<\/a> which was done again in China. Something less than 30,000 people took part and were followed for just under a decade, on average.<\/p>\n

\n
\"Eggs,<\/a>
Source: Xu L, Lam TH, Jiang CQ, Zhang WS, Zhu F, Jin YL, Woo J, Cheng KK, Thomas GN. Egg consumption and the risk of cardiovascular disease and all-cause mortality: Guangzhou Biobank Cohort Study and meta-analyses. Eur J Nutr. 2019 Mar;58(2):785-796. doi: 10.1007\/s00394-018-1692-3. Epub 2018 Apr 21. PMID: 29680985.<\/a><\/figcaption><\/figure>\n<\/div>\n

Here, no association was found between egg consumption and the risk of cardiovascular disease, ischaemic heart disease, stroke or all-cause mortality.<\/p>\n

The comparison was between eating less than 1 egg with 7 or more per week<\/span>.<\/p>\n

To draw more definitive conclusions, however, let's move on to meta-analyses that analyse lipids.<\/p>\n

This meta-analysis of 2017<\/a> found that egg consumption increases total cholesterol, \"bad cholesterol\" (LDL-C) and \"good cholesterol\" (HDL-C) by 5.32, 5.28 and 2.08 mg\/dL, respectively, but does not significantly change total cholesterol:HDL-C ratio, LDL-C:HDL-C ratio and triglycerides.<\/p>\n

\n
\"Eggs,<\/a>
Source: Rouhani MH, Rashidi-Pourfard N, Salehi-Abargouei A, Karimi M, Haghighatdoost F. Effects of Egg Consumption on Blood Lipids: a Systematic Review and Meta-Analysis of Randomized Clinical Trials. J Am Coll Nutr. 2018 Feb;37(2):99-110. doi: 10.1080\/07315724.2017.1366878. doi: 10.1080\/07315724.2017.1366878. Epub 2017 Nov 7. PMID: 29111915.<\/a><\/figcaption><\/figure>\n<\/div>\n

This 2019 meta-analysis<\/a> found that the consumption of more than four eggs a week<\/span> instead of equivalent amounts of egg substitutes resulted in greater increases in total cholesterol, LDL-C and HDL-C, not triglycerides.<\/p>\n

And finally this 2020 meta-analysis<\/a> comes to much the same conclusions as the previous ones, but notes that this increase is greater in healthy populations and in people who consume more than one egg per day.<\/p>\n

So we can draw some conclusions.<\/p>\n