In a research article published in the journal Heart, a team of researchers from China and the UK reports that a moderate level of egg consumption (up to 1 egg/day) was associated with a lower incidence of cardiovascular disease in a Chinese population.
This prospective cohort study of the general Chinese population demonstrated a significantly inverse association of egg consumption with CVD, ischemic heart disease, hemorrhagic stroke, ischemic stroke, as well as major coronary events. In particular, daily egg consumers (up to 1 egg/day) had a 26% lower risk of hemorrhagic stroke, a stroke subtype with a higher prevalence rate in China than in high-income countries. Image credit: Conger Design.
Eggs are a prominent source of dietary cholesterol, but they also contain high-quality protein, many vitamins and bioactive components such as phospholipids and carotenoids.
Previous studies looking at associations between eating eggs and impact on health have been inconsistent, and most of them found insignificant associations between egg consumption and coronary heart disease or stroke.
Peking University Health Science Center researchers Liming Li and Canqing Yu and their co-authors set out to examine the associations between egg consumption and cardiovascular disease (CVD), ischemic heart disease, major coronary events, hemorrhagic stroke and ischemic stroke.
The team used data from the China Kadoorie Biobank study, an ongoing prospective study of 512,891 adults aged 30-79 years from 10 geographically diverse survey sites (five urban and five rural) across China.
The participants were recruited between 2004 and 2008 and were asked about the frequency of their egg consumption. They were followed up to determine their morbidity and mortality.
At the start of the study period, 13.1% of participants reported daily consumption (usual amount 0.76 egg/day) and 9.1% reported never or very rare consumption (usual amount 0.29 egg/day) of eggs.
The analysis of the results showed that compared with people not consuming eggs, daily egg consumption was associated with a lower risk of CVD overall.
In particular, daily egg consumers (up to one egg/day) had a 26% lower risk of hemorrhagic stroke — the type of stroke with a higher prevalence rate in China than in high-income countries — a 28% lower risk of hemorrhagic stroke death and an 18% lower risk of CVD death.
In addition, there was a 12% reduction in risk of ischemic heart disease observed for people consuming eggs daily (estimated amount 5.32 eggs/week), when compared with the ‘never/rarely’ consumption category (2.03 eggs/week).
“This was an observational study, so no firm conclusions can be drawn about cause and effect, but it had a large sample size and took into account established and potential risk factors for CVD,” the scientists said.
“The study finds that there is an association between moderate level of egg consumption (up to 1 egg/day) and a lower cardiac event rate.”
“Our findings contribute scientific evidence to the dietary guidelines with regard to egg consumption for the healthy Chinese adult.”
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Chenxi Qin et al (China Kadoorie Biobank Collaborative Group). Associations of egg consumption with cardiovascular disease in a cohort study of 0.5 million Chinese adults. Heart, published online May 21, 2018; doi: 10.1136/heartjnl-2017-312651
