(by Nicola Simonetti) A study from the Feinberg School of Medicine, Northwestern University of Chicago, published in JAMA (2019; 321 (11): 1081-95), combined data from six previous studies involving a total of 29.615 people followed for an average of 17,5 years, finding a 6% increase in the risk of cardiovascular disease when the average number of eggs consumed per day increases by half an egg.
“Those who ingest an excess of cholesterol see their risk of developing cardiovascular disease and mortality increase. Our data do not close the door to the consumption of eggs (each contains 186 mg of cholesterol) but - says Dr Norrina Allen, co-author of the work - they invite their limitation. A moderate consumption is not rejected even if the genetic modalities of the individual cholesterol metabolism must be taken into account ”.
Similarly, a study by Brazilian researchers pointed the finger at breakfast nerds warning them that this "bad habit" increases the risk of cardiovascular disease by four to five times. The same risk for the "tiratardi" of dinner.
The Chicago researchers counted 5.400 cardiovascular problems (fatal and non-fatal: 2.088 cardiac events, 1.302 strokes, 1.897 heart failure and 113 deaths) related to excessive egg consumption. In particular, it was possible to record a direct correlation between an increase in egg consumption and an increase in the risk of cardiovascular disease. But this ratio has weakened, but not eliminated, taking into account the total ingestion (and not only deriving from the egg) of cholesterol.
In the scientific world, reservations have arisen regarding this work, of which, among other things, the method has been criticized.
“The role of cholesterol as well as in the development of heart disease has been debated for over thirty years. The particular contribution of cholesterol derived from eggs was also found in several papers with results - Prof Dennis Bruemmer, cardiologist at the Heart and Vascular Institute and associate professor of medicine at the University of Pittsburgh Medical Center told Reuter - variables and discrepant. This study has obvious limitations, including self-reporting at a single point in time, which limits its validity ”.
While it is true that eggs contain quite a bit of cholesterol - about 200 mg, the maximum daily amount recommended in current guidelines - "eating them in moderation is probably nutritionally acceptable - reiterates Bruemmer - Moderation means less than an egg per day on average, including eggs found in foods such as bread ".
Criticisms have also been made to Brazilian work, published in the scientific journal "European Journal of Preventive Cardiology" which warns: "skipping breakfast and having dinner just before (less than 2 hours) going to bed increases the risk from 4 to 5 times of death, recurrence of heart attack and angina ”. The study involved patients discharged after a heart attack but their number was judged insufficient to derive valid consequences.
Far more consistent, however - says Camille Gaubert in “Sciences et Avenir” (1 May 2019) which also reports the opinion of prof. Eric Van Belle - case history involving over 6.500 Americans. Five out of 100 of them did not eat breakfast and were exposed to a risk of cardiovascular event greater than 87% and a mortality of 19% higher than that of those who, on the other hand, usually ate breakfast in the morning.
In support, the A. notes that "epidemiological studies provide solid evidence of a relationship between skipping breakfast and increased risk of overweight and obesity with related consequences on heart and circulation health as highlighted by the" American Heart Association "in 2017.
Why? The reason lies in the prolongation of fasting between the end of the dinner and the following meal in the middle of the following day. This "prolonged fasting" increases the concentration, in the blood, of ghrelin (appetite hormone), reduces insulin in the circulation and therefore leads to eating more, increasing the risk of diabetes and its complications.