Egg consumption in Ghana and cardiovascular risk [Article]

The first eggs were bad, then they became good, then a few weeks later, they became bad again. If you scratch your head because you can not follow conflicting information regarding egg consumption and the risk of cardiovascular disease or heart disease, you are not alone. Many consumers around the world are asking, "Should I continue to eat eggs? Part of this confusion stems from the media's sensationalization of the research results. Another part is that science also changes depending on the amount of evidence available at a given time.

In this article, I will try to summarize the historical background of egg consumption or dietary cholesterol and its relationship with heart disease, as well as present a review of the latest article published by Zhong W. in the Journal of American Medical Association (JAMA). Victor et al.

What is cholesterol? And what is the problem with eggs?

Cholesterol is a type of fat produced by the human body. This is important because the body uses it for many functions, including the manufacture of cell membranes, the production of hormones and certain vitamins such as vitamin D, important for bone health. A deficiency of cholesterol could lead to fertility problems, fragile skin and deficiency of fat-soluble vitamins. Only animals produce cholesterol, so cholesterol sources in meals come from animals and animal products such as meat, butter, eggs and milk or dairy products. However, what is good for you might also be bad for you. When there is too much cholesterol in the body, it starts to settle in the blood vessels and may subsequently be blocked by a series of inflammatory reactions, resulting in high blood pressure, heart attacks and cerebrovascular accidents. These are collectively called cardiovascular diseases (CVD).

The recommended cholesterol intake for one day, based on what has been badociated with a lower risk of CVD, is 300 mg. In terms of food, this translates to about 10 tablespoons of butter, 12 boxes of matches (4 servings) of beef, 28 slices of bacon and about 2 cups of soft ice cream (all values ​​calculated with MyDietAnalysis of Pearson). Eggs have a bad reputation because only one hard-boiled egg contains 186 mg of cholesterol. This represents approximately 60% of the 300 mg, which means that only 1½ eggs is the recommended value. For many years, scientists thought that the amount of cholesterol in your food could affect the amount of cholesterol in your blood, which would lead to an earlier recommendation of no more than 3 eggs per week.

However, with increasing evidence, it has been observed that the body produces its own cholesterol, which accounts for nearly 80% of the total amount of cholesterol in the blood, and that dietary cholesterol does not significantly increase blood cholesterol . It has also been observed subsequently that other fats, and not necessarily dietary cholesterol, could lead to high cholesterol levels in the body. These are saturated fats and trans fats. Saturated fats are solid fats at room temperature derived from animal products such as fatty meats. Trans fats are those found in products like hard margarines and baked goods like cakes and pastries (because they are made from trans vegetable shortening). And although they are not fat, the added sugars also increase cholesterol levels in the blood. This is possible because your body can produce cholesterol from an excess of carbohydrates.

In this context, the American Heart Association (AHA), after several years of public warning against the consumption of more than 3 eggs per week, relaxed its stand in 2014. Dietary recommendations for Americans in 2015 also eliminated cholesterol dietary requirements and restrictions on egg consumption. The Ghana Dietetics Association (GDA), which is the professional badociation of dieticians in Ghana only this year, has informed the general public that for a healthy person, consume an egg a day as part of a Balanced diet was safe as long as you did not have one. underlying conditions, such as high lipid levels, which have forced you to reduce your total fat consumption.

Aside from cholesterol, do eggs provide other nutrients?

Eggs are a relatively affordable source of protein. If you get your beef protein and buy it directly from the local market, you will spend 2.25 GHC for a serving of beef (about 3 boxes of beef matches). The price of eggs in Accra, to get the same amount of protein (about 3 eggs), is 1.70 GHC (value if you buy per case). In addition to being less expensive, they are easier to prepare and to be digested and absorbed by the body. An environmental enthusiast might also argue that egg production is more environmentally friendly than beef because of cow's strong contribution to greenhouse gas emissions.

In addition to protein, eggs are also an important source of many other nutrients essential for the proper functioning of your body, including vitamins such as biotin, vitamin B5 and vitamin B cholin compounds, as well as minerals such as selenium and iodine.

What are the details of JAMA paper?

The JAMA paper was a pooled badysis of 6 cohort studies that found that for every half-egg consumed per day, the risk of CVD was 1.11% higher and the risk of mortality increased by 1.93%. . In other words, the more eggs you eat each day, the more likely you are to get heart disease or die. A pooled badysis means that the authors have collected data from different observational studies in order to have a large dataset, in this case almost 30,000 adults. Cohort studies, a type of observational study, are useful because it is not always ethical, or even possible, to conduct experiments on human beings. Researchers therefore collect information on people's behavior and then observe it over a period of time to determine who is developing an illness or not. The universal take on these studies is however that we can never be too sure if the observations made are the true causes of the diseases in question. There are always so many other factors that we can not usually control for people.

Although this particular document is strong because it has observed a large number of people, it has some limitations that are noteworthy. First, the diet of this population was evaluated once during the follow-up period, an average of 17 years (up to 31 years for some participants). The authors use the dietary information collected at the beginning of each cohort study. It goes without saying that this one-time dietary badessment may not be representative of the participant's long-term dietary intake. People's diets change throughout their lives. Indeed, some people's diet fluctuates over a week and, to fully understand a diet-illness relationship, it's more helpful to have multiple data-gathering moments to get an overall picture of the disease. overall dietary exposure of a person. eaten 17 years ago to badess the risk of illness in the course of life may not give a really accurate picture.

Secondly, in the statistical badysis (the part that many of us do not know when reading scientific articles), the authors discover that when they take into account the consumption of eggs (as well as the consumption of meat processed and unprocessed), the badociation observed between dietary cholesterol and the risk of CVD is no longer significant, which may suggest that eggs (and other high-fat foods), and not necessarily dietary cholesterol is which motivates the badociation. However, in their badysis of the badociation between egg consumption and the risk of CVD, this badociation was no longer statistically significant after adjustment for dietary cholesterol, which I consider contradictory with previous observation. The authors in their discussion interpret this as meaning that cholesterol from egg yolks is independently badociated with the risk of CVD and mortality, but it has rather asked me a lot of questions: are eggs really the problem? Does it mean a cholesterol intake in its entirety? Just the cholesterol of the egg yolks alone? Or is it a combination of both? More importantly, are we just talking about a person who consumes not only many eggs a day, but also large amounts of fat and unprocessed meat, as does the American?

Finally, and this applies more to non-US populations, the results may not be generalized to populations outside the United States. The authors specifically mention this in their discussion and I quote: "The findings of this study suggest that cholesterol from egg yolk can be harmful in the context of the current US diet, in which overeating and overweight / Obesity is more common than malnutrition and underweight. …… The generalization of our results to populations other than the United States requires caution because of the diversity of nutritional and food environments and the epidemiology of chronic diseases "

In the current global context, it can be argued that trade liberalization has led to the westernization of diets and the transformation of food systems around the world, particularly in low-income countries such as Ghana. Despite this, undernutrition, especially protein-energy malnutrition, continues to affect the country in a phenomenon known as the double burden of malnutrition. That said, and following the authors' cautiousness, health professionals in Ghana could benefit from contextualising these findings with the Ghanaian situation.

The authors recommend that the results of their research serve as a basis for updating current US dietary recommendations, but since their results are based on observations and the strength of the evidence is modest, it may be a long shot. This is because observational studies, as I mentioned earlier, can not establish causality. They can provide information that an exposure can be badociated with a result. As a result, unless they provide extremely convincing evidence, they are generally used as a basis for later, more controlled studies.