It was known that unhealthy eating habits have a direct impact on bad cholesterol and, therefore, are associated with a higher risk of cardiovascular accidents. In that case, this new study confirms that, on the contrary, adopting a healthy diet increases levels of high-density lipoproteins, which are responsible for transporting cholesterol to the liver for excretion, thus protecting the heart (“good” cholesterol).
To reach this conclusion, a group of scientists from the National Cardiovascular Research Center and the Aragonese Institute of Health Sciences (in addition to other centres) cross-sectionally analysed the dietary habits of 1,290 people who participated in a trial called Aragon Workers Health Study. This study, based on the responses of the participants to a questionnaire about the frequency with which they consumed a selection of 136 products over a year, made it possible to differentiate two dietary patterns: on the one hand, a Mediterranean diet profile ( rich in vegetables, fruits, nuts, white meats, fish and olive oil) and a second Western diet profile (based on the intake of dairy products, red meat, fast food, derivatives of refined cereals and pastries).
Through blood samples obtained from individuals of both dietary profiles, the researchers proved that the participants who followed a diet more in line with the Mediterranean diet had good cholesterol figures almost 10 per cent higher than the figures of the participants with greater adherence to the Western diet pattern (54.8 mg/dl in the first case versus 49.9 mg/dl in the second).
These results show the relationship between diet and the later appearance of fatty plaques in the arteries ( atherosclerotic disease ) before it manifests signs of vascular obstruction. In addition, these data are consistent with previous observational studies that had already shown that, in general, higher consumption of processed foods and foods of animal origin, characteristic of more Western diets, is associated with lower values of “good cholesterol”.
Sugars and refined carbohydrates increase triglycerides.
According to researchers in the Epidemiology and Population Genetics Area of the National Center for Cardiovascular Research Foundation, “high consumption of foods with added sugars and refined carbohydrates increases visceral fat, reduces the sensitivity of insulin and stimulates the creation of reserve fats and triglycerides in the liver, which could cause a decrease in HDL cholesterol levels. On the contrary, in the words of the expert, “the favourable effect of the Mediterranean diet could be due to the consumption of olive oil in the context of a diet rich in fruits and vegetables.
Good cholesterol, a cardiovascular protector
Cholesterol is an indicator of cardiovascular risk. Total cholesterol figures are made up mainly of the sum of HDL cholesterol (or “good” cholesterol), high-density lipoproteins that protect against cardiovascular disease, and LDL cholesterol (or “bad” cholesterol), which are high-density lipoproteins. Low-density cholesterol that, when accumulated in the blood, form fatty plaques that clog the arteries ( hypercholesterolemia ). This obstruction can cause ischemia (decreased irrigation) and even myocardial infarction or cerebral vascular accidents if prolonged over time and causes rupture of the blood vessels.
In general terms, optimal HDL cholesterol levels equal to or greater than 40 mg/dl are considered in the case of men and equal to or greater than 50 mg/dl for women. However, “the individual interpretation of these values is not so relevant, but the relationship between the different types of lipoproteins and their analysis, taking into account other risk factors such as age, family history, hypertension, smoking, etc.
Adherence to the Mediterranean diet is associated with a 30% reduction in the risk of cardiovascular death and, therefore, with a lower frequency of myocardial infarctions, strokes and death from cardiovascular causes.
Excess cholesterol could cause female infertility.
A new study published in the Proceedings of the National Academy of Sciences supports a link between high cholesterol and female infertility. The results of the experiments carried out by Monty Krieger of the Massachusetts Institute of Technology (United States) and his team in a murine model point in that direction.
The research team found that eggs exposed to excess cholesterol can be activated prematurely and become unavailable for fertilisation. Therefore, some forms of female infertility could be associated with abnormal cholesterol metabolism.
Specifically, cholesterol would play a vital role in the meiosis process, essential for producing functional sperm and ovules. In both humans and mice, meiosis pauses at a stage called metaphase II; It is a stop until the sperm fertilises the egg. After fertilisation, the ovules are released, meiosis is completed, and the development of the new individual begins.
Analysing the infertility of genetically modified females, scientists discovered that an excess of cholesterol could cause the ovules to behave as if they had been fertilised, which prevents the completion of meiosis and causes them to cease to be functional.