All About Cholesterol
Cholesterol is one of the nutrients with the worst reputation as far as food is concerned. Traditionally, its serum levels have been linked to an increase in cardiovascular risk. However, at present, this relationship has been refuted for various reasons that we’ll explain in this article.
Contrary to what many believe, the influence of diet on blood cholesterol levels and lipid profiles is limited. Lifestyle influences these parameters, but not as decisively as one might think.
What is cholesterol?
The first thing we must define is cholesterol as such. A group of lipoproteins in charge of transporting fatty acids through the blood is known under this name. Within this group there are two main representatives: HDL (known as good cholesterol) and LDL (known as bad cholesterol).
The first lipoprotein transports fat from the tissues to the blood, while the second performs the opposite action. It was stated that maintaining low total cholesterol levels, but high HDL levels, could reduce the risk of developing atheromatous plaques and, with it, of cardiovascular accidents.
It should be noted that cholesterol can be introduced exogenously into the body, through diet. But it’s also synthesized endogenously, as confirmed by a study published in the journal Redox Biology.
So, the internal production of cholesterol depends, to a great extent, on its dietary intake. If the intake of the nutrient is increased, the synthesis is reduced, which implies an efficient regulation mechanism.
In parallel, it’s possible to make a more precise classification of the types of cholesterol that exist in the human body. LDL can be broken down, in turn, into various molecules known under the name of VLDL, which have the ability to oxidize.
The cholesterol oxidation dilemma
At this point, we must point out that the most current research has stopped attributing an increase in cardiovascular risk to the increase in general cholesterol levels. This problem is attributed to the oxidation rate of the VLDL fraction. The fact that lipoproteins are oxidized negatively conditions their functions, making them more prone to accumulation.
According to research published in the Free Radical Biology & Medicine journal, lipoprotein oxidation is linked to systemic inflammation, both being understood as risk factors for the development of cardiovascular-type pathologies. In this way, the level of total cholesterol isn’t as important as its oxidation rate.
What foods is cholesterol found in?
Dietary cholesterol can be found in foods such as meat or eggs. This can be absorbed at the intestinal level or eliminated in the feces. The intake of other substances that partially block its absorption, such as fiber, depends to a large extent on this.
The microbiota profile can also affect the body’s ability to metabolize the nutrient, in the same way as the production of bile acids.
Foods from the plant kingdom, as a general rule, contain low amounts of cholesterol or may even be free of the substance. For this reason, patients with cardiovascular problems have been recommended to increase the consumption of plant foods. However, their importance lies in their antioxidant content.
How can diet affect the lipid profile?
As we have pointed out, diet plays a less important role than previously thought when it comes to modulating a person’s lipid profile. However, it’s possible to exert certain changes in total cholesterol and lipoprotein levels by making changes in diet.
The regular intake of fiber has been shown, for example, to be capable of lowering the level of total cholesterol, from a partial blockage of its absorption in the intestine. Above all, the soluble fiber present in apples (pectin) and oats (beta-glucans) performs this function.
The consumption of omega-3 fatty acids can also affect the lipid profile, increasing HDL levels. On the other hand, the contribution of trans-type fatty acids, from subjecting lipids to high temperatures, is capable of increasing the rate of oxidation and inflammation of the organism, in turn increasing the total cholesterol level.
Besides, this type of fat, whose spatial conformation is altered, also increases the total LDL level. There’s solid evidence that the inclusion of trans-type lipids in the diet is a risk factor for cardiovascular disease.
In addition, a hypercaloric diet or one with an excessive content of simple carbohydrates such as sugar can also have an effect when it comes to increasing total cholesterol levels. At the same time, it produces increased inflammation and oxidation by means of insulin resistance.
Medication and cholesterol
Although diet plays a role with limited potential when it comes to modulating the lipid profile, certain drugs are capable of varying the levels of lipoproteins in the body.
On the one hand we have statins, drugs responsible for reducing total cholesterol, prescribed for patients diagnosed with hypercholesterolemia.
However, these types of drugs have significant side effects. As we mentioned, the association between cholesterol and cardiovascular risk isn’t as direct as previously believed, so it isn’t often necessary to reduce lipoprotein levels, but, rather, to limit their oxidation. In addition to this, these drugs cause liver stress that ends up being harmful.
Apart from statins, there are other drugs that can influence lipoprotein levels – in this case, increasing them. These are anabolic steroids, hormones used in the context of playing sports, despite the fact that they’re prohibited by official organizations. This class of drugs increases HDL levels.
What can you do to improve cardiovascular health?
Worrying about lowering cholesterol levels isn’t usually the best option to ensure adequate cardiovascular health.
When the objective is to guarantee an adequate state of health, the first thing is always to improve your diet. Increasing the consumption of vegetables (with a significant content of antioxidants), oily fish, and healthy fats can be a positive step to optimize the functioning of the heart.
In the same way, it’s advisable to respect the daily fiber requirements, both soluble and insoluble. It must be taken into account that the intestinal microbiota is related to the metabolism of nutrients and to health in general.
In addition, it’s crucial to perform physical exercise on a regular basis, since sport can improve the functioning of the body and the health of the heart. Tissue hypertrophy and an increase in muscle capacity are generated, making the organ more efficient.
Neither can we forget the importance of ensuring good rest and avoiding stress as far as possible. Depressive situations or bad social relationships negatively affect cardiac function, posing a great risk.
Cholesterol isn’t the enemy we thought it was
According to what we have mentioned, the position of science regarding serum cholesterol and the consumption of fats and dietary cholesterol has varied in recent years. These days we’re aware of the need to include lipids in our diets and to maximize our intake of antioxidants. This helps to prevent systemic inflammation that is detrimental to our health.
Gone are the recommendations to limit the consumption of eggs, for example. We now know that they aren’t unhealthy and neither do they influence cardiovascular function. For this reason, the existing restrictions have been lifted.
However, there are still many unknowns that remain unresolved when it comes to cardiovascular disease. There are no precise and simple methods to estimate cholesterol oxidation, which could clear up many doubts.
Even so, we now know that this is much less important than what we had previously thought. For this reason, current dietary patterns are far removed from conventional ones, being much more restrictive as far as carbohydrate intake is concerned.
If you want to improve your health, remember that the fundamental thing is to propose a diet with a high content of antioxidants, in which there’s no lack of quality proteins and fats. In addition, you must ensure you do physical exercise on a regular basis.
All this should be combined with good rest and relaxation with no place for stress. Nutrition professionals are trained to design a plan tailored to the individual needs of each patient.
- Guo S., Lu J., Zhuo Y., Xiao M., et al., Endogenous cholesterol ester hydroperoxides modulate cholesterol levels and inhibit cholesterol uptake in hepatocytes and macrophages. Redox Biol, 2019.
- Zhong S., Li L., Shen X., Li Q., et al., An update on lipid oxidation and inflammation in cardiovascular diseases. Free Radic Biol Med, 2019. 144: 266-278.
- Sima P., Vannucci L., Vetvicka V., B glucans and cholesterol. Int J Mol Med, 2018. 41 (4): 1799-1808.
- Islam A., Amin MN., Siddiqui SA., Hossain P., Sultana F., et al., Trans fatty acids and lipid profile: a serious risk factor to cardiovascular disease, cancer and diabetes. Diabetes Metab Syndr, 2019. 13 (2): 1643-1647.
- Millán, Jesús, et al. “La auténtica dimensión del colesterol-no-HDL: colesterol aterogénico.” Clínica e Investigación en Arteriosclerosis 28.6 (2016): 265-270.
- Zhong, V. W., et al. “La asociación entre la ingesta de colesterol y el consumo de huevos con el riesgo cardiovascular.” Panorama actual del medicamento 43.422 (2019): 291.
- García-Ríos, Antonio, et al. “Microbiota intestinal:¿ un nuevo protagonista en el riesgo de enfermedad cardiovascular?.” Clínica e Investigación en Arteriosclerosis 31.4 (2019): 178-185.
- Luna, Juan Gabriel Calle. Estudio de subfracciones de lipoproteínas de densidad intermedia (IDL) y muy baja (VLDL) y su relación con distintos factores de riesgo cardiovascular. Diss. Universidad de Murcia, 2016.
- Lama Toro, Alexis. “El debate sobre la importancia del LDL colesterol y uso de estatinas.” Revista chilena de cardiología 37.3 (2018): 217-219.
- Aliaga Muñoz, Begoña. “Dietoterapia de las enfermedades cardiovasculares.”
- Garcia-Silva, Jaqueline, et al. “Estrés, ira y dieta mediterránea como factores predictores del síndrome metabólico.” Medicina Clínica 151.2 (2018): 59-64.