Cholesterol
Cholesterol is a hydrophobic fatty substance that circulates in the blood with the help of lipoproteins and is a major structural component of cell membranes and several hormones (androgens, estrogens, cortisol, corticosterone, aldosterone, etc.). It also contributes to the production of vitamin D, bile acids and the metabolism of fat-soluble vitamins. Cholesterol is produced endogenously in the liver and exogenously from food.
Its high levels in the blood are associated with vascular damage and cardiovascular diseases. The levels of lipids in the blood can be easily measured and include the measurement of:
1. total cholesterol (TC).
2. low-density lipoprotein cholesterol (LDL-C), also referred to as “bad” cholesterol, which transports cholesterol from the liver to the cells. At high concentrations, there is a risk of vascular blockage.
3. high-density lipoprotein cholesterol (HDL-C), also referred to as “good” cholesterol, which removes LDL cholesterol from the walls of the vessels and transports it to the liver from where it is excreted in the bile.
4. triglyceride (TG) levels.
Elevated TC and LDL-C levels negatively affect cardiovascular health. Hyperlipidemia is a major causative factor in the occurrence of atherosclerosis and coronary heart disease (CHD). Reducing total cholesterol by 10% can reduce cardiovascular risk by up to 30%.
Some factors that influence the increase in LDL are smoking, alcohol, hypertension, diabetes, obesity, physical inactivity, inflammation and heredity (familial hypercholesterolemia).
In familial hypercholesterolemia, genes make it difficult for the body to remove excess LDL, resulting in high levels of it in the blood. It is estimated that 1 in 500 people have familial hypercholesterolemia. If a parent has familial hypercholesterolemia, there is a 50% chance that their son or daughter will inherit this disorder.
Dietary Strategy
In order to reduce blood cholesterol levels, based on the factors mentioned above, changes are required in our diet and in our daily habits. Specifically, the following are recommended:
o Adopting a diet with an emphasis on fruits, vegetables, legumes, whole grains and sources of “good” fatty acids.
o Replacing red meat, rich in animal fat, with lean sources of protein (chicken, fish, eggs)
o Replacing full-fat dairy products with semi-skimmed, low-fat (1.5 – 2% fat)
o Quitting smoking
o Limiting and avoiding alcohol consumption
o Losing weight for people with excess body fat and maintaining a healthy weight
o Incorporating physical exercise into your daily routine (at least 150 minutes of moderate-intensity exercise per week is recommended)
o Managing stress
o Getting a good night’s sleep, at least 7-8 hours a day
Many studies have observed the relationship between cholesterol in food and cholesterol in the blood, as well as possible ways to treat the occurrence of cardiovascular diseases.
The nutritional strategy previously focused mainly on limiting dietary cholesterol intake (<300 mg/day for the general population and <200 mg/day for people with elevated LDL cholesterol).
The scientific community now knows that the amount of cholesterol we consume through our diet plays a minimal role in the levels of cholesterol in our blood. The cholesterol present in the blood is produced by the liver, which uses saturated and processed fats as raw materials for its production. Therefore, it is more important to reduce these fats, as they increase cholesterol 3 times more than dietary cholesterol, because they act on the increased endogenous synthesis which constitutes 80% of its total production.
It is therefore recommended to replace saturated and trans fats with unsaturated fats ω3, ω6 as it has been shown to significantly reduce cholesterol. Sources of “good” fats (monounsaturated and polyunsaturated) are vegetable oils, such as olive oil, sunflower oil, soybean oil, safflower oil and corn oil, nuts, seeds and fatty fish.
In conclusion, diet is one of the key factors in dealing with the problem. Therefore, by following simple dietary rules, changing small things in our daily lives, and incorporating exercise into our lives, we can see a great improvement in cholesterol levels and consequently in our quality of life.
SOURCES
Brownawell AM, Falk MC., 2010. Cholesterol: where science and public health policy intersect. Nutr Rev.
