What is cholesterol?
Cholesterol is a fat that is necessary for life: in fact, it is one of the principal components of our cell membranes and participates in the synthesis of vitamin D and other substances.
Cholesterol contributes to keeping the cell membranes rigid and whole, stabilizing their structure. It is mostly produced by our bodies, but can be partially introduced by your diet.
When it is present in excess, cholesterol increases the likelihood of developing heart diseases, leading to heart attacks and strokes.
A study conducted in Italy found that, starting in the late ‘90s, subjects showed a significant increase in cholesterol levels (from 205 to 211 mg/dl for men and from 207 to 217 mg/dl for women), with concomitant increase in the prevalence of hypercholesterolemia, from 20.8% to 34.3% for men and from 24.6% to 36.6% for women.
Generally, high cholesterol (technically called “hypercholesterolemia”) is not associated with direct symptoms. This is the reason why it makes sense to periodically check your cholesterol levels by having a simple blood test done.
Excess LDL cholesterol accumulates in deposits lining the internal walls of blood vessels, in agglomerations known as atheromas, which can obstruct blood flow and thus increase the probability of cardiological problems. Contrarily, high concentrations of HDL cholesterol (“good” cholesterol) are associated with a reduced number of cardiological problems.
Cholesterol and triglycerides do not circulate in their free form, but are associated with specific proteins known as lipoproteins.
The presence of conditions such as difficulty metabolizing lipids, genetic anomalies (such as inherited hypercholesterolemia) or environmental factors can alter these complex relationships.
The most important lipoproteins are:
- Low density lipoproteins (LDL), whose function is to transport cholesterol throughout the body;
- High density lipoproteins (HDL), involved in the removal of excess cholesterol, as well as preventing the accumulation of atherosclerotic deposits;
- Very low-density lipoproteins (VLDL), particularly rich in triglycerides.
Additional factors to take into consideration are:
- diabetes (a disease characterized by high concentrations of glucose, caused by abnormal quantities of insulin or abnormalities in its functioning);
- cigarette smoke (which damages the blood vessels);
- arterial blood pressure;
- levels of HDL cholesterol (optimal level for men: >1.0 mmol/L or >40 mg/dL; optimal level for women: >1,2 mmol/L or >45 mg/dL);
- levels of LDL cholesterol (optimal value for adults <100 mg/dL);
- family history of early cardiological illness;
- age (men, 45 and over; women, 55 and over);
- sex (women are more vulnerable than men);
Fortunately, most of these factors can be modified.
Changing your lifestyle by following a balanced diet and engaging in regular physical activity (not necessarily a sport, sometimes a brisk walk of at least 30 minutes almost every day is sufficient, and if possible, walking upstairs) can be an effective first step in keeping cholesterol levels under control and, consequently, preventing problems involving the heart and the circulatory system.
What to eat to lower your cholesterol
According to the current recommendations and guidelines for the prevention of heart disease, a varied and balanced diet helps prevent or postpone the onset of cardiovascular illnesses.
Foods of plant origin, like fruit, vegetables and grains, are your heart’s best friends: according to the guidelines, it is fundamental to consume 5 or more portions of fruit and vegetables per day and 6 or more portions of grain (pasta and rice, for example, preferably whole wheat and brown, respectively).
Consuming regular amounts of fruit and vegetables can contribute to reducing our cholesterol levels (total and LDL) and keeping arterial blood pressure low, as well as exercising a beneficial action on the gastrointestinal tract.
The beneficial effects of fruit and vegetables have been attributed to their high content of nutritional fiber, vitamins, minerals and substances with protective effects (especially anti-oxidants), while consuming grain (especially if whole or unrefined grain) ensures the correct intake of complex carbohydrates, vitamins, minerals and fiber.
In addition, an adequate intake of foods rich in mono and polyunsaturated fats can lower levels of LDL cholesterol if used instead of saturated fats. Monounsaturated and polyunsaturated fats are found mostly in vegetable oils (extra virgin olive oil is the first among them, for quality and beneficial properties), in most nuts, olives and seeds (for example, flax seeds), in avocados and fish (blue fish, mackerel, sardines, anchovies, cod and salmon are excellent sources of polyunsaturated fats and Omega-3).
The Mediterranean diet is an ideal cuisine, based on the association of “good” nutrients in proportions that make it complete from a nutritional standpoint, and therefore synonymous with a healthy dietary regimen. The Mediterranean diet includes ample amounts of plant products; fruit, vegetables and legumes, as well as fish (rich in polyunsaturated fats), while limiting consumption of red meat and saturated fats.
What not to eat if you have high cholesterol
A healthy diet can help reduce cholesterol levels; actually, the key thing is to reduce the proportion of “bad” cholesterol and increase the quota of “good” cholesterol.
In particular, it is advisable to avoid or limit your intake of:
- Saturated fats. At room temperature, these fats are solid, and are present in high amounts in foods based on animal products, like meat (particularly the fatter cuts), poultry (especially in the skin), dairy products and cheese made from whole milk and lard, as well as in some vegetable oils, including coconut and palm oil. Studies have shown that consuming saturated fats increases levels of LDL cholesterol and, consequently, reducing the amount of saturated fat in your diet is an effective way of reducing LDL cholesterol. Saturated fats should represent no more than 10% of total caloric intake.
- Trans fats, present above all in foods based on hydrogenated oils and fats (ex: margarine, crackers, potato chips). Hydrogenation is a process involving the addition of hydrogen to an unsaturated fat in order to stabilize it at room temperature.
- Cholesterol. The amount introduced in the diet contributes to increasing cholesterol levels, though less so than intake of saturated fats. Foods high in saturated fats are usually also high in cholesterol (like egg yolks, shrimp and dairy products made with whole milk, including butter, cream and cheese), so reducing the amount of foods you eat containing saturated fats also reduces your intake of cholesterol. There are some exceptions, though, like egg yolk and, to a lesser degree, shellfish, which are high in cholesterol but relatively low in saturated fats.
- Simple sugars. In general, you should consume food that contains complex carbohydrates (bread, pasta, etc.) instead of food rich in simple sugars (sweets, soda and soft drinks, candy).
How to fight bad cholesterol
A prevention-based strategy that includes a healthy diet, weight control and regular physical activity and excludes smoking is essential to keeping circulating LDL cholesterol levels within normal values.
For some people, however, altering their lifestyle and taking dietary supplements can prove insufficient to keep “bad” cholesterol under control, making it necessary to undertake a pharmacological treatment to reduce levels of cholesterol in the bloodstream: in any case, remember that you should always consult your physician.
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