Cholesterol is an essential substance for animal life. It is part of the membrane of all cells and is the starting molecule for the synthesis of substances as important as vitamin D, myelin or steroid hormones (estrogens, testosterone, cortisol, progesterone).
no plants, including fruits and vegetables, nor any other non-animal life form synthesizes cholesterol. Therefore, it is not even in by-products unless some animal source has been added, for example milk, egg, fatty meats, butter or tallow.
Fruits, vegetables and cardiovascular health
While humans need cholesterol to live, they don’t need it in their diet. In the endoplasmic reticulum of any cell all the cholesterol you need is synthesized from carbohydrates, proteins or other lipids. In addition, liver cells produce additional amounts of cholesterol primarily intended for hormone synthesis.
This endogenous synthesis, especially hepatic, is the most important source of cholesterol in the blood (cholesterolemia) and is largely conditioned by genetic factors.
So dietary cholesterol does not appear to be a problem for cardiovascular health, at least not a determining factor. If our body doesn’t need cholesterol, it won’t even absorb it from the intestines, or it will do so in very small amounts. So much so that the Scientific Report of the Advisory Committee on Dietary Guidelines of the United States eliminated the maximum daily cholesterol limit in 2015, until then it recommended not exceeding 300 mg/day, as well as establishing no minimum requirements1.
The main risk to cardiovascular health is saturated fat, which is the main type of fat in animal products, which also contain cholesterol and often high amounts of salt, especially in processed products.
And is that not even blood cholesterol is the problem itself, but LDL. Although LDL is called “bad” cholesterol, it is not cholesterol, but a lipoprotein that transports cholesterol. The oxidation of the LDL-cholesterol complex is what increases the risk of cardiovascular diseases, especially atherosclerosis. But not only LDL cholesterol is oxidized in the bloodstream, but also triglycerides.
Although the general dietary recommendations are to reduce cholesterol intake, reduce saturated fat intake and increase unsaturated fat intake, there are scientists who discuss its real effect on atherosclerosis, highlighting The International Network of Cholesterol Skeptics, and scientific studies that find no relationship between a high intake of unsaturated fat and a low intake of saturated fat with reduced risk of cardiovascular disease.
What seems clear is that:We don’t need to eat cholesterol without saturated fat. The only essential fatty acids for humans are polyunsaturated α-linolenic (18:3ω-3, an omega-3) and linoleic (18:2ω-6, an omega-6). If we have them, our body is able to synthesize all the other lipids it needs. You don’t need to avoid fat completely. You need to get essential fatty acids and other essential nutrients that are dissolved in it, for example fat-soluble vitamins. There is widespread acceptance that dietary saturated fat may increase the risk of cardiovascular disease. Some vitamins and other antioxidant substances they can reduce the effect of free radicals and are related to a cardioprotective effect.
Fresh fruits and vegetables are excellent foods for all of these points:They do not contain cholesterol. They contain low levels of saturated fat and salt, which are major dietary factors in cardiovascular risk. Fatty fruits such as avocados or olives, nuts, vegetables and seed oils such as sunflower oil are a source of mono and polyunsaturated fatty acids that help improve the lipid profile, include essential fatty acids and fat-soluble vitamins. They are a source of vitamins and antioxidants such as vitamin C and vitamin E, and phenolic compounds such as flavonoids, known for their cardioprotective action. They contain phytosterol, the plant analogue of cholesterol. Phytosterol is not absorbed in the intestine and reduces the absorption of cholesterol. In addition, there are preliminary studies that point to a possible action against lung, stomach, ovarian and breast cancer.
Vegetarians with high cholesterol
Although fruits and vegetables are cholesterol-free and low in saturated fat, being a vegetarian does not equate to having low cholesterol. As stated, internal synthesis and therefore genetic factors have the greatest impact on blood cholesterol levels.
Nor does it mean that all plant products have a heart-healthy lipid profile. Vegetable oils high in saturated fat such as palm oil, vegetable derivatives with trans fatty acids such as margarine or fried foods can have a negative effect on the lipid profile.