What is the function of cholesterol?
This is a broad question, so the broadest answer is that cholesterol is a component of animal cell membranes that is synthesized in the liver and helps communicate between other cells throughout the body. To be a little more specific:
- Membrane fluidity – Cholesterols main role is as a buffer against the changes that occur in cells due to temperature fluctuations.
- Nerve conduction – Cholesterol is a large component of something known as the myelin sheath, membranes that wrap around axons in cells of the nervous systems and help promote signal conduction. To drive this point home, a 2019 study published in JAMA found that lowering serum cholesterol levels in patients diagnosed with type 2 diabetes had more severe diabetic peripheral neuropathy (DPN). DPN is a risk in type 2 diabetics as chronically elevated blood sugars can destroy nerve tissue. The study demonstrated that lowering cholesterol levels was associated with a higher number of nerve lesions and reductions in nerve conduction velocity.
- Precursor – Cholesterol is needed for the synthesis of bile, and therefore is important for fat digestion and the proper absorption of fat-soluble vitamins such as A, D, E, and K. Cholesterol is also involved in the actual synthesis of vitamin D and other steroid hormones throughout the body, including sex hormones.
All of this to say that cholesterol has a critical role in our body, otherwise humans wouldn't have evolved a mechanism in the body to produce it ourselves!
What are the various forms of cholesterol?
In order to move around the body, cholesterol is carried by certain proteins known more specifically as lipoproteins, and chylomicrons:
- Chylomicrons: these triglyceride (TG) rich particles are synthesized in the intestine and transport cholesterol and TGs to peripheral tissues and the liver.
- VLDL: these very low-density lipoproteins deliver TGs to muscle and fat tissue
- LDL: these low-density lipoproteins contain the majority of cholesterol and more easily bind to agents in the walls of arteries
- HDL: these high-density lipoproteins actually remove cholesterol from peripheral tissues and return it back to the liver, reducing the chance of atherosclerotic plaques from building up.
How does cholesterol affect heart health?
One of the prevalent myths out there is that knowing the amount of cholesterol in the body helps you predict your risk of heart disease or overall cardiovascular events, but the actual story is more meaningful. The carrier proteins we spoke of earlier provide a more important picture.
When the low-density lipoproteins are damaged, they have the potential to stick to the inner lining of our blood vessels, the endothelium. These lipoproteins carrying cholesterol, which doesn't dissolve in blood, can start to accumulate and induce concerning levels of inflammation and form clots.
How do sugars impact the synthesis of cholesterol?
When added sugars are consumed, typically the kind containing no nutritional benefit outside of the additional sweetness, the body will raise insulin levels as these sugars enter the body. As insulin levels increase, the body also increases the levels of LDL to help convert those sugars into fats. These added sugars act rapidly in the body, while natural sugars such as those from fruit, are absorbed slowly. Additionally, exposure of proteins or lipids to sugar can lead to the development of agents known as advanced glycation end products that have been indicated in conditions such as Alzheimer's, diabetes, degenerative and kidney diseases.
They cause inflammation, contribute to organ damage, and may also damage cardiac muscle that helps pump the heart.
What should I do about my diet?
Low-fat isn't as beneficial as one might think if it cuts out both the harmful and beneficial fats. Those beneficial fats are known as monounsaturated fatty acids (MUFA) and can benefit a variety of metabolic processes.
Researchers have shown that increasing your intake of MUFAs can balance cholesterol levels in the blood, lowering LDL by 5% while those consuming saturated fats saw LDL levels rise by 4%.
Dietary sources of MUFAs include the classic olive oil, hazelnut and avocado oils, as well as macadamia and hazelnuts. These agents also help improve blood sugar regulation as those consuming a diet rich in MUFAs saw an 8.8% increase in insulin sensitivity, lowered HbA1c levels (known as Glycated hemoglobin, a form of hemoglobin that is chemically linked to a sugar), and improved HOMA-IR scores (Homeostatic Model Assessment, a method used to quantify insulin resistance).
Nature to the rescue!
Boldocynara is a complex of artichoke, milk thistle, boldo, and dandelion.
- Milk thistle has been shown to be a potent liver protector, and reduces fasting blood glucose levels and HbA1c levels in those with type 2 diabetes mellitus.
- Artichoke has been shown to improve how well the body tolerates glucose, and in one study of 143 adults, an extract of artichoke taken daily for six weeks reduced total cholesterol by 18.5% and LDL cholesterol by 22.9%! Researchers think this may be due to the levels of luteolin in artichoke.
- Boldo has traditionally been used for complaints of the gastrointestinal tract and helps digestion by inducing bile secretion from the gallbladder. Bile helps to breakdown fats into smaller droplets that are easier to digest by the intestinal cells.
- Finally, dandelion intake showed a decrease in 'bad' fats present throughout the body as well as increasing 'good' fats.
References:
https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2734805
https://www.ncbi.nlm.nih.gov/books/NBK305896/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3066069/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3546618/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4383754/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4955926/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5409724/
https://pubmed.ncbi.nlm.nih.gov/10758778
https://pubmed.ncbi.nlm.nih.gov/11317662
https://pubmed.ncbi.nlm.nih.gov/21912106/
https://pubmed.ncbi.nlm.nih.gov/27340676/
https://pubmed.ncbi.nlm.nih.gov/27434027
