We’ve all been born under the stigma of cholesterol. From the day you were born, the cholesterol in your food and your blood cholesterol levels have determined your health prognosis.
Though it remains poorly understood, cholesterol continues to play a central role as a dietary indicator. Concerns about cholesterol have given rise to the creation of functional foods, shaped food advertising, dictated the principles behind dietary guides and influenced our dietary habits.
The story of the study of cholesterol begins two centuries ago, and it has been influential in places as disparate as Tsarist Russia, post-war Japan and the United States. Studies about blood lipids and related diseases have won at least 11 Nobel prizes.
The issue of pharmacological treatments for high cholesterol has become the subject of passionate debates, among them a recent confrontation between the British Medical Journal and The Lancet. So it’s no surprise if you disagree with your doctor about cholesterol.
A quick portrait of cholesterol
From a strictly chemical perspective, cholesterol is a molecule that belongs to the sterol family. It s found exclusively in the tissue and blood plasma of vertebrates, and certain levels are vital for human health. In normal conditions, though, all organisms are capable of generating all the cholesterol they need. The highest concentrations of cholesterol in the human body are found in the liver, spinal cord and brain.
Cholesterol forms part of all our cell membranes. It helps our bodies synthesize vitamin D, bile, steroid hormones including cortisol, cortisone and aldosterone, and the sexual hormones progesterone, estrogen and testosterone. They also play an important role in brain synapses and even in immune system function. Finally, cholesterol can also form deposits on the walls of our arteries under certain conditions, leading to the well-known condition atherosclerosis. That can be a risk factor for many different cardiovascular conditions, including coronary heart disease.
A little bit of context
In the 1950s, groundbreaking epidemiological studies began to observe the role of fatty diets in contributing to blood lipid concentration, atherosclerosis and and cardiovascular risk. One of the most known studies was the famous Seven Countries Study, which catapulted Ancel Keys to fame and popularized the Mediterranean diet. The NIH also began the Framingham Heart Study, which continues today and has published over 3,000 scientific papers.
In 1964, Konrad Bloch described how the body metabolizes and regulates cholesterol and fatty acids, a work that won him the Nobel Prize in medicine. Three years later, Donald Fredrickson discovered that not all lipoproteins work the same for everyone. He opened up the possibility for genetics to play a role in developing prognostics for cardiovascular health.
By 1973, Arno Motulsky and Joseph Goldstein had developed the foundations for the first genetic classification of hyperlipidemia, or high blood lipid concentration. Three years later, Akira Endo discovered the first statins, substances that have become protagonists in pharmacological treatments for hypercholesterolemia and atherosclerosis. The first treatment was approved for commercial use in the United States in 1987. Since then, scientists have made many advances in their understanding of atherosclerosis, from the role of genetics and diet to factors like tobacco and exercise, in addition to the developments in pharmacology.
Despite existing doubts, this remains clear
Eighty to 90% of cholesterol that circulates in the blood is synthesized within our own bodies. The rest comes from cholesterol ingested in food. But saturated and trans-saturated fats contribute more to cardiovascular risk than cholesterol.
Familial hypercholesterolemia is a genetic disease that causes especially high levels of cholesterol. It often occurs because the liver does not completely eliminate cholesterol because it lacks LDL receptors. More than half of familial hypercholesterolemia patients present symptoms of the illness before 55 years of age.
While blood cholesterol levels have long been used as a health indicator, the metric can have little to no relevance to overall health. Though advertisements for products such as Danone’s Danacol yogurt warn of grave consequences if blood cholesterol surpasses 200 mg/dl, in reality, it is only useful when understood in relation with other variables.
The stigma of dairy products
Many people find themselves conflicted between their concerns about high cholesterol and their consumption of milk and dairy products. Dietary recommendations to consume a certain quantity of milk everyday are outdated. Fortunately, we no longer need to drink milk to fulfill our nutritional needs.
Dairy products or milk often are less the problem than the other foods that they tend to accompany: bread, cookies, breakfast cereals, chocolates high in sugar. If you do drink milk, up-to-date dietary recommendations suggest choosing fat-free milk, though the most current research points to the benefits of fermented milk products like yogurt above milk itself.
The doctor’s orders
We do know, though, that cardiovascular risk depends on many more important factors than the cholesterol levels. One of those elements is the quantity and kind of LDL lipoproteins. Your doctor can use software to interpret that data if you require a more detailed analysis.
Your doctor’s advice will truly help you understand your cardiovascular risk. To focus only on your cholesterol is to disregard the last 70 years of scientific research—and to fall into the trap of marketing gimmicks like “functional foods.”
The dietary guidelines to prevent heart disease are the same ones recommended to prevent cancer or diabetes. Keep these principles in mind:
-Focus on healthy foods and dietary patterns, not on individual nutrients.
-Move towards a vegetable-based diet, and avoid ultra processed foods that are dense in energy, salt, sugar and saturated and trans-saturated fats.
-The key ingredients of a health diet are fruit, vegetables, legumes, nuts, whole grains, fish, low-fat dairy products and vegetable oils.
-Remember that, in addition to strictly dietary issues, physical inactivity and habits like tobacco usage and alcohol consumption will also increase your cardiovascular risk.
-Age and genetics also have an impact on your cardiovascular health.