5 cholesterol myths – busted

Cholesterol. Just about everyone has heard of it, but myths and misunderstandings about it are rampant. Here are the 5 cholesterol myths that I encounter most often when speaking to clients and people who attend my seminars:

Myth #1: “High cholesterol runs in my family – my doctor says I have to take statins because I can’t lower my cholesterol with dietary change.”

There is a tiny kernel of truth in this myth: an inherited condition called familial hypercholesterolaemia causes severely elevated cholesterol from the time of birth, and development of atherosclerosis (clogging of the arteries with cholesterol-laden plaque) at a young age, resulting in premature coronary artery disease. As a result, men affected by this genetic disorder have a greater than 50% chance of developing coronary heart disease before age 50, and affected women have a 30% risk by age 60. Affected individuals typically have a serum cholesterol above 7.5 mmol/L, and also typically develop fatty deposits known as ‘xanthomas’ in their tendons.

However, only 1 in 500 Caucasians is affected by familial hypercholesterolaemia, which means your high cholesterol is far more likely to be driven by your diet and lifestyle habits than your genes. (Certain ethnicities e.g. French Canadians; Afrikaaners, Ashkenazi Jews and Indians from South African; Tunisians; Christian Lebanese; Icelanders; and Finns from North Karelia have higher prevalence rates due to the ‘founder effect’ which occurs when a subpopulation is formed through the immigration of a small number of individuals who carry the genetic defect).

Bottom line: If your mum or dad have high cholesterol and you do too, it’s far more likely to be due to the fact that you inherited the family recipe book than that you inherited any kind of genetic defect that predisposes you to high cholesterol. Eat like populations who rarely get heart disease (see Myth # 5) and your cholesterol will almost certainly drop.

Myth #2: “High cholesterol levels have nothing to do with heart disease”

Cholesterol denialism – the refusal to accept that cholesterol plays any role in cardiovascular disease – is a popular pursuit. Even the ABC’s flagship science program, Catalyst, got in on the act, with a 2-part program aired in 2013 devoted to ‘debunking’ the cholesterol-heart disease connection which was eventually taken down from the ABC’s website (having already escaped into the wilds of YouTube) after an internal review found the programs breached the ABC’s impartiality standards; the whole sorry mess probably contributed to the show’s axing by ABC management.

Cholesterol denialists such as Uffe Ravnskov, the Weston A. Price Foundation and apparently, Catalyst‘s Maryanne Demasi, ignore mountains of evidence demonstrating clearly that cholesterol plays a causative role in heart disease:

  • As mentioned above, people with familial hypercholesterolaemia develop premature atherosclerosis; those who inherit the defective gene from both their mother and father (homozygotes) frequently die of cardiovascular disease in their 20s, with no other risk factor beside elevated LDL.
  • Conversely, people with familial hypobeta lipoproteinemia, a condition that causes extremely low LDL levels, have a dramatically lower risk of developing cardiovascular disease, which results in a 9 and 12 year longer life expectancy for males and females respectively.
  • Multiple epidemiological (population-based) studies have demonstrated that “in populations that maintain very low levels of serum cholesterol, e.g., total cholesterol <150 mg/dL [3.9 mmol/L] (or LDL cholesterol <100 mg/dL [2.6 mmol/L) throughout life… we find a near-absence of clinical CHD [cardiovascular disease].”
  • Having a high cholesterol level is a powerful predictor of increased risk of cardiovascular disease in both young and middle-aged adults, especially males, and the relationship is continuous and graded – that is, the higher the cholesterol level, the higher the risk of cardiovascular disease and mortality.
  • Intervention studies have found that reducing serum cholesterol level by just 10% – easily achievable with dietary change – at age 40 reduces the relative risk of coronary heart disease by 50%.

Myth # 3: “We need to eat cholesterol for hormone synthesis and brain function”

There’s no denying that cholesterol is a crucially important building block, essential to the formation of steroid hormones including testosterone, oestrogen, cholecalciferol (vitamin D) and cortisol; bile salts; and the membranes and myelin sheath that form the ‘white matter’ of our brain and spinal cord. The fact that cholesterol is so critical to human function explains why we have such a huge capacity to make our own cholesterol – known as de novo synthesis – from acetyl Co-A, which in turn is derived from metabolism of carbohydrates and fats. In other words, we make cholesterol out of the carbohydrate and fat in our diet.

Both the liver and intestine are capable of synthesising considerable quantities of cholesterol depending on the body’s requirements – up to 800 mg per day in a person on a low-cholesterol diet.

The brain synthesises its own cholesterol, since the blood-brain barrier prevents cholesterol in the general circulation from entering the brain. Through its de novo synthesis and efficient recycling of cholesterol, the brain maintains the constant cholesterol concentration in its membranes and myelin that is crucial for its stable function.

Hence there is absolutely no requirement for consuming any cholesterol in the diet, and no conceivable mechanism by which dietary cholesterol could ‘balance’ hormones or promote healthy brain function.

Myth # 4: “Low cholesterol levels cause cancer”

The observation several decades that low cholesterol levels were seen in people with certain types of cancer fuelled claims by cholesterol denialists that lowering serum cholesterol would raise the risk of cancer. However, this association turns out to be reverse causation – having cancer, particularly advanced cancer, results in a reduced serum cholesterol level.

Cancer cells actually feed on cholesterol, avidly absorbing it from the bloodstream and accumulating it in their mitochondria (energy-producing units within the cell). The more rapidly-growing and aggressive the cancer, the higher the concentration of cholesterol within it, and hence the lower the serum cholesterol level.

Research dating back to the 1980s demonstrated that women whose breast tumours contained more LDL cholesterol were more likely to die of breast cancer, while hepatocellular carcinoma (primary liver cancer) is actually dependent on cholesterol for growth.

Research conducted in China found that counties with the lowest serum cholesterol levels – resulting from a largely plant-based diet – had not only the lowest rates of cardiovascular disease, but also the lowest rates of cancer.

Myth # 5: “Having a low cholesterol level is dangerous”

It’s always been a source of amusement for me when my cholesterol results have been flagged as ‘abnormal’ by the lab – abnormally low. The reality is, there really is no such thing as ‘too low’ when it comes to an unmedicated cholesterol level. Instead,

“the levels of plasma cholesterol usually seen in Western industrialized societies [and hence, the laboratory reference ranges to which your results are compared] are inappropriately high

In fact, a plasma LDL level of just 0.65 mmol/L (25 mg/dl)] would be sufficient to nourish body cells with cholesterol. Newborn babies’ LDL is just 0.78 mmol/L (30 mg/dl), while humans raised on a low fat diet typically have LDL levels of 1.3-2.1 mmol/L (50-80 mg/dl); only people whose diet regularly contains animal products typically have a plasma LDL above 2.6 mmol/L (100 mg/dl).

And, as mentioned in Myth # 2, people with a genetic condition that causes extremely low LDL cholesterol enjoy a 9-12 year longer lifespan. Bearing that in mind, does having a ‘low’ cholesterol level sound dangerous to you now?

There are so many sources of misinformation on health and nutrition on the web, and in popular books and media. How is a person with no background in science supposed to distinguish accurate and reliable sources from misleading and biased ones? My EmpowerEd program equips you with vital skills that you need to navigate this confusing territory so you can make the best nutrition and health care choices. Register for your 1 month free trial here.

Leave your comments below:

Leave A Response

* Denotes Required Field