While we are consistently encouraged to keep our cholesterol levels in check for the sake of our heart health, common sense dictates that we should be somewhat cautious here. After all, cholesterol is an essential element in the body and, for instance, is integral to the structure and function of all our cells, including those in the brain.
The great majority of cholesterol in the bloodstream does not come from our diets, but is made in the liver. One wonders if, somehow, the body is intent on some sort of slow suicide, or if its manufacturing of cholesterol reflects its need for this substance.
Studies have linked low levels of cholesterol with worse outcomes in certain, specific aspects of health. There has been, for instance, previous evidence linking cholesterol-reducing interventions with deaths due to accidents, suicide and violence (e.g. murder).
Recently, I came across a British Medical Journal study dating from 1990 that made for interesting reading . This study aggregated the results of 6 cholesterol-lowering trials in people without a prior history of cardiovascular disease (e.g. heart attack or stroke).
The individual interventions were either a drug or dietary change. Each trial was well-conducted, and had a comparison group which was not exposed to the intervention.
Overall, the intervention groups in whom cholesterol levels were reduced were:
- At no reduced risk of death overall
- At no reduced risk of death due to heart disease
- At a significantly increased risk (43 per cent) of death due to cancer
- At a significantly increased risk (76 per cent) of death due to accidents, suicide and violence
The increased risk of death due to cancer seemed to be due to the findings of one specific trial, in which individuals were treated with the fibrate drug clofibrate. If this trial was removed from the analysis, the risk of death from cancer was not significantly raised.
However, the increased risk of death from accidents, suicide and violence was a consistent finding, and it held true even when the researchers split their analysis into studies of diet-alone or drug therapy-alone interventions. In other words, dietary intervention to lower cholesterol increased the risk accidents, suicide and violence, and so did medication.
This consistency in the results does suggest something real is going on, and specifically that lowering cholesterol increases the risk of these issues. Accidents, suicide and violence may not appear very connected, but one could all argue they are all going to be more likely in individuals whose brains are prone to, say, impulsivity or aggression.
The authors of the review speculated as to how cholesterol reduction might cause the increase in death rates due to accidents, suicide and violence seen across the individual studies.
There is some experimental evidence that modifying the fat in the diet has both neurochemical and behavioural consequences. In laboratory rats these include altered fluidity and cholesterol content of cell membranes within the central nervous system and effects on maze learning, pain threshold, and physical activity. Monkeys fed a diet low in saturated fat and cholesterol (modelled on American Heart Association recommendations) were significantly more aggressive than control animals consuming a diet high in fat and cholesterol.
But the authors went on to say that similar studies are entirely lacking in humans. They do, however, point our attention to studies which show low blood cholesterol levels are more common in, say, criminals, individuals with history of violence or conduct disorder, and murderers with a history of violence.
While this evidence is old, I think it adds to the current body of evidence which supports the role of cholesterol in healthy brain function. There has been at least some acknowledgement in the scientific literature that cholesterol-reducing treatments can impair brain function.
Cholesterol reduction is presented to us by most health agencies and health professionals as a ‘no-brainer’: why wouldn’t you want to bring your cholesterol level down (you’d be mad not to, almost)? Well, one reason for perhaps not wanting to lower cholesterol levels is that it can have unforeseen consequences (which can be devastating).
1. Muldoon MF, et al. Lowering cholesterol concentrations and mortality: a quantitative review of primary prevention trials. BMJ 1990;301:309-14
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I came off high doseage statins 16 weeks ago, against medical advice, after my total cholesterol level plummeted to 3.3mmol. I had removed the carbs from my diet in the preceeding 2 months, and my triglycride reading was a very healthy 1, along with a healthy HbA1c.
Why on earth should I be encouraged to continue with statins, being a 65 year old female with no cardiac history? But I was quizzed on my state of depression! Well, yes, I was feeling low, very low at being pushed to take all manner of drugs. Now off the lot of them, I am as happy as Larry, in fact I no longer have unpleasant dreams, and I haven’t a clue as to my “cholesterol” status, as it is irrelevant. My glucose levels are consistently normal ( home testing only, so I have no idea of my HbA1c).
I have returned to the weight I was at age 35, and have a diet rich in natural fats and quality proteins, just as I served up then as an active mother and housewife. The decline started that year, 1983. So, 30 years of bad dietary advice and excess interference from GPs!
And loads of time to enjoy life as I don’t venture near the surgery these days.
I can lend support to what Jennifer (above) says but I will not relate my terror of going to the GPs Surgery for an annual health check simply as I require selegiline to keep my brain in order after having to have a quadruple 23 years ago. Why the public cannot purchase drugs from a pharmacy without the need for a medical prescription never ceases to frustrate me. I can travel to other countries and purchase medication OTC but not in the UK or the US without a prescription. Some four years ago on getting the results of my annual test I was informed that my cholesterol level was a tad high and the GP was about to place me on statins but she could not see my heels for the dust as I made a quick, very quick, exit! A neighbour of mine has been on statins for 12 years during which time he has wandered around in a daze and totally disassociated from the world around him. Tell me the old, old story!
“I haven’t a clue as to my “cholesterol” status, as it is irrelevant.”
I wouldn’t be so quick to dismiss the significance of serum cholesterol, especially if it indicates that your thyroid isn’t functioning optimally. There are many benefits to be had, besides lowering a cholesterol number, if suboptimal thyroid function is remedied.
“While we are consistently encouraged to keep our cholesterol levels in check for the sake of our heart health, common sense dictates that we should be somewhat cautious here. After all, cholesterol is an essential element in the body and, for instance, is integral to the structure and function of all our cells, including those in the brain.”
There are two ways in which high serum cholesterol can be lowered to ‘normal’ levels. First, one can choke off the production by pharmaceutical means, depriving the body of the building blocks for cell walls, steroid hormones and vitamin D and perhaps leading to violence and suicides, as the study suggests.
Secondly one can improve the ‘clearance’ or ‘utilization’ of cholesterol in the liver by thyroid supplementation. The former method treats cholesterol as a toxin. The latter treats cholesterol as a nutrient and I doubt that such a method of cholesterol reduction would result in violence and suicide.
The aggressive behavior of rats whose cholesterol is drastically lowered points to the connection between brain function and the need for cholesterol to nourish the nervous system.
But a similar finding in humans, although it may have relevance, is so extreme in its implications that I have a hard time taking it very seriously. And I’m not one of those people who thinks it’s bad to eat saturated fats or that cholesterol per se is the enemy.
There are societies whose diets tend them towards lower cholesterol (I’m thinking of the Mediterranean countries where folks eat a lot of fresh fruits and vegetables, olive oil and fish, such as Greece, for example). The Greeks don’t strike me as any more suicidal or violence prone than any other group.
However, if the study subjects had such artificially, radically lowered cholesterol levels that they were more or less lacking cholesterol all together, then aberrant behavior might be expected, because cholesterol is essential for life. So I’d be curious to know just how low the serum cholesterol of violent or suicidal subjects was. What was the definition of “low” in this study?
Rita,the people in the Mediterranean also eat lots of animal protein,fatty protein at that.Lots of lamb and cheese.Ask any Greek.
Any reference for thyroid supplementation? And I assume you are suggesting it when there is hypothyroidism. Turned around, maybe high cholesterol suggests hypothyroidism? No idea. Just a thought.
The majority of modern Greeks and Italians don’t eat “Mediterranean” any more. And yes, it would be interesting to see what the typical untreated level of cholesterol is for a variety of diets (Masai, Kitawans, Okinawans, etc).
Finally, this is an intriguing study, suggesting many interesting human-based experiments. Wonder why it hasn’t been followed up by anybody.
You can find the entire paper here:
I still have happy memories of my first trip to Florence, almost 30 years ago, when I discovered that the preliminary pasta was served in very small portions, and the T-bone steak, in all its glory, covered most of the plate…
Rita: read my comment immediately above yours. The fact that some Mediterraneans have low cholesterol in their blood does not, per se, indicate a high probability that these people are deficient in cholesterol. It could mean that they are efficient at utilizing it such that there is little cholesterol pooling in their blood.
Mike S: There are many references that attest to the cholesterol-lowering effect of thyroid hormone. The mechanism is not controversial. (Here is one such study http://jcem.endojournals.org/content/86/10/4860.full. You can google others.)
The controversy relates to eligible candidates for such therapy. Conventional medical wisdom is that only those who are diagnosed by blood tests as hypothyroid would benefit from thyroid supplementation.
Some claim that thyroid supplementation is undesirable due to “cardiac effects”:
“Thyroid hormones [predominantly 3,5,3′-triiodo-l-thyronine (T3)] regulate cholesterol and lipoprotein metabolism, but cardiac effects restrict their use as hypolipidemic drugs.”
The American Association of Clinical Endocrinologists acknowledges,
“Normalization of a variety of clinical and metabolic end points including resting heart rate, serum cholesterol, anxiety level, sleep pattern, and menstrual cycle abnormalities including menometrorrhagia are further confirmatory findings that patients have been restored to a euthyroid state.”
But the AACE states in its guidelines that high cholesterol should not be used to indicate hypothyroidism.
Despite the AACE guidelines, there is a school of thought that claims that hypothyroidism cannot be ruled out by reason of normal blood tests. Mark Starr is one such proponent. He claims that hypothyroidism is a disease of the mitochondria and that blood tests are only indirect measurements of thyroid function. (Google his book on Amazon. There are also podcasts and Youtube talks.)
Starr, and other ‘functionalists’, such as Blanchard, claim that the only way to determine whether some is hypothyroid is to try supplementing the hormone and see whether symptoms resolve. According to this school of thought, high cholesterol would be a sign of hypothyroidism.
The argument against the functionalists is that their claims are too ‘non-specific’. Anything and everything could be due to hypothyroidism, say the critics. The functionalists reply that anything could be due hypothyroidism because thyroid is required by every cell in the body and so a deficiency could manifest itself in any or many of numerous ways. And on and on goes the debate.
My feeling is that normal cholesterol levels indicate that lipid homeostasis is functioning properly: ie, cholesterol is being taken up by the liver and excess dietary cholesterol is being eliminated as bile salts.
Given the choice between a pharmaceutical that blocks the production of cholesterol or a hormone that facilitates its utilization which would you prefer?
I have recently ploughed through ‘The Magnesium Miracle’ by Carolyn Dean and found within the section on ‘Cholesterol and Hypertension’ a sub-section entitled ‘Magnesium acts like a natural statin’.
This sub-section appears to be largely based on a Review by Rosanoff, A. and Seeling, M from 2004 (which can be found in full at http://www.jacn.org/content/23/5/501S.full.pdf+html ).
While this blog article would clearly disagree with some of the ‘claims’ for the efficacy of statins noted in the Review, it is an interesting exposition of the importance of maintaining the ‘proper’ level of magnesium required to facilitate a ‘natural’ control of mevalonate production.
It would be interesting to know whether the UK diet is as poor at providing the essential ‘mineral’ Magnesium as the US diet – which Dean claims provides about 80% of RDA for men, and only 70% of RDA for women.
Today’s Daily Mail ( so it must be true) (not)
“Can sugary cereal and a chocolate drink really lower your