The holy grail of health these days is to have low cholesterol levels. And cholesterol lowering drugs such as statins are prescribed to many people, whether or not they have had a heart attack, to get their cholesterol levels as low as possible. And statin drugs certainly achieve this goal, so on paper everybody taking these things are much healthier. Unfortunately in reality these drugs cause a whole range of side effects covered by the Youtube video. This blog is going to look at a couple of studies linking memory loss, aggression and suicide to low cholesterol levels.
But before we begin, if we watch the video we see the words mevalonate inhibition. This is how statins lower cholesterol levels. It is well complicated. Click on the Wiki link if you want to know more detail. However here is a brief and hopefully not too wrong an explanation. The mevalonate pathway is how the body produces cholesterol in the liver. Statins compete at the 1st step by docking into the cholesterol receptors in the liver so it can’t produce mevalonic acid. The liver cells sense a reduction in liver cholesterol levels and seeks to compensate by drawing LDL and VLDL cholesterol out of the blood circulation. Cholesterol is then reprocessed as bile salts, excreted and ultimately recycled by an internal bile salt circulation. Bingo, cholesterol levels drop and the doctors and the pharmaceutical companies are delighted. However, the person taking the statin may not be quite so happy. Referring back to Cholesterol 1 blog, even Collins dictionary of medicine says cholesterol is an essential body ingredient and in the blog I refer to cholesterol being important in the brain to develop the synapses. So we are now going to look at the role of cholesterol in the brain.
The brain contains about 25% of the total cholesterol in the body and over 2% of the weight of the brain is cholesterol. Dr Frank Pfrieger is studying the work of glial cells in the brain1. Glial cells are support cells to the synapses and he found they released a substance that allows the synapses to form and function. The substance he found? Cholesterol.
The first study we are going to look at was conducted by Jian Zhang2 To quote from the abstract
The authors concluded that, among non African-American children, low total cholesterol is associated with suspension or expulsion and that low total cholesterol may be a risk factor for aggression or a risk factor for other biologic variables that predispose to aggression.
There were 4,852 children in the study, aged 6 – 16. These finding applied to the children with a total cholesterol level in the lowest 25%. If we or children are behaving aggressively, we are all hardly happy.
The second study was published in the British Journal of Psychiatry in 2000 and related to a study done on 100 people admitted to A & E following an attempted suicide, called parasuicide3. Again to quote from the conclusion
The data confirms previous reports of low cholesterol in parasuicide. This is the first reported investigation of the construct of impulsivity in relation to cholesterol. We hypothesise that the reported increased mortality in populations with low cholesterol may derive from increased suicide and accident rates consequent on increased tendencies to impulsivity in these populations.
Later in the report the authors say that epidemiological evidence strongly suggests the existence of a J-shaped curve in relation to total cholesterol and mortality. The principal cause of death in the low cholesterol populations are trauma (road traffic accidents, homicide, etc) and suicide. They refer to previous studies bearing this out. Interestingly, they think it is to do with low serotonin levels in the brain, with either reasonable cholesterol levels being important for the availability of serotonin or low levels of omega 3 causing cholesterol to act as a ‘surrogate marker’.
Finally there is statins and memory loss. A leading proponent of this is Dr Graveline, the author of the above video clip. He experienced 2 episodes of global amnesia shortly after taking statins. Click on the link to read an interview with him. Dr Graveline is an American GP but trained as an astronaut with NASA working as a flight surgeon and participating in space medical research, so a very bright man. He has written a book Lipitor, thief of memory, statin drugs and the misguided war on cholesterol. In the first incident he describes returning from a walk and his wife finding him wandering aimlessly about the driveway. He did not recognise her and refused to enter his home. He stopped taking Statins, then was prescribed them again a year later. This time he regressed back to his teen years, with good memory for school friends and events but no memory of anything after that.
To conclude: to reduce cholesterol levels by taking statins may make your doctor happy and convinced that you are healthier. However, as far as the brain is concerned, it needs a good supply of cholesterol to function properly and if that level is artificially lowered, it leaves us open to depression, aggression and memory loss.
- Pfreiger FW. Role of glia in synapse development. Current opinion in neurobiology 2002, 12; 486-490 [↩]
- Zhang J, Muldoon MF, Mckeown RE, Cuffe SP. Association of serum cholesterol and history of school suspension among school-age children and adolescents in the United States. American journal of epimediology Vol 161, issue 7 pp691-699 [↩]
- Garland M, Corvin A, Goldne J, Fitzpatrick P, cunningham S, Walsh N. Total serum cholesterol in relation to psychological correlates in parasuicide. British Journal of Psychiatry 2000 177:77-83 [↩]