One of the more positive developments around statins of late, I think, has been the increasing awareness of the sorts of health issues they can induce. It is now becoming much more recognised, for instance, that these drugs can impact on mental functioning, including memory. Back in 2012, the FDA in the US issued a warning that: “There have been rare post-marketing reports of cognitive impairment (e.g. memory loss, forgetfulness, amnesia, memory impairment, confusion) associated with statin use.” I was therefore interested to read about a recent study that tested the impact of statins on memory in animals.
In this study, guinea pigs were treated with simvastatin (2 mg of drug per kg of animal per day) or atorvastatin (1 mg/kg/day) [1]. The researchers tested the effects of the drug on something known as ‘long term potentiation’ in a part of the brain known as the hippocampus. The hippocampus is believed to be the major seat in the brain of learning and memory, and improved long term potentiation is taken as a sign of improved functioning here. Both types of statin were found to reduce long term potentiation.
The guinea pigs were also exposed to a ‘water maze test’, which is often used in animal experiments to test learning and memory (particularly ‘spatial’ learning and memory). Statin therapy was found to significantly reduce what is termed as ‘working memory’ – the ability to hold multiple pieces information in the mind, and sometimes described as ‘short-term memory’. The authors of the study concluded that: “Our results may help to explain some of the behavioural changes reported in some people after beginning statin treatment.”
This is not the only study that has raised suspicions about the ability of statins to compromise brain function. In September I wrote about a similar study, this one published in the journal PLoS One. It tested the effects of two statins: pravastatin (Pravachol) or atorvastatin (Lipotor) on rats [2]. Before, during and after treatment, the rats were subjected to tests of learning and memory. Both these tests were adversely affected by pravastatin (but not atorvastatin).
I have met many people who claim that statins appeared to cause their memory and mental functioning to deteriorate. Some people appear to be more affected by others. It’s useful for individuals to be aware of this issue because increasing numbers of people are set to be prescribed statins if the new guidelines for cholesterol management (in the US) take hold. Often, when someone’s brain function drops off it’s assumed to be just ‘one of those things’, and part and parcel of the ageing process. Being mindful of the fact that statins (or some other medication) may be playing a role here can spare people a lot of suffering.
References:
1. Maggo S, et al. Effects of HMG-CoA reductase inhibitors on learning and memory in the guinea pig. Eur J Pharmacol. 2013 Dec 1 [Epub ahead of print]
2. Stuart SA, et al. Chronic Pravastatin but Not Atorvastatin Treatment Impairs Cognitive Function in Two Rodent Models of Learning and Memory. PLoS ONE 8(9): e75467
