‘Raised’ cholesterol linked with improved survival in the elderly

The idea that cholesterol causes cardiovascular disease comes from studies which find that higher cholesterol levels are linked with raised risk of heart disease and stroke. However, it’s important to bear in mind that such studies are ‘epidemiological’ (also termed ‘observational’) in nature, which means we cannot infer from them that cholesterol causes heart disease (just because two things are associated with each other, that does not necessarily mean one is actually causing the other).

Also, cardiovascular disease is a major killer, but it’s not the whole story. If we want to assess the impact of any factor on health, I think it pays to take as wide a view as possible. We can do this by looking at that factor’s relationship with overall risk of death. This is especially important for cholesterol, as low levels of this substance in the bloodstream are actually associated with heightened risk of potentially fatal conditions including cancer.

These considerations seem to be even more important in the elderly, as previous evidence has linked lower cholesterol levels with enhanced mortality. One such study was published late last year in the journal Clinical Nutrition [1]. In this study, elderly individuals (average age 81) admitted to hospital had their total cholesterol levels assessed. They were then monitored for an average period of about 3½ years.

Cholesterol levels were split into ‘quartiles’ (each quartile represents 25 per cent of cholesterol values, with the ‘top quartile’ representing the top 25 per cent of cholesterol values while the ‘bottom quartile’ represented the lowest 25 per cent of cholesterol values).
The mortality rate in those of in the lowest quartile (total cholesterol of 1.76-4.00 mmol/l) was about 93 per cent, but in the group in the top quartile (total cholesterol of 5.5-8.3 mmol/l) it was significantly lower at 76 per cent.

The authors calculated that each 1 mmol/l increase in cholesterol was associated with a more than 15 per cent reduction in risk of death.

Now, just to be clear, this is epidemiological evidence, again, and it cannot be used to infer that raised cholesterol actually protects against death. One of the reasons for this is that lowered cholesterol can be a sign of malnutrition (not uncommon in the elderly). In this study, low cholesterol was also found to be associated with lower levels of the blood protein albumin (low albumin suggests malnutrition). However, if malnutrition is the explanation, then it does raise at least some questions about the promotion of low-fat (sometimes semi-starvation) diets for cholesterol reduction. Most importantly, these diets have, as whole, not been found to reduce mortality, and there is some evidence that they may in fact be harmful to health.

The authors of this study make mention of the supposedly dangerous low-density lipoprotein (LDL) form of cholesterol. Specifically they allude to the fact that LDL cholesterol comes in different forms, ranging from small, dense forms that are believed to have potential to damage blood vessels, up to much larger, lighter forms that do not. They point out that long-lived individuals have been found to have a preponderance of presumably non-harmful LDL in their bloodstreams.

In the final analysis, we don’t know from this sort of evidence what the truth is. However, this sort of evidence should, I think, be more widely known, and should also cause us to question this vogue for driving cholesterol levels down. Cholesterol is an innate body constituent present in every cell membrane and is a major component in the brain. It is also a constituent of several key hormones, vitamin D and bile (for the digestion of fat). There seems little doubt that low levels of this substance can genuinely compromise health.

The bottom line is that cholesterol reduction is not without risk, though it’s something easy to forget that when we are bombarded with information about the supposedly perilous nature of cholesterol and the need to ‘keep it under control’.

References:

1. Weiss A, et al. Serum total cholesterol: A mortality predictor in elderly hospitalized patients. Clin Nutr 2012 Nov 23 [epub ahead of print]

14 Responses to ‘Raised’ cholesterol linked with improved survival in the elderly

  1. Madeleine Morrow 25 January 2013 at 10:58 pm #

    Assuming that cholesterol does have a direct effect on cardiovascular disease and that low cholesterol does have an effect on mortality in the elderly, could there perhaps be an optimal cholesterol level?? Could this level change across the life cycle – so that as we get to be elderly (if not yet having suffered cardiovascular disease) our cholesterol level can be allowed to rise a bit? I rather like the idea of being old and enjoying as many cotes de bouef as I like so long as my teeth stick around!

  2. audrey wickham 26 January 2013 at 6:30 pm #

    Up until about ten years ago I had my father’s family low blood pressure. It is now high. My GP thought my cholesterol was too high – it was just over the borderline. She went through all the food I should be eating and I ticked every box. She told me that what I ate made ten-percent of my cholesterol. I asked if that is so what is the point of buying anything to reduce my level. She couldn’t see any point in buying the stuff on TV and we agreed that as my level was always the same it must be what I am safe with.

    I also see the half moon of coloured blocks, very Mondrian, which I have found out is a not serious manifestation of migraine but no other indications. I have in the last six months taken a daily dose of Brewers Yeast in powder form and one small black coffee with half a teaspoonful of Black Strap Molasses every day. I can’t tell you which is aiding my short term memory but I can tell you with complete truth my memory is now incredibly good. I even remembered the name of a teacher I had in 1943 – I was cleaning my hair brush and I wondered who it was that taught me how to do it when her name came to me. I even remember where I have put things down. It is truly remarkable. I think it is the yeast that is good for memory – my grandmother died at 93, because she fell out of bed drunk and hit her head – she had all her marbles and was bored out of her mind. She took a yeastvite all her life which is why I decided to start taking it. The Mondiran coloured half moon has in the last couple of times it has come onto my vision lost all its colour and if it weren’t for the very slight partial loss of a word or two on my computer I wouldn’t know the migraine manifestation was there.
    I was advised to take Statins but haven’t. My only medicine is 75ml of Thyroxine and a flu jab in October. I haven’t had a cold/flu for as long as I have had them – over twenty years. I could, of course, drop dead in the next ten minutes but that’s not the way I feel right now. It is great having a good memory, because I have never in my life had a very good short term memory

  3. Ross 27 January 2013 at 2:27 am #

    this is a very brief overview of the alleged issues with cholesterol (read as “hoax”), but more needs to be mentioned, specifically how having a high Triglyceride count from blood tests in combination with high LDL is more the concern than just cholesterol on its own – a major fact that GPs tend to forget (or ignore).

  4. tony kerstein 27 January 2013 at 9:21 pm #

    As a volunteer for 2 organisations, one dealing with the elderly and one with many elderly volunteers I have noticed that the fittest and healthiest have high cholesterol levels, from 6 to, in one case, an exceptionally fit and young looking 85 year old, 10 mmol.
    Some were bullied by their doctors into taking statins but gave them up after suufering side effects like memory loss and muscle pains. Needless to say, these side effects were not accepted (and therefore not reported) by their doctors.

  5. Sheryl 28 January 2013 at 3:33 am #

    Have there been studies on people who have high cholesterol and then put on a statin to lower it having brain chemistry disturbances, such as a higher rates of depression? What I’m wanting to know is there a negative effect in the brain from statin type drugs? Or is there a general negative effect in the brain chemistry of low cholesterol individuals?

  6. Lorraine 29 January 2013 at 4:38 pm #

    Thank you Dr Briffa for another interesting article. We need to hear about more studies that make us question conventional wisdom.

  7. John 3 February 2013 at 11:19 am #

    I think huge strides have been made in assembling and interpreting research data. Genomics shows us that there are greater differences between two individuals, even from the same family, than there are differences between a fly and a worm. ( Human genome has 3.2 billion base-pairs, 3.2 Gb; Common Fruitfly genome has 120 million base-pairs, 120 Mb; Roundworm genome has 97 million base-pairs, 97 Mb.) Only 2% of genetic material in the Human Genome encodes for genes that express Proteins. The other 98% of our genetic material is not yet fully understood and appears to regulate biochemical behaviour, including such effects as ageing. I agree with Dr Briffa that we should not jump to conclusions too quickly. Research into the effects of pharmaceuticals on Humans will yield more meaningful results when it can be correlated to each of our individualised genomes. As computer networks become more able to do the huge number-crunching required, it should become apparent that each person might have his or her own optimal cholesterol level.

  8. amira 9 February 2013 at 9:37 am #

    I read about the bad side effects of Statins so I stopped it for more than a year then the doctor told me to take it again. I took it – Lipitor- for a month then I stopped. I know that I have high cholesterol, high blood pressure and prediabetic. I take tablets for blood pressure and Glocophage only.
    I wonder to go back to the Lipitor or not?
    Doctors are giving us poisons rather than medication! But sometimes we need these poisons to prevent something worse!

  9. Rob 11 February 2013 at 11:40 am #

    I was found to have raised cholesterol levels and put on statins ( I am 65, slim-ish and active) and the effects were horrible: gruesome nightmares and depression the following days. I tried three different types, but they all either gave me sleep disturbances or “the fidgets” like an amphetamine come-down. I decided to abandon them and face the consequences. I have a diet of mostly home-cooked food, balanced between steamed vegetables, meat and fish, eggs and dairy. Nothing to excess. I become more sceptical of “experts” the older I get – they always seem to be moving the goalposts. I’ve decided to listen to my body, rather than them and enjoy whatever time I have.

  10. dieticians 14 February 2013 at 3:50 am #

    Yes, it is really important to take care of our diet especially during our adulthood so we prevent common diseases. Eating healthy foods is actually a habit that should be started from childhood. Hence, parents should inculcate this in the minds and hearts of their children.

  11. Christina Major 5 March 2013 at 3:03 pm #

    Good info. The thing about studies is that they can show you whatever you wish, depending on how you look at the data. Even studies about vitamin C can show you it’s toxic, even though we need it to survive.

    Just eating a diet of fresh fruits and veggies and high quality meats (naturally raised & organic), while dumping processed foods will go a long way to making people healthy. I dropped my cholesterol over 150 points just by eliminating boxed foods.

  12. Leaf Eating Carnivore 15 March 2013 at 6:02 am #

    @Amira: You sound like you have Metabolic Syndrome, which is a function of hyperinsulinaemia, which is caused by eating a diet with more carbohydrates than your body can tolerate – probably exacerbated by PUFAs and Trans Fats.

    I fixed the same issue by going very low carb for life. I eat high fat (sat, mono and omega-3), moderate protein (animal), and less than 40 net (gross – fiber) carbs/day (from nonstarchy vegetables, mostly leafy. Little to no fruit, no grains, no roots, no tubers, NO SUGARS.

    Remember – ALL digestible carbs turn into SUGARS, which raise your blood glucose, which raises you insulin, which can lead to insulin resistance and thence to T2 diabetes.

    Go to http://www.proteinpower.com. Read their books and blogs. Do what they say, and you will probably fix what ails you.

  13. Zack 6 April 2013 at 1:25 pm #

    I think this guy does a great job explaining exactly what is going on with cholesterol in a way the average Joe can understand.

    http://anameyoucantrust.blogspot.com/2013/03/cholesterol-whats-up-with-that.html

  14. Nic 27 May 2013 at 1:17 pm #

    @Sheryl – The FDA cautions that some individuals have suffered from cognitive impairment (memory loss, forgetfulness, confusion) due to statin drugs. So yes, apparently they can affect the brain.

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