What does cause heart disease?

(Part one of an occasional series)

So what does cause heart disease then, if it is not cholesterol?  This is question I am often asked – with varying degrees of accusation – by other doctors. Usually after I’ve given a talk dismissing raised cholesterol as a risk factor.

The simplest answer is that the most important causal factor of cardiovascular disease aka the development of plaques (thickenings) in the arteries, is stress (sorry about that rather clumsy form of words). However, as with many simple answers, explaining how stress causes ‘heart disease’ is a bit more complicated.

Which means, gentle reader, that we must go back to the beginning of the whole story, and weave a number of interconnected strands together.

The first strand here is to explain what ‘stress’ may be. I must admit that this is not easy, because few people have an agreed definition of stress. Many concepts are bandied about, and everyone has their own ideas on the subject, but most of them are rather too vague to be of any real use.

I define stress as a measurable dysfunction in the Hypothalamic-Pituitary-Adrenal axis (HPA-axis). But that may be jumping ahead rather too fast, and it requires many steps to get to this point. The first step is to attempt to break stress down into its component parts.

To do this, we have to start by accepting that stress has two basic components. There is the Stressor – the thing causing stress, and the Stressee – the individual affected by the stressor. Without making this important distinction, we will constantly mix up two concepts that need to be kept separate.

For example, many people talk about having a stressful day. I would immediately ask. Does this mean you were impacted on by lots of different stressors e.g. a traffic jam, a tight work deadline, your children getting ill. Or that you found yourself unable to cope with stressors that you would normally be able to cope with. Or both. [To be truthful I would rarely ask this, as I don’t want people shuffling away from me at the dinner table. But I might think it].

By looking at stress as having a cause, or causes, (the stressor), and then looking at their impact upon an individual (the stressee) we can start to disentangle the things that cause stress, from their actual impact.

In addition to this important distinction, there is also a need to accept that different stressors can create positive or negative effects, depending on how the person reacts to them.  Without getting too tangled in this issue, I will attempt put these first ideas into their simplest possible form

Stress has four distinct components:

  • Stressor – positive
  • Stressor – negative
  • Stressee reaction – positive
  • Stressee reaction –negative

Positive stressors could be:

  • Exercise
  • Winning the lottery
  • Giving a well-accepted speech
  • Watching your children perform on stage

Negative stressors could be:

  • Using cocaine
  • A close relative dying
  • Severe criticism at work/being bullied
  • Getting hit by a bus
  • Watching your army comrades being blown to bits by an IED

Some negative stressors are very short acting and, as such, the human psyche and physiology can cope and restore homeostasis (unless the trauma is gigantic). The problems start to arise when negative stressors act hour after hour, day after day, week after week. For example, being repeatedly physically or sexually abused as a child. Or being bullied day after day at work.

Problems created by a constant battering of negative stressors are also made significantly worse if your coping mechanisms are poor. Being bullied at work is not so bad if you have a good social life, a supportive partner, and a loving family. It also helps significantly if you are physically, fit and free from significant chronic disease.

If, however, you have no friends, no supportive family, and you have a chronic illness that weakens you, it does not take too much else to tip your system over the edge.

Unfortunately, early life trauma, and abuse, can leave people with very poor coping mechanisms. In addition, people who have suffered repeated negative stressors through their childhood often find themselves in a cycle of repeating negative behaviour. They are also likely to have poor coping skills, and difficulty with interpersonal relationships.

Effectively, therefore, the same ‘stressor’ can have very different effects on people, depending on their resilience. This resilience can be both psychologically and physically determined, and is hugely important. A ‘strong’ person can cope with stressors that might seriously damage a ‘weak’ person.

Some people say that stress can be simplified into the flight or fight response being constantly activated and eventually ‘burning’ out. Whilst it is true that a constantly stimulated flight or fight response is key to understanding the physiological damage that ‘stress’ causes, it is not the only factor in play.

A lack of social support is not the same thing as the flight or fight response. However, it can create significant problems with production of stress hormones. Depression is not the flight of fight response going wrong. Not having human contact, or touch, can damage your hormonal and autonomic/unconscious nervous systems just as much as being bullied.

In short, stress is not just determined by external factors, such as perceived – or real – threat. A vastly important aspect of stress lies within the individual, their responses to life events, and their resilience. As social animals, loneliness is just as damaging, if not more so, than someone threatening to fire you.

In my world, therefore, being depressed is a form of ‘stress’, and it causes exactly the same type of physiological damage as, say, post-traumatic  stress disorder. This is why you cannot look at an event in someone’s life e.g.  losing their job, or getting divorced, or suffering a car crash and loss of a limb, and score this from one to ten on how stressful this is.

  • Loss of job =2
  • Moving house = 3
  • Getting divorced = 4

For some people losing a job may be a blessed relief. For other a terrible humiliating shame. Others may just shrug their shoulders and move on.

For some of us, an apparently trivial event can be devastating e.g. a passing comment on our appearance.  Others will just laugh it off. Some years ago I was told by a doctor that stress couldn’t be a cause of heart disease because he had seen a well-off lady living in rose covered cottage in the country who had just had a heart attack.

I just replied ‘How do you know she wasn’t stressed?’ The externally idyllic existence may, in reality, be a battleground. Perhaps her smiling, smart, well-off, magistrate husband got home and beat the living daylights out of her every weekend. If so, it wouldn’t be the first time – and most certainly would not be the last.

In short, there is no point in guessing if someone is stressed. Often, there is no point asking them either. Most of us play complex internal games with regard to stress. Where it is considered a badge of honour to be ‘stressed’ and working incredibly hard – people will tell you how stressed they are. – even if they are not. Equally, if you have had a terrible upbringing, you may be so desensitised to stress that you cannot even recognise that you are suffering.

At this point I should probably attempt to bring together what makes up the concept of ‘stress’

Stress consists of stressors, and the stressee. Stressors can be positive, or negative. They can be psychological, or physical.

The same stressor can have a completely different impact on the stressee depending on their resilience.

Resilience can be damaged by such factors as:

  • Abuse in childhood
  • Long-term illness
  • A lock of supportive relationships, friends, family, church

Resilience will be improved by

  • A loving upbringing
  • Good health
  • Supportive relationships
  • Good interpersonal skills

There is no point in guessing is someone is suffering the physiological consequences of stress. Equally, there is no point in asking someone if they are stressed – they may well not know. The only way to know if someone is actually suffering from the consequences of repeated negative stressors is to measure their biochemistry and physiology.

Part two: How to measure if a person is ‘stressed’.

28 thoughts on “What does cause heart disease?

  1. Maureen Berry

    Dr Kendrick, can I ask if you have any thoughts / opinions on Magnesium and Iodine supplementation? I know this is somewhat off topic, but I respect your opinion and would be interested to know if you have looked at these minerals at all.

    1. Dr. Malcolm Kendrick Post author

      I have looked at minerals and supplementation. To the point where I am working with a company producing a supplement. It contains magnesium, as a deficiency in magnesium is a clear risk factor for CVD. It also contains, potassium, l-arginine, coenzyme Q 10 etc. I think that keeping up the levels of vital nutrients is important. I am most interested in l-arginine and its impact on NO synthesis. I know nothing about iodine. I think that a body lacking essential nutrients is less likely to cope with stressors – or whatever form

  2. axelle

    Very interesting, Thank you. I have some questions: could a poor diet low in the essential nutrients that we are all suppose to feed our body’s cells / blood / muscles / bones / brain… in order to keep the ‘machine’ up and running optimally constitute of a stress? Serious stress caused by nutritional deficiencies? And therefore be a stress contributing to heart disease? Could also a intake of those essential nutrients (either via food or supplements) be preventive to heart disease? Thank you.

  3. dearieme

    But if it’s stress, why did rates of heart disease go up for several decades, peak somewhere around the 60s-70s, and then go down for several decades?

    As I understand it, these figures can’t be explained by smoking, or the age distribution of the population, or changes in diet. It’s not obvious that they can be explained by changes in stress either.

    1. Chain Reaction

      Are you talking death rates or incidence of the condition? Treatments have advanced, and around what period was it that Ambulance crews were elevated to the status of paramedics with defibrillators carried on board? The techniques of the first responders have improved greatly which means arrests result in fewer fatalities perhaps?

      1. dearieme

        Incidence. There’s no sign that the decline has anything to do with medics, though that doesn’t stop some of them trying to claim credit. None of them claim blame for the earlier increase. Those who think the whole phenomenon is to do with infection take encouragement from the recent discovery of the dependence of lower back pain on infection.

  4. dearieme

    By the way, I don’t think it’s logically incumbent on you to provide an answer to what causes heart disease; showing that it ain’t cholesterol is a perfectly fine feat in itself.

  5. Sue Richardson

    Another breath of common sense and sound advice. I wish you lived round the corner and were my best friend Dr K! The trouble with stress if even if you knew you were suffering from it and why, sometimes there is nothing you can do about it. It’s absolutely true that medication is no substitute for friends and a loving family, but you can’t manufacture these two ‘commodities’ out of thin air, so it’s difficult to find an answer that ‘fits all’.

  6. Chain Reaction

    I think the minerals issue is a valid point. Our soils used to be much richer in organic matter. This locked a lot of carbon into the soils. Craig Sams founded Green & Blacks, was an early proponent of Fair Trade, ties with the Soil Assoc. and campaigns on many things green. Craig suggests this loss of carbon from soils has been the prominent contribution to GHGs over the last century. That aside.
    Soils rich in organic matter are rich in biodiversity and the king in this domain is the earthworm. Earthworm casts are rich in a gelatinous something-or-other that promotes field capacity. High field capacity basically means the soils receives and retains precipitation better, as a better sponge might. The rain brings dust from the atmosphere and some of that dust arrived from space. The dust seeds the raindrops that fall from the clouds. So every raindrop has some dust. I’d guess there is a mineral cycle at work in this, that the vital trace elements find there way into soils via this cycle.
    If the soil is intensively farmed, is low in organic matter, and has low field capacity there will be a lot of run-off, of water and minerals. Intensive NPK agriculture may be low in the trace minerals, I dunno. Certainly Sir Julian Rose and Peter Kindersley think intensively farmed produce may not compare with organically farmed.
    There is a clue. BIochar added to soils (terra pretas) greatly elevates the fertility and it looks to be something to do with mineral retention and availability.
    If anyone has time on their hands it is a worthy line of enquiry to investigate. I’m occupied with something else

    1. Maria Prince

      I live in rural South Island of NZ, where sheep, beef and dairy farming dominate society (not necessarily the economy). Most farmers around us use manufactured fertilisers and pesticides but I have met farm consultants/soil scientists that advocate holistic farming practices like feeding the soil with naturally occurring compost/mulch – but using scientific methods, to improve soil quality because it has a huge improvement on cow health and milk yields. It could be that what is good for the cow is also good for people.

      Incidentally, I’ve just started taking a magnesium/selenium supplement (NZ soils are supposedly low in both). I would swear that I am calmer and I don’t react to the day to day stressors of balancing work and family life as I did a month ago.

      1. Dr. Malcolm Kendrick Post author

        I am becoming increasingly convinced that intensive farming techniques (whilst allowing many more billions to live free from starvation) a reducing vitamins and minerals and various other nutrients from out diet. I am more and more warming to the idea of supplementation.

      1. Chain Reaction

        “.. .. intensive farming techniques (whilst allowing many more billions to live free from starvation) .. ..”

        I haven’t had time to be entirely empirical about this – but there is line of thought that intensive agriculture doesn’t elevate yield especially, what it does is restore yields from where they would have been before soils became depleted of their natural levels of fertility when they were rich in organic matter and field capacity arising from healthy and diverse soil culture and ecology. In his book, ‘Harmony’, HRH Prince Charles is keen to make this point with his co-authors Tony Juniper and Ian Skelly.
        If HRHs point is true, that intensive farming only compensates for a loss of former fertility and yields, then the narrative that intensive farming is necessary to prevent starvation is as fictional as the idea that saturated fat and cholesterol cause heart disease. Fictional narratives support fictional markets which generate very real incomes and profits, but do so as part of bipolar arrangement whereby the profits are privatised while the risks are accumulated and ‘socialised.’
        The soil culture, as would be deemed a natural phenomenon and eventuality, could well work as a mineral elevator via which minerals are assimilated into, and converted to, suitably bio-available biochemical species that plants, animals, and we can utilise. I do not know if the mineral elevator idea is a valid one, but I do know if it were then intensive agriculture and dressing by NPK results in a comparatively sterile and inert environment in which such a natural phenomenon could not reside.
        Intensively farmed produce is acknowledged for being less hardy or less disease resistant that organic counter-parts, and news has travelled that the plants are lower in poly-phenols.
        Plenty of food for thought, I think.

  7. George @ the High Fat Hep C Diet

    Particulates from air pollution and smoking are possible causes of atherosclerosis and may explain why it is found in ancient mummies, as ancient fires were not well-ventilated.
    There was also a greater exposure to industrial chemicals to and OTC and prescription medicines with cardiotoxic effects in past generations. Many of these are probably still unidentified. When lead was in petrol this may have played a role.
    A chemical such as a food additive or pesticide will be tested for mutagenic and carcinogenic effects but it will not, and cannot easily, be tested for cardiotoxic effects unless these become suspected for some reason.

  8. steve whitaker

    I also think that certain foods, and not all the ones that everyone suspects(high fat, salt added etc), may also contribute to heart/artery disease, for instance I read a report on many(nearly 30 I think from memory) studies that looked at different types of coffee and the way they were brewed, and the effect it had on the serum lipid levels.

    They found that “french press”, a cafateire to you and me, of coffee in decent levels of quantity(I think it was about 10 cups a day) increased the blood lipid levels of ldl.

    now to me that isn’t the ldl causing heart disease as I believe the ldl is there doing its job to try and fix a problem, i.e. irritation/inflammation in the artery walls somewhere, which has been caused by karwenol/cafestol (?) in the coffee, i.e. chemical damage that needs repairing.

    I also believe as creatures of habit/addiction, that a process of such, drinking loads of cafetiere coffee each day would eventually lead to a build up of plaque in the artery walls, esp when you coupled it with the damage we are doing to ourselves with all those processed carbs, omega-6 oils that most commercial fried food is cooked in nowadays etc.

    putting all those habits together, long term, I believe it leads to chronic heart disease, and the more I read “studies” and the reports on such studies all seem to be pointing to the same thing, processed foods, sugar, too much omega-6, and loads of other foods we ingest that are the real cause of heart disease, not blood lipids, its just conflicted doctors eminating usually(saturate fat is killing you) from the US wont accept that it might be the case, for obvious reasons, as well as UK governments and the majority(no, not you Dr.Kendrick) of doctors in the UK.

    I do hope one day it changes, and we all get back to eating real food in the right quantaties, and de-stress our lives so we can be allowed to die naturally.


  9. steve whitaker

    The paper only talks about “deaths” from CHD, not incidence, which I read as people are surviving heart attacks/strokes whereas they would have died in 1970 from the same heart attack/stroke, i.e. medical intervention is keeping them alive nowadays.

    It would be interesting to see what the numbers look like for incidence of MI/Stroke since the beginning of record taking, as I suspect that that figure is on the rise somewhat, and will continue to do so as the levels of obesity increase over the years, which surely is a known large risk factor.

    Stroke for example, is happening in younger and younger patients, and is no longer an “old persons” problem, they are common in early 40 year olds nowadays, and younger! shocking and devastating to the person suffering it, carer or patient.

    I’m sure the WHO will have the data, if anyone cares to crunch the numbers if you have access to them and know how to use them?

    I think Zoe Harcombe has written about this before,



  10. Arie Brand

    Malcolm, have you got any views on the so-called Pauling-Rath unified theory of heart disease? As you know Pauling believed that the basic cause of heart disease was “a chronic, sub-clinical vitamin C deficiency — due to a missing liver enzyme caused by the ancient GULO genetic defect in primate DNA”. The formation of plaque was to him basically a repair mechanism for arteries weakened by this vitamin C deficiency and not coping adequately with the pump action of the heart. The basic element in plaque he took to be Lp(a). Lysine binds Lp(a). So the therapy is to increase the intake of vitamin C to strengthen the arteries and to take lysine (plus proline and arginine) at the same time to prevent the formation of plaque.

    I do not know of any attempt to seriously test this theory and it seems that thus far its defenders can only point to anecdotal evidence.

  11. mikecsmith

    I’ve been retired for nearly two years and during that time have given to research stress, brain and body foods. From my research it seems to me that we in the western world tend to eat far to much carbohydrate, this imbalance being responsible for increased levels of diabetes, Alzheimers, heart disease and strokes


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