23 September 2019

Lead again

I am returning to lead, the heavy metal. Not the verb to lead, or a noun – such as a dog lead. Yes, English is complicated, with the same word meaning several different things, which can lead to confusion.

I am indebted to Leon Vd Berg for bringing my attention to another paper about lead that I had missed. Which is slightly surprising as I tend to look for such papers. However, such is the daily avalanche of medical publications that it is literally, impossible to keep up.

There are several things about the paper that I found fascinating. However, the first thing that I noticed was that…. it hadn’t been noticed. It slipped by in a virtual media blackout. It was published in 2018, and I heard nothing.

This is in direct contrast to almost anything published about diet. We are literally bombarded with stories about red meat causing cancer and sausages causing cancer and heart disease, and veganism being protective against heart disease and cancer, and on and on. Dietary articles often end up on the front page on national newspapers.

Here is one such headline from the Daily Mail 7th August 2019

‘Eating chicken instead of steak, lamb or sausages 'slashes a woman's risk of developing breast cancer by 28%'

Mind you, here is another headline from the Daily Mail 8th Sept 2019

Chicken 'causes cancer': Oxford University scientists say people who eat poultry are at increased risk of developing deadly disease.’

Tricky thing eating chicken. It can cause and prevent cancer simultaneously. You read it here first.

However, the point I wish to make is not so much the utter nonsense and constant contradictions of dietary studies. Nor is it the fact that the increased, and decreased risk in such studies, is minute. Sitting well within the boundaries of reasonable chance. Which is why you keep getting contradictory studies.

Researcher one:      ‘I just threw a head – all throws of a coin must be heads.’

Researcher two:       ‘No, sorry, I just threw two tails – most throws of a coin end up tails

Researcher one:      ‘Hold on, forget your tails, I just go four more heads – in a row – most throws end up heads, not tails.’

The correct term for this is idiot research, and those who do it are – primarily – idiots. However, none of this nonsense is really important. The point I am trying to make here is that this type of dietary research hogs the limelight.

It seems that whatever else Ancel Keys did not achieve – scientific truth and accuracy, for starters – he most certainly did manage to convince almost everyone in the World that diet is the single most critical important factor for health.

In years gone by, people ate food because they enjoyed eating it. This still happens in France. Imagine that. Nowadays every meal comes with implied fearmongering, and high-level criticism. Are you destroying the world or not – you evil scum.

‘Hold on, it’s only a bacon sandwich. With a fried egg and a bit of cheese grated on top…. Yes, I suppose you’re right, I am personally responsible for the destruction of the Amazonian rain forest. Forgive me father, for I have sinned.’

Destruction of the planet is only one aspect of eating, it’s also destruction of your health – with added moral judgement. If you go to Slimming World, you can eat various tasteless stuff, but you are allowed ‘sins.’ A sin would be something you really like eating, but it is so deadly, that it is a sin to eat it. Chocolate, for example. Get thee behind me Satan.

I don’t understand how anyone manages to eat anything nowadays. I have almost given up eating salads because someone will always remark ‘Oooooh, that’s healthy.’

My reply used to be. ‘I am not eating it because it is healthy, I am eating it, because I enjoy it.’ Nowadays I just grunt in a vaguely non-threatening way. I do not say. ‘No, a healthy meal would be a full English breakfast with bacon, eggs, sausages, fried bread. a few more sausages and a bit of lard melted on top.

I do not say this because, in truth, almost all diets are perfectly healthy. Vegetarian, paleo, keto, vegan (with a few essentially nutrients thrown in, so you don’t die), HFLC, etc. In fact, the only non-healthy diet would be the one recommended by all the experts around the world.

Namely, High carb, low fat (HCLF). The ‘eat well plate’, ‘the food pyramid’ – whatever it is now called. Stay away from that, and you will be fine.

Rule one of diet.       Everything the ‘experts’ recommend, is wrong.

Rule two:                   Eat food you enjoy – and enjoy eating

Rule three:                Eat food that looks like food

Rule four:                   Cook your own meals – when possible

Rule five:                   Try fasting from time to time

Rule six:                     That’s it

Where was I? Oh yes, lead. The heavy metal. The thing that, unlike diet, makes no headlines whatsoever, the thing that everyone ignores. Here is one top-line fact from that study on lead, that I missed:

‘Our findings suggest that, of 2·3 million deaths every year in the USA, about 400 000 are attributable to lead exposure, an estimate that is about ten times larger than the current one.1

Yes, according to this study, one in six deaths is due to lead exposure. I shall repeat that. One in six. Eighteen per cent to be exact, which is nearer a fifth really.

Of course, this study is observational, with all the usual caveats associated with such studies. Indeed, many people commenting on this blog have stated that correlation [found in such studies] does not mean causation. I think you will find that this does not include me – although I may have said it by mistake. It is true that correlation does not mean causation, up to a point. However, once that point has been reached, causation can be considered proven.

For example, in observational studies, smokers were found to have fifteen times the risk of lung cancer. That is a powerful enough correlation to prove causation – beyond any reasonable doubt. There is no point in setting up a controlled clinical trial to prove this. In fact, any such trial would be completely unethical.

The question is, at what level of increased risk/correlation can causality be accepted. There is no absolute clear-cut answer to this Life ain’t black and white. However, most epidemiologists will tell you that unless the odds ratio (OR) is above two, you cannot attempt to claim causality. Too much noise, too many possible confounders.

Which means (deep breath, waiting for statisticians to attack this mercilessly) you need to find that a ‘factor’ is associated with at least a doubling of risk, before you do not simply crumple up the published paper and throw it in the bin.

Most dietary studies get absolutely nowhere near two. We have risks such as one point one (1.10), or one point three. One point three (1.3) is a thirty per-cent increase in risk. Here for instance is a review of red meat and colo-rectal cancer

‘As a summary, it seems that red and processed meats significantly but moderately increase CRC risk by 20-30% according to these meta-analyses.’  2

Figures like this, from an observational study, mean only one thing. Crumple, throw, bin. Remember also, they are only looking at one form of disease colo-rectal cancer (CRC).  The impact on overall mortality (the risk of dying of anything) would be minuscule, if it could even be found to exist at all. Of course, overall mortality is not mentioned in that CRC paper. Negative findings never are.

So, on one side, we have papers (that make headlines around the world) shouting about the risk of red meat and cancer. Yet the association is observational, tiny, and would almost certainly disappear in a randomised controlled trial, and thus mean nothing.

On the other we have a substance that could be responsible for one sixth of all deaths, the vast majority of those CVD deaths. The odds ratio, highest vs lowest lead exposure, by the way, depending on age and other factors, was a maximum of 5.30 [unadjusted].

Another study in the US found the following

‘Cumulative lead exposure, as reflected by bone lead, and cardiovascular events have been studied in the Veterans’ Normative Aging Study, a longitudinal study among community-based male veterans in the greater Boston area enrolled in 1963. Patients had a single measurement of tibial and patellar bone lead between 1991 and 1999. The HR for ischemic heart disease mortality comparing patellar lead >35 to <22 μg/g was 8.37 (95% CI: 1.29 to 54.4).’ 3

HR = Hazard Ratio, which is similar, if not the same to OR = Odds Ratio. A Hazard Ratio of 8.37, means (essentially) a 737% increase in risk (Relative Risk).

Anyway, I shall repeat that finding a bit more loudly. A higher level of lead in the body leads to a seven hundred and thirty-seven per cent increase in death from heart disease. This is, in my opinion, correlation proving causation.

Looking at this from another angle, it is true that smoking causes a much greater risk of lung cancer (and a lesser but significant increase in CVD), but not everyone smokes. Therefore, the overall damage to health from smoking is far less than the damage caused by lead toxicity.

Yet no-one seems remotely interested. Which is, in itself, very interesting.

It is true that most Governments have made efforts to reduce lead exposure. Levels of lead in the children dropped five-fold between the mid-sixties and the late nineties. 4 Indeed, once the oil industry stopped blowing six hundred thousand tons of lead into the atmosphere from vehicle exhausts things further improved. Lead has also been removed from water pipes, paint, and suchlike.

However, it takes a long old time from lead to be removed from the human body. It usually lingers for a lifetime. Equally, trying to get rid of lead is not easy, that’s for sure. Having said this, chelation therapy has been tried, and does seem to work.

‘On November 4, 2012, the TACT (Trial to Assess Chelation Therapy) investigators reported publicly the first large, randomized, placebo-controlled trial evidence that edetate disodium (disodium ethylenediaminetetraacetic acid) chelation therapy significantly reduced cardiac events in stable post–myocardial infarction (MI) patients. These results were so unexpected that many in the cardiology community greeted the report initially with either skepticism (it is probably wrong) or outright disbelief (it is definitely wrong).3

Cardiologists, it seems from the above quotes, know almost nothing about the subject in which they claim to be experts. Just try mentioning glycocalyx to them… ‘the what?

Apart from a few brave souls battling to remove lead from the body, widely derided and dismissed by the mainstream world of cardiology, nothing else is done. Nothing at all. We spend trillions on cholesterol lowering, and trillions on blood pressure lowering, and more trillions on diet. On the other hand, we do nothing active to try and change a risk factor that kicks all the others – in terms of numbers killed - into touch.

Funny old world. Is it not?

Next time, back to diet, because everyone knows how important diet is…. Only joking.

1: https://www.thelancet.com/journals/lanpub/article/PIIS2468-2667(18)...

2: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4698595/

3: https://www.sciencedirect.com/science/article/pii/S0735109716015989

4: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1240871/pdf/ehp0110-00...