This is a contribution from a member of THINCS, 
The International Network of Cholesterol Skeptics
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Nov 14, 2003

WHAT PROTECTS THE FRENCH FROM HEART DISEASE?

It's Not What You Think!

However you look at heart disease, those pesky French throw a huge spanner in the works. They should get heart disease, and they don’t, at least they don’t get very much; about one quarter the rate in the USA and UK, despite virtually identical ‘classical’ risk factors. This was first noticed by Hugh Tunstall-Pedoe in 1978. He called it the ‘French Paradox,’ a term that flits in and out of favour.

But what are the French figures exactly? I think they are worth looking at because they are extremely interesting. However, rather than looking at the figures in isolation, I think it is a good idea to compare France with another country, to highlight the almost perfect disparity between the French risk factors and their rate of CHD.

The best country to compare with France directly, is Britain, as these are two countries that have virtually the same population, and GDP, and are geographically very close. This removes a few variables.

The figures I have used come from the British Heart Foundation and the BMJ.

CLASSICAL RISK FACTORS vs. HEART DISEASE
(UK & FRANCE MEN AGED 45 - 64)  

Average total cholesterol level

France 6.1mmol/l
UK 6.2mmol/l

Average HDL ‘good cholesterol’

France 1.3mmol/l
UK 1.3mmol/l

Average systolic blood pressure

France 150mmHg
UK 148mmHg

Average body mass index (BMI)

France 26.6kg/m²
UK 26.6kg/m²

Rate of smoking

France 33%
UK 29%

Consumption of saturated fat % of calories

France 25.7%
UK 27.0%

Rate of type II diabetes (amalgamation of a number of studies)

France ~2.0%
UK ~2.0%

Death rate from CHD ICD 414 classification

France 128/100,000/year
UK 487/100,000/year

Now that’s what I call a paradox.

In truth, I don’t call it a paradox at all. Because a paradox is an apparently inexplicable finding for which there really is an explanation - if only we could find it. This is akin to the wobble in the orbit of Neptune, inexplicable until it was realised that there was another planet out there.

But if you don’t believe that the classical risk factors are that important in CHD, then you aren’t looking at a Paradox at all. What you are looking at is proof that the generally accepted risk factors can only play a minor part in causing CHD. As Magritte would say ‘ce n’est pas un paradox.’

RATE OF DEATH FROM CHD MEN
AGED 45 - 64 (France vs UK)

However, so deeply ingrained is the belief in classical risk factors that this apparently contradictory evidence had to be explained away; a reason for the low rate of CHD in France had to be found, one that did not damage the current orthodoxy.

You may ask why, when confronted with these two choices, the preferred option was to look for a French protective factor, rather than a UK ‘killing’ factor? There are two or three interconnected reasons. But the main one is that the British rate of CHD is roughly what you might expect from their level of risk factors, in relation to other countries - give or take a hundred per-cent or so either way. But the French rate stands out like a sore thumb. It is a country with a high level of risk factors, and a very low rate of CHD. Sixty million living, breathing, contradictions.

And so, confronted with these facts, a desperate scramble began to find out what was protecting the French. What do the French do, it was asked, that is different from the British? Well, of course, they drink lots of red wine, eat lots of garlic and lightly cook their vegetables (thus retaining essential anti-oxidants). And by a remarkable coincidence, these three things were then found to be protective against CHD. Or were they?

For, if you search the literature closely, four things emerge

1.      Alcohol does protect against CHD

2.      Red wine provides no more protection than any other form of alcohol

3.      Garlic does not protect against CHD

4.      Anti-oxidants do not protect against CHD

This has never stopped people claiming that these three factors are protective. But if you look at the data closely, the evidence vanishes into thin air.

I’m not going into the studies here in any detail, but I would lay a small challenge to anyone who doubts that what I am saying is true. If you can find one single study that has demonstrated a significant reduction in CHD mortality that is attributable to garlic, anti-oxidants or red-wine consumption (rather than any other form of alcohol), then I will admit that I got this seriously wrong. But I think you’re going to have to search hard, because I looked at study after study and could find nothing.

One caution, you will find plenty of evidence clearly demonstrating that these three factors definitely have an impact on risk factors in the blood, such as LDL and HDL levels, and these data have been extrapolated to make the claim that they are truly protective. But a positive impact on ‘surrogate’ markers in the blood does not mean a reduction in mortality.

To use an example in the same area, hormone replacement therapy (HRT) was claimed to reduce the rate of CHD, primarily because it raised ‘good’ HDL levels. This became far more than just a hypothesis, it became accepted medical orthodoxy, and millions of women were prescribed HRT for this very reason. Until the clinical trials were carried out, which have all clearly demonstrated that HRT increases the risk of death from CHD - despite raising HDL levels. (Which should tell you something very important about the currently accepted risk factors, but I’m not going down that route this time.

Moving back to the French ‘protective’ factors for a moment. Look, for example, at Garlic. The main reason why it is supposed to protect against CHD is because it lowers cholesterol levels. But the average cholesterol level in the UK and France is identical. So, how does garlic protect against CHD? By lowering cholesterol levels you fool. But I thought you said the average cholesterol level in the UK and France was the same. Repeat these sentences until reduced to a gibbering wreck.

The basic fact is that, when you look at the ‘supposed’ French protective factors in any detail, you can find all sorts of evidence that they have a beneficial effect on risk factors in the blood. Paper after paper, enough to stretch to the moon and back. However, what you will not find amongst this endless stream of data is any evidence of reduced mortality or morbidity. Which is kind of important.

In short, when you cut through all the hype, there are no such things as French ‘protective factors’, which means that there is no explanation for the 400% difference in the rate of CHD between the UK and France. A bit of a gaping hole, I would vouchsafe. One that has not yet been filled.

Mind you, on the surface, the theory that social dislocation causes CHD doesn’t explain the low rate of CHD in France either. The total number of immigrants living in the UK and France is almost identical. About four million in each country, both of which have a population of nearly sixty million.

Internal migration, from region to region, is also very similar. And when it comes to general stress, the French take far more anxiolytics (anti-anxiety drugs) than the British. Whether or not this means anything much, other than a cultural phenomenon whereby the French are keener on taking drugs, is open to debate.

Overall, however, there appears to be nothing at all to explain the low rate of French heart disease, either within the classical risk factors, or the emigration/social dislocation model. Or is there?

Here is where I return to a thought that I had twenty years ago, and which triggered my lifelong interest in heart disease. I was at a meeting where a study was presented which showed that rabbits who were fed in a less stressed fashion - by a technician who liked rabbits; had less arterial disease than rabbits fed by another technician - who didn’t think much about rabbits one way or another.

Aha, I thought, so unstressed eating may protect against CHD? If this is also true of humans, I speculated, then populations where eating is an important part of family life should have a low rate of heart disease; on the other hand fast food cultures will have a high rate of CHD. A bit of a leap I admit, but an interesting thought to pursue?

So, I looked around the world at eating habits, and ended up focussing on France. If one thing above all stands out about French culture, in relation to British culture, it is their attitude to food and eating. The average Brit treats meals as a refuelling exercise, the French, most clearly, do not. They spend hours eating meals, relaxing, enjoying the food. It is a social occasion.

I began to wonder it were really possible that the French way of eating protects them against CHD? If so, how? What is the biological explanation? And can this possibly be related to emigration/social dislocation and stress.

I won’t bore you with the entire journey, but it comes down to this. From a metabolic perspective the body is either in an anabolic state: eating, digesting and storing food; or it is a catabolic state: rushing about, using up energy.

The hormones that switch on catabolism are the stress hormones: adrenaline, growth hormone, glucagon and cortisol. The hormone that switches on anabolism is insulin; and insulin and the stress hormones are direct antagonists in many organs. Insulin switches off sugar production in the liver, stress hormones switch it on. Insulin makes fat and muscle cells absorb sugars and fats. The stress hormones do the opposite.

It is apparent, therefore, that if you eat whilst under stress you will be in a conflicting state of raised insulin levels, and insulin resistance. Just to look at what happens in this state to the simplest metabolic substance, sugar.

When you eat sugar, it is rapidly absorbed, the level in the bloodstream rises, and insulin is released, causing the blood sugar level to drop. But if you are stressed, glucagon and cortisol will be trying to drive the sugar level up. In this situation, what can the metabolic system do? It will keep on cranking up the insulin levels to overcome the resistance to insulin, however, in most cases this is still not sufficient to overcome the resistance.

So what you will see in a person eating sugar whilst stressed is a combination of three things:

1.      A raised level of stress hormones

2.      A raised level of insulin

3.      A raised blood sugar level

All of these things damage the endothelium. Raised stress hormones also increase blood coagulability. In addition, hyperglycaemia induces a state of oxidative stress (release of free radicals) which stimulates platelets to stick together, which also creates oxidised LDL - both of which further promote thrombus formation

Thus, eating under stress creates the exact metabolic state, pro-coagulant state, that leads to endothelial damage and thrombus formation. I believe that this damage is the underlying cause of atherosclerotic plaques and premature death from heart disease.

Any proof of this? Well, the truth is out there.

Just to look at two studies. In the first study healthy volunteers were given stress hormones in levels designed to mimic post-aggression metabolism (PAM). This is a metabolic state that occurs when the body is damaged through some form of ‘aggression,’ a road traffic accident, surgery etc.

In this study, in those given the stress hormones, insulin sensitivity was reduced by 88% (A state of severe insulin resistance). And when they were given a glucose infusion, insulin and sugar levels sky-rocketed Heise T Metabolism Oct 1998

1.      The peak insulin level was 352 pmol/l vs 110pmol (or, approximately three times as high as in controls))

2.      The peak sugar level was 19.7mmol/l vs 7.2mmol/l (or, approximately three times as high)

So, it is clear that a high level of stress, and stress hormones, in conjunction with food, creates exactly the metabolic state that triggers atherosclerotic plaque development.

But can transient mental stress, rather than the physical stress of the post-aggression state, also cause insulin resistance. Indeed, it can.

‘It is concluded that acute mental stress induces a state of insulin resistance in IDDM patients, which can be demonstrated by an IGIT (insulin, glucose infusion test) to appear 1 h after maximal stress and to last more than 5 h.’ Moberg E Diabetologia Mar 1994

In short, both mental and physical stress can induce a state of insulin resistance, resulting in a form of transient syndrome X. So it becomes very clear that the basic mechanism by which eating under stress causes CHD is exactly the same as the state induced by emigration/social dislocation. The only difference is that eating under stress is a transient state, non-detectable when fasting, which is, as you may well have noted, when the vast majority of tests are carried out. So it is not surprising that no-one has spotted this yet.

Anyway, to return to the question posed in the title of this article. What protects the French? I think it is clear that they are protected not by what they eat, but by how they eat. By eating in a relaxed fashion they do not pit the system of anabolism and catabolism against each other, they do not trigger insulin resistance, and hyperglycaemic spikes, and therefore they do not damage the endothelium in the prandial/post-prandial state. Vive la France!

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