What I Think About the French Paradox — As a Nutritional Sciences PhD
The French Paradox is a phenomenon describing why heart disease deaths were lower than would be estimated in the French population during the early 1990s despite a high intake of animal products like butter and cheese. This idea is interesting because these types of foods are classically understood to increase the risk of cardiovascular disease yet this was not what the researchers who coined the term “French Paradox” observed.
Why could this be? Are we wrong about which foods increase heart disease risk? Is there something unique about butter and cheese that prevents heart disease? Is something else in the French diet…like wine, protective? Let’s explore some of these possibilities and take our own jab at figuring out the French paradox.
The original French Paradox
The French Paradox was described in 1993 in a paper indicating that despite having high saturated fat and cholesterol intake, low cardiovascular-related death rates were found in the French population (1). What makes this data paradoxical is that other industrialized countries with similar saturated fat and cholesterol intakes showed higher rates of heart disease deaths.
The authors of the paper analyzed dietary data that was self-reported by study participants (men aged 55–64) meant to be a representation of the French diet from the 1950s-70s. In the analysis, the French data was often compared to Finnish data. Consumption of milk and high-fat dairy products was even higher in Finland than in France. However, vegetable and wine consumption were higher in France. The led the authors to suggest high intakes of wine or vegetables could potentially explain the French paradox.
I want to take a look at this idea and also other ideas that might describe the French Paradox, including those suggesting that the French Paradox was an illegitimate finding from the start.
Vegetable intake could be beneficial by providing dietary fiber, polyphenols, and other bioactive compounds that might protect against heart disease.
However, some of the other countries studied also had very high vegetable intakes which led to a response by other researchers that wine may be a more important variable able to explain the French Paradox (2).
The mechanism by which wine might be protective is multi-factorial. A) Red wine contains many bioactive compounds like resveratrol and B) Wine contains alcohol (ethanol).
Mild to moderate alcohol intake is well understood to improve circulating high-density lipoprotein (HDL) cholesterol (thought to be protective against heart disease). This is because alcohol increases HDL transport from the liver into circulation (3). Once again though, many other countries were probably consuming at least as much alcohol in some form or another.
Resveratrol is more tricky to assess. It’s thought that to get a biologically significant dose of resveratrol you would need to drink at least 500 liters of red wine (4)! This makes the resveratrol argument a bit less convincing. However, wine does contain other types of polyphenols, and it's possible that some of these compounds are more bioavailable than resveratrol or could have stronger biological effects on reducing inflammation or oxidative stress, or by positively impacting fat absorption or metabolism.
Let’s not forget that the French population was consuming a lot of dietary fat. Resveratrol is fat-soluble. It’s possible that consuming wine and cheese together is more effective than consuming wine alone to boost absorption or bio-distribution of resveratrol. However, given the low doses of resveratrol in wine, this is still very unlikely.
Cheese and butter
Ah yes, now this essay is getting ripe. Cheese and butter consumption was certainly very high in the French diet and has also been questioned to have a role in explaining the French Paradox.
The first point I want to make is that cheese consumption in France cannot be compared to cheese consumption in the United States. In the US we consume mostly mass-produced cheeses and “processed cheese products”. These products cannot be compared to French cheeses because the microorganisms used to make the cheeses are different. Legendary French cheeses like soft-ripened cheeses of Normandy, the hard cheeses of the Alps, or the blue cheeses of southern France all have unique microorganisms that affect their nutritional value. Could something about the microorganisms in French cheeses or the compounds they produce be responsible for the French Paradox?
Short-chain fatty acids (SCFA)
Cheese and butter are two dietary sources of SCFA. These are the same SCFA produced by gut microbes after we consume dietary fiber and SCFAs may explain why consuming dietary fiber is beneficial for human health. It’s possible that cheese and dietary fiber could be targeting some of the same biological pathways! SCFA (especially one called butyrate) are now being studied to have positive benefits on metabolic health and obesity (5).
In 2015, a group of researchers tested how cheese consumption influences SCFAs in the gut by feeding 15 healthy young males three types of isocaloric diets containing either low-fat milk, cheese (semi-hard cow’s milk), or butter but no other dairy products (6). Both the cheese and milk diets increased two types of SCFAs (Acetate and propionate) but only cheese increased butyrate.
Ripened and moldy cheeses
Another group of researchers was interested in how ripened cheese consumption may have favorable effects on blood glucose concentrations and liver fat accumulation in mice that were obese and diabetic.
Ripened cheese consumption reduced liver fat accumulation in obese and diabetic mice (7). The same effect WAS NOT seen when mice consumed a non-ripened cheese. Three popular ripened cheeses widely consumed in France are Brie, Camembert, and Roquefort.
Moldy and blue-veined cheeses contain compounds that have anti-bacterial properties. Feeding mice a protein extract from Roquefort cheese reduced inflammation in mice injected with an inflammatory stimulus (8). This is very important because inflammation and heart disease go hand-in-hand.
These data indicate several mechanisms (possibly related) by which consumption of these types of cheeses could reduce the risk of heart disease and improve metabolic health. Cheese is also a dietary factor more unique to France than wine or vegetable consumption.
Was the French diet accurately assessed?
One criticism of the French Paradox is whether the original claims made by the authors linking diet to heart disease risk were accurate.
One group of researchers addressed the work by suggesting a “time-lag” hypothesis and stated that the only reason heart-disease deaths were lower in France when compared to Britain (which had a similar intake of saturated fat and cholesterol) was that the foods high in saturated fat and cholesterol had become popular in France much later and were not in the diet long enough to contribute significantly to heart disease.
This is a nonsensical argument based on what we know about the French diet over the last 150 years. Although it would be an exaggeration to say the French were gorging on butter, cheese, and fatty meats at every meal, these fat sources likely played a large role in their diet compared to vegetable oils and shortenings.
Another way we know these foods were important to the 20th-century French diet is because we see them pop up in French colonial Vietnam during the late 1800s through mid-1900s. Some examples are the popularity of liver pâté, butter, and snails in Vietnamese cuisine (cheese never really caught on).
Other critics argue that the French were under-reporting heart disease deaths in the 1990s but even the author stating this admits that this claim would only partially explain the French Paradox (9).
The state of the French Paradox
Even in 2020, researchers are still trying to figure out the French Paradox with attention turning once again to wine but now with more focus on how wine intake could positively impact the gut microbiome (10).
Interestingly, another study hypothesized that low intake of oxidized cholesterol in the French population could be the major factor behind the French Paradox. This idea makes sense because oxidized cholesterol is a major driver of atherosclerotic plaque formation (11).
In the modern world, rates of heart disease and obesity are increasing in many countries including France as the “western diet” is being exported all over the globe (12).
What was once a Paradox…can no longer be observed. And it’s not just happening in France. Many of the so-called “Blue zones” are losing their significance of having the healthiest and long-lived populations. This is likely due to the increased “Westernization” of traditional diets to include more highly processed food ingredients like vegetable oils and sugar.
Although there has been a lot of push over the last 20 years to improve diet quality in the United States, the prescribed “pseudo-Healthy American Diet” is not living up to its expectations since obesity and prediabetes are now afflicting nearly 50% of adults in 2020 (13).
Perhaps, some may think, if we can just crack the code of the French Paradox and the Blue Zones we can finally figure out the secret to a healthy diet!
Summary and my take on the French Paradox
Michael Pollan is a food writer who I have a great deal of respect for. He addressed the French Paradox in his 2008 book In Defense of Food, where he suggested that the sum of foods eaten together in the French diet might be responsible. I tend to agree with that sentiment; perhaps it was the overall diet and lifestyle habits combined and the factors discussed above are all contributing in some way to the French Paradox?
Of all of the hypotheses discussed, French cheese consumption has the most merit. Time and time again, cheese consumption pops up as being beneficial towards metabolic health and now we have strong supporting mechanisms, like SCFA production.
There were some flaws in the original study that need to be addressed. It would have been interesting if the data in France were stratified by region since French cuisine (and cheese) is very regional. 2013 data show that heart disease is a bit less prevalent in the south of France where more vegetables and Roquefort cheese may be included in the diet.
The type of saturated fat consumed in the original study was also not discriminated for in the author's algorithm. Cheese, beef bourguignon, and vegetable shortening all contain different types of saturated fats with DIFFERENT biological effects. This is an important variable missing from the data and analysis.
Although we don’t have a definitive explanation for the French paradox, it probably involves cheese AND a slew of the other factors discussed. There is still plenty of room for speculation.
One thing that is more certain is that the unhealthy Western pattern of eating is now driving heart disease worldwide. What is the most basic solution? By consuming more REAL FOODS like vegetables, cheese, or even a glass of wine, we can take a step towards having a healthier diet. Cheers and Santé.
Brandon J. Eudy, PhD
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