by Ron Brown, Ph.D., author of The Body Fat Guide
"Ron Brown is a certified fitness trainer who doesn't have an inch of flab on his body. He'll tell you what you can do to become fit and trim too."
TALK TO AMERICA, Washington DC
THE FRENCH POPULATION consumes as much saturated fat and cholesterol as populations in other Western nations, but France has the least prevalence of cardiovascular disease among studied Western nations (Artaud-Wild et al., 1993). To explain this phenomenon, called the French paradox, researchers have investigated cardioprotective properties of resveratrol in red wine that is consumed in large quantities by the French, but no epidemiological studies support the red wine hypothesis throughout Europe (Opie & Lecour, 2007; Semba et al., 2014). The search to identify additional cardioprotective factors in the French diet that may apply to other countries has recently examined other food items like traditional cheeses (Petyaev & Bashmako, 2012). Cheese and dairy products that are high in saturated fat and cholesterol are often consumed raw in the traditional French diet, without pasteurization. This article presents a brief literature review to explore whether cardioprotective effects exist in raw versus pasteurized dairy consumption. This article also introduces a hypothesis which proposes that raw dairy consumption is associated with the French paradox, and the article recommends further epidemiological studies to investigate a possible association in other countries.
Cholesterol Oxidation Products
Epidemiologists first identified the French paradox in the 1980s when the French population’s fat intake was just under 40% of calories (Ferriere, 2003). Since that time, efforts have been made to reduce saturated fat intake in Western nations in order to reduce coronary heart disease rates. However, several meta-analyses that specifically focused on dietary saturated fat intake found no association with saturated fat and cardiovascular disease (Chowdhury et al., 2014; Siri-Tarin et al., 2010). Based on these findings, dietary cholesterol may be a more likely causative factor that increases risk for cardiovascular disease.
Research has shown that cholesterol undergoes chemical changes in thermally treated animal-based food like dairy products, which generates harmful cholesterol oxidation products or COPs (Hur, Park, & Joo, 2007). These oxidized cholesterol products have been found to damage arteries in the cardiovascular system much more than natural, unprocessed cholesterol. The most common oxidized cholesterol product found in heat-treated animal-based food is 7-ketocholesterol. Total COPs may account for between 1–10% or more of the cholesterol in heat-treated or processed animal-based food. Because saturated fat is naturally present in animal-based foods, and because these foods contain artery-damaging COPs when heated, this could explain why saturated fat has been mistakenly linked with causing cardiovascular disease. In other words, saturated fat in heated animal-based food may be only an indicator of dietary cholesterol and harmful COPs. Because saturated fat consists of single carbon bonds only and no double bonds, it is not as susceptible to oxidation when heated.
paradox is unique among modern Western nations, but it is not unique among
primitive tribes. For example, the Masai tribe of Kenya, Africa, consumes large
amounts of Kule naoto, a fermented raw
milk which provides the Masai’s main dietary source of nutrients (Mathara et
al., 2008). Yet, like the French, the Masai people have low prevalence of
cardiovascular disease despite their high intake of dietary cholesterol and
saturated fat (Mann et al., 1964). However, unlike the French, the Masai do not
include much grain or fruit in their diet, and therefore the Masai people
consume little or no red wine, preferring instead to drink the blood of their
cattle. And while the rural Masai people are very physically active, by
contrast, contemporary French lifestyles incorporate many labor-saving
conveniences. Therefore, it appears that unheated raw dairy consumption is one
of the few common dietary and lifestyle factors that the Masai people share with
the French population.
Traditional Raw Cheese
Researchers examined consumer attitudes toward purchasing traditional cheeses in France and in Norway, and it was found that most French people preferred traditional unpasteurized cheese while most Norwegians preferred pasteurized cheese (Almli et al., 2011). Interestingly, Scandinavian countries have a higher prevalence of cardiovascular disease than France, which is consistent with the French paradox (Artaud-Wild et al., 1993). Most French people regularly eat approximately 400 types of cheeses among over 1,000 cheeses produced throughout various regions of the country. The French spend 6.8% of their food budget on cheese and consume 24.6 kilograms (over 54 pounds) of cheese annually. Raw cheeses account for 10% of the 1.9 million tons of annual cheese production in France (Almli et al., 2011), Therefore, in combination with other raw dairy products, it is hypothesized that raw cheese consumption is associated with the French paradox.
Risks and Benefits of Raw Milk
The French preference for raw milk consumption is reflected in the popular distribution of raw-milk vending machines throughout France, as seen in the illustration below.
The World Health Organization Collaborating Centre at the University of Franche-Comté summarized the health risks and benefits of consuming unpasteurized dairy products (Vuitton, n.d.). While acknowledging the potential for foodborne illnesses in contaminated raw dairy, cases of contamination are rare in commercially available raw dairy products in France due to strict production processes and managed microbiological control procedures to keep the product safe. Also, pasteurization does not prevent secondary contamination that may occur during processing, packaging and storage. In other words, either dairy products are clean and safe to consume or they are not, regardless if they are raw or pasteurized. Raw milk is also claimed to have beneficial effects on intestinal flora by providing probiotic organisms (Baruzzi et al., 2011).
Cheese and wine
are equally important cultural icons in France (Roberts & Micken, 1996), and
neither food is traditionally thermally treated. While red wine contributes
high levels of vital antioxidants that may contribute to the low rate of
cardiovascular disease in the French paradox, a hypothesis for an additional
factor proposes that raw dairy contributes a lower level
of pro-oxidants or COPs which may be equally if not more important
in accounting for the country’s lower rate of cardiovascular disease. Further
research should rigorously explore the relationship
between consumption of raw and pasteurized dairy and prevalence of
cardiovascular disease in France and in other countries.
epidemiological study can only investigate associations, however, and is not
sufficient to establish a causative relationship between cardiovascular disease
risk and pasteurized dairy consumption. In the event that a significant
association is discovered in the proposed epidemiological study, and since
clinical studies are also lacking to test the cardiovascular risk of consuming
pasteurized dairy compared to raw dairy, it is recommended that dietary clinical
trials test for indicators of cardiovascular disease in subjects consuming raw
versus pasteurized dairy, perhaps with and without red wine. Furthermore, if a
causative relationship is established between pasteurized dairy and increased
risk for cardiovascular disease, this could lead to even more detailed research
examining the health implications of thermally-treated dairy processing.
there appears to be sufficient evidence from peer-reviewed research literature
to propose a hypothesis that raw dairy products are associated with lower rates
of cardiovascular disease in the French paradox. Compared to thermally-treated
dairy consumed in other Western nations, raw dairy in France contains fewer
cholesterol oxidation products that harm arteries in the cardiovascular system.
Future epidemiological and clinical research should explore this association.
Almli, V. L., Næs, T., Enderli, G., Sulmont-Rosse´, C., Issanchou, S., & Hersleth, M. (2011). Consumers’ acceptance of innovations in traditional cheese. A comparative study in France and Norway. Appetite, 57, 110–120. doi:10.1016/j.appet.2011.04.009
americansinfrance.net. (2013). Photo retrieved January 29, 2013 from http://www.americansinfrance.net/attractions/Tournus-Raw-Milk-Vending-Machine.cfm
Artaud-Wild, S. M., Connor, S. L., Sexton, G., & Connor, W. E. (1993). Differences in coronary mortality can be explained by differences in cholesterol and saturated fat intakes in 40 countries but not in France and Finland. A paradox. Circulation, 88, 2771–2779. doi:10.1161/01.CIR.88.6.2771
Baruzzi, F., Poltronieri, P., Quero, G. M., Morea, M., & Morelli, L. (2011). An in vitro protocol for direct isolation of potential probiotic lactobacilli from raw bovine milk and traditional fermented milks. Applied Microbiology and Biotechnology, 90, 33–142.
Chowdhury, R., et al. (2014). Association of dietary, circulating, and supplement fatty acids with coronary risk: A systematic review and meta-analysis. Annals of Internal Medicine, 160, 298–406.
Ferrieres, J. (2003). Coronary disease; The French paradox: Lessons for other countries. Heart, 90, 107–111.
Hur, S. J., Park, G. B., & Joo, S. T. (2007). Formation of cholesterol oxidation products (COPs) in animal products. Food Control, 18, 939–947. doi:10.1016/j.foodcont.2006.05.008
Mathara, J. M., Schillinger, U., Guiga, C., Franz, C., Jutima, P. M., …& Hozapfel, W. H. (2008). Functional characteristics of Lactobacillus spp. from traditional Maasai fermented milk products in Kenya. International Journal of Food Microbiology, 126, 57–64. doi:10.1016/j.ijfoodmicro.2008.04.027
Opie, L. H., & Lecour, S. (2007). The red wine hypothesis: From concepts to protective signaling molecules. European Heart Journal, 28, 1683–1693. doi:10.1093/euheartj/ehm149
Petyaev, I. M., Bashmako, Y. K. (2012). Could cheese be the missing piece in the French paradox puzzle? Medical Hypotheses, 79, 746–749. http://dx.doi.org/10.1016/j.mehy.2012.08.018
Roberts, S. D., & Micken, K. S. (1996). Le fromage as life. French attitudes and behavior toward cheese. In K. P. Corfman, & J. G. Lynch (Eds.), Research frame synergies: Vol. 23. Advances in consumer research. Provo: Association for Consumer Research.
Semba, R. E., et al. (2014). Resveratrol in red wine, chocolate, grapes not associated with improved health. JAMA Internal Medicine, Published online May 12.
Siri-Tarin, P. W., Sun, Q., Hu, F. B., & Krauss, R. M. (2010). Meta-analysis of prospective cohort studies evaluating the association of saturated fat with cardiovascular disease. American Journal of Clinical Nutrition, 91, 535–546.
Vuitton, D. A. (n.d.) Risk versus benefit of raw milk consumption. WHO Collaborating Centre; University of Franche-Comté; 25030 Besançon, France. Retrieved January 28, 2012 from http://www.oikos.no/newsread/readimage.aspx?WCI=GetByID&IMAGEID=4&DOCID=10680
wineterriors.com. (2009). Photo retrieved January 29, 2013 from http://www.wineterroirs.com/2009/06/wine_news23.html