Cheese: The latest piece of the French paradox puzzle?
Despite the fact that they have a high dietary intake of saturated fats, the French boast lower rates of coronary heart disease and cardiovascular mortality than other countries. Dubbed the ‘French Paradox’, scientists have sought to understand the reasoning behind the phenomenon, suggesting it may be due to higher consumption of red wine which contains the antioxidant resveratrol.
The team of Denmark-based researchers say that cheese may also play a role.
“Fermented dairy products have been proposed as functional foods with cholesterol-lowering effect [that] protect against cardiovascular disease compared with non-fermented dairy products,” said the study.
“…Overall, this metabolomics study suggests that cheese could be an important piece in the French paradox puzzle.”
The researchers, led by Hong Zheng from the Department of Food Science at Aarhus University, analysed and compared faecal and urine samples after consumption of milk, cheese and butter. They suggest that cheese may beneficially modify the gut microflora, expelling greater amounts of butyrate – a compound associated with cardiovascular disease – than butter and increasing short-chain fatty acids.
However, the study - funded by Arla and the Danish Dairy Research Foundation – was small in size and the researchers have called for further investigations into the exact metabolic mechanisms linking cheese consumption, gut microflora and cholesterol metabolism.
The scientists, who published their findings in the Journal of Agriculture and Food Chemistry, say that their results add to the findings of a 2011 cohort study which found a modest inverse association between dairy consumption and cardiovascular disease.
The researchers used data from a previous study by Soerensen et al in which 15 healthy men aged 18-50 years were randomly allocated to one of three diet groups for two weeks.
The first was high in 1.5% fat semi-skimmed milk, the second high in semi-hard cow’s cheese with equal amounts of dairy calcium (1.7 g/day) while the third control group consumed butter but no other dairy product. The diets were isocaloric and similar in fat content.
Soerensen had previously collected five different fecal samples between days 10-14 and urine samples on day 14. All samples had been frozen, allowing Zheng et al. to analyse the metabolic profile for their study using nuclear magnetic resonance spectroscopy .
The researchers led by Zheng found that levels of the microbiota-related metabolite hippurate were significantly higher in the cheese group compared with the milk group. They suggest that gut microbiota is stimulated in different ways depending on fermentation levels of dairy.
“Fecal butyrate level [also] tended to be increased significantly after cheese consumption relative to intake of the other two diets.”
“Our results lead us to suggest that cheese consumption is associated with an increased level of short-chain fatty acids in the gut, possibly induced by stimulation of beneficial gut microbiota, as well as an increased extent of lipid excretion with resultant beneficial effects on cholesterol metabolism.”
A 2012 study published in Elsevier suggested that cheese may be a factor in explaining low cardiovascular mortality rates in France. They looked specifically at moulded cheese, such as Roquefort, and identified cholesterol-inhibiting metabolites produced by Penicillium roqueforti as potential mechanisms at work.
Source: Journal of Agriculture and Food Chemistry
Published online ahead of print March 2015 DOI: 10.1021/jf505878a
“Metabolomics Investigation To Shed Light on Cheese as a Possible Piece in the French Paradox Puzzle”
Authors: H. Zheng, H. Bertram et al.