Study under review: Mediterranean diet intervention in overweight and obese subjects lowers plasma cholesterol and causes changes in the gut microbiome and metabolome independently of energy intake.
The prevalence of obesity and associated adverse effects on human health have increased to alarming levels throughout the world. Obesity is a risk factor for hyperlipidemia and cardiovascular disease and many other chronic diseases. Elevated total plasma cholesterol has been positively associated with mortality from heart disease, and lowering total cholesterol has been shown to decrease this risk.
The gut microbiome has been linked to obesity and other chronic diseases. Since diet has been shown to affect the composition and function of the microbiome, this raises the question of whether dietary patterns can influence obesity and chronic disease risk factors independently of caloric intake.
There’s some evidence that certain dietary patterns can promote both a reduction of the well-known CVD risk markers and improve the correlating microbial colonization of our intestines, even independent of weight loss. One such dietary pattern is the Mediterranean diet (MD). However, a lot of the research supporting the MD’s health benefits are observational studies or based on animal models. The relative paucity of randomized controlled trials exploring the MD’s effects on CVD risk markers and the microbiome, especially independent of weight loss, motivated the authors of the study under review to conduct a study to investigate whether an eight-week adherence to a Mediterranean diet pattern, without alteration of calories or exercise, could help decrease plasma cholesterol levels and improve the functioning of the gut microbiome in obese and overweight sedentary participants.
Obesity is associated with a host of cardiovascular risk factors. However, there is evidence suggesting that certain dietary patterns can reduce some of these risk factors, even independent of weight loss. The Mediterranean diet (MD) is one such diet that could have this effect, possibly by changing the gut microbiome. However, randomized controlled trials exploring this question are relatively rare, which motivated the researchers behind the study under review.
Other Articles in Issue #67 (May 2020)
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Safety Spotlight: The Dark Side of Broccoli
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Can polyphenols prevent our brains from slowing down?
This recent meta-analysis found a minimal effect on one measure of cognition, but there's much more room for more evidence.