In recent years, natural yogurt, raw sauerkraut or kombucha have been touted for the heart. Recent headlines claim that a diet rich in live microbes and in
fermented foods would even lower “bad” cholesterol. An Australian study published in Nutrition Research just reviewed this promise.
A diet rich in live microbes improves waistline and good cholesterol
Researchers from Newcastle University followed 58 adults and estimated the amount of live bacteria provided by their daily diet. They then compared these intakes to different cardiometabolic markers, such as cholesterol, insulin or weight. The clearest effects, however, did not concern the famous “bad” cholesterol.
The researchers first ranked more than 200 foods according to their estimated content of live microbes. The medium/high group mainly included raw, unpeeled fruits and vegetables and yogurt, for an average consumption of 300 g per day, lower than that of foods low in microbes.
The higher the food intake of this group, the lower the weight, BMI, waist circumference and fasting insulin, while the
HDL cholesterol (“good cholesterol”) was rising. The researchers did not observe a significant link with the
LDL cholesterol ‘(“bad cholesterol) or total cholesterol, and foods very low in microbes were associated with higher blood pressure.
“Important point: the study observes a statistical link, it does not demonstrate that a food alone “lowers” insulin“, underlines the PresseSanté site.
Good and bad cholesterol: where do fermented foods really work?
HDL, often described as the “good” cholesterol, helps transport excess fats to the liver, while excess LDL promotes deposits in the arteries. In the article, each 1 mg/dL increase in HDL is associated with 2 to 3 percent less cardiovascular risk. “These markers are well established as cardiometabolic risk factors due to their relationship with obesity“, explained the authors of the study.
In this cohort, the increase in HDL and the decrease in fasting insulin provide a more favorable metabolic profile, with no demonstrated effect on bad cholesterol or triglycerides. The authors summarize: “Therefore, the consumption of foods with a medium and high content of live microbes may have a protective role in managing the risk of cardiovascular diseases.” and specify that “the evaluation of both the composition of the intestinal microbiota and the production of beneficial metabolites, such as short-chain fatty acids, could provide valuable insights into the underlying mechanisms“.
Fermented foods and raw plants: how to integrate them into your daily life
In daily life, this medium/high group of living microbes corresponds mainly to raw plants and a few
fermented foods unpasteurized. In France, this can look like natural yogurt and two or three servings of raw fruit or vegetables per day, sometimes with fermented milk or kefir, raw sauerkraut or lacto-fermented vegetables. The authors point out that their study, based on dietary questionnaires and carried out with 58 adults, does not prove a cause and effect link; caution is therefore necessary in the event of immunosuppression or pregnancy.