Nuts and Heart Disease
Nuts are great foods. Not only for us, but for our gut bacteria. The two combined also increases our heart health, it turns out.
Studies on nuts and urolithins
New research is finding that when we eat whole natural nuts such as walnuts, hazelnuts, pistachios, and almonds, intestinal probiotics will consume a healthy element from the nuts called ellagitannin.
When our probiotics eat ellagitannins they produce a group of compounds called urolithins. As it turns out, these urolithins prevent artery damage and the resulting inflammation that leads to atherosclerosis – the hardening of the arteries.
In a study from Spain’s Rovira i Virgili University, when patients with metabolic syndrome consumed a moderate amount of nuts daily for twelve weeks, their intestinal bacteria produced higher quantities of these heart-healthy urolithin metabolites. These were found circulating within their bloodstream, while the group that did not eat the nuts did not have these metabolite levels.
Other research confirms findings
In a follow-up study published in May, researchers from Spain’s Research Group on Quality, Safety and Bioactivity of Plant Foods from the government’s Department of Food Science and Technology (CEBAS-CSIC) conducted laboratory studies that confirmed the mechanisms of the urolithin metabolites produced when probiotics consumed nuts. The researchers utilized human cells from the walls of the aortic artery and duplicated inflammation associated with the buildup of artery plaque.
They introduced urolithin A and urolithin B produced from probiotic colonies fed with ellagitannins – which are abundant in nuts and some other plant-based foods.
The researchers found that the urolithins blocked the process of inflammation among the artery cells. This, they discovered, was produced by the urolithins blocking the process of adhesion by pro-inflammatory monocytes.
The researchers concluded that, “our results suggest that these metabolites might be involved, at least in part, in the beneficial effects against cardiovascular diseases attributed to the consumption of ellagitannin-containing foods.”
Brazil nuts also reduce inflammation according to other research.
In April, the Spanish researchers published another study that showed how urolithins produced by probiotic bacteria consumption of pomegranate ellagitannins (as pomegranates, like nuts, have significant quantities of ellagic acid) significantly reduced inflammatory factors within the colon. The study was published in the Journal of Agricultural Food Chemistry.
What all this means is that when we feed our (healthy) intestinal probiotic colonies ellagitannin-containing foods such as nuts and pomegranates, they produce compounds that keep our arteries healthy, keep our colon healthy, and likely reduce inflammation throughout the body.
Giménez-Bastida JA, González-Sarrías A, Larrosa M, Tomás-Barberán F, Espín JC, García-Conesa MT. Ellagitannin metabolites, urolithin A glucuronide and its aglycone urolithin A, ameliorate TNF-α-induced inflammation and associated molecular markers in human aortic endothelial cells. Mol Nutr Food Res. 2012 May;56(5):784-96.
Tulipani S, Urpi-Sarda M, García-Villalba R, Rabassa M, López-Uriarte P, Bullo M, Jáuregui O, Tomás-Barberán F, Salas-Salvadó J, Espín JC, Andrés-Lacueva C. Urolithins are the Main Urinary Microbial-Derived Phenolic Metabolites Discriminating a Moderate Consumption of Nuts in Diagnosed Metabolic Syndrome. J Agric Food Chem. 2012 May 27.
Heber D. Pomegranate Ellagitannins. In: Benzie IFF, Wachtel-Galor S, editors. Herbal Medicine: Biomolecular and Clinical Aspects. 2nd edition. Boca Raton (FL): CRC Press; 2011. Chapter 10.
Giménez-Bastida JA, Larrosa M, González-Sarrías A, Tomás-Barberán F, Espín JC, García-Conesa MT. Intestinal Ellagitannin Metabolites Ameliorate Cytokine-Induced Inflammation and Associated Molecular Markers in Human Colon Fibroblasts. J Agric Food Chem. 2012 Apr 16.