HealthDay News — Adhering to a Meditteranean diet may lower the risk for stroke in patients with a particular genetic variant that makes them susceptible to type 2 diabetes and metabolic problems, researchers have found.
Patients with this specific polymorphism who ate a Mediterranean diet were at no greater risk for stroke than those without the genetic variant, Dolores Corella, DPharm, PhD, of the University of Valencia in Spain, and colleagues reported in Diabetes Care.
“These results, based on a dietary intervention study, support the benefits of a Mediterranean diet, especially for genetically susceptible individuals, and emphasize the importance of studying entire dietary patterns rather than individual components,” the researchers wrote.
The polymorphism — rs7903146(C>T) — affects the TCF7L2 gene and has been associated with type 2 diabetes in previous studies, but it’s involvement in cardiovascular disease is understood less well.
So Corella and colleagues analyzed data from 7,018 patients who participated in the PREvencion and DIetaMEDiterranea randomized controlled studies to determine the association between the polymorphism, plasma lipids and cardiovascular disease among three groups: a control group, and two groups on a Mediterranean diet supplemented with either extra virgin olive oil or mixed nuts.
About 14% of participants were homozygous carriers (TT) of the TCF7L2-rs7903146 polymorphism. After a median 4.8 year follow-up, the researchers found a significant association between the TT variant of the TCF7L2 gene, type 2 diabetes (OR 1.87; 95% CI: 1.62-2.17) and fasting glucose (P<0.001).
At baseline, patients with the TT genotype who adhered poorly to the Mediterranean diet had higher fasting glucose concentrations than those without the variant (132.3 mg/dL vs. 127.3 mg/dL, P=0.001). Greater adherence to the Mediterranean diet over follow-up significantly reduced fasting glucose, total cholesterol, low-density lipoprotein cholesterol and triglycerides (P<0.05 for all).
The diet also appeared to lower the risk for stroke in patients with the TT genotype during the five year period — the low-fat control group had a significantly higher incidence of stroke (aHR 2.91, 95% CI: 1.36-6.19, P=0.006), whereas those on the Mediterranean diet had a significantly reduced incidence of stroke (aHR 0.96, 95% CI 0.49–1.87, P=0.892).
“Our novel results suggest that Mediterranean diet may not only reduce increased fasting glucose and lipids in TT individuals, but also stroke incidence,” the researchers concluded.
These associations were observed regardless of the type of Mediterranean diet, they added, noting that overall diet may be more important than specific foods in lowering stroke in patients with this genetic variant.