BARCELONA — Additional supplementation of olive oil in the diets of patients with type 2 diabetes may reduce their risk of cardiac problems, according to research presented at an international congress on prediabetes and metabolic syndrome.
In a preliminary study to identify a potential mechanism through which the Mediterranean diet protects against cardiovascular disease, Dr. Mohammed Hammami, head of the biochemistry laboratory, faculty of medicine, Monastir, Tunisia, and colleagues analyzed the relationship between homocysteine and other modifiable cardiovascular risk factors, including diet, in type 2 diabetes patients.
Previous work has linked high levels of homocysteine to a high prevalence of macroangiopathy, coronary heart disease, and renal insufficiency in patients with type 2 diabetes. In addition, clinical trials testing vitamin supplementation in these patients have resulted in decreased homocysteine levels in patients with diabetic dyslipidemia, suggesting that lowering homocysteine levels could reverse the lipid problems.
The researchers recruited 70 patients with type 2 diabetes and evaluated their nutritional habits based on a validated food frequency questionnaire. On average, those with diabetes consumed foods high in fat. Dr. Hammami and his colleagues measured mean homocysteine levels, which were 13.6 plus or minus 6.06 micromol/L for the group; 27.5% of participants had levels of plasma homocysteine assessed as high (greater than 15 micromol/L). Further studies showed an inverse correlation between homocysteine levels and dietary saturated fatty acids or daily cholesterol intake.
According to Dr. Hammami, plasma homocysteine levels were lower in patients with diabetes who consumed extra virgin olive oil than in those who consumed little or none (10 micromol/L vs. 14 micromol/L, respectively). “Our study supports other studies showing the beneficial effects of the Mediterranean diet on the cardiovascular risk factors, essentially on homocysteine levels,” he said.
“We have revealed a potential mechanism by which a Mediterranean type of diet may affect coronary risk,” Dr. Hammami continued. “The consumption of olive oil, the major fat in this diet type, may lead to decreased levels of homocysteine.”
He suggested that his study “should be followed up by investigations on the effects of the different components of olive oil”—not only oleic acid but also minor components such as vitamins and polyphenols—”on the reduction of homocysteine levels.” Dr. Hammami said he plans to do more extensive patient recruitment and supplementary analysis on such things as thiolactonase activity measurement.