Foods commonly consumed as

part of a Mediterranean diet

In a large study, individuals who strictly followed a Mediterranean diet had lower levels of platelets and white blood cells (WBCs) than those who deviated from the diet.

And the lower cell counts were associated with lower levels of inflammation.

The research also suggested the diet as a whole, and not just certain components, was responsible for these markers of improved health.

Marialaura Bonaccio, PhD, of the IRCCS Istituto Neurologico Mediterraneo NEUROMED in Italy, and her colleagues reported these findings in Blood.

The team noted that the Mediterranean diet—which is characterized by a wide consumption of plant foods, cereals, legumes, fish, and olive oil, as well as moderate wine consumption—has long been hailed as a heart-healthy eating plan. And previous research suggested the diet can reduce inflammation.

But the connection between the diet and levels of platelets and WBCs, 2 specific inflammatory markers in the body, has remained unclear.

“We undertook this study to understand the correlation between consuming a Mediterranean diet and specific health markers, including platelet levels and white blood cell counts, which can more specifically explain the diet’s benefits in reducing the long-term risk of cerebral and heart disease or other chronic conditions,” Dr Bonaccio said.

To do this, she and her colleagues analyzed the eating habits of 14,586 healthy Italian men and women aged 35 and older. At baseline, all subjects were healthy.

The researchers measured total platelet and WBC counts and grouped participants according to their levels (low, normal, or high), based on age- and gender-specific cut-offs.

Participants with high platelet levels were younger and had a greater incidence of high cholesterol and increased levels of common inflammation marker C-reactive protein when compared to subjects in the normal or low-platelet categories.

Individuals in the high-WBC category were mainly younger, male, and smokers. They had a higher body-mass index and higher levels of C-reactive protein and blood glucose than subjects in the other groups. They also showed higher prevalence of high blood pressure and high cholesterol.

The researchers determined participants’ adherence to a Mediterranean using 2 dietary scoring systems, the Mediterranean diet score or the Italian Mediterranean Index, which helped to accurately determine intake levels and portion sizes.

Results of these analyses revealed that adherence to the Mediterranean diet was directly related to lower levels of platelets and WBCs (P<0.0001 and P=0.008, respectively), which was correlated with lower levels of inflammation.

When compared with participants who did not follow the eating plan as closely, subjects who strictly followed the diet were less likely to belong to the group with the highest platelet counts (odds ratio=0.50) and more likely to belong to the group with the lowest WBC counts (odds ratio=1.41).

“Because the study included healthy participants, the lower levels of platelets and white blood cells in those who were more strictly consuming a Mediterranean diet indicate that this eating plan could account for substantial changes within normal ranges of variability,” Dr Bonaccio said.

“This is an important finding that has implications for how these anti-inflammatory markers are tracked among the general population.”

The researchers also evaluated the role of specific components of the diet to help clarify the observed correlation, including food antioxidant content and fiber intake, both of which have previously been connected to cardiovascular benefits.

These components only partially accounted for the link between the diet and WBC count. And they did not fully explain the correlation to platelet levels.

“An important finding of this study is that it indicates that the Mediterranean diet as a whole, and not just a few specific ingredients, is likely responsible for the beneficial health outcomes among the healthy population and should be encouraged as part of healthy eating habits,” Dr Bonaccio said.

“Building on these important findings, we continue to study this population to determine if the dietary habits may have an influence on cardiovascular disease-related mortality.”

Mediterranean diet tied to decreased platelets, WBCs