Using the nutrigenomics technique, scientists report in Nutrition & Metabolism that people with the highest intakes of fruit and vegetables have significantly lower levels of markers of inflammation, and thereby supporting recommendations to consume five servings of fruit and vegetables a day.
“In this context, nutrigenomic approaches have been performed as a potential useful tool to increase fundamental knowledge concerning the interactions between diet and gene expression,” wrote the researchers, led by José Alfredo Martinez from the University of Navarra in Pamplona, Spain.
“Thus, this study found, apparently for first time, that healthy adults with a high consumption of fruits and vegetables had lower [levels of pro-inflammatory markers in white blood cells],” they added.
The offers promise for reducing the risk of developing chronic inflammation, brought about by an over-expression or lack of control of the normal protective mechanism. Chronic inflammation has been linked to range of conditions linked to heart disease, osteoporosis, cognitive decline and Alzheimer's, type-2 diabetes, and arthritis.
Last month findings from the European Prospective Investigation into Cancer and Nutrition (EPIC) appeared to question such recommendations when it reported that for every 200 grams (about two servings) of total fruits and vegetables eaten per day, the incidence of cancer was reduced by mere 4 per cent.
The study, published in the Journal of the National Cancer Institute, was the largest on diet and cancer to date, and included 142,605 men and 335,873 women. The participants were followed for an average of about nine years, during which time over 30,000 cases of cancer were diagnosed.
Despite these weak links, experts from across the globe were quick to note, however, that the results do not undermine recommendations for eating at least five servings of fruit and vegetables a day, with studies reporting cardiovascular benefits.
The new study adds weight to such claims, with the highest intake of fruit and vegetable consumption – at least 660 grams per day – associated with significant reductions in levels of markers of inflammation, including C-reactive protein (CRP), interleukin-6 (IL-6) and tumour necrosis factor-alpha (TNF-alpha).
Martinez and his co-workers recruited 120 health subjects with an average age of 20.8 and an average BMI of 22.3 kg/m2. The levels of proinflammatory markers were assessed by measuring the expression of mRNA in white blood cells, while the intakes of fruit and vegetables were assessed by a food-frequency questionnaire.
Data showed that the highest average intakes of fruit and vegetables were associated with lower concentrations of CRP, and lower expression of IL6, TNF-alpha and NF-kappa-B1.
In addition, the highest intakes of antioxidants (at least 11.8 milligrams per day) were also associated with lower levels of CRP, and the gene expression in white blood cells.
“The fruit and vegetable consumption was inversely associated with mRNA expression of certain pro-inflammatory markers from [white blood cells] in healthy young adults, suggesting a beneficial effect of high fruit and vegetable consumption on decreasing pro-inflammatory status and providing new light for the nutrigenomic involved-mechanisms as well as new tools for the assessment of nutrient-gene interactions,” concluded the researchers.
Source: Nutrition & Metabolism
“Fruit and vegetable consumption and proinflammatory gene expression from peripheral blood mononuclear cells in young adults: a translational study”
Authors: H.H.M. Hermsdorff, M.A. Zulet, B. Puchau, J.A. Martinez