Nutrition & Immunity

HOT TOPIC: NUTRITION & IMMUNITY by Dr Julie Wallace, University of Ulster.
Dietary choline and betaine intakes in relation to concentrations of inflammatory markers in healthy adults: the ATTICA study
Detopoulou P, Panagiotakos DB, Antonopoulou S, Pitsavos C and Stefanadis C
American Journal of Clinical Nutrition, 2008; Vol. 87, No. 2, 424-430

 Choline is found in a variety of foods including meat, fish, eggs, bran and some vegetables and can be also endogenously synthesized in the liver. Betaine, a derivative of choline, is found in wholegrain cereal products and in some vegetables.  Choline functions in neurotransmission and is an essential part of VLDL while betaine acts as an osmolyte and as a methyl donor functioning in the remethylation of homocysteine a is widely recognized a risk factor for cardiovascular disease (CVD).
Indeed betaine and choline intake and status have been inversely associated with homocysteine concentration. While mechanism linking plasma homocysteine concentration (tHcy) with CVD is not fully understood, tHcy been shown to be related to inflammation.

The aim of the study presented by Detopoulou et al was to investigate associations among dietary choline and betaine intake and markers of inflammation including C-reactive protein (CRP), interleukin (IL)-6, tumor necrosis factor (TNF)-α and tHcy in apparently healthy men and women recruited as part of the ATTICA study, an epidemiologic study of apparently healthy inhabitants from the Attica area in Greece. For the current analysis 1514 men and 1528 women provided fasting blood samples.  Dietary intakes were evaluated using a food-frequency questionnaire, and the intakes of were calculated from food-composition tables, supplemented with data on the choline and betaine content of foods.

The results showed that dietary choline and betaine were inversely associated with concentrations of CRP and IL-6 after adjustment for various factors such as age, sex, smoking etc. Furthermore, choline intake was also inversely associated with TNF-α, and betaine intake was inversely associated with tHcy.  Moreover, the combination of a high dietary intake of choline and betaine was associated with lower concentrations of all the investigated markers.  Choline intakes were similar to that reported in other observational studies however, betaine intake was higher possibly owing to more frequent consumption of betaine rich plant based foods. 
In an accompanying editorial Steven Zeisel1 provides a number of plausible mechanisms that could explain the observations of decreased inflammation among individuals with higher betaine and choline intakes including epigenetic mechanisms and decreased oxidative stress.  He also notes that the effects of dietary choline and betaine on these markers of inflammation were of the same magnitude as those reported for the Mediterranean diet, a diet rich in vegetables, cereals and fish which provide good dietary sources on choline and betaine. The current paper provides an interesting finding that clearly will require confirmation in other observational and intervention studies. 

1. Zeisel SH.  Is there a new component of the Mediterranean diet that reduces inflammation?  American Journal of Clinical Nutrition, 2008; Vol. 87, No. 2, 277-278.