Diet can decrease or increase RA susceptibility

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Diet can decrease or increase RA susceptibility

Rheuamawire

Aug 18, 2004

Janis

Manchester, UK - A systematic review of dietary intake and biological

markers measured before rheumatoid arthritis (RA) onset shows that risk

of RA may be increased or decreased by dietary factors [1]

" There was evidence of a protective effect of higher consumption of

olive oil, oil-rich fish, fruit, vegetables, and beta-cryptoxanthin.

Lower serum concentrations of antioxidants were associated with an

increased risk of RA in 3 studies, " Dr Dorothy J Pattison (University of

Manchester, UK) and colleagues report in the July 2004 issue of the

Journal of Rheumatology.

Pattison systematically reviewed studies that examined the association

between diet and RA onset. The search included all relevant reports of

studies with comparison groups, including case-control and cohort

studies. The analysis focused on studies that measured dietary intake

and reported associations between food and/or nutrients and the onset of

RA. The analysis also included studies that assessed nutrient exposure

using biological markers of dietary nutrient intake. Ecological and

cross-sectional studies were excluded. The primary outcome measure was

onset of RA. Thirteen studies met the inclusion criteria, but because of

differences in study design the data could not be pooled.

Higher fish consumption had a protective effect against RA onset in 2

studies, and a third found that subjects with the lowest levels of

omega-3 fatty-acid intake from fish consumption had the highest risk for

RA. Two case-control studies found that higher olive-oil consumption was

associated with a statistically significant reduced risk of developing

RA.

The role of caffeine in RA risk is uncertain. Pattison said that 1 study

found increased risk of seropositive RA with high caffeinated-coffee

consumption, but other studies found no clear association. A

multivariate analysis using baseline data from the Nurses Health Study

found that greater caffeinated-coffee consumption was associated with a

significant increase in RA risk.

In contrast, alcohol consumption may be protective. A case-control study

found the lowest risk of RA in women with the highest alcohol

consumption, but no significant association was found in the Iowa

Women's Health Study.

Lower RA risk was also associated with higher intakes of fruit, cooked

(but not raw) vegetables, and cruciferous vegetables. " In 2 of these

[studies], beta-cryptoxanthin, a carotenoid found in fruits and

vegetables, and vitamin C were also found to be strongly protective

against developing RA, " the investigators write.

No association between calcium intake and RA onset was found in the Iowa

Women's Health Study but a small inverse association was found in other

studies.

Higher consumption of meat was also associated with a small reduction in

RA risk.

" Several studies found that associations were present in seropositive

but not seronegative RA or that the associations were stronger in

seropositive compared with seronegative disease, suggesting that diet

might play a role in the etiology and even contribute to a more severe

disease course, " Pattison notes.

Like RA, lower cardiovascular disease risk has been associated with

increased dietary intake of fish oils, fruits, and vegetables. The link

is likely to be inflammation: in both inflammatory cardiovascular

diseases and inflammatory rheumatoid diseases, fish oil provides a

source of anti-inflammatory fatty acids, and fruits and vegetables

provide damage-preventing antioxidants.

Sources

Pattison DJ, on RA, Symmons DPM. The role of

diet in susceptibility to rheumatoid arthritis: a systematic review. J

Rheumatol 2004; 31:1310-1319.

I'll tell you where to go!

Mayo Clinic in Rochester

http://www.mayoclinic.org/rochester

s Hopkins Medicine

http://www.hopkinsmedicine.org