Long-term gluten consumption not associated with CHD risk in healthy individuals
Long term gluten consumption in adults without celiac disease and risk of coronary heart disease: prospective cohort studyLebwohl B, Cao Y, Zong G, et al. - BMJ 2017; 357: j1892
Celiac disease is associated with an increased risk of coronary heart disease (CHD), which is reduced after treatment with a gluten-free diet . There is evidence suggesting that gluten, a storage protein in wheat, rye and barley, may promote inflammation in the absence of celiac disease or non-celiac gluten sensitivity, leading to concerns about its potential to increase the risk of obesity, metabolic syndrome, neuropsychiatric symptoms, and CV risk in healthy individuals [2,3]. Therefore, gluten avoidance has become popular. There are, however, no long-term, prospective data assessing the relationship of dietary gluten with the risk of CHD in individuals without celiac disease [4,5].
In this large, prospective study, the association of estimated long term intake of gluten with the development of incident CHD (fatal or non-fatal MI) was evaluated in 66714 women in the Nurses’ Health Study and 45303 men in the Health Professionals Follow-up Study, using validated data on dietary intake collected every four years, over the course of 26 years.
- Gluten intake correlated inversely with alcohol intake, smoking, total fat intake, and unprocessed red meat intake, whereas it correlated positively with whole grain intake and refined grain intake. Gluten intake did not correlate strongly with sodium intake.
- Compared with participants in the lowest fifth of gluten intake, who had a CHD incidence rate of 352 per 100 000 person years (PY), those in the highest fifth had a rate of 277 events per 100 000 PY, leading to an unadjusted rate difference of 75 (95%CI: 51 - 98) fewer cases of CHD per 100 000 PY.
- After adjustment for age, participants in the highest fifth of gluten intake had a decreased risk of subsequent CHD compared with those in the lowest fifth in men (HR: 0.88; 95% CI: 0.80 - 0.97) and in the pooled analysis (HR: 0.87; 95% CI: 0.80 - 0.93).
- After adjustment for several factors, the association was no longer significant (HR: 0.98; 95% CI: 0.91 - 1.06) in the pooled cohorts.
- Further adjustment for refined grains showed that participants in the highest fifth of gluten intake had a lower CHD risk (HR: 0.85; 95% CI: 0.77 - 0.93).
- Further adjustment for whole grains cancelled the association between gluten intake and incident CHD. Participants in the highest fifth had a risk of CHD that did not differ from those in the lowest group (HR: 1.00; 95% CI: 0.92 - 1.09).
- The assessment of gluten intake as a continuous variable resulted in a multivariate HR of 0.99 (95% CI: 0.98 - 1.01) for each 1 g increase in daily intake.
In a large, prospective study, the consumption of foods containing gluten was not significantly associated with the risk of CHD. Estimated gluten intake was correlated with whole grain and refined grain intake. The adjusted analyses on refined and whole grain intake suggest the potential that people who severely restrict gluten intake may also significantly limit their intake of whole grains. This may be associated with adverse CV outcomes. These findings do not support a gluten restricted diet in the general population of asymptomatic individuals without celiac disease for the reduction of CHD risk.