Grapefruit consumption improves vitamin C status in periodontitis patients

Previous studies demonstrate a relationship between a lack of vitamin C and increased risk of periodontal disease. In the present study we examine the vitamin C plasma levels and inflammatory measures in periodontitis patients before and after the consumption of grapefruit.

Fifty-eight patients with chronic periodontitis were assigned to the test group (non-smokers n=21, smokers n=17) and a diseased control group (non-smokers n=11, smokers n=9). Furthermore, 22 healthy subjects were recruited to compare vitamin C plasma levels between periodontally diseased and healthy subjects. Clinical evaluations, including plaque index (PI), sulcus bleeding index (SBI), probing pocket depths (PPD) and plasma vitamin C levels, were performed at baseline, and after two weeks of grapefruit consumption.

At baseline, we observed significantly reduced plasma vitamin C levels in the test group and diseased controls in comparison with the healthy controls. On principle, smokers showed lower levels of vitamin C (mean 0.39 +/- 0.17 mg dl(-1)) than non-smokers (mean 0.56+/-0.29 mg dl(-1)). After grapefruit consumption, the mean plasma vitamin C levels rose significantly in the test group compared to the diseased controls (non-smokers: 0.87+/-0.39 mg dl(-1), smokers: 0.74+/-0.30 mg dl(-1)). Furthermore the SBI was reduced in the test group (non-smokers: from 1.68+/-0.6 to 1.05+/-0.6, p<0.001), whereas PI and PPD were unaffected.

The present results show that periodontitis patients are characterised by plasma vitamin C levels below the normal range, especially in smokers. The intake of grapefruit leads to an increase in plasma vitamin C levels and improves sulcus bleeding scores. Longer term studies are necessary to determine whether other periodontal outcomes improve with such supplementation especially in smokers.