Grapefruit helps fight gum disease, say British dentists

London: Eating grapefruit could help fight gum disease. That’s the conclusion of research published in the new edition of the British Dental Journal (BDJ). Researchers found that eating two grapefruits a day significantly increased the vitamin C levels of those suffering from gum disease.

Because vitamin C promotes the healing of wounds and boasts antioxidant properties, it contributes to the therapy and prevention of the condition. The effect was observed for smokers and non-smokers alike.

The two-week study examined the effect of consuming grapefruit on a mixed group of smoking and non-smoking subjects. At the start of the study, virtually all of those taking part exhibited plasma vitamin C levels well below the normal range, with the smokers’ levels 29 per cent lower than the non-smokers’. A proportion of the group was then selected to consume two grapefruits per day after a main meal for the duration of the research.

Grapefruit raised the ascorbic acid plasma levels of all those who had consumed it. In non-smokers the mean level increased from 0.56 milligrammes (mg dl¹) to 0.87 mg dl¹. In smokers the mean level almost doubled, from 0.39 mg dl¹ to 0.74 mg dl¹. While smokers’ levels enjoyed a greater increase, the fact that they started from a lower baseline meant that their levels were still below those of the non-smokers. The levels of the remainder of the group, who did not consume any grapefruit, were unchanged.

The researchers also observed a significant reduction of the sulcus bleeding index, that is bleeding from the gums, after grapefruit consumption. They concluded that this effect was also likely to have been caused by the improved vitamin C supply.


1. The grapefruits consumed in the study were acquired from a supermarket and each weighed approximately 300g. Each grapefruit contains approximately 92.5 mg of vitamin C. Those taking part in the research were advised not to brush their teeth immediately after consuming the grapefruits. This is because citrus fruits are acidic and can weaken tooth enamel making it susceptible to erosion.

2. The research was carried out by the Friedrich Schiller University in Germany. It is published in the 27 August edition of the British Dental Journal (BDJ), the scientific journal of the British Dental Association. Please acknowledge the BDJ as the source of the research.

3. The British Dental Association is the trade union and professional association for dentists practicing in the UK, representing 20,000 members working in all aspects of dentistry.

4. For further information, please contact the BDA on 0207 563 4145/6.