Study · Frontiers in public health · 2022Conflicts declared

Vitamin C, fiber and oral cancer in southern China

What it found

In a study of 764 people in southern China, those with oral cancer reported eating less fiber and vitamin C than people without it.

The link held after accounting for smoking, drinking and other factors.

What they found

Studies in people

Lower intake in cases

People with oral cancer reported eating less fiber and vitamin C than controls. The average daily fiber intake was 8.15 g/day in patients and 8.88 g/day in controls, while vitamin C was 108.86 mg/day in patients and 118.27 mg/day in controls.

Higher intake, lower odds

Those with the highest fiber intake had lower odds of oral cancer than those with the lowest intake, after adjusting for many factors. A similar pattern was seen for vitamin C.

Stronger links in some groups

The link between fiber intake and oral cancer was stronger in women and in people who did not drink alcohol. The same was true for vitamin C.

Other findings

Fiber and vitamin C sources

Vegetables and fruits were the main sources of both fiber and vitamin C in this group. Grains, soy foods, meat, eggs, dairy, pickles and processed meat were not significantly related to vitamin C intake.

What the authors conclude

  • They conclude that higher dietary fiber and vitamin C intakes were linked to a lower incidence of oral cancer in a southeastern Chinese population.
  • They advise that further well-designed, particularly large-scale cohort studies, are needed to corroborate their findings.

How it was done

Dietary fiber and vitamin C have been suggested to play a role in cancer development, but few studies have looked at their link to oral cancer risk, especially in developing regions.

They compared 382 patients newly diagnosed with oral cancer to 382 hospital controls matched by age and sex in Fujian Province, China. Participants reported their usual diet over the previous year using a food frequency questionnaire.

What it can’t tell you

  • This was a case-control study, so it can show a link but cannot prove that eating more fiber or vitamin C prevents oral cancer.
  • People reported their past diets, which may not be perfectly accurate, and the authors note that recall bias and measurement error are difficult to avoid.

The paper

Title
Relationship Between Dietary Fiber and Vitamin C Intake and Oral Cancer
Type
Study
Evidence
Studies in people
Summarised from
Full text
Cite
Wang J, Fan Y, Qian J, et al (2022). Relationship Between Dietary Fiber and Vitamin C Intake and Oral Cancer. Frontiers in public health. doi:10.3389/fpubh.2022.880506Free full textPubMed 35646749DOI

Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error