News - Low intake of vitamin B6 may be linked to the symptoms of irritable bowel syndrome
The results of a new study, published in the academic journal Nutrition Research, suggest that a low intake of vitamin B6 may result in more severe symptoms of irritable bowel syndrome (IBS).
Vitamin B6 is a water-soluble B vitamin, which plays vital roles in numerous metabolic processes in the human body. It aids a number of physiological processes including energy production; synthesis and breakdown of amino acids; and the metabolism of fats, essential fatty acids, protein and homocysteine. It is also required for the production of DNA and RNA, and plays an important role in immune function, and in the health of nerve, muscle and red blood cells. Vitamin B6 is found in wholegrain cereals, vegetables, poultry and fish as well as in some fruits like bananas and avocados.
IBS is one of the most common disorders diagnosed by doctors. It is estimated that 10-20% of people experience IBS at some point. It occurs more often in women than in men, and it begins before the age of 35 in about 50% of people.
The main symptoms of IBS are abdominal pain, usually associated with bloating and gas, bouts of stomach cramps, and diarrhoea or constipation or alternating bouts of both. Mucus may be present in the stool, but there is usually no blood or pus. IBS causes a great deal of discomfort and distress, but the condition poses no serious threat to health. It can, however, have an adverse effect on a person's quality of life. The exact causes of IBS are unknown, but it may be triggered by stress, a malfunctioning immune system or a problem with how the muscles move food through the digestive tract.
Dietary intake has been the focus of previous research into IBS. However, attention to specific nutrients has been rare. As a result, researchers Ligaarden and Farup, at the Department of Medicine, Innlandet Hospital Trust, Gjøvik, Norway, sought to determine the association between the severity of IBS symptoms and the intake of specific nutrients.
The researchers performed a cross-sectional study involving 17 participants with IBSaccording to the Roma II criteria. The participants were asked to record their IBS symptoms every evening for seven days. The gastrointestinal symptoms recorded included abdominal pain/discomfort; urgency and bloating (recorded as none, mild, moderate, or severe: score 0-3); stool frequency as number of stools per day; stool consistency according to the Bristol stool scale form (score 1-7); and straining and incomplete bowel movement as yes/no (score: 1 or 0). An IBS sum score (score 0-15) was then calculated using the scores of irritable bowel syndrome symptoms. Intake of food was also assessed via the use of a food diary.
The researchers then explored the associations between the IBS sum score and dietary intakes, and found that the intake of vitamin B6 was the only component of the diet significantly associated with the IBS sum score. The median (average) daily intake of vitamin B6 for the study participants was 0.9mg per day (recommended daily intake is 1.6mg per day or more for men and 1.2mg per day or more for women), and a high symptom score was significantly associated with a low intake of vitamin B6.
The researchers commented: "A significant inverse association between intake ofvitamin B6 and severity of IBS symptoms might have clinical implications."
Ligaarden SC, Farup PG. Nutr Res 2011; 31:356-61.