You’ve heard it before and now you’ll hear it again: Eat more fibre! At least that’s the conclusion of a study reported on by NutraIngredients-USA, which found an association between higher fibre intake, primarily insoluble fibre, and lower systolic blood pressure. Insoluble fibre is one of two types of fibre which serve different purposes in the body—insoluble fibre passes through your digestive system, adding bulk to wastes and promoting digestive motion, while soluble fibre binds to water and other compounds, keeping them in the digestive tract. The research, published in the British Journal of Nutrition, looked at data from 2,195 Americans ages 40 to 59 who participated in the International Study on Macro/micronutrients and Blood Pressure (INTERMAP). During four visits between 1996 and 1999, researchers measured the participants’ blood pressure, collected 24-hour urine samples, and administered 24-hour dietary surveys to evaluate fibre intake. After adjusting for lifestyle and dietary factors that could affect blood pressure, researchers found that:

• Higher intake of insoluble fibre was associated with lower blood pressure. The researchers calculated that, for every 4.6 grams of insoluble fibre per 1,000 kilocalories consumed, systolic blood pressure was 1.81 mmHg lower. Soluble fibre intake was not associated with blood pressure.
• Raw fruit was the main source of insoluble fibre in the participants’ diets, followed by whole grains and vegetables.

It’s important to note that more clinical research is needed to show whether increasing insoluble fibre intake can reduce blood pressure. However, fibre has previously been associated with decreased risk for diabetes and markers of cardiovascular disease, and increased weight loss, so this study may provide just one more reason to ensure you’re getting adequate amounts of fibre in your diet. Insoluble fibre, in particular, can be found in many delicious foods like wheat bran, wheat germ, whole wheat, popcorn, beans and lentils, vegetables and their skins, fruits and their peels, and nuts and seeds.

Source: British Journal of Nutrition