If you eat more fiber you will probably have a lower risk of first time stroke, researchers from the University of Leeds’ School of Food Science & Nutrition in Leeds, United Kingdom, reported in the journal Stroke.

Dietary fiber comes from plants, the part that our body does not absorb when digesting food. Fiber can be insoluble or soluble (dissolves in water). No fiber can be digested. However, soluble fiber as it goes through the digestive tract, changes its form when it is fermented by bacteria. Soluble fiber absorbs water and becomes gelatinous as it does so. However, the form of insoluble fiber remains unchanged as it goes through the gut.

According to prior studies, dietary fiber can help reduce some of the risk factors associated with stroke, including hypertension and high blood levels of LDL (low-density lipoprotein), also known as “bad cholesterol“.

In this latest study, the team found that for every seven-grams more fiber we consume daily, our risk of first time stroke goes down 7%. Seven grams of pasta may be found in one serving of whole wheat pasta plus two servings of vegetables or fruit.

Co-author, Diane Threapleton, M.Sc., and Ph.D. candidate, said:

“Greater intake of fiber-rich foods – such as whole-grains, fruits, vegetables and nuts – are important for everyone, and especially for those with stroke risk factors like being overweight, smoking and having high blood pressure.”

The researchers gathered and analyzed data from eight studies published between 1990 and 2012. Four of the studies focused on ischemic stroke, which occurs when a blood clot blocks the flow of oxygen-rich blood to the brain. Three focused on hemorrhagic stroke, when a blood vessel leaks blood into the brain or on its surface.

The authors combined the findings from the eight studies and factored in variables that may influence stroke risk, such as smoking and age.

The American Heart Association and UK health authorities recommend that adults consume 25+ grams of dietary fiber each day. Americans eat much less than this. The average British adult only consumes 14 grams of fiber per day.

In order to get your twenty-five plus grams, you need to consume 6 to 8 servings of grains and 8 to 10 servings of vegetables and fruits daily.

Threapleton said:

“Most people do not get the recommended level of fiber, and increasing fiber may contribute to lower risk for strokes. We must educate consumers on the continued importance of increasing fiber intake and help them learn how to increase fiber in their diet.”

Stroke in the USA – stroke is directly connected to 137,000 deaths each year in the USA. It is the fourth leading cause of death in the country. Stroke is also a leading cause of disability among those who survive strokes.

Stroke in the UK – approximately 150,000 people in the UK have a stroke each year. It is the third most common cause of death. And as in the USA, it is a leading cause of disability among survivors.

Apart from consuming an adequate amount of dietary fiber each day, the American Heart Association recommends that people get plenty of exercise and not smoke if they want to minimize their risk of stroke and other heart and vascular diseases.

Study leader, Dr. Victoria Burley, from the School of Food Science and Nutrition, University of Leeds, said “Increasing your fiber intake doesn’t necessarily mean wholesale change to your diet. It might just mean switching from white bread to wholemeal (whole grain), or from corn flakes to bran flakes. It’s a simple measure with a lot of benefits.”

The study was funded by The Department of Health (England) and Kellogg Marketing and Sales (UK) Limited.

Fruits and vegetables (1)
Fruits, vegetables, nuts and whole grains are important for adequate dietary fiber intake

In an Abstract in the journal, the authors concluded:

“Greater dietary fiber intake is significantly associated with lower risk of first stroke. Overall, findings support dietary recommendations to increase intake of total dietary fiber. However, a paucity of data on fiber from different foods precludes conclusions regarding the association between fiber type and stroke. There is a need for future studies to focus on fiber type and to examine risk for ischemic and hemorrhagic strokes separately.”

Some edible plant products are high in both soluble and insoluble fiber. For example, the skins of plums and prunes are a good source of insoluble fiber, while their pulps are rich in soluble fiber.

The following are good sources of soluble fiber:

  • Legumes, including beans, lupins, peas, etc.
  • Oats, barley, rye and chia
  • Some fruits, such as the pulp of apples and pears, plums, berries, bananas (ripe), prunes (and prune juice)
  • Some vegetables, including carrots, broccoli, and Brussels sprouts
  • Root vegetables and tubers, including onions and sweet potatoes
  • Some seeds, such as psyllium seed husk and flax seeds
  • Nuts, e.g. almonds are very high in soluble fiber

The following are good sources of insoluble fiber:

  • Whole grains
  • Wheat and corn bran
  • Legumes, including peas and beans
  • Seeds and nuts
  • Potato skins
  • Some vegetables, including celery, nopal (a Mexican cactus), zucchini (courgettes), cauliflower, and green beans
  • Some fruits, such as bananas (unripe)
  • The skin of some fruits, such as tomatoes (they are fruits) and kiwifruits

Studies over the last couple of decades have demonstrated a range of health benefits associated with high-fiber diets. Below are some examples:

Written by Christian Nordqvist