Past research has suggested that people who eat lots of fiber have a lower risk of heart disease. Now, new research published in the BMJ finds that increasing dietary fiber intake after a heart attack may prolong survival.
Each year, around 1 million people in the US have heart attacks. According to the National Heart, Lung and Blood Institute, many people survive heart attacks and go on to live full, active lives. But subsequent survival after such an adverse event can be dependent on lifestyle changes.
The research team, including Shanshan Li of the Departments of Epidemiology and Nutrition at Harvard School of Public Health in Boston, MA, says that it is important to identify what steps heart attack patients need to take in order to modify their lifestyle and increase survival.
With this in mind, the investigators set out to determine whether increasing fiber intake following a heart attack may impact long-term health.
They assessed data from the Nurses' Health Study involving 121,700 female nurses, alongside data from the Health Professional Follow-up Study involving 51,529 male health professionals. Both studies required participants to complete questionnaires regarding their lifestyle habits every 2 years.
High fiber intake after heart attack 'reduces overall death risk by 25%'
The team identified 2,258 women and 1,840 men who survived a first heart attack, or myocardial infarction (MI). During the 9-year follow-up, 682 of the women and 451 of the men died.
All subjects were divided into one of five groups dependent on their fiber intake after a heart attack.
Researchers found that increasing fiber intake after a heart attack may prolong survival.
Results of the study revealed that participants in the top quintile - those who had the highest fiber intake - had a 25% reduced risk of dying from any cause in the 9 years after their heart attack, compared with those in the bottom quintile who ate the lowest amount of fiber.
Overall, the team found that the higher a patient's fiber intake after a heart attack, the longer they were likely to live.
These results remained significant even after adjusting for other factors that may influence long-term survival after a heart attack, such as age, medical history and diet and lifestyle factors.
The researchers then assessed the effects of three different fiber types - cereal, fruit and vegetable. They found that only cereal fiber was strongly linked to increased long-term survival following a heart attack. Participants' main source of fiber was from breakfast cereal.
Since heart attack survivors have a higher risk of death than the general population, the research team says they are often motivated to make lifestyle changes. However, they point out that many heart attack survivors are initially treated with medication. Reliance on such dugs can diminish the desire to adopt a healthier lifestyle.
As a result, they note that:
"Future research on lifestyle changes post-MI should focus on a combination of lifestyle changes and how they may further reduce mortality rates beyond what is achievable by medical management alone."
According to the Dietary Guidelines for Americans from the US Departments of Agriculture and Health and Human Services, women should consume at least 25 g of fiber each day and men should consume at least 38 g a day. However, less than 5% of Americans follow these recommendations.
High fiber intake has been associated with an array of health benefits. Earlier this year, Medical News Today reported on a study suggesting that a diet rich in fiber may protect against asthma, while other research indicates that a fiber-rich diet may protect against obesity and diabetes.
According to the Mayo Clinic, many fruits - particularly raspberries, pears and apples - are a good source of fiber. Other foods high in fiber include grains, cereal, pasta, nuts, seeds and many vegetables, such as artichokes, broccoli and green peas.