Combating the rising rates of type 2 diabetes and hypertension has been a challenging endeavor for the medical community in the United States.
However, new research suggests that incorporating fiber into your diet may help prevent these serious health conditions.
According to the Centers for Disease Control and Prevention (CDC), approximately 1 in 3 U.S. adults has high blood pressure, and about 100 million have diabetes or prediabetes.
Both conditions significantly increase the risk of cardiovascular disease.
This week, new research to be presented at the American College of Cardiology (ACC) Middle East Conference 2019 found that patients with hypertension and type 2 diabetes who consume a high-fiber diet can significantly reduce their risk of these health issues.
What the Study Found
Researchers monitored the fiber consumption of 200 participants, with an average age of 50, all diagnosed with diabetes and hypertension. Participants were given ‘diet prescriptions’ that included detailed lists of various foods and portion sizes. Health checks were performed at the study’s outset, and then at 3 and 6 months intervals.
“I’ve done extensive work in the areas of obesity and atherosclerosis related to type 2 diabetes and hypertension. This time, I wanted to explore how dietary modifications, specifically a high-fiber diet, could help my patients improve their cardiovascular risk factors,” lead study author Dr. Rohit Kapoor, medical director of Care Well Heart and Super Specialty Hospital, told Healthline.
Participants adhered to a daily caloric intake of 1,200 to 1,500 calories, with the recommended daily allowance (RDA) for fiber set at about 30 grams. For the purpose of this study, their fiber intake was increased by up to 25 percent, reaching approximately 38 grams—equivalent to about 1.5 cups of high-fiber cereal.
Over the course of 6 months, the high-fiber diet significantly improved several cardiovascular risk factors, leading to:
- 9 percent reduction in serum cholesterol
- 23 percent reduction in triglycerides
- 15 percent reduction in systolic blood pressure
- 28 percent reduction in fasting blood sugar
“The results were remarkable! These findings highlight the importance of dietary counseling and the vital role that dietitians and diabetes educators play,” Kapoor noted.
Fiber intake was meticulously tracked through various methods, including participants sending photos of their meals via WhatsApp to verify fiber content and portion sizes. Additionally, participants received phone calls three times a week to recall and log their dietary intake in detail.
Probiotic Fiber
Dr. William Li, author of “Eat To Beat Disease: The New Science of How Your Body Can Heal Itself,” states that dietary fiber has been recognized as a key component of a heart-healthy diet since the 1970s.
He explains that foods high in fiber have long been associated with lowering cholesterol and blood pressure, improving blood sugar metabolism, and aiding in weight loss.
“It was initially believed that fiber binds to the bad cholesterol in the intestines before it can be absorbed into the bloodstream, and that fiber stimulates gut motility, helping us excrete harmful fats and sugars,” Li said. “However, researchers have since discovered that fiber may also feed our healthy gut bacteria, the microbiome.”
Li elaborated that the bacteria digest the fiber into beneficial fragments known as short-chain fatty acids (SCFAs).
These SCFAs enhance health by improving lipid metabolism, lowering cholesterol, helping control blood sugar, and reducing inflammation.
“The role of dietary fiber as a ‘prebiotic’ for gut health and its subsequent impact on metabolic changes that protect the heart is revolutionizing our understanding of how fiber defends against heart disease,” Li concluded.
Two Types of Fiber — Both Are Important
“Fiber is the part of plant foods that is non-digestible, and it comes in two forms: soluble and insoluble,” explained Shelley Wood, MPH, RDN, a clinical dietitian at Santa Clara Valley Medical Center.
Wood clarified that both types of fiber are beneficial for weight management and that a high-fiber diet can reduce the risk of certain cancers, such as colorectal cancer.
“Soluble fiber is effective in lowering unhealthy LDL cholesterol. It also helps slow down digestion, which can assist in controlling blood glucose levels in diabetics. You can find soluble fiber in foods like beans, oats, and peas,” Wood said.
In contrast, insoluble fiber helps prevent constipation and aids in removing waste from the body by speeding up the transit of food through the digestive system, thereby promoting regularity. Wood noted that insoluble fiber can be found in foods such as wheat bran, vegetables, whole grains, and fruits consumed with their skin.
“Studies have demonstrated that diets high in fiber often result in a healthier weight, which by itself is beneficial in preventing many chronic diseases,” said Wood. “Fiber is also essential for good digestive health because it acts both as a laxative and a fermentative agent, as well as providing necessary nourishment for our gut microbiota.”
Getting More Fiber in Your Diet
“The easiest way to increase your fiber intake is by sticking to fruits and vegetables. The skin of these foods, in particular, contains the majority of their fiber. So, if you’re eating an apple, leave the skin on,” advised Tasha Temple, MS, CDE, a registered dietitian at Gwinnett Medical Center in Atlanta, in an interview with Healthline.
Temple cautioned that when it comes to fiber, more isn’t necessarily better. Consuming too much fiber, especially without adequate water intake, can cause discomfort and constipation.
While recommending a daily intake of 25 to 30 grams of fiber, Temple emphasized, “Anything above that, and you need to ensure you’re drinking enough water to activate the fiber and help it move through your digestive system.”
According to the Office of Disease Prevention and Health Promotion, foods with the highest fiber content include:
- High-fiber bran ready-to-eat cereal: 14 grams in ¾ cup
- Cooked yellow, navy, or small white beans: nearly 10 grams in ½ cup
- Shredded wheat: 5 grams in 1 cup