The Good Carb for Diabetes and Heart Disease

You need these carbohydrate foods if you are obese or at risk of cardiovascular disease, prediabetes, the metabolic syndrome, or type 2 diabetes. Which carbs? Fiber-rich, whole-plant foods. In this blog, we examine the health benefits of soluble fiber. Soluble fibers (SF) dissolve in water to form a gel-like material. SF bypasses the digestion of the small intestine and slows the absorption and digestion of carbohydrates. Good sources of soluble fiber include oats, peas, beans, apples, citrus fruits, carrots, barley, and psyllium. Insoluble fiber from whole grains are essential for optimal health.

Soluble Fiber Helps Reduce the Risk of Heart Disease!

Soluble fiber helps to lower LDL cholesterol by binding bile (which contains cholesterol) in the small intestines. Specific soluble fiber lowers cholesterol in two ways. Water-soluble fibers (specifically, beta-glucan, psyllium, pectin, and guar gum) were most effective for reducing serum LDL cholesterol concentrations, without affecting high-density lipoprotein (HDL) concentrations.¹

How does fiber reduce cholesterol levels? First, the liver can convert 75% of  the cholesterol into bile. About 98% of the bile is reabsorbed into the bloodstream and is eventually returned to the liver to be secreted again. Soluble fibers have an affinity to bile acids and sweep them into the stool instead of allowing them to be reabsorbed into the bloodstream. More cholesterol is converted into bile to replace the lost bile.

Studies found interesting data illustrating that for every 10 g of additional fiber added to a diet, the mortality risk of CHD decreased by 17–35%.² β-glucan is a soluble fiber. β-glucans are predominant cell-wall components of cereal grains, particularly oats and barley. However, lower amounts of β-glucans are in other cereals such as spring wheat, winter wheat, sorghum, rye, rice, millet, and spelt. Fermentation of oat β-glucan by gut bacteria creates more of a short-chain fatty acid propionate.³ Propionate significantly inhibits cholesterol synthesis in humans.⁴

Soluble Fiber Improves Type 2 Diabetes!

Soluble fiber slows the rate of gastric emptying and steadies the blood glucose curve. It keeps glucose from entering the blood too rapidly.⁵

Soluble dietary fiber has been shown to reduce insulin resistance in female non-diabetic individuals.⁶ More recently, a randomized, double-blinded, month-long study showed that 10-20 grams of additional SF given to individuals with type 2 diabetes produced remarkable results. The fasting blood glucose, 2-hr insulin, fasting C-peptide, 2-h C-peptide, and triglyceride (TG) levels were significantly improved in both SF groups. The 20 g/day soluble DF group showed significantly improved fasting blood glucose and low-density lipoprotein levels and a significantly improved insulin resistance index. In addition, 10 and 20-g/day soluble DF (Dietary Fiber) groups significantly improved the waist and hip circumferences and levels of triglycerides compared to the control group that did not receive additional fiber.⁷

A meta-analysis of 28 studies showed that added soluble fiber at a median dose of at least 13 grams daily (half of the individuals had more, half had less)—the equivalent of one tablespoon of soluble fiber—reduced HbA1c levels by .58%. This reduction was as effective as some drugs prescribed for diabetes.⁸

It is much better to get the bulk of the 35-40 grams of fiber from whole plant foods than supplements. Why? Because healthful foods contain many antioxidant vitamins and anti-inflammatory compounds that work synergistically to improve your health. When that is not possible, supplementary soluble fiber can be helpful especially in type 2 diabetes. If you have any gastrointestinal condition, please check with your health care provider before using fiber supplements.

High Fiber Diet Is a Double Win for Diabetes!

A randomized, crossover study examined the effects of two diets on 13 individuals with type 2 diabetes mellitus following two diets, each for six weeks. Both diets, prepared in a research kitchen, had the same macronutrient and energy content. The match-up in the contest was the American Diabetes Association-recommended diet (ADA) with 24 grams of fiber (8 grams soluble fiber and 16 grams insoluble fiber) verse a high-fiber diet (HFD) of 50 grams (25 soluble fiber and 25 grams insoluble fiber). Only high-fiber plant foods were consumed: no fiber supplements were taken.⁹

The high-fiber diet reduced plasma total cholesterol concentrations by 6.7 percent, triglyceride concentrations by 10.2 percent, and very low-density lipoprotein (VLDL)cholesterol concentrations by 12.5 percent. (VLDLs carry triglycerides and other fats to the cells. LDLs function as trucks that haul cholesterol to the cells and arteries. Elevated levels of VDLD and LDL are risk factors for cardiovascular diseases). There were, in this study, more additional benefits.

By the end of the sixth week of the high-fiber diet, as compared to the ADA diet, plasma glucose concentrations were 13 mg per deciliter [0.7 mmol per liter] lower. The high-fiber diet also lowered the area under the curve for 24-hour plasma glucose and insulin concentrations, measured every two hours, by 10 percent and 12 percent HFD, respectively.

Soluble Fiber Improves Your Gut Health!

Did you know the status of your gut health helps to shape your cardiovascular health, your risk for diabetes, and even your mental health? Inadequate intake of soluble fibers reduces beneficial gut bacteria. It changes the metabolism of the gut microbiota to utilize amino acids that produce pro-inflammatory compounds and other metabolites.¹⁰

Dietary fibers, primarily soluble fibers, provide the gut microbiota’s primary energy source. SDFs have prebiotic effects by increasing the beneficial bacteria and improving the intestinal environment.¹¹ Fermentation of soluble fiber and resistant starches by gut microbes produces helpful byproducts that lower the pH, activate cancer-killing enzymes in the colon, and inhibits inflammation in the gut. Slavin J. Fiber and Prebiotics: Mechanisms and Health Benefits. Nutrients 2013, 5(4), 1417-1435; https://doi.org/10.3390/nu5041417))

Soluble Fiber Improves Appetite Control

SF increases satiety, improves appetite control, and helps maintain a healthy weight. When soluble, viscous fiber enters the intestines, it produces glucagon-like peptide (GLP-1) and peptide YY (PYY). ¹² These two gut hormones promote satiety (a sense of satisfaction after you eat). Second, dietary fiber may significantly decrease energy intake.¹³

Cooking Tip:

Legumes, cabbage, broccoli, and Brussels sprouts contain gas-producing raffinose. Studies show that soaking and rinsing beans until the water is clear before you cook them can significantly decrease their raffinose content and help prevent gas production in the colon and subsequent flatulence.¹⁴ Lentils are the least likely legume to produce flatulence. Drinking plenty of water to stay hydrated and chewing food thoroughly can help your body adjust and ease side effects like gas and bloating.

Conclusions:

Regularly consuming a diet high in fiber-rich foods, especially soluble fiber, improves blood glucose levels in type 2 diabetes and can potentially lower cardiovascular risk factors. If a person cannot achieve the daily recommended 35 to 50 grams of fiber, psyllium supplementation may be helpful. Individuals who have impaired glucose metabolism, metabolic syndrome, or diabetes should emphasize low to moderate glycemic, fiber-rich foods.

Individuals with inflammatory conditions (acute diverticulosis, IBS-D Crohn’s, ulcerative colitis, or obstruction) should counsel with their health provider before trying to incorporate a high-fiber diet. Increasing fiber gradually over a six-week framework will help reduce temporary discomfort and flatulence.

 

 

 

 

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