Two new studies add to the huge body of research showing that perhaps the most important dietary recommendation is to eat lots of fiber, which is found in plants. The first study is a review of 185 prospective studies and 58 clinical trials of 4,635 people followed for more than 135 million person-years (Lancet, January 10, 2019). The study shows that increasing your intake of fiber is associated with:
• reduced body weight
• lowered systolic blood pressure
• lowered LDL cholesterol
• a 15 to 30 percent decrease in heart attacks and deaths from heart attacks
• reduced risk for strokes and death from strokes
• reduced risk for type 2 diabetes
• reduced risk for colorectal cancer
You keep on gaining health benefits until you reach at least 25 to 29 grams of fiber per day. In this analysis, increasing the amount of fiber in the diet was significantly more important in preventing disease than reducing glycemic index or glycemic load (dietary efforts to lower how high blood sugar rises after meals).
The second study, called the Graandioos Study, showed that eating high-fiber whole grain products reduced inflammation, while eating the same products made with refined grains (white flour) increased risk for inflammation (The Journal of Nutrition, September 03, 2019; Scientific Reports. Aug 29, 2018;8:13036). Inflammation increases risk for heart attacks, certain cancers and premature death. In this double-blind, randomized prospective study from Holland, normal-weight, overweight and obese postmenopausal women were fed meals that contained whole wheat bread and muffins, or bread and muffins made from white flour that had been colored to resemble whole wheat, for 12 weeks. Those on the refined wheat foods had increased markers of inflammation and higher blood sugars, while those eating whole wheat foods had lowered results of the same markers. The study also showed that 12 weeks on the the higher-fiber diet reduced the amount of fat deposited in the liver and increased the diversity of gut bacteria.
If you can recognize a food as part of a plant, it will contain fiber, because fiber is the structural material of plants that is found in all vegetables, fruits, roots, whole grains, beans, nuts and other seeds. Eat large servings of these fiber-rich foods, even if you are trying to lose weight. See More Fiber from Whole Foods is Better.
If you want to lose weight, are diabetic or have a problem with constipation, use whole (un-ground) grains instead of products made from any kind of flour, even if the label claims that the flour is “whole wheat” or “whole grain.”