Fiber ain't important, eh?
http://www.healthyfellow.com/344/dietar ... t-disease/
Last week I wrote a column highlighting the most recent evidence that a high fiber diet can help protect against a variety of cancers. Today I’ll focus on the role that this dietary component can play in helping to reduce the risk of developing cardiovascular disease and all of its related complications.
In July, a study appeared in the Journal of Epidemiological Community Health. 772 volunteers who were at high risk for cardiovascular disease participated in this trial. They were all assigned either a low fat diet or one of two “Mediterranean style diets” for a 3 month period. Dietary questionnaires were administered to determine nutrient intake and blood tests were taken pre and post trial.
* The volunteers who consumed the most fiber (the upper 20%) showed the greatest declines in fasting blood sugar and total cholesterol. They also demonstrated higher HDL “good” cholesterol readings.
* LDL “bad” cholesterol only dropped significantly in those who ate the largest quantities of soluble fiber, which is found in such as foods as berries, broccoli, chia and psyllium seed supplements.
* Reductions in C-reactive protein, an inflammatory marker, were also found in those consuming the largest amount of fiber.
The authors of the trial concluded that, “increasing dietary fiber intake with natural foods is associated with reductions in classical and novel cardiovascular risk factors in a high-risk cohort”. (1)
Another recent trial presented in the European Journal of Clinical Nutrition determined that eating foods rich in any kind of fiber (insoluble, soluble or total fiber) may result in a reduced likelihood of stroke by up to 36%. These findings are based on a population study of over 26,000 Finnish male smokers with ages ranging from 50 – 69. This is, again, considered a high-risk group that apparently was afforded potentially life saving support via adequate to optimal fiber consumption. (2)
If dietary fiber does, in fact, protect from cardiovascular disease, then there must be a mechanism behind its ability to do so. Here are some of the proposed ways that roughage may shield against heart disease and strokes.
* Blood Pressure - Both population and scientifically controlled studies frequently find that higher levels of dietary fiber are associated with lower blood pressure (BP) readings – a risk factor for both heart disease and stroke. A recent study also discovered that replacing a low fiber, refined bread with a higher fiber bread resulted in decreased systolic BP and pulse pressure. (3,4,5)
* Chronic Inflammation - A recent scientific review of the medical literature examined 7 studies that related to fiber consumption and levels of the inflammatory marker, C-reactive protein (CRP). CRP may contribute to hardening of the arteries (atherosclerosis) and the accumulation of arterial plaque which can lead to heart attacks and stroke. 6 of 7 trials reported 25 – 54% reductions in CRP concentrations in those supplementing with fiber. Another trial, which followed 3,428 men (aged 60 – 79) over the course of 7 years, found that higher fiber intake not only reduced CRP levels, but also lowered other inflammatory markers (interleukin-6 [IL-6]), decreased fat build up in the liver and appeared to reduce the risk of developing diabetes. (6,7,8)
* Elevated Cholesterol - Adding fiber supplements to conventional cholesterol lowering therapy (statin medications) has an additive effect and results in greater reductions in total cholesterol, LDL cholesterol and Apo B. Since I’m not a supporter of statin medications, I was relieved to learn that this same form of fiber (hydroxypropylmethylcellulose – HPMC) can effectively lower cholesterol without any pharmaceutical assistance as well. Other forms of fiber, such as beta glucans derived from oats, are also effective in improving lipid profiles. (9,10,11)
* Metabolic Syndrome and Diabetes - Out of control blood sugar is a major health threat which contributes to many health conditions. Including plenty of fibrous food and supplements in one’s daily routine can help temper post meal blood sugar response. In essence, it slows the digestion of carbohydrates and simple sugars. This is in turn helps to support arterial function and blood flow which is impaired by a poor diet that promotes cardiovascular disease. One of my favorite recent studies involves a group of American Samoans who replaced their “modern eating habits” with a traditional Samoan meal plan (rich in coconut, fish and various sources of “plant-based fiber”). This dietary shift resulted in numerous heart-healthy changes: an increase in HDL “good” cholesterol, reduced abdominal fat and metabolic syndrome risk factors (elevated blood lipids, high blood pressure and insulin and mid-section obesity). (12,13,14,15,16,17,18)