Refined Carbohydrates: The Food Industry’s Dirty Little Secret

Letter The cholesterol theory of cardiovascular disease is a fraudulent endeavour that has wasted large quantities of tax payers money and has lead to unnecessary medical treatments for many millions of people. That cholesterol in the diet is the cause of cardiovascular disease is provably false. In fact, the early studies that proponents built their case upon had methodological flaws and bias that have since been exposed in the scientific literature and popular press. Evidence has been mounting against the cholesterol theory of cardiovascular disease since its inception in the 1950’s and more recently the nutritional sciences have all but abandoned the absurd line of reasoning that suggests that eggs in the diet are the cause of atherosclerosis. However, for a long period the cholesterol theory of cardiovascular disease has obfuscated the true cause of cardiovascular disease, which is likely the high intakes of refined carbohydrates and sugars in the Western diet.  

Refined carbohydrates are problematic in human nutrition because during the milling process the grain loses much of its vitamin, mineral and fibre content. Micronutrients in the grains are required for correct metabolic function and reliance on refined cereal grains in the diet results in multiple nutrient deficiencies. For example, refined grains can lose up to 85 % of the mineral bulk during processing (here). Chromium is required as a co-factor in the correct functioning of the insulin receptor and its removal during processing may increase the risk of insulin resistance. Research has shown that chronic sub-clinical deficiencies are common in Western populations and this may relate to high intakes of refined grains. Refining also removed most of the fibre from cereal grains, which increases the rate at which digestion of the starch can occur, and this in turn increases the glycaemic index (GI) and insulin response.

Highly refined carbohydrates have been shown to be associated with metabolic syndrome. Metabolic syndrome in turn is associated with elevated levels of low density lipoprotein (LDL) and very low density lipoprotein (VLDL), known risk factors for cardiovascular disease. In contrast, whole grain diets may be associated with protection from the metabolic syndrome. For example, researchers1 analysed the 3-day food records and blood of 535 healthy individuals aged between 60 and 98 years to assess the whole grain intake and risk factors for the metabolic syndrome. The overall prevalence of metabolic syndrome in this group of subjects was around 40 %. The results showed a significant inverse trend between whole grain intakes and metabolic risk factors and cardiovascular disease risk. When the deaths of 89 subjects were investigated, a significant inverse trend was found between whole grain intake and mortality from cardiovascular disease.

When the subjects were placed in quartiles based on whole grain intake, there was a clear progression of increasing fasting glucose concentration and body mass index across decreasing quartiles of whole grain intake. Placing the subjects in quartiles for refined grains showed increases in fasting glucose and a higher prevalence of metabolic syndrome across increasing quartiles of refined grains. Those subjects with higher intakes of whole grains had median intakes of 2.9 servings per day. This group of individuals had a 32 % lower prevalence of metabolic syndrome compared to those individuals consuming less than one serving of whole grains per day. The authors recommended that young adults should increase whole grain servings to over 3 servings per day in order to protect from the development of metabolic syndrome.

Taken as a whole, these results suggest that eating refined carbohydrates increases the risk of developing metabolic syndrome, a disorder that is associated with obesity, diabetes and cardiovascular disease. Despite agreement from other studies, the mainstream medical community continues to ignore the effects of refined carbohydrates on the cardiovascular system, instead focusing on cholesterol. Generally, Western diets contain too many refined carbohydrates, and this may be the reason for the high rates of lifestyle diseases associated with these populations. The Mediterranean diet may offer protection from development of the metabolic syndrome (here) because it can reverse the insulin resistance that is the causative agent. The Mediterranean diet is high in whole grains and fibre which may explain some of its protective effects. Other diets with similar high intakes of whole grain foods also appear to offer beneficial effects in this regard.


1Sahoun, N. R., Jacques, P. F., Zhang, X. L., Juan, W. and McKeown, M. 2006. Whole-grain intake is inversely associated with the metabolic syndrome and mortality in older adults. American Journal of Clinical Nutrition. 83: 124-131

About Robert Barrington

Robert Barrington is a writer, nutritionist, lecturer and philosopher.
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