I advise my diabetic patients and people who are trying to lose weight to avoid all foods made with refined carbohydrates because they cause a high rise in blood sugar. Even if you are not diabetic (yet) and are not concerned about your weight (yet), you should understand why the large amounts of refined carbohydrates in the typical Western diet can harm you.

Refined sugars and refined grain products (anything made from flour, milled corn or white rice) have had vitamins, minerals and other nutrients removed in processing. Some but not all of these nutrients may be added back in enriched flours or fortified foods.

From 1600 to 1930, more North Americans died from the vitamin deficiency diseases, beriberi and pellagra, than from any other cause. These diseases disappeared when governments legislated that all flour had to have three vitamins, thiamin, niacin and riboflavin left in or added back. Over the last 70 years, the incidence of heart attacks in the United States had been increasing until Congress legislated that folic acid must be left in or added back to flour; now the heart attack rate is decreasing. However, diabetes and obesity continue to increase at alarming rates in all age groups.

Where carbohydrates are found in plants, the B vitamins are also found. Carbohydrates are combinations of sugars, either as single sugars or chains of sugars from two to millions. When you eat carbohydrates, enzymes in your intestines break them down into single sugars and only single sugars can pass from your intestines into your bloodstream, where they can be used for energy, stored as sugar in your liver or muscles or be converted to fat. Many different chemical reactions then break down sugar one step at a time to release energy. Each reaction must be started by an individual chemical called an enzyme and the B vitamins are parts of these enzymes that start the reactions that break sugar into energy.

If any of the B vitamins are not available, the conversion of carbohydrates to energy is blocked. Instead, the carbohydrates are converted to fat which:

* raise blood levels of triglycerides;
* uses up the good HDL cholesterol, which lowers blood levels of HDL and increases risk for heart attacks;
* is stored in fat cells primarily in your abdomen;
* helps form plaques in arteries, which makes them stiff and raises blood pressure; and
* blocks insulin receptors on cells so you cannot respond adequately to insulin. This causes you to produce more insulin, which makes you hungrier, makes you store more fat, and leads to diabetes in susceptible people.

When you eat carbohydrates that have been separated from the B vitamins, minerals and perhaps other nutrients which have not yet been identified, you increase your risk for diabetes, obesity, heart attacks and high blood pressure. We do not have enough dependable research to know if taking the B vitamins separately (in other foods or supplements) is as healthful as eating the B vitamins as they come in nature, paired with the carbohydrates in whole grains, beans and other seeds, vegetables and fruits. Your best bet is to eat your carbohydrates as nature packages them, and limit or avoid those that have been refined into sugars, flour and milled grain products.