(LifeWire) - Carbohydrates and cholesterol have bad reputations. Carbohydrates bring to mind calories and weight gain. They are also forbidden for those on Atkins-style weight loss diets, which have become hugely popular in recent years. Cholesterol, of course, is well known for its links to heart disease.
Now, new research suggests that carbohydrates and cholesterol are not just trouble individually, but they also work together in harmful ways. In particular, researchers have questioned whether a high-carb diet might raise levels of cholesterol in the blood.
The short answer is yes. But the full answer is more complicated and appears to depend on the kind of carbohydrates you eat. There are both "good" and "bad" carbohydrates, just as there is "good" and "bad" cholesterol.
What Exactly is Cholesterol?
Cholesterol is a waxy fat that is essential to cell membranes and brain function. But if the body has too much "bad cholesterol," known as LDL, the excess is deposited into the arteries. On the other hand, "good cholesterol", or HDL, works like a clean-up crew in the bloodstream, ferrying LDL to the liver for safe disposal.
Total cholesterol tests measures blood levels of HDL, LDL, and triglycerides (the main form of fat in food and in the body). High levels of LDL and triglycerides increase the risk for heart disease and stroke, while a high level of HDL cholesterol is considered heart-healthy.
So Where Do Carbohydrates Fit In?
Bad carbs are simple carbohydrates, such as refined sugars, white flour, potatoes, and white rice. Such foods are digested quickly and trigger a burst of insulin, the main hormone responsible for converting food into energy. But the more insulin that is produced, the more likely that excess calories will be stored as fat, resulting in higher triglyceride and LDL levels.
Good carbs are complex carbohydrates, such as whole grains, brown rice, dried beans, fruits, vegetables, and nuts. These foods are digested more slowly, so they do not cause an insulin jolt and are less likely to boost LDL and triglyceride levels.
Unfortunately, bad carbohydrates make up a large part of the typical American diet. These simple carbohydrates are found in white bread, baked and mashed potatoes, french fries, sugar-sweetened beverages, and most cookies, pizzas, and pastas.
A July 2007 study in the Journal of the American College of Cardiology reported that diets high in bad carbohydrates increase a woman's risk for developing heart disease. In a commentary within the same journal, Dr. Frank Hu, of Harvard Medical School and Harvard School of Public Health, explained that such research underscores the impact of bad carbs on cholesterol and emphasizes the need to go beyond limiting fat intake as a strategy for heart health.
Instead, Dr. Hu recommends several steps:
- Choose whole grain foods over refined grains.
- Avoid sugar-sweetened beverages, which are the source of almost half the added sugar in the American diet.
- Replace carbohydrates (especially sugars and processed flour) with healthy proteins such as beans, peas and nuts, as well as unsaturated fats, such as olive oil, canola oil and other vegetable oils.
Sources:
Merchant, Anwar T., Sonia S. Anand, Linda E. Kelemen, Vlad Vuksan, Ruby Jacobs, Bonnie Davis, Koon Teo, and Salim Yusuf . "Carbohydrate Intake and HDL in a Multiethnic Population." The American Journal of Clinical Nutrition Vol. 85, No. 1 (January 2007): 225-230. 21 Feb. 2008
<http://www.ajcn.org/cgi/content/abstract/85/1/225>.
Hu, Frank B. "Diet and Cardiovascular Disease Prevention: The Need for a Paradigm Shift?" The Journal of the American College of Cardiology Vol. 50 (3 July 2007): 22-24. 21 Feb, 2008
<http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6+18-4PON236-C&_user1>.
Beulens, Joline W.J., Leonie M. de Bruijne, Ronald P. Stolk, Petra H.M. Peeters, Michiel L. Bots, Diederick E.Grobbee, and Yvonne T. van der Schouw. "High dientary glycemic load and glycemic index increase risk of cardiovascular disease among middle-aged women: a population-based follow-up study." Journal of the American College of Cardiology 50.1 (3 July 2007): 14-21. Science Direct. 26 Feb. 2008 <http://www.sciencedirect.com.ezp1.harvard.edu/science?_ob=ArticleURL&_udi=B6T18-4P0N236-8&_user=209690&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000014438&_version=1&_urlVersion=0&_userid=209690&md5=404385561844269aea681ed4bb1b6cc7>.
