National Cholesterol Education Month: Sorghum for the Win
September is National Cholesterol Education Month. According to the Centers for Disease Control and Prevention, high cholesterol affects 102 million adults in the United States. However, high cholesterol can affect people of all ages, not just adults (1).
Healthline defines cholesterol as a type of lipid and a waxy, fat-like substance that our liver produces naturally (2). Cholesterol is important for the formation of cell membranes, certain hormones, and vitamin D. Because cholesterol cannot travel through the blood on its own, the liver produces lipoproteins to help transport it. The two major forms of lipoprotein are low-density lipoprotein (LDL) and high-density lipoprotein (HDL). Sometimes these are referred to as “good” cholesterol (HDL) and “bad” cholesterol (LDL). If your blood contains too much LDL cholesterol, it is referred to as high cholesterol. If high cholesterol is not treated, it can lead to serious health problems like heart disease, heart attack, and stroke (2).
On the other hand, HDL cholesterol, or “good” cholesterol helps return LDL cholesterol to your liver to be removed from your body. Healthy levels of HDL cholesterol can help lower the risk of blood clots, heart disease, and stroke (2).
The most common form of heart disease often caused by high cholesterol is coronary heart disease (CHD), also called coronary artery disease. It develops when the coronary arteries become too narrow. The coronary arteries are blood vessels that supply oxygen and blood to the heart. Coronary heart disease develops when cholesterol builds up on the artery walls, creating plaques. These plaques are what cause the arteries to become narrow, which can eventually lead to a heart attack (3).
In order to keep the heart healthy, you should maintain good cholesterol levels. Certain lifestyle changes can often improve cholesterol. For some people, lifestyle changes are enough, but for others, medication prescribed by a physician might also be necessary. The Mayo Clinic shares a list of five lifestyle changes to help improve cholesterol levels (4).
(1) Eat heart-healthy foods
(2) Exercise on most days of the week and increase your physical activity
(3) Quit smoking
(4) Lose weight
(5) Drink alcohol only in moderation
More research is being done on how certain dietary ingredients affect cholesterol levels. A research article from the Journal of Nutrition studied the effects of the extractable lipid fraction of grain sorghum whole kernels and on cholesterol metabolism in hamsters (5).
According to Carr, et al. (2005), there are several components of plant-based foods that are effective at lowering cholesterol. These include plant sterols, policosanols, and phenolic compounds. Grain sorghum is a rich source of phytochemicals that includes all three of those components. Unfortunately, sorghum has been mostly overlooked for its health benefits as it is mainly used for animal feed and ethanol production (5).
In this study, male hamsters were separated into groups and fed a diet supplemented with either 0.0, 0.5, 1.0, or 5.0% grain sorghum lipids (GSL) by weight. The study lasted four weeks. Several measurements were taken during and after the study including, cholesterol absorption, plasma, liver and gallbladder lipids, and a fecal sterol analysis.
A number of results indicated positive effects when grain sorghum was added to the hamsters’ diets. Hamsters that were fed dietary grain sorghum lipids (GSL) showed significant decreases in non-HDL cholesterol (containing mainly LDL cholesterol) concentrations in a dose-dependent manner. Hamsters fed 0.5% GSL showed an 18% reduction, 1.0% GSL showed a 36% reduction, and 5.0% GSL showed a 69% reduction compared with controls (5).
Cholesterol absorption efficiency was measured, and results indicated that it was significantly reduced at each level of GSL intake. Hamsters fed 0.5% GSL showed a 62.5% absorption rate, 1.0% GSL was 59.7%, and 5.0% GSL was 56.6% absorption rate, compared to the control at 67.2%. Carr, et al. say that studies in both humans and animals have documented that plant sterols are the component of sorghum most likely to inhibit cholesterol absorption (5). Because cholesterol absorption is also directly correlated with plasma non-HDL cholesterol concentrations, the study suggests that GSL lowers non-HDL cholesterol by inhibiting cholesterol absorption. They went on to explain that “although plant sterols reduce cholesterol absorption, policosanols may inhibit endogenous cholesterol synthesis (5).”
Additional results from the study determined that liver esterified cholesterol was also significantly reduced in the GSL-fed hamsters, with a maximum reduction in the diet containing 1.0% GSL. The overall consensus was that “grain sorghum contains beneficial components that could be used as food ingredients or dietary supplements to manage cholesterol levels in humans (5).”
Read the full study here: https://academic.oup.com/jn/article/135/9/2236/4664083
(1) September is National Cholesterol Education Month. (November 2013). Centers for Disease Control and Prevention. https://www.cdc.gov/cholesterol/cholesterol_education_month.htm
(2) Everything You Need to Know About Cholesterol. (2020). Healthline. https://www.healthline.com/health/high-cholesterol
(3) What to know about coronary heart disease. (July 2019). Medical News Today. https://www.medicalnewstoday.com/articles/184130#causes
(4) Top 5 lifestyle changes to improve your cholesterol. (August 2020). Mayo Clinic. https://www.mayoclinic.org/diseases-conditions/high-blood-cholesterol/in-depth/reduce-cholesterol/art-20045935
(5) Carr, T., Weller, C., Schlegel, V., Cuppett, S., Guderian, Jr., D., Johnson, K. (2005). Grain Sorghum Lipid Extract Reduces Cholesterol Absorption and Plasma Non-HDL Cholesterol Concentration in Hamsters. The Journal of Nutrition, 135(9), 2236–2240. https://doi.org/10.1093/jn/135.9.2236