The GI Chart
Source: International GI Database [Internet]. Sydney, Australia: The University of Sydney, Human Nutrition Unit, School of Molecular Biosciences. c2011 [updated 2011 December 1; cited 2012 March 26]. Available here.
The low GI values of lentils make them an ideal staple in a diabetic kitchen. In fact, numerous published studies have shown the benefits of a low-GI diet in diabetes management. In 2008, the Canadian Diabetes Association Guidelines recommend replacing high-GI carbohydrates with low-GI carbohydrates for better blood sugar control. In particular, a significant reduction in glycated hemoglobin (HgA1C), a blood marker indicating the average amount of sugar present in the blood in the last three months, was associated with a low-GI diet. Lentils, with their low GI values, are the perfect food to be eaten regularly in a diabetic diet.
Lentils and Blood Sugar Control
Pulse consumption has been associated with a reduction in developing Type 2 diabetes. Some studies have also shown that pulse intake may improve glucose tolerance. One of the reasons for such a benefit is that pulses lower postprandial (post-meal) glucose and insulin responses. One study found that lentils not only benefit the glucose response from the meal in which they are eaten, but also the subsequent meal eaten four hours later.
Lentils and Weight Loss
Obesity and overweight are risk factors for developing Type 2 diabetes. The 2011 Clinical Practice Recommendations from the American Diabetes Association recommend weight loss for all overweight and obese individuals who have diabetes or are at risk for diabetes.
Eaters of lentils and pulses generally weigh less. Data from the 1999–2002 National Health and Nutrition Examination Survey (NHANES) showed that people who regularly ate pulses weighed less and had a 23% lowered risk of increased waist size and a 22% lowered risk of being obese.
In a recent study, lentils were investigated for their effects on appetite, blood sugar, and satiety. When coupled with a high-GI meal, lentils were able to make participants feel full earlier, resulting in a decrease in overall food intake. Lower blood sugar was also observed four hours after eating the lentil meal when compared to the control group.
Lentils and Carbohydrate Counting
Some people may be using the carbohydrate-counting method to manage their blood sugar. Half a cup of cooked lentils is equivalent to one carbohydrate serving.
References
Thomas D, Elliott EJ. Low glycaemic index, or low glycaemic load, diets for diabetes mellitus. Cochrane Database Syst Rev. 2009 Jan 21;(1):CD006296.
Thomas D, Elliott EJ. The use of low-glycaemic index diets in diabetes control. Br J Nutr. 2010 Sep;104(6):797-802. Epub 2010 Apr 27.
Papanikolaou Y, Fulgoni VL 3rd. Bean consumption is associated with greater nutrient intake, reduced systolic blood pressure, lower body weight, and a smaller waist circumference in adults: Results from the National Health and Nutrition Examination Survey 1999-2002. J Am Coll Nutr. 2008 Oct;27(5):569-76.
Jenkins DJ, Wolever TM, Taylor RH, et al. Slow release dietary carbohydrate improves second meal tolerance. Am J Clin Nutr. 1982 Jun;35(6):1339-46.
Higgins JA. Whole grains, legumes, and the subsequent meal effect: implications for blood glucose control and the role of fermentation. J Nutr Metab. 2012;2012:829238. Epub 2011 Oct 30. Mollard RC, Zykus A, Luhovy
Numerous health organizations recommend eating pulses including lentils on a regular basis. Canada’s Food Guide recommends obtaining protein from sources such as lentils on a regular basis to reduce the amount of saturated fat intake. As pulses, including lentils, are naturally high in fibre and protein, the 2010 Dietary Guidelines for Americans also makes a similar recommendation as part of the MyPlate program. For better health, they recommend varying your protein food choices to include more beans and lentils, up to 3 cups per week.
Lentils and Lowering Cholesterol
The Heart and Stroke Foundation of Canada recommends a heart-healthy diet with foods that are high in fibre and soluble fibre to help lower cholesterol. Lentils are an excellent source of fibre. Just 100 grams of green lentils packs in 20 grams of fibre – that makes up 80% of your days’ worth of the fibre you need.
How Do Lentils Compare to Other High-Fibre Foods?
Researchers from the Tulane University School of Public Health and Tropical Medicine reviewed 10 randomized clinical trials and found that people eating a high-legume diet reduced their total cholesterol by 11.8 mg/DL and their LDL cholesterol (the bad cholesterol) by 8.0 mg/DL.
Lentils and Blood Pressure
In addition to the high fibre level, lentils are also good sources of potassium. Potassium is a vital mineral that aids in regulating blood pressure. The landmark Dietary Approaches to Stop Hypertension (DASH) study identified that a diet rich in produce, pulses (including lentils), and whole grains, and low in sodium, was associated with an impressive reduction in blood pressure.
Lentils and Heart-Disease Prevention
Recent scientific studies identified C-reative protein (CRP) as a marker of acute inflammation recognized as an independent predictor of future cardiovascular disease. A 2006 study found that the risk of having elevated levels of CRP was 63% lower among participants who ate a diet high in fibre. As lentils are an excellent source of fibre, that is good news for lentil lovers.
In addition to the high fibre content, lentils are also high in folate content. In addition to preventing neural-tube defects, folate also plays an important role in lowering artery-damaging homocysteine, a potential risk factor for cardiovascular disease. Out of all the plant foods, lentils contain the most folate.
Want one more reason to love heart-friendly lentils? How about their good content of magnesium. Magnesium is like a natural calcium channel blocker medication. Studies have found that high intake of magnesium is associated with lower risk of sudden cardiac arrest. One hundred grams of lentils provides about one-third of your daily magnesium needs.
Overall, intake of lentils is an important part of a dietary approach to preventing coronary heart disease. The National Health and Nutrition Examination Survey (NHANES) Epidemiologic Follow-Up Study found that people eating pulses four times or more per week had a 22% lower risk of coronary heart disease, compared to those eating pulses less than once a week.
Bazzano LA, Thompson AM, Tees MT, et al. Non-soy legume consumption lowers cholesterol levels: A meta-analysis of randomized controlled trials. Nutr Metab Cardiovasc Dis. 2011 Feb;21(2):94-103. Epub 2009 Nov 25.
Bazzano LA, He J, Ogden LG, et al. Legume consumption and risk of coronary heart disease in US men and women: NHANES I Epidemiologic Follow-up Study. Arch Intern Med. 2001 Nov 26;161(21):2573-8.
