By Stephanie Karl, Nutritionist at Dubai’s Upandrunning Medical Centre
Native to the Arabian Gulf, dates have been a staple food of the region for centuries and have long been known for their health benefits. As well as boosting energy, increasing iron and aiding digestion, their anti-inflammatory and antioxidant properties can treat various conditions.
In areas outside the Gulf, the intense sweetness of dates has often led to misconceptions about their place in a healthy diet. Dates are high in sugars which are classed as carbohydrates and impact blood glucose levels.
However, it is crucial to note that blood glucose rises at profoundly different rates depending on the type of carb and the amount. This article aims to clear up any confusion about carbohydrates and demonstrate why certain carbs – including dates – are beneficial for a healthy lifestyle when consumed in moderation.
Which carbohydrates are healthy?
Diets high in refined or simple carbs can lead to obesity and diabetes, while diets that restrict carbs can promote an unhealthy and unrealistic approach to nutrition and contribute to long-term health and performance issues.
Dietitians agree that it is most important to educate people about the types of carbohydrate you choose to eat and the portion size. Like fats, different sources of carbohydrates are healthier than others.
Some of the healthiest global cuisines are predominantly made up of carbohydrates such as whole grains, vegetable starches, fresh and dried fruit and pulses. These healthy carbs are more natural and deliver vitamins, minerals, fibre and an abundance of important and essential phytonutrients.
By contrast, other regional cuisines are heavily reliant on highly refined cereals, cakes and juices. These items contain easily digested carbohydrates that may contribute to weight gain, interfere with weight loss and promote diabetes and heart disease. (1,2)
What is the role of carbohydrates?
Carbohydrates are known as saccharides and provide energy for the body. Depending on how refined or simple there are, carbs will break down at differing speeds into sugars and raise blood glucose. Each gram of carbohydrate consumed provides four calories. The body breaks carbohydrates down into glucose, which is the primary energy source for the brain and muscles.
Carbs are one of three energy macronutrients that the body needs in larger amounts and these provide calories. The other two are fat and protein. Some foods contain all three energy nutrients in varying amounts such as cooked lentils. Another important aspect of carbohydrates is fibre content which slows the breakdown of nutrients for absorption and helps manage blood glucose levels. (3)
What are the different types of carbohydrates?
Carbohydrate foods are often classified as simple or complex molecules.
Simple carbohydrates
Foods which have either one sugar molecule such as glucose are easily and quickly used for energy by the body. Because of their simple chemical structure, they lead to a faster rise in blood sugar. Simple carbs include sweets, sugar, most fruit, sweet sauces, and fruit juices.
Complex carbohydrates
Longer chain sugars are classed as polysaccharides and often contain more vitamins, minerals, protein and fibre. They take longer to digest and therefore have less immediate impact on blood sugar. Some complex carbohydrates such as potatoes, white rice and white bread contain mostly starch, with little fibre, nutrients or protein.
The glycemic index – a better way to classify carbs
Complex and simple carbohydrates do not account for the direct effect on blood sugar and this is why the glycemic index (GI) was developed. It is considered a superior way to categorise carbohydrates, especially starchy foods and carbohydrates which have other nutrient qualities such as fibre and protein. By using this index, we can better understand the overall nutritional benefits of dates.
The glycemic index ranks carbohydrate foods on a scale of 0-100, with 100 being glucose. This is based on how much and how quickly they raise blood sugar levels after consumption. High glycemic index foods such as white rice are rapidly digested and cause significant fluctuations in blood sugar. Low glycemic index foods – such as whole oats or cooked lentils – are digested more slowly and cause a more gradual rise in blood sugar.
Consuming high glycaemic foods over time – which causes spikes in blood glucose – will lead to an increased risk of type 2 diabetes and weight gain.
Many factors can affect a food’s glycemic index:
- Fibre content affects the rate of digestion and drives a more gradual rise in blood sugar. (1)
- Processing speeds up digestion and absorption.
- Ripeness increases sugar content.
- Fat, protein and acid content slow the conversion of carbohydrate into sugar.
The University of Sydney in Australia maintains a searchable database of foods and their corresponding glycemic indices. Pure glucose is assigned as 100, cherries are 22 and dates are 49. Given that low glycaemic foods are below 55, dates are classified as a low GI food.
How important is portion size when consuming carbs?
Another helpful measure of a food’s effect on blood sugar is glycemic load (GL). This accounts for the portion size eaten and the type of carbohydrate in a particular serving. It is calculated by multiplying the food’s GI by the number of grams of carbs in the portion, divided by 100.
A portion of two dried dates weighs around 48g with 36g of carbs and a GI of 49. This calculates to a GL rating of 18 which is in the medium range. (3,4,5,6,7)
Rather than treating all carbs the same, we should look at the glycaemic index and glycaemic loads of foods to bring a more nutritional approach to the management of blood glucose levels. This is especially important in diabetic diets and weight management programmes. (9)
How to control your blood sugar level
The management of blood sugar levels is a challenge for many people, especially those with diabetes who are advised to be more conscious about their carbohydrate intake. (10,11)
Using the glycaemic index classification tool for rating carbohydrates, we can make better choices to understand the effects of carbs and their impact on raising blood glucose.
For health reasons we may focus on low GI carbohydrates, but other carbs can also have a place in our diet. The portion size is the key to how much can be consumed to maintain a healthy range.
Despite their sweetness, dates have a low GI due to the high fructose content and dietary fibre which slows down absorption. While further research is warranted, studies into the glycaemic effect of consuming dates, in both healthy and diabetic subjects, have drawn similar conclusions. Consumed in moderation, such as two portions, dates were found to have no significant effect on glucose levels. (11,12)
References
- Mozaffarian D, Hao T, Rimm EB, Willett WC, Hu FB. Changes in diet and lifestyle and long-term weight gain in women and men. N Engl J Med. 2011;364:2392-404.
- AlEssa H, Bupathiraju S, Malik V, Wedick N, Campos H, Rosner B, Willett W, Hu FB. Carbohydrate quality measured using multiple quality metrics is negatively associated with type 2 diabetes. Circulation. 2015; 1-3. https://www.hsph.harvard.edu/nutritionsource/carbohydrates/carbohydrates-and-blood-sugar/
- Liu S, Willett WC. Dietary glycemic load and atherothrombotic risk. Curr Atheroscler Rep. 2002;4:454-61.
- Foster-Powell K, Holt SH, Brand-Miller JC. International table of glycemic index and glycemic load values: 2002. Am J Clin Nutr. 2002;76:5-56.
- Willett W, Manson J, Liu S. Glycemic index, glycemic load, and risk of type 2 diabetes. Am J Clin Nutr. 2002;76:274S-80S.
- Jenkins DJ, Wolever TM, Taylor RH, Barker H, Fielden H, Baldwin JM, Bowling AC, Newman HC, Jenkins AL, Goff DV. Glycemic index of foods: a physiological basis for carbohydrate exchange. Am J Clin Nutr. 1981; 34: 362–366.
- Wolever TM, Jenkins DJ, Jenkins AL, Josse RG. The glycemic index: methodology and clinical implications. Am J Clin Nutr. 1991;54:846–854.
- Bantle JP, Wylie-Rosett J, Albright AL, Apovian CM, Clark NG, Franz MJ, Hoogwerf BJ, Lichtenstein AH, Mayer-Davis E, Mooradian AD, Wheeler ML. Nutrition recommendations and interventions for diabetes: a position statement of the American Diabetes Association. Diabetes Care. 2008;31(Suppl 1): S61–78.
- https://bateel.com/en_ae/nutritional-facts
- FoodData Central (usda.gov)
- AlGeffari MA, Almogbel ES, Alhomaidan HT, El-Mergawi R, Barrimah IA. Glycemic indices, glycemic load and glycemic response for seventeen varieties of dates grown in Saudi Arabia. Ann Saudi Med. 2016;36(6):397–403.
- Alkaabi JM, Al-Dabbagh B, Ahmad S, Saadi HF, Gariballa S and Al Ghazali M. Glycaemic indices of five varieties of dates in healthy and diabetic subjects. Nutr J. 2011; 10:59.
