Diabetes and diet: Food choice and combination

This is a very important aspect in the prevention and management of diabetes. It is so important that the World Health Organization (WHO) monitors the diet recommendation for diabetics every five years and reviews the approved diet in accordance with new research and advances in medicine. The St Vincent Declaration of October 1989, marked the point at which five yearly targets were introduced in the management of diabetes.
This is aimed at reducing the diabetes disease burden in the world. It also means that health practitioners have to update their knowledge because serious mistakes have been made in the past by following out-dated recommendations which have been found to be harmful. I will mention some of them as I proceed.
A brief history of diet in diabetes treatment
Despite the fact that diabetes was first described in 600BC, people with diabetes were placed on a starvation diet until 1921. Most of them died as a result of the ailment. The discovery of insulin helped to prolong life. Between that time and the 1970’s, carbohydrates were misunderstood and a high-fat, low-carbohydrate diet was encouraged. This diet led to weight gain and a high incidence of cardiovascular complications (heart related diseases) in diabetics. Today, a lot of people are still misinformed and are following a low carbohydrate diet (it is similar to the case of the flat earthers!). Due to continuous research, by the 1970’s, carbohydrates were better understood and had been further classified into ‘Simple’ and ‘Complex’ carbohydrates. A lot of research in the 1980’s led to the understanding of the relationship between food and blood glucose level, and the emergence of the classification of food based on how rapidly they raise blood sugar level when eaten, i.e. Glycaemic Index (G.I). Complex carbohydrates have a low G.I which means they release sugar slowly, thereby causing a low insulin requirement. Simple carbohydrates have a high G.I and conversely release sugar fast, leading to a high demand for insulin. The 1990’s witnessed a fine-tuning of the recommendations for diabetics’ diet. Today, it is accepted that the management of patients with type 2 diabetes should include individualised nutrition therapy and an exercise programme. Diet therapy must be tailored to a patient’s financial status. A diabetic can lead a normal healthy life and it can also be prevented in certain pre-disposed persons.
Classes of food and their recommendation
You may have been wondering about the importance of fats and protein in the management of diabetes. Well, I had to stress the type of carbohydrate because it is the most important factor, and accounts for 50% of the food intake. Protein – It is advised that protein from vegetable sources be eaten rather than animal sources. This is partly due to the fact that the latter tends to be high in saturated fat. Moderate protein consumption is also advised, and diabetics who have renal problems are to be placed on a low-protein diet. Fat – It is advised that the fat intake of a diabetic should be reduced, with saturated and trans fats e.g. butter becoming very minimal. Saturated fat may affect insulin sensitivity. Unsaturated fats like soya bean oil, groundnut oil, olive oil, should be used in cooking. I had explained earlier that insulin encourages the depositing of fat from food while at the same time, preventing the burning of stored fat in the body for energy.
This increases the blood cholesterol level, which we know is bad for the health. For sweetening food, fructose is better than sucrose. Fructose is present in fruits and honey, while sucrose is the white table sugar. Fructose causes a lower insulin response in both healthy and diabetic patients. Fructose in conjunction with a high fiber, high carbohydrate and low-fat diet in type 2 diabetic patients, leads to improved fasting glucose level. I have to mention the fact that there are sweeteners called non-nutritive such as saccharin, aspartame. The safety of non-nutritive sweeteners have been questioned, but some people find them useful as an alternative to sucrose. Alcohol – It is relevant that diabetics avoid alcohol consumption. The moderate consumption of red wine (one glass a day), may have beneficial effects for the heart.
Other alcohol consumption may cause hypoglycaemia (blood sugar level below normal) and has also been associated with an increased risk of cataracts. There is also need for increased Vitamin C intake because the human eye contains 60 times the concentration in blood plasma and it may help to prevent eye lens modification. Another vitamin that is good for preventing or delaying ocular effects of diabetes is vitamin E. There is a general need for a wide variety of vitamins and minerals to be obtained from the diet. Chromium is the mineral that is most important in the function of the pancreas. It is believed to potentiate the action of insulin. Its supplementation is not advised and it is better from dietary sources. Foods with a high chromium content are, whole grains, legumes, nuts and brewer’s yeast. It is generally advised that a diet rich in fruits and vegetables with the corresponding benefit of antioxidants is good for both diabetics and normal people. Dietary sodium restriction is an important part of diabetic management. Sodium has been implicated in the development of insulin resistance, elevation of blood pressure and increase in calories from food. Sodium reduction is difficult for people who eat a lot of processed food because it is added in many forms during food processing, both to enhance food taste and as a preservative, e.g. as sodium chloride (salt) it is used in almost all foods, sodium bicarbonate in pastries and soft drinks, sodium bisulphite in wines, etc. Dietary sodium should be kept as low as possible, because there is enough in food from nature without need to add any at all. Fibre is highly desirable in the diet of both diabetic and non-diabetic people. Fibre may be further classified into soluble and insoluble fibre. Soluble fibre is the more beneficial fibre. Fibre has the effect of reducing the glycaemic index of food by delaying digestion in the stomach and causing a slower release of sugar. High fibre foods are filling and satiating when eaten. Fibre also lowers cholesterol level in the blood.
Factors Affecting Glycaemic Index and Tips for Everyday Food Choice
Some of the factors affecting the Glycaemic Index of food include;
a) The physical form of the food- The intact fibrous coat of legumes likes beans, corn, makes sugar release slower. Processed and finely ground food like white wheat flour are easily digested and have a high G.I. while coarse wheat bran has a low G.I.
b) Cooking methods – cooking and processing of food makes the starch gelatinize and more available.
c) Fibre - Corn pap milled and used without separating the outer coat would have a lower G.I., than the sifted white one.
d) Sugar – The presence of sugar and the type of sugar, influences the G.I. When plantain ripens, the complex carbohydrate in the unripe plantain is converted to sugar therefore, unripe plantain has a lower G.I. than ripe plantain.
e) Type of starch
Tips: The way we combine our food when we eat them can help to lower the G.I. of the food e.g. a plate of rice with vegetables will have a lower G.I than just a plate of rice. Beans of yam pottage cooked with a generous amount of vegetables e.g. Ugwu (pumpkin leaves), will have a lower G.I. than either food on its own. Potatoes eaten with the skin will have a lower G.I than peeled potatoes. Yam, sweet potatoes and coco-yam are better than potatoes and have a lower G.I. An orange eaten with the flesh inside, is better than just sucking the juice. Fried foods are better avoided.
Meal frequency: Food intake should be planned to prevent large swings in blood glucose level. The common three meals a day system of feeding allows for too wide a gap between meals and large meals when taken. This causes a high blood sugar level after a meal (post-prandial glycaemia) and low blood sugar before the next meal. These meals, broken up into half their quantity and taken at well spaced intervals of about 3-hourly, will give a more steady blood level. Where the nature of work does not permit this, healthy snacks in between the mealtimes may come in handy. For patients on insulin, flexible regimen for insulin administration such as the use of pen-injectors is advised.
I do hope that these articles on Type 2 diabetes have been helpful. I will reply each of the mails I have received directly. I have tried to explain in simple language, basic critical points. I also pruned down a lot of information and stuck to the essential ones. A lot of funds needs to be pumped into research on our traditional foods because very useful information is being lost as old folks are dying with invaluble knowledge.