Prevention of type 2 diabetes
The number of diabetics in the whole world and in our country is growing significantly. 50 years ago, diabetes was around 2% of the population, while today it is around 10%. Another 2% of the population do not know that they have diabetes , and about 5% of the population is in the stage of so-called prediabetes . A third of our population will develop diabetes during their lifetime. Globally, the number of people with diabetes is expected to double between 2000 and 2025. Type 2 diabetes mainly contributes to this enormously increasing number of diabetics .
There is no doubt that the increase is primarily due to lifestyle changes. On the other hand, however, it is clear that type 2 diabetes is typically familial. However, this is not true genetics . About 10 so-called candidate genes for diabetes have been discovered . But it can also be created without them. Common habits and traditions apply in families – the way of cooking and eating, the relationship to exercise and sports, and probably the same intestinal bacteria in the family. It has also been proven in our population that the offspring of two type 2 diabetics will become ill with diabetes in practically 100% of cases, an individual with one diabetic parent or a sibling of a diabetic in more than 60% of cases. Monozygotic twins will both get type 2 diabetes almost 100% of the time.
In type 1 diabetes, the family incidence is much smaller. The risk in the population is below 1%, a sibling or offspring of a type 1 diabetic has a risk of about 6%, and monozygotic twins have a common incidence of about 40%.
In the field of diabetes prevention , significant medical successes have been recorded in recent years . Not only individuals benefit from prevention, but health care costs are also reduced . Type 2 diabetes is a serious disease that increases the morbidity of the population and increases the costs not only of treating diabetes, but also of treating the main complications of diabetes: heart and blood vessel disease , malignant tumors , and kidney disease .
A big problem is the low willingness of individuals to change their diet and lifestyle. That is why many people focus more on pharmacological prevention of the onset of diabetes, because it is much easier to take preventive pills than to change lifestyle.
The following factors have been found to reduce the incidence of type 2 diabetes:
- treatment of hypertension with newer drugs ( ACE inhibitors and sartans ),
- physical activity ,
- weight reduction ,
- dietary influences (see below),
- drug therapy used before the onset of diabetes (especially some drugs for obesity and diabetes).
A total of three types of measures can be used to prevent type 2 diabetes :
- Measures aimed at changing lifestyle, including changing diet and increasing physical activity . At first glance, these measures are cheap and very successful in preventing and treating type 2 diabetes, so they seem to be very effective. However, patient adherence to this change is low. If the lifestyle change was successful in the studies, it was a very expensive measure, accompanied by regular consultations with a doctor, psychologist , trainers and nutritional therapists .
- Pharmacological measuresare, as will be shown below, also very effective, although they are also relatively expensive. However, they can be implemented in the long term without much effort on the part of the patient, which is why they are successful and promising measures.
- Surgical treatment of obesityreduces the risk of diabetes up to 40x within 2 years and still 3x within ten years.
Weight reduction and diabetes prevention
Patients were previously persuaded to reduce their weight as much as possible. Today, we strive for a so-called moderate weight loss (5-10% of weight), which has the greatest impact on the incidence of metabolic complications of obesity and is also realistic for every patient. In addition, it is known that greater weight loss may not increase the effect of weight reduction on metabolic diseases, including diabetes.
In an American study (Wiliamson), 43,000 American women who had never smoked were followed. During 12 years, the incidence of certain diseases (including tumors) was evaluated depending on weight loss.
| Table 1: Risk reduction after weight reduction according to Williamson | ||
| Reduction up to 10% | Reduction over 10% | |
| DM 2nd type | -43% | -35% |
| Tumors all | -39% | -32% |
| Obesity-related tumors | -50% | -40% |
| Total mortality | -20% | -20% |
The so-called therefore, a moderate reduction in weight can reduce the incidence of diabetes by half. Another of its effects is a reduction in the incidence of cancer . Overall mortality is mainly related to the occurrence of cardiovascular complications of obesity, and there the effect of weight reduction is smaller. Weight reduction is one of the most effective procedures in the prevention of diabetes, as shown by the experience with bariatric surgery in the prevention of diabetes.
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Dietary influences and the development of diabetes
Qualitative changes in the diet also have a significant effect on the incidence of diabetes. There is no so-called superfood that reduces the incidence of diabetes. Coffee is closest to this label (see below).
A higher intake of polyunsaturated (vegetable) fats reduces the incidence of diabetes. A higher intake of saturated fat and trans fatty acids (animal fats and most industrially produced fats) increases the incidence of diabetes and exacerbates insulin insensitivity. Eating foods with a lower glycemic index and higher fiber content also leads to a reduction in the incidence of type 2 diabetes.
In one American study (Salmeron), 84,000 people were followed for 14 years using ideological questionnaires. They found 2,500 new cases of diabetes. The same caloric dose of fats and sugars (carbohydrates) had no effect on the difference in the incidence of diabetes. A 5% increase in fat intake has no effect on diabetes risk. The risk of diabetes did not change even the intake of monounsaturated ( omega-3 ) fatty acids , with which foods are often enriched today. A 5% increase in polyunsaturated fat intake reduced the risk of diabetes by 40%, while a 2% increase in trans fat intake increased the risk by 40%. Replacing 2% of energy from trans fatty acids with polyunsaturated fatty acids will reduce the risk of diabetes by 40%. Limiting animal and processed fats is key in reducing the incidence of type 2 diabetes.
When we say to a patient, “You got diabetes,” almost everyone responds, “How could I get diabetes if I don’t eat sweets?” Sugar intake really doesn’t play a role in the development of diabetes. Even anti-obesity drugs that reduce appetite do not reduce the incidence of diabetes . They act similarly to antidepressants and reduce especially the intake of sweet snacks and stress eating with sweets. According to these results, it is not recommended to reduce sugar intake, or allows intake of carbohydrates in a healthy preventive diet.
The public therefore mistakenly associates the development of diabetes with excessive sugar intake. We have reservations in educating the public, and we need to convince them of the relationship of diabetes, above all, to higher energy intake in general (large amounts of sweet drinks also play a role here) and fat intake in meat and obesity.
On the other hand, significant results were achieved when monitoring cereal fiber intake in a Finnish study. 150 people were followed for 10 years. The intake of cereal fiber reduces the incidence of diabetes by up to 60%. Whole grains have no effect on diabetes prevention.
Very interesting are the studies dealing with the intake of nuts in relation to diabetes. Nuts contain more polyunsaturated fatty acids. A higher intake of nuts reduces the incidence of type 2 diabetes by up to a third.
| Table 2: Relative risk of diabetes by frequency of nut intake (according to the American Nurses’ Health Study) | ||||
| Intake of nuts | practically never | less than once a week | 1-4 times a week | 5-7 times a week |
| Relative risk of DM2 | 1.0 | 0.92 | 0.84 | 0.73 |
So perhaps nuts can be recommended in the prevention of diabetes.
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Extensive studies have looked at the administration of omega-3 fatty acids and polyunsaturated fatty acids in capsules and dietary supplements and supplemented foods for the development of type 2 diabetes. They did not come to an unambiguously positive conclusion.
Another important issue is coffee intake. An older large-scale study is conducted on 17,000 Dutch people aged 30-60. The trend was clearly present. The risk of those who drank 7 or more cups of coffee per day was 50% compared to those who drank 2 or fewer cups per day. Other studies have shown that even 3-4 cups of coffee a day reduce the risk of type 2 diabetes. Coffee also has other positive effects on the heart and blood vessels and on the occurrence of tumors. The greatest effect is with 4 cups a day and mortality decreases by up to 20%. In women, mortality from heart and vascular diseases and from tumors is decreasing, in men only mortality from heart and vascular diseases and not from tumors.
For many years it has been argued that protein intake has no effect on the incidence of type 2 diabetes. This is indeed true of plant-based proteins. It’s more complicated with meat and animal proteins. In European and American studies, the negative influence of so-called secondary processed meat (sausages, pasties, meatloaf, hamburgers) has been proven. The risk increases more than 2x, depending on the amount of these foods in the diet. One serving per day can increase the risk by almost 2x.
Table 3: Risk of type 2 diabetes per one serving of meat product per day according to Fung:
| Type of meat product | Increase in risk |
| Red meat | 1.26× |
| Total secondary processed meat total | 1.38x |
| Sausage | 1.73x |
| Hotdog | 1.49x |
From the above, there is again a significant risk of type 2 diabetes when consuming secondary processed meat. A moderate risk was also present with red meat. Therefore, from the point of view of preventing type 2 diabetes, the intake of poultry meat and rabbit meat is optimal.
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Environmental pollution and the risk of type 2 diabetes
Air pollution, both industrial and traffic, can be conclusively linked to the risk of diabetes. In one Danish study, diabetes was more common the closer the subject lived to a major traffic artery .
Undoubtedly, other influences also apply, so-called organic pollutants or endocrine disruptors (substances or mixtures of substances that interfere with the normal functions of the endocrine system and can thus disrupt the physiological functions of hormones ). These are organic substances that penetrate the body and are stored there for a long time. They mainly come from three types of environmental pollution: from plasticizers (e.g. phthalates and bisphenols ), from flame retardants (e.g. from exhaust gases, from home electronics) and from dyes and fertilizers. All these groups of substances are closely monitored. Production processes are changing and the risk is perhaps decreasing.
Image by Foto-Rabe from Pixabay
Dietary prevention of type 2 diabetes: summary
Overall, the extensive options for dietary prevention of type 2 diabetes can be summarized as follows:
- prevention of obesity, or weight reduction of at least 5%,
- reducing the intake of saturated fats and trans fatty acids (animal and industrially hardened fats),
- a reduction in intake, especially of secondary processed meat,
- increasing the intake of polyunsaturated (vegetable) fatty acids,
- intake of foods with a lower glycemic index (i.e. with fiber),
- intake of rather complex carbohydrates (carbohydrates),
- intake of coffee and nuts.
In Czech conditions, these rules briefly mean eating fruits and vegetables, limiting the intake of animal fats. Of the fats, it is advisable to eat those that contain little trans fatty acids and at the same time eat more foods with a content of polyunsaturated fatty acids. Today, you can orientate yourself well by the information on the label.
Many studies have looked at the relationship between the development of type 2 diabetes and alcohol intake. The lowest incidence of diabetes (lower than among abstainers) is among those who drink a small quantity (up to 10) g of alcohol per day. Undoubtedly, higher income is significantly harmful. Mortality significantly depends on alcohol intake, practically equally in the diabetic and non-diabetic groups.
Diet practices are very important in the prevention of type 2 diabetes. Sadly, our population is typically exposed to foods with a high potential to cause diabetes – foods high in animal fat and processed meats.
Physical activity is also very effective in preventing diabetes. At the same time, high physical activity is not always necessary, even regular walking is sufficient. Exercise reduces the risk of type 2 diabetes by up to 50%. This applies to strength and endurance loads, including walking. At least half an hour of high-intensity exercise 3-4 times a week is recommended. As a guide, it should be verified by sweating that requires a change of clothes.
The diabetes risk score shows that the approach to diabetes prevention should be comprehensive. In this index, fruit and vegetable intake is emphasized as the most readily available dietary provision.
The calculation of the risk of diabetes is quantifiable, and the so-called diabetes risk score was introduced by Scandinavian authors . To calculate the risk, a population sample of approximately 5,000 people aged 35–64 was monitored for 10 years. The score can reach a maximum value of 20, and a value of 9 or more is considered risky for the development of diabetes.
Only a few tenths of a percent of patients with a score of 0–3 will develop diabetes. With a score of 4-8, 1-2% of the population will get diabetes, with a score of 9-12, 2-10% of people will get diabetes, with a score of 13-20, around 20-30% of people will get diabetes within 10 years. The given score can therefore be used to detect risk in clinical practice and to initiate targeted prevention.
Table 4: Type 2 diabetes risk score under 10 years (maximum value 20, high risk 13 or more, moderate 9–12)
| Patient characteristics | Number of points |
| Age 45-54 | 2 |
| Age 55-64 | 3 |
| BMI 25-30 | 1 |
| BMI over 30 | 3 |
| Waist circumference : men 94–102 cm, women 80–88 cm | 3 |
| Waist circumference: men over 102 cm, women over 88 cm | 4 |
| Pharmacotherapy for hypertension | 2 |
| History of hyperglycemia | 5 |
| Physical activity less than 4 hours per week | 2 |
| Less than the daily intake of fruits and vegetables | 1 |
Among other risk factors in men, it is known that the incidence is lower with a lower level of the male sex hormone – testosterone . However, testosterone administration should be managed by an endocrinologist in men with proven testosterone deficiency .
An interesting study was published in 2019 on the incidence of type 2 diabetes in 80,000 women in France (Tatulashvili et al.).
Table 5: Characteristics of women and the detected increase or decrease in the risk of DM2
| Characteristics of a woman | Increase or decrease in the risk of DM2 |
| Onset of menstruation at age 14 and later | 12% risk reduction |
| Menopause age 52 and later versus transition before age 47 | 30% risk reduction |
| Use of hormonal contraception (all types) | 30% increase in risk |
| Women who were breastfed themselves | 10% risk reduction |
| Number of menstrual cycles during life (470 vs. 390) | 25% risk reduction |
| Menopause Menarche Interval (38 years versus 31 years) | 34% risk reduction |
| Longer menstrual interval (32 days versus 24 days) | 23% increase in risk |
However, these effects are difficult to influence, in both men and women, with regard to these risks, it is advisable to prevent the development of obesity and maintain adequate physical activity.
Administration of phytoestrogens , for example from soy, did not have a convincing effect on reducing the risk of diabetes in studies.
Those born with a low birth weight (below 2.5 kg) are also at risk of type 2 diabetes. BMI ( body mass index : weight/height squared) decreases in children after birth . The moment when BMI stops falling and begins to rise is called BMI rebound . This usually occurs around age 7. If it is earlier, the risk of type 2 diabetes is higher; if this phenomenon occurs later, on the contrary, the risk is lower.
Type 2 diabetes is therefore a disease for which we can detect at-risk individuals today and at the same time we have effective preventive measures available. The most important measure is regular physical activity, preventing obesity and limiting secondary processed meat products in the diet.
From treatment measures, it is important to focus on people with hypertension. They live at a high risk of diabetes, and the doctor can reduce the risk by choosing the appropriate medication for hypertension. The same is the case with mental illnesses, where a number of drugs also increase the risk of diabetes, but the doctor can make the appropriate choice to choose drugs that reduce the risk. A number of patients with mental illness respond very positively to education about a healthy lifestyle, i.e. increasing physical activity and diet. They like to record their physical activity, food intake and they like to cook. It is therefore a mistake not to pay attention to these patients in the field of health education and diabetes prevention.
Prediabetes
The onset of type 2 diabetes is preceded by several years by prediabetes. This is defined as glycemia of 5.6 mmol/l to 6.9 mmol/l or so-called impaired glucose tolerance when examining the glycemic curve. The diagnosis can also be established based on the so-called glycated hemoglobin , which reflects the sugar level 3 months ago.
Prediabetes is a significant disease. It increases the risk of heart and blood vessel disease as well as diabetes. Preventive measures should be the same as for the prevention of type 2 diabetes. However, it should be more intensive because the risk of transitioning to diabetes is high. Medicines can also be prescribed by a doctor for prediabetics.
Gestational diabetes
Diabetes can exist before pregnancy and carries risks for both mother and child. Gestational diabetes refers to diabetes that develops during pregnancy. It usually disappears after pregnancy. However, a woman remains at risk of type 2 diabetes throughout her life and should follow preventive measures on an ongoing basis.
