Cycling and the reduction of diabetes in people over 50

A number of 415 million, a number destined to grow more and more to reach 650 million within the next twenty years. Behind these numbers there are people, for every figure a life is undermined by a specific disease: diabetes. The International Diabetes Federation says that 1 in 10 adults will suffer from diabetes by 2040. In addition, the IDF also notes the substantial impact that this disease has on the world economy, absorbing about 12% of health expenditure (equivalent to € 600 billion). But let's try to go beyond the figures and understand exactly what diabetes is and how to prevent this disease that is very well known in the name but little in real life.

Learn about diabetes mellitus

Man may be the captain of his fate, but he is also the victim of his blood sugar.Wilfrid G. Oakley

Glycaemia is the keystone around which the world of diabetes revolves. The same term is given to different diseases with only one common point: hyperglycaemia. This characteristic is then contained in the Latin adjective mellitus, which means “ containing honey”,” as sweet as honey”: the adjective was added by the English Thomas Willis in 1675 for the fact that the blood and urine of diabetic patients had a sweet taste, a characteristic also known already at the time of the ancient Greeks.
Glycaemia is typically between 60 and 99 mg/dl in non-diabetic individuals. The blood sugar of a non diabetic person never drops below 55-60 mg/dl. After meals this interval can reach 130-150 mg/dl, depending on the amount of carbohydrates (sugars) consumed in the diet.

Type 1 diabetes, erroneously defined in the past as 'juvenile diabetes', is a not too rare form of diabetes that generally appears in the first part of life (between 2 and 25 years). It is an autoimmune disease: the immune system quickly destroys the beta cells that produce insulin, a hormone essential for the body because it regulates the amount of glucose in the blood avoiding the phenomenon of high blood sugar. This disease is irreversible, so the patient diagnosed with type 1 diabetes will necessarily have to take daily, and for life, doses of insulin (hence the definition of insulin-dependent diabetes). The causes of this disease are still unknown but, as an autoimmune disease, it is thought to be triggered by a combination of genetic and environmental factors. Symptoms of type 1 diabetes include abundant and frequent urine, thirst and excessive hunger, sudden and unmotivated slimming.

Even if the pregnancy progresses physiologically, during the nine months some hormones produced by the placenta hinder the action of insulin. This is demonstrated by the fact that, towards the end of gestation, for the same number of calories introduced with food, a woman produces three times as much insulin as a woman of the same age that is not pregnant. It is a completely natural process, which the body generally copes with without any problems. Sometimes, however, it happens that in some women with particular genetic characteristics, the pancreas is not able to meet this need to produce more insulin, and here the blood glucose values are higher than normal: we are in the presence of gestational diabetes. Generally, gestational diabetes tends to disappear at the end of pregnancy, however, women who have suffered from it have a higher risk of developing type 2 diabetes in later life. Although it is a transient condition, if it is not diagnosed and properly treated, it can lead to consequences, even serious ones, for both mother and child.

Diabetes is treated during pregnancy mainly through a diet designed to ensure the right calorie intake necessary for the growth of the fetus, to prepare the maternal body for childbirth and breastfeeding, as well as to avoid episodes of hypoglycaemia or hyperglycaemia for the mother's body. It cannot, however, disregard the practice of physical activity. The symptoms to be controlled are: unjustified increased thirst, frequent need to urinate, loss of body weight, visual disturbances and frequent infections such as cystitis and candidiasis. In addition, there are risk factors such as obesity and familiarity with a diabetic patient that can significantly increase the likelihood of experiencing this form of diabetes.

It is by far the most common form of diabetes (affecting 90% of cases) and is typical of mature age. There are two situations: either not enough insulin is produced to meet the needs of the body (insulin secretion deficit), or the insulin produced does not work satisfactorily (insulin resistance). The result in both cases is hyperglycaemia. This type of diabetes is said to be non-insulin-dependent because the injection of external insulin, unlike type 1 diabetes, is not vital. The underlying causes of the disease are generally to be found in hereditary and environmental factors. In-depth studies have shown that there is a hereditary transmission factor, not yet well clarified, that exposes some populations or even some families to this disease.

In addition to the hereditary character, there are aspects of the person such as obesity: cells need sugar to live, the more cells they need to feed the greater the need for insulin. In obese people, therefore, insulin is produced in insufficient quantities. Sedentary life, stress and some diseases are included in the list of environmental triggers. They impose additional work on the pancreas because they increase the need for glucose and therefore insulin. If the pancreas is weakened by a hereditary predisposition to diabetes, these causes accelerate the onset of the disorder. Age also plays its role: the aging of the organism is reflected in the functionality of all organs, not least the pancreas which, as it ages, is no longer able to respond promptly to the request for insulin received.

It is important not to underestimate some risk factors that make some people more likely than others to develop type 2 diabetes.

The main risk factors are:

• Obesity (BMI greater than or equal to 30 kg/m2 for DM2)
• Physical inactivity.
• Hypertension (PAS greater than or equal to 140 mmHg e\o PAD greater than or equal to 90 mmHg)
• HDL-cholesterol (not more than 35 mg/dl)
• Triglycerides (greater than or equal to 250 mg/dl)

The symptoms are generally not as evident as in type 1 diabetes and are easily ignored, running the risk of late diagnosis.

Some of the symptoms are types of type 2 diabetes: feeling tired, frequent need to urinate even at night, unusual thirst, sudden and unjustified weight loss and blurred vision.

Preventing diabetes with cycling: mission possible

Type 2 diabetes in most cases does not involve insulin therapy, but only balanced diet and exercise. The basic cure for type 2 diabetes is therefore a balanced diet, low in fat but without excluding bread, pasta, rice, potatoes and fruit. Physical activity is the other mainstay of therapy, as it promotes the consumption of glucose in the muscles and helps to maintain normal blood sugar levels. In fact, several studies have shown that sport, proper nutrition and frequent control of blood glucose could lead to a drastic decrease - up to 40% - of cases of diabetes.

Constant physical activity - many researches now confirm - clearly improves the cells' capacity to absorb glucose, thus increasing the number of insulin receptors. In particular, one of the most suitable sports for those suffering from diabetes has proved to be cycling, since it is an aerobic activity, of a repetitive and constant type. The bike works against this disease because it activates 70% of our muscle mass, positioned in the lower limbs. And not only that. Cycling also has the advantage of being a non-traumatic sport, with faster muscle recovery times, and offers the opportunity to travel significantly longer distances than other disciplines.

An extensive Danish study, published in the journal PLOS Medicine, involved almost 25,000 men and 28,000 women between 50 and 65 years: researchers at the University of Southern Denmark (Syddansk Universitet) examined the health status of participants for several years and collected information on their lifestyle, in particular on the level of physical activity and nutrition. The aim of the work was to demonstrate that even a simple daily commitment such as cycling can help prevent diabetes. The results were clear: cycling reduces the risk of getting diagnosed with diabetes and the more you pedal, the further away you get the disease, with positive effects that are obtained even starting at a late age, after 50 years. The study shows that those who start cycling late (on average) get a 20% reduction in the risk of diabetes. The beneficial effects of two-wheelers emerge independently of other factors that may affect the risk of disease, such as nutrition, weight problems.

To understand the link with diabetes, however, we need to take a step back: Type 2 diabetes develops because of insulin resistance, i.e. when insulin hormone works less well. This is because there are excessive deposits of fat (or triglycerides) within the muscle fibers. Muscle fiber has the ability to "read" how much energy it has at its disposal, thanks to a particular enzyme, and to send a "message" if it needs more reserves. If there is fat in the fibers, the enzyme considers that the energy is already present and therefore the request to take sugar from the blood does not start. This does not activate the glucose "transporters". Initially, in the face of this phenomenon, the body compensates by producing more insulin (the hormone that regulates blood glucose levels), but in the long run this process fails because the work of the pancreas - where the insulin is produced - decreases. That's why a mild activity like cycling can positively influence this process, reversing the course: cycling burns the triglycerides, used as the first fuel, especially if physical activity is low intensity. This activates the glucose carriers and lowers blood sugar levels.

In summary, if a diabetic measures his blood sugar before and after a good ride, he sees the difference: the value goes down. But how much physical activity, though mild, do you need to do to see these benefits? Let's point out that there's no need to overdo it. In terms of reducing blood sugar levels, moderate exercise is also more effective than intense physical activity: 30 to 60 minutes of cycling per day is enough to take advantage of the anti-diabetes benefits of two wheels. A study published in Medicine and Science in Sports and Exercise showed that cycling at a moderate pace for an hour allows overweight people with diabetes to halve their blood sugar levels in the next 24 hours. Even cycling faster for only half an hour can reduce levels for an entire day, but only by 19%. What if we don't find suitable and safe outdoor itineraries? You can also cycle indoors: using an indoor exercise bike the benefit is exactly the same, which is a loss of fat mass of 1.2 kilos per month, provided you always follow a proper diet.