• by: Fondazione Valter Longo Onlus Editorial Staff
  • April 20th, 2020

Diabetes Mellitus is a metabolic disease characterized by high blood sugar levels (hyperglycemia) caused by insulin metabolism deficiency. Insulin is a hormone produced by the pancreas which controls blood sugar levels. Inadequate production and/or poor insulin sensitivity can give rise to hyperglycemia and, therefore, diabetes mellitus.

According to the World Health Organization (WHO), the number of diabetics among the world’s adult population is almost 422 million (1). In Italy, the National Institute of Statistics (ISTAT) estimates that there are over 3 million people living with diabetes: 5.3% of the entire population (2).

High blood sugar causes nearly 4 million deaths every year and the International Diabetes Federation (IDF) reports that in 2017,  global healthcare spending on diabetes among adults was 850 billion dollars (3).

Diabetes is often “sneaky”, since individuals can be asymptomatic and become aware of their condition only years after onset. The classic symptoms, in acute cases, are episodes of increased thirst and diuresis (polydipsia and polyuria), weight loss, increased appetite, fatigue, discomfort, acetone breath, and abdominal pain. In severe cases, loss of consciousness and confusion may also occur (4) (5).

Sustained high blood glucose levels can lead to several complications including: renal failure, diabetic ulcers, amputation of the limbs, loss of vision, and nerve damage. In addition, the overall risk of premature death increases: diabetic adults are 2-3 times more likely to be at risk for heart attack and stroke. In fact, about 3% of world blindness is caused by diabetic retinopathy (1) (3) .

If the current trend cannot be reversed, the WHO predicts that by 2045 the sick will reach 629 million. As a result, the WHO has agreed on a global goal to stop the increased rates of diabetes by 2025 (3) (1).

According to the epidemiological data relating to COVID-19, among the pre-existing conditions that make individuals more vulnerable to infection, diabetes is one of the main causes (6). Although the risk of contracting the infection seems to be the same as that of the general population, the data available today show that the prognosis in people with diabetes who contract the virus is worse (7). The probability of complications such as pneumonia and respiratory failure, even with a fatal outcome, is higher than that in non-diabetic individuals (8).

Before March 20, 2020, according to data from the Istituto Superiore di Sanità (ISS), there were 163 coronavirus deaths from diabetes, 33.9% of the total deaths (9). The reason for this increased vulnerability are not yet clear, but according to researchers from the Diabetes Research Institute (DRI) of the San Raffaele Scientific Institute, it seems that the major risk factors in diabetic subjects are old age and other preexisting conditions, like cardiovascular and kidney disease (7). The DRI points out that information regarding this new infection is premature and, in some ways, contradictory. The DRI therefore recommends the utmost caution in offering suggestions, since they cannot be based on solid and rigorous scientific evidence yet (7).

Diabetes is a complex condition that, in fact, can be distinguished and divided into different types:

  • Type 1 diabetes: autoimmune disease in which the immune system destroys beta cells in the pancreas that produce insulin. In this case, hyperglycemia is due to lack of insulin production and is therefore referred to as “insulin-dependent” diabetes. Type-1 diabetes is known as “juvenile diabetes”, since its onset is more common in childhood, and hardly occurs beyond the age of 40.
  • Type 2 diabetes: characterized by reduced sensitivity to insulin by the target cells and/or by the reduced secretion of insulin. The disease usually occurs in adulthood, in individuals 40 years of age or older. However, the age of onset is becoming lower and lower due to the prevalence of childhood obesity.
  • Gestational diabetes: can appear during pregnancy.
  • Other forms of diabetes: can be related to genetic defects in the pancreas or insulin response, or to pancreatic diseases caused by taking medications.

Risk Factors

To date, no measures are known for the prevention of type 1 diabetes, but effective approaches are known to prevent type 2 diabetes and all its complications, including premature death (1).

Among the risk factors for type 2 diabetes, several are related to a poor lifestyle and are thus easily modifiable:

  • Excess body weight
  • Sedentary lifestyle
  • Overeating
  • Cigarette smoking
  • Hypertension (high blood pressure)
  • Hypercholesterolemia (high levels of LDL cholesterol)
  • High triglyceride levels

Numerous studies show that proper nutrition and regular physical activity are indispensable tools for the prevention of diabetes, and represent a real component of integrated therapy for diabetic patients. It is important to consume foods rich in fiber, such as legumes, seasonal vegetables, whole grains, and nuts. The intake of simple sugars present in sweets and packaged products should be limited. Starchy foods such as pasta, white bread and white rice must also be reduced. Additionally, saturated fats in animal products, which are commonly found in cheeses, meat, and salami, as well as hydrogenated fats used in industrial products like sweet and savory snacks, chips, and crackers, should not be consumed often. Furthermore, regarding sugar intake, only one serving of fruit should be consumed daily.

In diabetic subjects, alcoholic beverages should only be consumed in small quantities, since in addition to providing calories and sugar, they can cause sudden drops in blood glucose (hypoglycemia). In general, if diabetes is under control, the quantities allowed are the same as the general population: 125 ml glass of wine per day for women and two for men, and avoid drinking on an empty stomach. Alcohol is a toxic substance for our nervous system, and in the case of neuropathy, care must be even more rigorous.

In diabetics, smoking must be avoided at all costs. Cigarettes not only expose individuals to all the complications of the disease, but above all, make it difficult to control and manage blood sugar.

Physical activity, suitable for everyone’s ability and age, contributes to weight loss and helps control blood sugar because it enables the muscles to use and consume glucose as an energy source. Exercise increases insulin sensitivity and helps lower blood pressure, as well as improves the body’s lipid profile.

Practical Recommendations

  • Monitor weight.
  • Stick to the Longevity Diet as much as possible: choose fresh vegetables and fiber-rich foods, consume protein preferably of vegetable or fish origin, and choose good sources of fat such as extra virgin olive oil and nuts.


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