Coffee consumption and the risk of diabetes

In my previous post, Is your love for coffee possibly killing you or maybe it gives you a better chance of living?, I explained what coffee is and also mentioned the two major species in the world market. That is, Coffea arabica and Coffea canephora which constitute 60% and 48% of the world market respectively.

Also, I identified that coffee is one of the most consumed beverages in the world. Coffee contains Caffeine which is responsible for the stimulating effect it have. It also contains some other components like the phenolic compound, potassium and magnesium etc. Another important thing to note from my last post is that the caffeine content in a cup of coffee will be determined by the processing method and also the species.

In case you missed it or you've probably forgotten what it's all about you can click here to read the post. Today I'm going to be talking about another impact of drinking coffee on human health which is impact of drinking coffee on diabetes.

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What is diabetes?

Diabetes is a disease that is characterized by a high level of blood sugar (that is, 126 mg/dl or higher; mg/dl = milligram per deciliter) over an extended period of time and it is caused by problems with the hormone insulin. That is, either the pancreas can no longer produce enough insulin or the body can no longer effectively utilize the insulin produced by the pancreas.

Although this disease is commonly referred to as just diabetes but to be more specific it is called Diabetes mellitus (DM) and it should not be confused with another type of group of diseases known as Diabetes insipidus (DI). Patients suffering from DI produces a large amount of dilute urine and experience increased thirst which is similar in DM but it has an unrelated mechanism to DM. Another distinction of DI from DM is that patient suffering from DM has increased sugar level and the urine also contain glucose.

The common symptoms of diabetes are frequent urination and increased rate of hunger and thirst. After a while, a patient suffering from diabetes may develop other symptoms such as itching of the skin, blurry vision, tiredness, weight loss, and heavy breathing. Chronic cases also predispose its victims to the risk of cardiovascular disease, kidney disease, and slow healing sores.

According to WHO, there are 347 million people in the world with diabetes. WHO also predicted that it will become the 7th leading cause of death in the year 2030. Also, the majority of people with diabetes in the world has type 2 diabetes.

Role of Insulin and types of diabetes

To understand the role of insulin in the body is very important to explain how the lack of it can cause diabetes. Insulin helps to maintain blood sugar level and it works together with glucagon to achieve this balance. The pancreas also produces this second hormone, Glucagon.

Whenever you consume food, it will be broken down within your body into smaller particles which the body can utilize through the process called digestion. ^{(I once made an interesting post on digestion)} The end product of carbohydrate digestion is glucose which is requires by the cells as a source of energy. When there is too much glucose in the body, the pancreas releases the hormone insulin which sends information to the liver which in turn makes the calls absorb the excess glucose. Glucose is stored in our body as glycogen.

Glucagon works similarly to insulin but in a reverse process instead. When the glucose level of the blood is too low, the pancreas releases the hormone Glucagon. Glucagon sends information to the liver which makes the body release the stored sugar in form of Glucagon.

• Type 1 diabetes: This is the type of diabetes that occur when the pancreas can no longer produce enough insulin
• Type 2 diabetes: This is the type of diabetes that occurs when the body cannot effectively use the insulin that has been produced by the pancreas.
• Gestational diabetes: This type of diabetes occur in pregnant women who do not have a previous record of diabetes but suddenly have an increased blood sugar level.

Literature review

"Coffee Consumption and Risk of Type 2 Diabetes Mellitus among Middle-aged Finnish Men and Women"

This study was conducted by Jaakko Tuomilehto and his team. The objective of the study was to determine the relationship between coffee consumption and type 2 Diabetes mellitus among middle-aged Finnish Men and Women. Finland has the highest coffee consumption in the world ^ref

Participants were gotten from surveys conducted in the years 1982, 1987, and 1992. All the participant for these 3 surveys were combined and the participants in the initial surveys were between the ages of 25 64 years. The final sample comprised of 6974 men and 7654 women between the ages of 35 64 years after people between the ages of 25 34 years were excluded because of the fewer cases of type 2 diabetes. Also, participants with incomplete data or history of stroke, coronary heart disease, or diabetes were excluded.

The result

The study had a mean follow-up of 12 years and 175,628 Person-years of follow up. (I explained Person-years in my previous post. For example, if 100 participants in this study were followed up for a year, they make 100 person-years. If the same number were followed up for two years, it will become 200 person-years.)

There were 381 incident case of type 2 diabetes. The hazard ratio of diabetes associated with daily consumption was calculated after adjustment for confounding factors.

Confounding factor is that factor that can affect but the dependent and independent variable. For example, in our topic of discussion, coffee consumption and diabetes smoking can be a confounding factor. Studies have shown that heavy coffee consumers tend to smoke and smoking may also increase the risk of diabetes.
• Hazard ratio (HR) is the ratio of a hazard to occur. If the hazard ratio is 2, that means the risk for the event to happen is twice. If it is 1, it means there is no difference and if it is lesser than 1 it means it is less likely to occur.

The authors reported the HRs for both men and women of coffee diabetes associated with the amount of coffee consumed in a day. The daily coffee consumptions are 0 - 2, 3 - 4, 5 - 6, 7 - 9, and ≥10 cups of coffee per day. HRs for women were 1.00, 0.71, 0.39, 0.39, and 0.21 while for men were 1.00, 0.73, 0.70, 0.67, and 0.45 respectively to the daily consumption of coffee. Data for both men and women were combined and the sex-adjusted and multivariate-adjusted HRs were 1.00, 0.76, 0.54, 0.55, and 0.39 respectively.

In conclusion

The authors found out that drinking coffee has an inverse association with the risk of type 2 diabetes. In other words, the more coffee you consume means the less likelihood of type 2 diabetes but the reason for this association remains unclear.

A similar result to this study was also reported in other studies. In this study in a population of Dutch men and women, the authors reported a lowered risk of type 2 diabetes is associated with coffee consumption. In another article, the authors reported to have found similar result among Japanese cross-sectional study 1916 men and 2704 women and that coffee has a preventive effect against diabetes.

Personal Notes From Me

It has been interesting for me since I started exploring the impacts of drinking coffee on human health. I am amazed by so many things I do not know before now that I now know.

It is a common knowledge that prevention is always cheaper and better than cure. Diabetes, like many other diseases that affect human, can be prevented or at least delayed by maintaining a healthy lifestyle.

Physical exercise and activities help in keeping the body in good condition. It also helps in maintaining a healthy body weight which also comes with a good look and also prevents obesity which exposes victims to greater risk of diabetes.

Avoid fast foods and junks as much as you can and go for the healthy meal. Fruits and vegetables are cheaper and healthier. Excess use of tobacco and alcohol can also expose one to the risk of the disease.

References

• https://en.m.wikipedia.org/wiki/Diabetes_mellitus
• https://en.m.wikipedia.org/wiki/Diabetes_insipidus
• https://en.m.wikipedia.org/wiki/Blood_sugar_regulation
• Coffee Consumption and Risk of Type 2 Diabetes Mellitus among Middle-aged Finnish Men and Women