To start with, let's explain it in a simple way: cancer is not a single disease, but rather a group of diseases in which some cells in the body start to divide uncontrollably. It's like if somewhere in your body, the brakes that usually prevent cells from going crazy suddenly break. So, when these cells lose control over their growth, they start forming tumors – clusters of abnormal cells – and if these spread throughout the body, we talk about metastases, which are the most dangerous form of cancer.

Most often, it is crucial to detect cancer early, as it is curable in the early stages. But what if we could go one step further? What if we could avoid it altogether?

And here comes calcium!

We all know calcium – it is particularly associated with strong bones and teeth. It is found in milk, cheese, yogurt, as well as in leafy greens, nuts, and fish with soft bones (like sardines). But here we are not just talking about diet. We are talking about dietary supplements, where calcium is concentrated in the form of capsules or tablets.

Scientists from the American Institute for Cancer Research, in collaboration with several European researchers, conducted an extensive analysis to examine how calcium affects the risk of developing colorectal cancer – one of the most common cancers. Their findings are surprising: people who took a daily dietary supplement containing calcium (in an amount of about 500 mg per day) had a 31% lower likelihood of developing this type of cancer.

Why this particular amount?

500 mg of calcium is not much – it's about the amount found in two deciliters of milk and two slices of cheese. However, in this study, they did not consider natural calcium from food, only that in supplement form. And according to their data, this form of calcium was the most protective.

Looking closer: the study involved thousands of individuals of different ages and lifestyles. They found that calcium from food, like milk or broccoli, did not have such a pronounced effect. It was the added calcium, in the form of a capsule or tablet, that was significant.

How does calcium affect cancer cells?

Science does not yet have a definitive answer, but there are several theories. One of them suggests that calcium binds to bile acids and other substances in the intestines that could otherwise irritate the intestinal lining and cause changes leading to cancer. Calcium is thus believed to act as a cleanser, neutralizing harmful substances before they adhere to the intestinal wall.

Another theory suggests that calcium promotes the death of abnormal cells before they develop into something worse. In any case, these are mechanisms that help the body defend itself.

What do other studies say?

Not every study is the same. In 2013, a similar study conducted at the University of Auckland in New Zealand did not find such a significant impact of calcium in preventing cancer. However, they highlighted in this study that calcium can have a protective effect on prostate cancer, which is the most common type of cancer in men. So, although the effects are not always the same for all types of cancer, there is a clear pattern that calcium can positively influence the reduction of risk.

According to the UK's National Health Service (NHS), over 42,000 people are diagnosed with colorectal cancer every year in the United Kingdom. In Slovenia, according to the latest data from the Cancer Registry, this number is around 1500 per year, which means that on average, 4 Slovenes come into contact with the disease every day. If with a simple dietary supplement we could reduce this number by a third, that would mean 500 fewer cases annually – which is significant.

What does this mean?

This means that you don't have to rush into searching for expensive medicines or exotic diets. Just knowing that calcium can act as a natural protection opens up many possibilities. Of course, a healthy diet rich in fiber, plenty of exercise, minimal alcohol consumption, and quitting smoking can also help reduce the incidence of cancer.

For an adult, the recommended daily amount of calcium is about 1000 mg, which means that an additional 500 mg in the form of a dietary supplement is still within safe limits.

Important note

As with all supplements, moderation is key, including with calcium. Too much calcium can eventually strain the kidneys or cause constipation. Before starting to take it for a long time, it is advisable to consult with a doctor or pharmacist, especially if you are already taking other medications.

Folk wisdom and calcium

For centuries, in folk medicine, animal bones, dairy products, and even eggshells have been used as sources of calcium. In our regions, it was a custom for grandmothers to crush eggshells into powder, boil them, and add them to dishes – today we know that this powder is actually rich in calcium. This was a kind of homemade supplement serving the same purpose as today's tablets.

In Japan, where they have one of the lowest rates of colorectal cancer in the world, they regularly consume calcium-rich soups made from fish and seaweed – similarly, the fundamental idea here is to strengthen the intestinal mucosa and detoxify.

So what to do then?

If you are in doubt, start with small steps. Check if your diet provides enough calcium. If not, consider a supplement – especially if you are over 50 years old or have a family history of cancer. However, it is important to remember that such a supplement is not a substitute for a balanced diet but simply an addition to it.

Conclusion?

In a world where we hear about new cancer cases every day, we can take comfort in the fact that nature – along with science – offers solutions. And calcium is one of them. It's not a magic wand, but the numbers don't lie: a 30% reduced chance of one of the most dangerous diseases is more than enough reason to take a moment to think about it during your next meal. Perhaps this decision could one day save your life.