From genetics to lifestyle: What’s driving global cancer rates among Gen Z and millennials?
Seventeen different cancers are becoming more prevalent among younger generations…
It has been over six years since her daughter succumbed to cancer, and her mother continues to wonder the why and how of it all. Abu Dhabi-based Ayesha Chabra, a retired radiologist recalls, “She was only 19, when she was first diagnosed with leukemia, just as she was about to start her university life in the US. We went through all the chemotherapy sessions, and after what seemed like an eternity, the cancer went into remission. We thought it was over. We could breathe again.”
Yet, the disease returned with a vengeance two years later. Chabra remembers the particularly excruciating time and the oscillations between hope and despair, “She was the more practical one, realising there was no hope, even though the rest of us kept fiercely believing there could be some miracle, just not wanting to accept the truth. But of course, we had to finally accept it in the end.” Chabra is still perplexed as she wonders, what could have been the cause. “We don’t have an answer, we might never. I don’t think one ever knows, really, when and how it can strike,” she says.
Chabra underscores the cruel nature of cancer and challenges the misconception that it predominantly affects older generations. In fact, new studies reveal a troubling rise in cancer among younger people.
The 17 cancers prevalent among young generations
A 2024 study conducted by the American Cancer Society analysed data from nearly 24 million cancer patients in US cancer registries over a 20-year span, starting in 2000. Researchers examined the 34 most common cancers and grouped data by cancer type, sex, and birth cohort — grouping people based on their birth years. They also accounted for age-related risk, as cancer naturally becomes more common as people age.
The findings are alarming. The study revealed that 17 different cancers are becoming more prevalent among younger generations. For instance, people born in 1990 are two to three times more likely to develop cancers of the small intestine, thyroid, kidney, and pancreas than those born in 1955.
Moreover, recent generations are being diagnosed with cancer at younger ages. The most significant increases have been in pancreatic and small intestine cancers among people under 30. In some cases, such as bowel cancer, the rising rates among young adults have even reversed the decline previously seen in older generations, suggesting that earlier public health gains are now being lost.
A surge in specific cancers
Among the various cancers affecting young people, certain types have seen particularly sharp increases. For instance, colorectal cancer. The diagnoses in young adults have nearly doubled since the 1990s, according to a 2022 study, published in the US-based JAMA Network Open, an academic journal, which also found a rise in other gastrointestinal cancers among younger populations.
Early onset breast cancer is another growing concern. From 2016 to 2019, the incidence rate rose by nearly four per cent annually among US women, according to a 2024 study published in the National Library of Health. Even lung cancer, historically linked to older smokers, is now disproportionately affecting younger women, including those who have never smoked.
Understanding these trends requires a closer look at the potential factors, contributing to the rise in diagnoses among younger generations.
So, why is this happening?
Cancer is a notoriously complex disease, influenced by genetics, lifestyle, and environmental factors, making it hard to pinpoint a single cause for its rise among younger generations. As Soha Abdelbaky, an oncologist based at Medcare Sharjah and Ruhil Badiani, a physician at Cornerstone Clinic, Dubai explain that it’s likely a combination of factors. Diets high in processed foods and a lack of physical activity are among the most common culprits.
As the experts explain, processed foods are a form of convenience, and yet, they can cause the most harm. They are filled with artificial flavourings and preservatives, which are linked to the development of cancer. Moreover, the high intake of sodium is also quite a risk, and can even lead to stomach cancer.
The dramatic increase in obesity rates in recent decades has fueled concerns about the risk of early-onset cancer. Changes in dietary habits, including increased consumption of ultra-processed foods, coupled with sedentary lifestyles, have been identified as contributing factors. Additionally, environmental pollutants and carcinogens present in the air, water, and food supply have been implicated by researchers...
However, the link between a diet and cancer isn’t always straightforward. Rajshri Menon, a Dubai-based oncologist elaborates, “While there's strong evidence linking processed foods to various health risks, including obesity, heart disease, and type 2 diabetes, directly proving their role in causing cancer is complex. Cancer often develops over the years, making it difficult to trace back to specific dietary choices.”
How processed foods raise the risk of cancer
Obesity: Processed foods often contribute to weight gain, which is linked to increased risk for several cancers, including breast, colon, and pancreatic cancer. In fact, a 2019 study published in the US-based medical journal Lancet, found that many of the cancers growing more common among young adults are linked to obesity.
Inflammation: The unhealthy fats, sugars, and additives in processed foods can contribute to chronic inflammation, a known risk factor for cancer.
Nutrient deficiencies: Processed foods are often low in essential nutrients, which can weaken the immune system and increase susceptibility to disease.
While a definitive study directly proving the causal link between processed foods and cancer may be elusive, the overwhelming evidence suggests that reducing consumption of processed foods is a prudent step towards promoting overall health and reducing cancer risk, explain the specialists.
Genetic factors and the environment
However, as Sivaprakash Rathanaswamy, a consultant surgical oncologist at Aster Hospital Qusais points out, obesity, processed foods, aren't the only reasons for cancer among those between the ages of 18 and 40, as most might not even follow such a lifestyle, either. What happens when people still eat healthily, and do regular exercise? Quite often, as he mentions, it's the rather devious combination of genes and the environment.
While obesity, sedentary lifestyle and processed foods are always considered the lead causes for cancer, these aren't the only reasons. Cancer is far too complicated a disease. Sometimes, people between the ages of 18-40 might not even follow such a lifestyle, either. Quite often, environmental toxins and genetics also have a role to play...
Researchers are also looking into the interplay between genetics and environmental factors in the rising cancer rates among younger people. A significant breakthrough in cancer research has been the identification of specific genes linked to cancer development. According to Stanford Medicine Healthcare, a US-based medical research portal, over 90 per cent of cancers exhibit some form of genetic alteration. These changes can be inherited or acquired through environmental factors, often over a prolonged period.
As Menon explains, there are three primary types of genes that can malfunction and contribute to cancer:
Oncogenes: These genes normally regulate cell growth. When mutated, they can become overactive, leading to uncontrolled cell growth and division.
Tumor suppressor genes: These act as brakes on cell growth, and when they malfunction, abnormal cells can grow unchecked.
Mismatch-repair genes: These correct DNA replication errors, but when mutated, they allow errors to accumulate, increasing cancer risk.
Normally, our body maintains a delicate balance between cell growth and death. Cancer occurs when this balance is disrupted, due to genetic alterations that favour excessive cell growth, explain Rathanaswamy and Menon.
Moreover, exposure to environmental toxins, such as air pollution, chemicals, and plastics, may also play a role in the increasing cancer rates, explains Abdelbaky. Even the increased use of medical imaging, such as CT scans, may contribute to higher exposure to radiation over time, potentially elevating cancer risk.
Changes in cancer detection and diagnostic methods
As Badiani explains, the new methods and changes in cancer detection have also played a role in better detection of cancer among among Gen Z and millennials. “There have been advances in screening technologies, such as improved imaging techniques and more sensitive diagnostic tools, that have led to earlier and more accurate detection of cancers that may have gone unnoticed in the past,” she explains.
As a result, more cancers are being diagnosed at younger ages, adds Rathanaswamy. Additionally, increased awareness and screening recommendations, such as lowering the starting age for colorectal cancer screening, have contributed to identifying more cases earlier. This heightened detection may partly explain the perceived rise in cancer rates among these generations, explain Rathanaswamy and Badiani.
There have been advances in screening technologies, such as improved imaging techniques and more sensitive diagnostic tools, that have led to earlier and more accurate detection of cancers that may have gone unnoticed in the past
Are there any preventive measures that we can take?
While there's no guaranteed way to prevent cancer, adopting healthy lifestyle habits and being aware of your risk factors can significantly reduce your chances. Here are some effective preventive measures, explained by the oncologists.
Lifestyle modifications:
Healthy diet: Consume a balanced diet rich in fruits, vegetables, whole grains, and lean proteins. Limit processed foods, red meat, and sugary drinks.
Regular physical activity: Aim for at least 150 minutes of moderate-intensity exercise or 75 minutes of vigorous-intensity exercise per week.
Maintain a healthy weight: Obesity increases the risk of several cancers. Strive for a healthy body weight.
Protect against sun exposure: Use sunscreen with a high SPF, wear protective clothing, and limit sun exposure, especially during peak hours.
Regular checkups and screenings
Genetic testing: If you have a family history of cancer, consider genetic testing to assess your risk and discuss preventive measures.
While cancer remains a formidable opponent, understanding its risks and taking proactive steps can help mitigate its impact, especially among younger generations.