Does a Helicobacter infection in your stomach increase your risk of stomach cancer?
An H. pylori infection demonstrably increases your risk of stomach cancer, but the risk for any individual remains limited. Get tested if you have not yet been treated, and discuss treatment with your doctor.
Yes, an infection with the stomach bacterium Helicobacter pylori demonstrably increases your risk of stomach cancer. The bacterium has been officially classified as a proven carcinogen and is considered the single largest known risk factor for stomach cancer. Yet the risk for any individual is smaller than you might expect: of all infected people, roughly 2% ultimately develop stomach cancer, and another 20% or so develop pre-cancerous conditions. More than half of the world's population carries the bacterium.
Whether you develop cancer depends strongly on the type of bacterium. Strains carrying certain proteins, particularly CagA and VacA, are more dangerous than strains without those proteins. Alongside the bacterial type, your genetic predisposition and environmental factors also play a role. Someone with an aggressive bacterial strain and an unfavourable genetic profile therefore has a considerably higher personal risk than someone with a milder strain.
The good news is that eradicating the bacterium with antibiotics works. Large studies involving tens of thousands of people show that those who are successfully treated have nearly half the risk of stomach cancer compared with those who remain untreated. This holds true even for people aged 70 and older, and the earlier treatment is given, the greater the benefit. Treatment is even worthwhile after early-stage stomach cancer has already been removed, to prevent recurrence.
One complication is that H. pylori is increasingly resistant to the standard antibiotics. As a result, standard therapies often fail to work. If you are being treated for an H. pylori infection and symptoms persist, it is wise to ask whether the bacterium has actually been eliminated.
Based on multiple large studies and meta-analyses, including a meta-analysis of 24 studies (48,064 persons) and a Korean population study of more than 916,000 persons. The classification as a Class I carcinogen comes from the International Agency for Research on Cancer.
Does eating a lot of sugar increase my risk of cancer?
Drinking large amounts of sugar-sweetened beverages is associated with a noticeably higher risk of certain cancers, particularly early-onset colorectal cancer and liver cancer. The association is observational, but consistent enough to make reducing soft drinks and fruit juice a concrete point of attention.
Does a chronic hepatitis B or C infection increase your risk of liver cancer?
Yes, a chronic hepatitis B or C infection strongly and demonstrably causally increases your risk of liver cancer. Get tested and treated if you carry the virus, and ask your doctor about periodic surveillance.
Does being overweight increase my risk of cancer, and if so, which types?
Excess weight increases your risk of at least 13 types of cancer, including uterine, colorectal, breast and liver cancer. Losing weight reduces that risk, although it remains unclear whether all methods of weight loss are equally effective for immune defence against cancer.
Does eating from plastic packaging increase your risk of cancer?
There is clear evidence that substances that leach from plastic, such as BPA and PCBs, are associated with cancer; for micro- and nanoplastics that evidence in humans is still lacking. Limit your exposure where you can, especially when heating food in plastic containers.
Does red and processed meat really increase your risk of colorectal cancer?
Multiple large studies consistently show that high consumption of red meat, and especially processed meat, raises the risk of colorectal cancer. The evidence is strong enough to warrant consciously limiting your intake of processed meat (sausage, bacon, deli meats).
Does alcohol increase your risk of cancer, even with one drink a day?
Yes, even one drink a day increases the risk of certain cancers, particularly breast and colorectal cancer. There is no safe lower threshold; drinking less or stopping reduces your risk immediately.