Is it true that smoking causes cancers other than lung cancer?
Smoking demonstrably causes several types of cancer beyond the lung, including bladder and liver cancer. Stopping completely reduces your overall cancer risk the most.
Smoking demonstrably causes more cancers than lung cancer alone. The link is strongest for bladder cancer: of all the cancers for which smoking has been identified as a cause, bladder cancer has the highest proportion attributable to it. Two large combined studies confirm this consistently. Smoking is also an established risk factor for liver cancer, alongside hepatitis infections and excess weight.
Smoking a water pipe (hookah) is not safe either. Compared with non-smokers, water pipe smokers have almost three times the risk of head and neck cancer, almost twice the risk of oesophageal cancer, and more than twice the risk of lung cancer. There are also signals pointing in the same direction for stomach and bladder cancer, but those are based on less well-designed studies. The idea that water pipe smoking is 'less harmful' than cigarettes is therefore not correct.
Nicotine itself also appears to contribute to stomach cancer through harmful processes in cells, but this has so far been shown almost exclusively in laboratory settings, not in people. The practical significance of this finding remains unclear.
Cutting down on smoking helps to some extent: people who smoke more than half as many cigarettes per day as before do lower their risk of lung cancer compared with heavy smokers. For the overall cancer risk as a whole, however, smoking less makes no demonstrable difference. Stopping completely is the only approach that genuinely reduces that risk.
This answer draws on several combined overviews and summaries of multiple studies. The researchers themselves point out that the studies differed considerably from one another in design and population, which reduces the certainty of some findings. The evidence is most convincing for bladder cancer and liver cancer. For stomach and bladder cancer in water pipe smokers, and for the role of nicotine in stomach cancer, the studies are clearly weaker or have been done only in the laboratory.
Can long-term inflammation in your body cause cancer?
Prolonged inflammation is one of the most robustly supported risk factors for cancer. Well-known causes such as smoking, substantial obesity, and certain infections are modifiable, so addressing them concretely lowers your risk.
Does sitting a lot increase my risk of cancer, even if I exercise?
Sitting a lot increases your risk of certain cancers, even if you exercise. In addition to moving regularly, try to reduce your sitting time itself, because the two only partially compensate for each other.
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 a lot of sugar increase my chances of getting cancer?
Drinking a lot of sugary drinks is associated with a higher chance of breast, prostate, and bowel cancer. Whether sugar itself is the cause is not yet certain, but the studies do give reason to limit your soft-drink intake.
Does poor sleep increase my risk of cancer?
Poor sleep, and sleep apnea and night-shift work in particular, is associated with an increased cancer risk. Whether you personally face a higher risk depends on which sleep problems you have; at the very least, have any apnea symptoms evaluated.
Does having type 2 diabetes increase your risk of certain cancers?
Research shows that type 2 diabetes is associated with a higher risk of certain cancers, and that link runs largely through the excess weight that often accompanies it. For most cancers, commonly used diabetes medicines show no raised risk.