Non-Hodgkin's Lymphoma - Risk Factors

Lifestyle Factors

Because of the rapid rise in NHL, investigators are looking for lifestyle factor that may contribute to this increase.

Body Weight, Shape, and Exercise. A 2002 study looked for any associations between lymphomas and body weight or shape or amounts of exercise. Overall, the researchers did not find any important relationships between non-Hodgkin's lymphomas and these lifestyle factors.

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Dietary Factors. A number of studies have observed an association between an increased risk for non-Hodgkin's lymphomas and high consumption of red meat (beef, pork, and lamb). Some have also found a higher risk with animal fats and trans fatty acids (hydrogenated polyunsaturated fats, which are contained in hard margarines and commercial baked goods and fast foods). There appears to be no higher risk with natural polyunsaturated fats (found in most vegetable and fish oils), and in fact, fish may be protective. Medical evidence suggests that milk may also be protective.

One major study observed a reduction in risk with high intake of vegetables. Another found no protection from vegetables, but did with diets rich in fruit. Vitamin supplements have no effect on NHL.

Despite these kinds of reports, the influence of diet on the development of non-Hodgkin's lymphomas remains speculative.

Alcohol Use. Studies on alcohol have been mixed, with some showing a higher risk, some a lower risk, and some no difference at all. A 2002 study reported, for example, some reduced risk from wine drinking but not from beer or other spirits. A 2005 study found that alcoholic beverages were linked to a reduced risk of developing NHL, but that the amount of protection depended on the type of NHL.

Smoking. There is no evidence that smoking increases the risk for NHL itself, although it has been linked with high-grade and follicular NHLs in people with lymphomas.

Infections

Viruses or other microorganisms also play a role in some lymphomas. A number are being investigated:

Epstein-Barr virus, the cause of mononucleosis, is highly associated with Burkitt's disease and NHLs associated with immunodeficiency diseases. It is also a risk factor Hodgkin's disease
Adult T-cell leukemia-lymphoma, which appears to be caused by a virus known as HTLV-I, has been found in southwestern Japan, the Caribbean, and the southeastern United States.
People who have stomach inflammation due to Helicobacter pylori or H. heilmannii bacteria are at increased risk for mucosa-associated lymphoid tissue lymphomas (MALT). (The use of antibiotics to get rid of the bacteria may cause remission in some patients who have an early stage form of lymphoma in an early stage.)
Human herpesvirus 8 has been associated with NHL.
Borrelia burgdorferi, the bacteria that causes Lyme disease, has been associated with primary B-cell lymphoma.
Heavy antibiotic use during adulthood may increase risk. A 2005 study found that adults who used antibiotics more than 10 times had 1.8 times the risk of developing NHL than nonusers. However, researchers were not certain if antibiotics themselves, or the underlying infections they treated, were responsible for the increased risk.