Eating Fish May Reduce Cancer Risk

Tinned fishRegular consumption of fish may reduce the risk of developing many forms of cancer including cancers of the esophagus, mouth, stomach, colon, and pancreas according to a study published in the American Journal of Clinical Nutrition in July 1999.

The study, conducted by Italian researchers, involved the comparison of over 8,000 people who had been diagnosed with various forms of cancer with 7,990 control subjects who were free of cancer. The study participants were from northern Italy and were younger than 75 years.

The researchers compared fish consumption amongst the cancer patients with those who were free of cancer. Fish consumption was divided into three categories, infrequent fish consumption (less than once a week), occasional fish consumption (once a week), and regular fish consumption (more than once a week).

The researchers found a strong link between fish consumption and a decreased risk of many forms of cancer. The link was strongest for cancers of the oral cavity, pharynx, and rectum, which were 50% less common amongst people consuming 2 or more servings of fish a day compared to those who consumed less than one serving a day.

Cancers of the colon, and esophagus were 40% less likely in regular fish eaters, cancers of the pancreas, stomach, larynx, and ovary were 30% less likely, and cancers of the endometrium were 20% less likely compared to those who consumed fish less than once a week.

Regular fish consumption also appeared to reduce the risk of cancers of the prostate, kidney, and gallbladder as well as both Hodgkin disease and non-Hodgkin lymphoma although the link was less significant for these cancers.

The major findings of the study are presented in the graph below.

Graph of fish consumption and cancer risk

Fish contains essential fatty acids (EFA’s) including omega-3 and omega-6 fatty acids as well as being rich in many vitamins such as vitamins A, D, E and K, and minerals such as calcium, iron, and phosphorus. Omega-3 fatty acids in particular have been shown to inhibit the growth of cancerous cells of the colon, prostate, and breast.

Most dietitians recommend people consume between 1 and 2 servings of fish a week. Some people are concerned that toxic substances in fish such as mercury may actually increase cancer risk however this study indicates that this is not necessarily the case. Even so, it is recommended that certain people such as pregnant mothers limit their consumption of certain fish known to contain high amounts of mercury. “Safe” fish that contain little or no mercury are generally the smaller fish varieties which includes salmon, cod, canned tuna, anchovies, sardines, mullet, herring, catfish, shrimp, and flounder.