Fatty fish protects against prostate cancer

October 31, 2006

Men who eat a lot of fatty fish run a lower risk of prostate cancer, concludes a new research paper from Karolinska Institutet (Sweden). The effect is likely to be attributable to the abundance of omega-3 fatty acids, although there is also a hereditary factor.

In Sweden, prostate cancer is by far the most common form of cancer; in countries such as China and Japan, it is much rarer. Just why the risk of developing the disease is country-dependent is hard to know for certain, but one reason could be differences in dietary habits. Substances that have often been identified as important in this context are EPA and DHA, two omega-3 fatty acids, which are found in abundance in fatty fish such as salmon, herring and mackerel. In cell experiments, scientists have seen that omega-3 fatty acids can prevent the development of cancer, but the exact value of having an omega-3-rich diet remains an open question.

To find out whether omega-3 fatty acids in food affect the chances of developing cancer, scientists asked 1,500 Swedish men with diagnosed prostate cancer about their eating habits and then compared the answers with a healthy control group. The results strongly support the hypothesis of the healthiness of omega-3 fatty acids. Men who eat salmon more than once a week run a 43 per cent less chance of developing prostate cancer than men who never eat salmon.

The scientists also analysed blood tests to find any genetic factors behind prostate cancer. Their results show that men who carried a special variant of the COX-2 gene were the only ones to benefit from the protective properties of fatty fish. The group of men who carried this gene variant and who often ate salmon had a 72 per cent lower chance than men who never ate fatty fish.

The researchers’ explanation for this is that the gene controls the outcome when omega-3 and omega-6 fatty acids, which are found in vegetable oils, compete for inclusion in hormone-like substances in the body known as prostaglandins. Prostaglandins derived from omega-3 fatty acids are anti-inflammatory and might well counteract the development of cancer, while prostaglandins derived from omega-6 fatty acids have the opposite effect.

Maria Hedelin, one of the scientists conducting the study, thinks that there are good reasons for eating fatty fish, despite the fact that 40 per cent of men actually lack the “protective” variant of the gene.

“This study shows that there is an interaction between dietary factors and our genes, but it’s always hard to say what role the genes play,” she says. “omega-3 fatty acids can still be good for men who don’t carry this gene variant in completely different ways.”

Source: Karolinska Institutet

Explore further: Research reveals link between immunity, diabetes

Related Stories

Research reveals link between immunity, diabetes

September 14, 2018
When it comes to diet-induced obesity, your immune system is not always your friend.

Big data studies scrutinize links between fatty liver disease and how cells make energy

September 14, 2018
Nonalcoholic fatty liver disease affects up to 40 percent of American adults. Though the condition produces no noticeable symptoms, one out of every five people with it will go on to develop a more serious condition called ...

Researchers discover a novel role of protein in important pathways that lead to cancer malignancy

August 31, 2018
Japanese researchers have revealed for the first time that a specific protein plays a critical role in the development and metastasis of highly aggressive prostate and breast cancer cells.

Novel therapeutic strategy for blood vessel related disorders, such as cancer and retinopathy

August 31, 2018
A multi-disciplinary team of scientists, led by prof. Peter Carmeliet (VIB-KU Leuven Center for Cancer Biology) has made several breakthrough discoveries concerning the metabolism of the individual building blocks of blood ...

Two molecules offer great potential to combat cancer and chronic infections

August 20, 2018
To fight viral infections, your immune system calls on CD8 T cells to kill the infected cells. The CD8 T cells can also be used in immunotherapy approaches to kill cancer cells, including the CAR T cell therapy currently ...

Baby poop may be source of beneficial probiotics

August 23, 2018
Probiotics seem to be everywhere these days—in yogurt, pickles, bread, even dog food. But there's one place that may surprise you: There are probiotics in dirty diapers.

Recommended for you

What can salad dressing tell us about cancer? Think oil and vinegar

September 20, 2018
Researchers led by St. Jude Children's Research Hospital scientists have identified another way the process that causes oil to form droplets in water may contribute to solid tumors, such as prostate and breast cancer. The ...

Novel biomarker found in ovarian cancer patients can predict response to therapy

September 20, 2018
Despite months of aggressive treatment involving surgery and chemotherapy, about 85 percent of women with high-grade wide-spread ovarian cancer will have a recurrence of their disease. This leads to further treatment, but ...

Testing fluorescent tracers used to help surgeons determine edges of breast cancer tumors

September 20, 2018
A team of researchers with members from institutions in The Netherlands and China has conducted a test of fluorescent tracers meant to aid surgeons performing tumor removal in breast cancer patients. In their paper published ...

Cancer immunotherapy might benefit from previously overlooked immune players

September 20, 2018
Cancer immunotherapy—efforts to boost a patient's own immune system, allowing it to better fight cancer cells on its own—has shown great promise for some previously intractable cancers. Yet immunotherapy doesn't work ...

New way to target advanced breast cancers

September 20, 2018
A cytokine signature found in certain kinds of breast cancer cells can not only serve as a diagnostic tool for HER2-negative cancers but also offer an effective treatment target.

Understanding epilepsy in pediatric tumors

September 20, 2018
Pediatric brain tumors are characterized by frequent complications due to intractable epilepsy compared to adult brain tumors. However, the genetic cause of refractory epilepsy in pediatric brain cancer has not been elucidated ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.