Omega-3 Fatty Acids and Cancer

Some properties of Omega-3 make these fatty acids potential anti-cancer molecules.

Their biological and molecular characteristics, as well as their ability to interact with other nutrients such as Omega-6 fatty acids and antioxidants , lead to the hypothesis that they can significantly prevent the onset of some forms of cancer.

Not only that: these molecules also have all the credentials to be able to enhance the effect of some anti-cancer therapies .

It is known that Omega-3s compete with linoleic acid , an Omega-6 fatty acid. The latter is a key nutrient for cancer.

Through this competition, Omega-3s would be able to reduce the quantities that the tumor mass takes from the bloodstream.

But the dispute between Omega-3 and Omega-6 is not limited to this phenomenon. In fact, the 2 types of fatty acids also compete in the activity of some enzymes that promote the formation of molecules that favor the development of cancer .

Furthermore , Omega-3s make tumor cells more sensitive to the action of free radicals , highly reactive molecules that damage cellular structures. In fact, cancer cell membranes are richer in unsaturated fatty acids, a group to which Omega-3s also belong, and poor in saturated fatty acids, which on the contrary make the membrane more rigid and less vulnerable.

Finally, while linoleic acid promotes the survival of neoplastic cells by activating a gene that prevents their death, Omega-3 promotes the self-destruction of tumor cells , thus limiting the expansion of cancer.

A question of budget

Some studies have shown that the protective effect of Omega-3 on cancer depends on the balance between these fatty acids and Omega-6. In particular, the higher the ratio of Omega-3, the lower the incidence of cancer.

In fact, it has been known for some time that if guinea pigs in which the development of a tumor has been artificially induced are fed a diet characterized by high levels of Omega-6, for example with corn oil , their mortality rate increases significantly.

Conversely, in the same animals, survival rates increase if they are given high-dose fish oil , a source of high quantities of Omega-3. Not only that: in these animals, a reduction in the size of the tumor mass can also be observed.

The Anti-Tumor Properties of a Diet Rich in Omega-3

These data obtained on animals support the hypothesis that Omega-3 can delay or even reverse the development of various forms of cancer. But studies conducted on humans also seem to confirm this theory.

Already in 1997, researchers at the University of Cape Town (South Africa) had demonstrated that a diet rich in fish , the main source of Omega-3, reduces the onset of cancer.

The authors of this study compared the incidence of colon cancer among residents of Cape Town and fishermen living in coastal villages. Although the city dwellers also ate a healthy diet, with plenty of fruits, vegetables, and nutrients known to protect against colon cancer , such as fiber, calcium, and antioxidants, the likelihood of developing this form of cancer was six times lower in the coastal villagers.

Blood tests revealed that those who lived by the sea had three times higher levels of Omega-3 in their blood than those in Cape Town. The researchers explained this difference by the greater amount of fish in the diet of those living in coastal areas.

These data have, therefore, demonstrated that an adequate ratio between Omega-3 and Omega-6 protects against the onset of colon cancer.

Anti-tumor therapies: Omega-3 as adjuvants

These results do not mean that Omega-3 can be considered the definitive remedy in the treatment of some forms of cancer. The data collected over years of experiments suggest that these fatty acids can give excellent results if used in combination with traditional treatments .

An example of this effectiveness was provided by researchers at Aston University in Birmingham (UK), who tested the potential of Omega-3 in the treatment of cancer patients suffering from cachexia .

The latter is a condition of extreme weight loss associated with physical and mental weakness . Unfortunately, this disorder affects half of individuals with cancer, becoming the cause of death in 10-25% of cancer patients.

Not only that: comparing the survival of individuals affected by the same form of tumor, those suffering from cachexia have a life expectancy halved.

However, British researchers have shown that the administration of eicosapentaenoic acid (EPA), one of the Omega-3s contained in fish oil , is sufficient to significantly reduce weight loss in just three months.

Another significant example was provided by scientists from the University of Iowa (Iowa City, USA), who analyzed the usefulness of Omega-3 in enhancing radio- and chemotherapy.

Both radiation and some chemotherapy drugs kill tumor cells by generating large amounts of free radicals, which damage membranes to the point that the cells self-destruct.

For their part, Omega-3s make cell membranes even more sensitive to the action of free radicals . This leads to an amplification of the effects of both radiotherapy and chemotherapy.

These findings confirm previous observations by researchers at the Allie M. Lee Laboratory for Cancer Research at the University of Nevada, Reno, who compared the usefulness of corn oil and fish oil supplementation in rats implanted with human breast cancer tissue.

In this case too, the treatment based on a chemotherapy drug, myotomycin C , had been augmented by the combined intake of Omega-3 present in fish oil, which amplified the effectiveness of the drug by 10 times, while at the same time reducing the growth rate of the tumor.

Furthermore, the toxicity of cyclophosphamide , another well-known chemotherapeutic drug that after 60 days of treatment killed 50% of the animals fed corn oil, was eliminated by the simultaneous intake of fish oil.

More recently, the journal Nutrition and Cancer published a study from the same university in which supplementation with high doses of Omega-3, 15 grams of EPA and DHA (docosahexaenoic acid), accompanied by a reduction to minimal levels of Omega-6 intake, allowed the healing of a patient suffering from a serious form of lung cancer .

Omega-3 and breast, colon and prostate cancer: proven efficacy

Since the first studies, several researches have confirmed the efficacy of Omega-3 intake in the prevention and treatment of various types of cancer.

First of all, the usefulness of these fatty acids in the case of colon cancer has been confirmed.

A study by the Catholic University of Rome has shown that daily treatment with Omega-3, specifically 4.1 grams of EPA and 3.6 grams of DHA, of patients with precancerous colon polyps is able to significantly decrease cell proliferation in just 2 weeks.

Not only that: the therapy was found to be well tolerable and free of significant side effects.

For these reasons, Italian researchers have concluded that fish oil represents a valid aid for individuals at high risk of colon cancer.

These results were later confirmed by a group of researchers from Harvard Medical School in Boston (USA). Their studies also demonstrated that regular intake of fish oil prevents the appearance of new precancerous polyps without side effects and being well tolerated by patients.

Other forms of cancer against which Omega-3s may be effective are prostate cancer and, probably, breast cancer.

In the case of breast cancer , very interesting data were obtained by Lillian Thompson and colleagues at the University of Toronto (Canada), who studied the effects of flaxseed intake on rats.

Researchers have demonstrated that these seeds contain, in addition to the Omega-3 alpha-linolenic acid, also lignan , a molecule that is able to block the production of estrogen, female hormones.

Both of these molecules, the authors of the research explain, can reduce the size of breast tumors by 50% . But while the Omega-3 fatty acid is more effective in cases of cancer already diagnosed, lignan exerts its antitumor action by blocking the formation of new neoplasms.

A study by the Lombardi Cancer Center in Washington (USA) has instead demonstrated that the intake of Omega-3 by pregnant women with significantly high levels of estrogen reduces the probability that their daughters will develop breast cancer in adulthood.

Finally, a study conducted at the Hôpital Bretonneau in Tours (France) has demonstrated that in the case of breast cancer, the levels of DHA present in adipose tissue are a factor capable of predicting sensitivity to chemotherapy.

Treatment of metastases

Another interesting potential of Omega-3 fatty acids in the oncology field concerns their ability to reduce the incidence of metastases .

In fact, for a tumor cell to migrate away from the original cancerous mass and colonize other areas of the body (thus causing a metastasis), it must adhere to the membranes that line both blood vessels and organs. The next step is to cross these membranes.

Omega-3s actually compromise the ability of tumor cells to adhere to membranes. This function is based on the inhibition of some molecules that regulate cell adhesion processes.

And if cancer cells manage to attach themselves to the membranes, omega-3 fatty acids can interfere with the next step by blocking the production of the enzyme collagenase. This molecule is needed to dissolve the membranes and allow cancer cells to pass through.

Several studies have confirmed these potentialities. Already in 1994, a French study conducted on 120 patients affected by breast cancer demonstrated that women whose adipose tissue associated with the breast is poor in Omega-3 alpha-linolenic acid have a 5 times higher probability of developing metastases.

Subsequently, researchers at the American Health Foundation in Valhalla (New York, USA) demonstrated that in rodents a diet rich in the Omega-3 EPA and DHA prior to surgical removal of breast cancer reduces the likelihood of its spread.

Not only that: the richer the diet is in these nutrients, the smaller the volume of any metastases that form in the animals.

Cancer patients who supplement their diets with EPA and DHA may experience the same effects. In fact, human tumor cells rich in these Omega-3s that move away from the original cancerous mass may grow more slowly and be less likely to colonize other parts of the body.

A helping hand for recovery

Finally, enriching your diet with Omega-3 can help you recover good health after surgery.

The demonstration of this potential comes from a study conducted at the Deaconess Hospital in Boston (USA). According to the data obtained in this research, cancer patients recovering from gastrointestinal surgery recover more quickly if they take Omega-3 with their diet compared to patients treated with standard postoperative procedures.

In particular, the intake of these Omega-3s is associated with a reduction in digestive problems, more regular kidney and liver functions, lower triglyceride levels and a 50% decrease in the number of postoperative infections.