Fish Versus Flax

Omega-3 fatty acids are protective nutrients that provide a wide range of health benefits. I’ve been recommending my patients get more of these vital oils because study after study has shown that they promote cardiovascular health, improve cognitive functioning, and inhibit tumor growth.

You can derive the benefits of omega-3s from both marine and plant-based sources, but which ones pack the most punch healthwise? A new study has some answers, but before I get to the results let me say a quick word about why adding more omega-3 to your diet is so important to your health.

Why You Need Omega-3 in Your Diet

Omega-3 is an essential nutrient that your body simply cannot do without. This polyunsaturated fat is found naturally in the brain and it is critical to cognitive performance and development through all stages of life.

The supernutrient also plays an important role in combating inflammation, keeping your immune system in top form, and lowering your triglyceride levels. Here are just a few of the well-established benefits of omega-3:

  • Boosts overall cardiovascular health by lowering triglycerides and decreasing the risk of arterial plaque.
  • Counteracts depression and cognitive decline.
  • Promotes eye health and lowers the risk of macular degeneration.
  • Supports fetal brain development.
  • Reduces factors that feed metabolic disorders such as obesity and diabetes.
  • Helps reduce and prevent insomnia and sleep apnea.
  • Decreases menstrual cramps in about 3 out of 4 women.
  • Lowers the risk on many cancers.

New Evidence On the Advantages of Fish-Based Omega-3 Oil

As most of my regular readers know, I usually recommend getting the bulk of your calories from plant-based foods. But when it comes to omega-3, the evidence indicates that marine sources are more effective than plant sources when it comes to tumor-fighting properties.

That’s the conclusion of new research published in the Journal of Nutritional Biochemistry, which compared the tumor-inhibiting capacity of three different types of omega-3 fatty acids:

  • Alpha-linolenic acid (ALA), a plant-based fatty acid found in flaxseeds, canola oil, and hemp seeds.
  • Eicosapentaenoic acid (EPA), a marine source found in fish such as wild salmon, mackerel, tuna, and sardines.
  • Docosahexaenoic acid (DHA), derived from phytoplankton such as seaweed.

This study compared the effects these different omega-3 formulations on mice that have an aggressive human form of breast cancer called HER-2. The researchers found that both plant and fish sources of omega-3 can suppress tumor growth, but the benefits in terms of cancer reduction really are unique among oils derived from marine (EPA and DHA) sources.

Although this was a mouse study (and my patients are all humans), these results may have very important implication for human health. Professor David Ma explains the significance of his research by noting that his study “is the first to compare the cancer-fighting potency of plant versus marine-derived omega-3s on breast tumor development. There is evidence that both omega-3s from plants and marine sources are protective against cancer and we wanted to determine which form is more effective.”

Ma and his colleagues found that roughly eight times the dose of plant-based omega-3 was required to get the same preventative benefits of a single dose of the marine-based variety.

Dr. Ma sums up his study by saying, “It seems EPA and DHA are more effective at this [cancer prevention]. In North America, we don’t get enough omega-3s from seafood, so there lies an opportunity to improve our diet and help prevent the risk of breast cancer.”


Based on this new study, Dr. Ma recommends that people get at least two to three serving of seafood each week. I couldn’t agree more, provided the fish you consume comes from quality sources.

I would suggest you opt for wild-caught seafood since farm-raised fish typically have lower levels of omega-3s and may come from fish that are fed antibiotics and treated with pesticides. Wild salmon, small albacore tuna, mackerel, cod, and sardines are a few of the fish with plentiful amounts of omega-3.

If you don’t care for seafood (or are concerned about possible mercury contamination), fish oil supplements are a great way of making sure you get plenty of omega-3s. These products are routinely tested for potential toxins and they have a good track record when it comes to making sure they don’t contain heavy metals or industrial chemicals.

The typical American diet does not include anywhere near enough of omega-3, which has proven safe and effective in counteracting the kind of inflammation that underlies numerous chronic diseases. But to get enough of this super nutrient you may have to look beyond good plant-based sources like flaxseed and hemp oil. If you’ll forgive an admittedly overboard pun, the latest evidence suggests that fish oil is your best way to net the benefits of omega-3.

Take good care,

Dr. Josh