Gut news as study finds more omega-3 benefits

Research from the UK has added to the well-known list of benefits provided by omega-3s: more bacterial diversity in the gut.

We have nearly 40 trillion bacteria in our gut and it’s been known for a long time that having diversity among these bacteria has many health benefits. Samantha Lynch, MS, RDN, LDN, a registered dietitian and nutritionist with a private practice in Vero Beach, says, “In addition to helping with the absorption and digestion of food and keeping our immune system strong, having diversified gut bacteria lowers the risk of diabetes, obesity, and inflammatory bowel disease.”

Omega-3s are essential fatty acids with a wide range of health benefits. They are not produced by the body; the only way to get them is from dietary sources.  A diet rich in omega-3s lowers “bad” cholesterol and reduces blood pressure and triglycerides – reducing the risk of heart disease and improving  overall cardiovascular health.

Studies have suggested that omega-3s can also reduce symptoms of rheumatoid arthritis, improve bone strength, protect against age-related cognitive decline and dementia, and reduce inflammation.

And now researchers from the University of Nottingham’s School of Medicine and King’s College London have found an association between omega-3 intake and the diversity of gut bacteria.

In a test group of 876 middle-aged and senior women, the research team set out to study the link between blood levels of omega-3 and the diversity of gut bacteria. Lead researcher Dr. Ana Valdes summarized the findings by saying that high blood levels of omega-3 “were strongly associated with the diversity and number of species of healthy bacteria in the gut.

“Our study is the largest to date to examine the relationship between omega-3 fatty acids and the composition of the gut microbiome.”

The team also found that high levels of omega-3 were associated with high levels of NCG, a compound that has been shown to reduce oxidative stress in the gut. (Oxidative stress is a complicated topic; suffice it to say to that it can cause cells to prematurely age and become dysfunctional.)

The study was published in the journal Scientific Reports.

One of the best sources of omega-3s are oily-fleshed, cold water fish such as wild Alaskan salmon, Atlantic mackerel, cod, haddock, trout, whitefish, herring, tinned sardines and canned light tuna. There are also non-fish sources of omega 3s; walnuts are by far richest source (at least among foods that are household names; chia seeds and flaxseeds are also high in omega-3s).

There are also widely-available omega-3 supplements, about which Lynch sounds a note of caution: “Before popping an omega-3 supplement, talk to your doctor or contact a registered dietitian who can review your medical history and the medications and supplements you are taking.  There are possible interactions between omega-3 supplements and certain medications, such as anticoagulants, which must be avoided.”  She adds that a healthcare professional will be able to provide a recommendation of particular food sources or omega-3 supplements that are appropriate for your specific situation.

Lynch says, “The UK study had a number of strengths, including its large size and the number of data points it evaluated. It had some limitations, however – the researchers relied on self-reported food questionnaires for dietary omega-3 intake, and there were no males in the study.” She adds, “I am very interested in seeing the results of additional studies, as the gut microbiome plays such an important part in preventing disease and in our overall health.”


Samantha Lynch’s office is located at 4445 Hwy A1A, Suite 239, in Vero Beach. She can also be reached via her website:

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