Question:
I’m thinking about adding omega-3 supplements to my shopping list after reading about a new study that showed taking fish oil supplements every day slows biological ageing, among other things. Are fish oil supplements a good idea for health?
Answer:
If the fountain of youth came in a bottle, would it be labelled with “omega-3″? These fashionable little fatty acids are credited with everything from sharpening our brains to soothing our joints, and now a new study suggests they may slow biological ageing – at least on a molecular level. But longevity claims aside, omega-3s are proven multitaskers, supporting heart health, brain function and regulating inflammation. So, are fish oil supplements the superhero of the supplement aisle or just another overhyped trend?
DHA (docosahexaenoic acid) and EPA (eicosapentaenoic acid) are well-known members of the omega-3 fatty acid family that play key roles in maintaining health and mental wellbeing. Our body is largely dependent on dietary sources of DHA and EPA, such as salmon, mackerel, sardines, anchovies, trevally, kahawai, some shellfish such as green-lipped mussels, and to a lesser degree white fish varieties such as snapper and tarakihi. However, a typical one-gram fish oil supplement also contains around 180mg EPA and 120mg DHA. And more concentrated fish oil supplements may contain 500mg or more of EPA and DHA per gram.
In a startling new study published in Nature Aging, researchers reported that omega-3 supplements reduced the biological age of a group of older adults by about three months over a three-year period, more so when a daily vitamin D supplement and regular exercise were added to the fish oil supplement. The participants’ biological age was determined using an epigenetic clock at the start and end of the three-year study. The 777 Swiss participants aged 70-91 were randomly assigned to take a daily vitamin D supplement (2000IU), and/or an omega-3 supplement (1g) and/or complete a home exercise programme.
While a three-month reduction in biological age over three years sounds promising, this measurement is derived from the use of an epigenetic clock that uses algorithms to combine measurements across the genome to quantify variations in biological versus chronological ageing. Although epigenetic clocks appear to offer a promising way to estimate biological age, their accuracy and real-world relevance remain debated. Critics point to limited longitudinal evidence, potential biases in their calibration, and uncertainty over whether they truly reflect ageing processes or just correlate with them.
What about all the other potential health benefits of these supplements? Omega-3 fats, particularly EPA and DHA from both fish and supplements, have been widely studied, especially in relation to cardiovascular disease. Observational research suggests higher fish consumption is linked to lower risks of heart disease, but it remains unclear whether this is due specifically to their omega-3 content or other factors, such as overall diet and lifestyle.
Early clinical trials supported the idea that omega-3 reduces cardiovascular risk by lowering triglycerides, blood pressure, and arrhythmia risk. Some studies found omega-3 supplements reduced heart attacks, stroke and cardiac deaths, particularly for people with pre-existing heart disease. But more recent large-scale trials have produced mixed results. Some found little benefit from low-dose omega-3 supplements, whereas a 2019 study (REDUCE-IT) using a high-dose EPA prescription supplement showed a 25% reduction in major cardiovascular events.
Similarly, data from observational studies and clinical trials show no consistent relationship between omega-3 intake and cancer risk. Nor does omega-3 supplementation improve cognitive function in healthy older adults or people with Alzheimer’s disease.
However, people with mild cognitive impairment may experience improvements in certain aspects of their cognitive function with omega-3 supplementation, though more research is needed to confirm this.
Differences in omega-3 formulations, dosage, and study populations likely contribute to the mixed findings.
While fish oil supplements may seem like a quick fix, the best evidence still supports eating fish and other seafood for their beneficial omega-3 and other valuable nutrients. So, before rushing to the supplement aisle, consider heading to the seafood counter instead – your body (and taste buds) might thank you for it.
