When I recently visited my 76-year-old mother, she seemed concerned and annoyed with me.
“Why did you tell me to take fish oil supplements?” she complained. “They’ll give me a stroke!”
Despite my telling her not to worry, she remained adamant, explaining that she had read about it in the newspaper and heard it on Radio 4’s Today programme, so it must be true.
The study, which recently made headlines and concerned my mother – and no doubt many others – was published in the journal BMJ Medicine.
It showed that regular consumption of fish oil supplements may be a risk factor for atrial fibrillation (AF or irregular heartbeat) and stroke.
Taking a fish oil supplement lowers your risk of developing conditions such as MS
No wonder my mother was worried.
But before you throw away your fish oil pills (also known as omega-3 pills) – as my mother was about to do after taking them for five years – let me tell you what I decided after examining the research ( and assessing many others). I will continue to get my daily supplement, not least because I hate eating fish! And I think you should continue too.
This is because the study was observational. In other words, no experiments were done; the researchers simply observed what happened to groups of people in terms of their health outcomes, some who had used fish oil and others who had not.
What observational studies tell us is whether there is a link between something (in this case, fish oil pills) and an outcome (the likelihood of developing AF or having a stroke).
But an association does not mean that it is so causes the sickness.
The journal BMJ Medicine published research showing that those who regularly consume fish oil supplements may be a risk factor for stroke
For years, coffee was linked to poor health and cancer, while we now know that it is generally good for you in moderation.
The problem was that the many studies showing that coffee drinkers had a higher risk of cancer were based on people who also smoked.
The best type of study is a randomized controlled trial – where half the participants are given fish oil and the other half a placebo (a fake tablet) – and the outcomes are looked at by researchers who do not know who is taking what.
Even these gold standard studies can be flawed.
I have spent much of my career looking at these issues, including writing a textbook on them.
I won’t get too technical, but one problem is, for example, that an error has been made in the way a study has been set up. For example, people who get the supplements are healthier than the placebo group to begin with, so their better results are wrongly attributed to the pills.
The Journal of the American Heart Association found that those who took the supplements daily for five years reduced their risk of dying from cardiovascular disease by 7 percent
The new research, by scientists from the US, China, Denmark and Britain, was based on data from more than 400,000 patients from the UK Biobank – an ongoing study that started in 2006. Participants underwent blood tests and completed questionnaires, after which they were followed up. for the next 30 years using their NHS data.
The results were surprising at first glance and somewhat alarming for someone like me who takes a fish oil pill every day – and recommends it to friends and family.
It found that if you were healthy and took omega-3 pills, you were 13 percent more likely to develop AF than if you didn’t take the tablets. The risk of stroke was 5 percent higher.
Most people with AF don’t know they have it. So perhaps those who took fish oil were more health conscious, so they got themselves checked more often and were therefore more likely to have their AF detected.
But what about the higher risks of stroke?
Although there was a small increase in the number of strokes, upon closer examination the statistical analysis showed that this difference could range from no difference at all to an increase of 11 percent.
This is, in layman’s terms, such an unconvincing range of figures that we cannot conclude that fish oil increases the risk of stroke.
There were other conflicting findings: Those who developed AF had a 13 percent lower chance that it would lead to a heart attack or stroke.
How could this be the case if fish oil were harmful? The only conclusion we can draw from this is that we cannot draw any conclusions from this study!
That’s why we need to look at better studies: randomized, controlled trials.
For example, in 2019, the Journal of the American Heart Association published a review of 13 studies involving more than 125,000 patients. It showed that taking fish oil supplements daily for five years reduced the risk of dying from cardiovascular disease by 7 percent.
Meanwhile, there is also some suggestion that fish oil may help prevent depression.
The cause of depression is not really understood. However, we do know that inflammatory chemicals such as cytokines can cross the blood-brain barrier and disrupt chemical messengers in the brain (called neurotransmitters) and increase the risk of developing it. That is if you have an inflammatory condition.
This was something I personally experienced: I have the inflammatory bowel disease ulcerative colitis and when I took fish oil after my father’s death, which made me feel blue, I really think the pills helped.
Omega-3 fatty acids can apparently also help with brain health. In 2022, the journal Cureus: Journal of Medical Science published a review of nine randomized controlled trials concluding that “omega-3 fatty acid intake increases learning, memory, cognitive well-being, and brain blood flow.”
The condition I fear most is dementia, which is another reason I use fish oil.
But the main reason is the potential impact on my life expectancy, which is critical healthy life expectancy.
Fish oil appeared to blunt the damaging impact of inflammation and cortisol increases caused by daily chronic stress, such as work deadlines, that are so common in our lives, according to a 2021 study in the journal Molecular Psychiatry.
Another study that year, in the highly respected journal Nature Communications, found that people with the highest levels of omega-3 fatty acids in their blood had 17 percent lower death rates from all causes than those with the lowest levels.
So where does this leave us? Based on my research into the science behind the headlines, I will continue to take my daily fish oil tablet. And I would advise my mother – and anyone else – to do the same.
@drrobgalloway