Nutritional Pearl: Eating Fish—How Low Can You Go?

Answer: Consuming even a comparatively small amount of fish—at least one 4-ounce serving of fish per week, on average—can affect your risk of stroke as well as other heart-related health conditions.

When a patient tells me that they don't like fish, one of the first things I ask them is what fish they have tried, and how it was prepared. Often, people have only ever been served those awful, breaded fish sticks that are full of monosodium glutamate and salt and have a strong, fishy taste.

Cooking techniques aside, there are still those who would rather avoid eating fish.

The Research

To receive a point in your Mediterranean Diet score, you should consume 2 or more 4-ounce servings of fish per week, but people in The Netherlands have historically eaten very little fish—with the typical Dutch person averaging less than 1 portion of fish per week. Will eating even that small amount of fish help prevent stroke, heart disease, or heart attack? A team of Dutch researchers made use of data gathered through a long-term, large scale study to assess the effects of their comparatively low fish intake.

The study EPIC-NL (European Prospective Investigation into Cancer and Nutrition - Netherlands) study began recruiting participants between 1993 and 1997. In 1996 the participants completed a food frequency questionnaire for their dietary habits over the course of the previous year, and the researchers validated those questionnaires by performing multiple 24-hour food recalls by phone with a representative sample of the participants.

The authors closed their research at the end of 2011 and used the National Health Statistics Registry as well as the Dutch Centre for Health Care Information to identify study participants who experienced heart-related events such as stroke (hemorrhagic or ischemic stroke), heart attack, heart disease diagnosis, or death from any heart-disease-related cause.

Then the authors could compare the fish intake of those who experienced any of those events with those who did not, taking into account such variables as age, gender, caloric intake, amount of physical activity, smoking status, fruit and vegetable intake, and fiber intake. They split fish intake into 3 different levels: consuming no fish at all (7.6% of participants), consuming less than 1 serving of fish per week (71.9% of those who consumed any fish at all), and consuming at least 1 serving of fish per week (28.1% of those who consumed fish).

The Results

The authors found that those who ate fish of any kind were slightly less likely (only 7% less likely) to experience a stroke than those who didn't eat any fish at all. That said, comparing those who didn't eat fish at all with those who ate some fish made no statistically significant difference for the risk of heart disease, heart attack, or death from any heart-related cause.

Similarly, when the authors looked at those consuming fatty fish as opposed to lean fish, they saw that those who consumed at least 1 portion of lean fish per week were 30% less likely to experience an ischemic stroke than those who ate no fish at all, while the overall risk of stroke (including both types of stroke) was unaffected.

Those who consumed only fatty fish were 14% less likely to experience a stroke of any kind, were nearly 50% less likely to have a heart attack and were just over 60% less likely to die of a heart-related cause.

What’s the Take Home?

Consuming even a comparatively small amount of fish—at least one 4-ounce serving of fish per week, on average—can affect your risk of stroke as well as other heart-related health conditions. If you don't like fatty fish like salmon or halibut, leaner fish like cod may be more to your liking.

Reference:

Hengeveld LM, Praagman J, Beulens JWJ, et al. Fish consumption and risk of stroke, coronary heart disease, and cardiovascular mortality in a Dutch population with low fish intake. Eur J Clin Nutr. 2018;72:942-950.