People who regularly eat fish as their primary source of animal protein have lower blood-glucose concentrations and a reduced risk of developing diabetes type 2 and cardiovascular disease, compared to other people, researchers from the University of Valencia reported in the journal Nutrición Hospitalaria. High consumption of cured and/or red meats has the opposite effect – it tends to raise the risk of diabetes and putting on weight.

Lead author of the study, Mercedes Sotos Prieto, said:

“In Mediterranean countries, consumption of foods that typically form part of the diet here has decreased in recent decades. The consumption of saturated fats mainly from red meats and industrial baking has increased and this is really worrying.”

Sotos Prieto and team had set out to try to better understand the dietary patterns of older individuals in terms of fish and meat intake. They also wanted to determine whether there might be an association between the Mediterranean diet and factors related to cardiovascular and diabetes risk.

The study, which forms part of the Predimed study (Prevention with a Mediterranean Diet) involved 340 adult males and 605 adult females aged from 55 to 80 years – they all had a high cardiovascular risk.

The Mediterranean population in this study was found to eat a large quantity of fish and red meat.

The authors reported that according to their finding, those on a particularly high fish-to-meat ratio generally had lower glucose concentrations, while individuals who ate significantly more red meat, especially cured meat were more likely to put on weight and/or become obese.

The authors wrote:

“The red meat consumption of the sample population reaches an average of once a day, which is high in comparison to dietary recommendations. This could be influenced by many weight-loss diets which recommend eating grilled veal.”

More specifically, excessive consumption of red meat was found to be associated with a higher risk of:

  • Developing cardiovascular diseases
  • Developing diabetes type 2
  • Hypertension (high blood pressure)
  • Slightly shorter life-expectancy – mainly because of a higher-than-normal rate of cancer or heart disease

Fish eaters, on the other hand, appeared to enjoy longer life spans, and a lower risk of developing several diseases.

The authors stress that this was a cross-sectional study, so no causal effect can be determined. They added that other studies have shown similar benefits from eating fish, including oily and white fish – especially with regards to diabetes type 2 risk.

They explained:

“Various hypotheses have been put forward that attempt to explain why the consumption of fish can be related to diabetes. The increase of omega-3 in the cells of the skeletal muscles improves insulin sensitivity.”

Sotos Prieto said:

“It is important to understand the dietary patterns of the Spanish population in order to learn whether dietary habits are changing. We should therefore strengthen dietary education.

We ought to establish dietary intervention programmes so that we do not stray from the Mediterranean diet. In other words, such a diet involves decreasing the amount of red meat that we eat and maintaining equal levels of fish consumption.”

The investigators found that men are more likely to be bigger red and cured meat eaters than women, while women tend to consume more white meat, such as chicken and turkey.

They found that the men and women in their study consumed similar amounts of fish.

Written by Christian Nordqvist