Higher levels of omega 3 fatty acids in seafood associated with lower risk of chronic kidney disease

Higher levels of omega-3 fatty acids found in seafood are associated with a moderately lower risk of chronic kidney disease and a slower decline in kidney function, according to research published by the BMJ.

These associations were not found with higher levels of plant-based omega-3 fatty acids.

Although the size of these associations is modest, the findings support current clinical guidelines that recommend adequate seafood and oily fish consumption as part of healthy diets, the researchers say.

Chronic Kidney Disease (CKD) affects around 700 million people worldwide and can lead to kidney failure and death. It is therefore necessary to identify the factors likely to prevent its appearance and progression.

Animal studies suggest that omega-3 polyunsaturated fatty acids (n-3 PUFAs) may have beneficial effects on kidney function, but evidence from human studies is limited and based primarily on dietary questionnaires, which may be subject to discussion. mistake.

To dig deeper into this, an international team led by researchers from the George Institute for Global Health and the University of New South Wales, pooled results from 19 studies from 12 countries up to May 2020 looking at links between levels of n-3 PUFA biomarkers and the development of CKD in adults.

Biomarkers included eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), docosapentaenoic acid (DPA), and alpha linolenic acid (ALA). The main dietary sources of EPA, DHA and DPA come from seafood, while ALA is mainly found in plants (nuts, seeds and leafy green vegetables).

CRF was identified by an estimated glomerular filtration rate (eGFR) of less than 60 ml/min/1.73 m2. eGFR measures the ability of the kidneys to remove waste and excess fluid from the blood. The normal range is 90-120ml/min/1.73m2.

A total of 25,570 participants were included in the main analysis. Their mean age ranged from 49 to 77 years and their mean baseline eGFR ranged from 76.1 to 99.8 mL/min/1.73 m2.

Sixteen studies recruited both men and women, and 15 recruited primarily white participants. A total of 4944 participants (19%) developed CKD during an average follow-up period of 11 years.

After taking into account other factors such as age, sex, race, body mass index, smoking, alcohol consumption, physical activity, heart disease and diabetes, Higher levels of total n-3 PUFAs from seafood were associated with a slight (8%) lower risk of developing CKD.

When participants were divided by n-3 PUFA levels, those with total n-3 PUFA levels in seafood in the fifth highest had a 13% lower risk of chronic kidney disease than those of the lower fifth.

Higher levels of total n-3 PUFAs in seafood, particularly DHA, were also associated with a slower annual decline in eGFR. For example, the annual decline in eGFR was lower by 0.07 ml/min/1.73 m2 for people whose total level of n-3 PUFA in seafood was in the upper fifth compared to those of the lower fifth.

Plant-based ALA levels were not associated with CRF.

These are observational results and the researchers acknowledge that differences in study design and methods may have affected their results. And they cannot rule out the possibility that some of the observed risk may be due to unmeasured factors.

Nevertheless, the results were similar upon further analysis and appeared consistent across age groups (60 or younger versus over 60), eGFR (60-89 versus 90 mL/min/1.73 m2 or plus), high blood pressure, diabetes, and coronary heart disease to begin with, suggesting they stand up to scrutiny.

“Although our results do not prove a causal relationship between seafood n-3 PUFAs and CKD risk, they are supportive and consistent with current clinical guidelines that recommend adequate seafood consumption as part of healthy diets, especially when seafood replaces the consumption of less healthy foods,” they write.

“Further randomized controlled trials are warranted to assess the potential beneficial role of n-3 PUFAs from seafood in the prevention and management of CKD,” they add.