A fish diet rather than any other type of diet appears to be associated with the greatest reduction in the risk of developing type 2 diabetes
A fish diet appears to be the best way of reducing the risk of developing type 2 diabetes in comparison to either a poultry, meat-based or even a vegetarian diet. This was the conclusion of an analysis of the UK Biobank by researchers from the UK, Thailand and Chile.
Type 2 diabetes is a metabolic disorder that results in hyperglycaemia and is a global health concern. One estimate from 2017 suggested that approximately 462 million individuals were affected (6.28% of the world’s population), leading to 1 million deaths per year.
Many cases of type 2 diabetes could potentially be prevented by lifestyle changes, including maintaining a healthy body weight, consuming a healthy diet, staying physically active, not smoking and drinking alcohol in moderation.
In fact, a 2017 systemic review identified how the risk of diabetes is reduced by increased consumption of whole grains, fruits and dairy, but that the risk is increased by greater consumption of red meat, processed meat and sugar sweetened beverages. However, there is some uncertainty over whether any specific type of eating pattern e.g., fish diet, poultry or vegetarianism, has a greater impact on the risk of developing diabetes.
For the present analysis, the team turned to the UK Biobank database to explore the associations between different diets and the risk of incident type 2 diabetes. In addition, the researchers examined the extent to which adiposity might impact on these associations.
Within the UK Biobank, participants complete food frequency questionnaires and based on responses, individuals were categorised as vegetarian, fish eaters, fish and poultry eaters and finally meat eaters. A number of participants reported eating a varied diet and the effect on this type of diet was analysed separately.
The results were analysed using Cox-proportional hazard models which provided a measure of the association between the different diets and the risk of type 2 diabetes and models were adjusted for several factors including age, sex, alcohol intake, smoking status etc.
Fish diet and the risk of type 2 diabetes
A total of 203,790 individuals were included in the analysis with 1.6% who were vegetarian, 2.2% fish diet, 1.1% fish and poultry eaters, 87.3% meat eaters and 7.8% who reported eating a varied diet. The mean age of the groups ranged from 52.8 to 56.5 years and after excluding the first two years, individuals were followed-up for a median of 5.4 years. During the follow-up, 5,067 (2.5%) participants developed type 2 diabetes.
Using meat eaters as the reference, a fish diet had the lowest risk of developing type 2 diabetes (hazard ratio, HR = 0.41, 95% CI 0.31 – 0.55, p < 0.0001), followed by fish and poultry eaters (HR = 0.61, 95% CI 0.44 – 0.86). The association with vegetarian and a varied diet were non-significant. However, in the fully adjusted models, a significant association remained only for a fish diet but not for fish and poultry eaters or any of the other diets.
Interestingly, general obesity was a partial mediator for fish diets, accounting for 49.8% of their lower risk of developing type 2 diabetes.
The authors concluded that fish diets produced the greatest reduction in the risk of developing diabetes and that this effect was largely due to the fact that fish eaters had a lower level of adiposity.
Boonpor J et al. Types of Diet, Obesity, and Incident Type 2 Diabetes: Findings from The UK Biobank Prospective Cohort Study Diabetes Obes Metab 2022