These results were highlighted in the paper titled “Polyunsaturated fatty acid intake and incidence of type 2 diabetes in adults: a dose response meta-analysis of cohort studies” by a team of researchers from Wannan Medical College, east China.
The global prevalence of the disease will increase from 171m in 2000 to 366m individuals by 2030.
T2D increases the risk for diabetes-related complications, like cardiovascular disease, retinopathy and premature death, thereby contributing to rising healthcare costs.
For this study, the researchers selected 25 cohort studies, featuring 54,000 patients, from PubMed, Embase, Cochrane Library and Web of Science databases, which assessed the association between polyunsaturated fatty acid intake (PUFA) and T2D.
Overall, they did not find a linear link between PUFA intake and the incidence of T2D.
When analysed by region, however, the researchers found that the total PUFA intake was associated with an increased incidence of T2D in Europe and Australia.
In contrast, the total PUFA intake was associated with a decreased T2D incidence in Asia, especially in relation to omega-3.
“An inverse association between long-chain omega-3 PUFA and T2D incidence was observed in the Asian population,” they wrote.
“The protective association of omega-3 PUFA consumption with T2D was reported by the Japan Public Health Center-based Prospective Study in men and the Shanghai Women’s Health Study. Chen et al. and Wallin et al. concluded omega-3 PUFA intakes were related to lower T2D risk only in Asian but not North American or European populations.”
The discrepancy was probably partly due to the difference in metabolism and lifestyle characteristics between Asians and Caucasians.
The Western diet is usually high in sugar, red meat and fried food, while Asians, especially the Chinese and Japanese, consume more fruits, vegetables, fish and tofu.
“The influence of genetic and gene-diet interactions on T2D in different populations needs to be further explored to understand the relationship between PUFA intake and T2D incidence,” added the researchers.
The researchers also noted differences in the disease risk dependent on the PUFA assessed.
For example, DHA intake was significantly associated with T2D incidence, by which the risk was highest when the DHA consumption reached 200 to 300 mg/d.
However, linoleic acid (LA) was associated with a decreased T2D incidence.
From the gender perspective, female intake of PUFA was associated with increasing T2D incidence, whereas the risk would decrease for males.
This is because males and females differ in the risk levels for diabetes, which may be attributed to sex-specific disparities in dietary habits and possibly led to varied PUFA profiles.
The gender differences may also be due to the unique distribution and function of different adipose tissue depots in men and women.
If analysed through the perspective of the duration of follow-up, there were no associations between the total PUFA intake and T2D if the duration of follow up was 10 years or more.
In conclusion, the scientists detected non-linear but significant associations between PUFA intake and Type 2 diabetes.
As such, it might be necessary to pay attention to the effects of PUFA and its intake on the worldwide ‘epidemic’ of the metabolic disease.
“Specific PUFA may differ in their health effects.
“The association between the type of PUFA intake and the incidence of T2D merit further evaluation,” concluded the scientists.
Source: Diabetology & Metabolic Syndrome
“Polyunsaturated fatty acid intake and incidence of type 2 diabetes in adults: a dose response meta-analysis of cohort studies”
Authors: Mingyuan Hu, et al