Recently, Prof. ZONG Geng from Shanghai Institute of Nutrition and Health (SINH) of Chinese Academy of Sciences(CAS), together with researchers from the Harvard T.H. Chan School of Public Health, reported participants with high habitual intake of linoleic Acid (LA) had lower risk of type 2 diabetes in the future. The study was published on Diabetes Care. 

LA, an essential fatty acid, is the dominant n-6 polyunsaturated fatty acid (n-6 PUFA) in the diet. Given the compelling evidence supporting benefits of dietary n-6 PUFAs on coronary heart disease, LA is recommended as an optimal energy source for maintaining long-term health. However, possible effects of n-6 PUFAs on type 2 diabetes (T2D) risk remain unclear. As the existing studies on the relationship between LA intake and diabetes risk reported inconsistent results, researchers conducted this large study with long follow-up to address this important question. 

The current study followed 214,028 U.S men and women from three large on-going prospective cohort studies: The Nurses’ Health Study (NHS), NHSII, Health Professionals Follow-Up Study (HPFS). N-6 PUFA intakes were estimated based on the data collected through validated food frequency questionnaires administered every 2 or 4 years and updated food composition databases.  

To represent long-term diet better, researchers calculated cumulative averages of diets from baseline to the end of follow-up. Self-reported incident diabetes during follow-up was confirmed using a validated supplementary questionnaire. 

During 4.93 million person-years of follow-up, 18,442 T2D cases were documented. Of note, LA accounts for >98% of total n-6 PUFA while, arachidonic acid (AA) is of <2% and associated with a higher type 2 diabetes risk. Besides, in an isocaloric substitution model, diabetes risks reduced significantly when LA iso-calorically replaced saturated fats, trans fats or carbohydrates respectively. 

Overall, the research suggested that increasing dietary LA at the expenses of unhealthy fats and carbohydrates may facilitate the prevention of type 2 diabetes. 

This study was sponsored by the National Institutes of Health, Unilever R&D and the Chinese Academy of Sciences. 

HRs for type 2 diabetes, with LA substituting for energy from other macronutrients. 
(Image provided by Prof. ZONG Geng's group)

Media Contact: 
WANG Jin (Ms.) 
Shanghai Institute of Nutrition and Health,
Chinese Academy of Sciences 
Email: sibssc@sibs.ac.cn