Published research suggested millennials may be able to improve their fat metabolism by regularly eating foods that contain polyunsaturated fats, including walnuts, salmon, tuna, flaxseed oil, grapeseed oil and canola oil1. Researchers had the participants complete a lead-in diet followed by meals high in saturated fat. Then, 16 participants were placed, for 7 days, on a diet rich in polyunsaturated fat and 10 on a control diet that was a typical American pattern. Lastly, participants consumed another two meals high in saturated fat.
The results? After adopting a polyunsaturated fatty-acid rich diet for a week, the researchers found the 16 subjects on the PUFA-rich diet were processing fat better with an improved metabolism. In addition, the subjects may be better protected against the negative effects of saturated fats such as high cholesterol levels, if they are consuming more PUFAs on a regular basis.
Researchers saw cholesterol levels go down in the study participants who consumed foods rich in polyunsaturated fats, even though they were young, healthy and didn’t have high cholesterol levels when the study began.
For the study, researchers enrolled 26 healthy men and women (ages 18-35) who visited the lab for screenings and to receive their meals. The typical American diet included a fat profile of 7% of polyunsaturated fat, 15% monounsaturated fat and 13% saturated fat, compared to the polyunsaturated fat-rich diet which was 21% polyunsaturated fat, 9% monounsaturated fat, and 5% saturated fat.
There are some study limitations that should be considered. The sample only tested apparently healthy young men and women, so these results may not be generalizable to other populations. As part of the study, participants were provided with all of the food and beverages that they were to consume daily. Though they were reminded to only consume what was given to them, it was a possibility for participants to consume other foods and beverages throughout the day. Also, the physical activity status and meal compliance for the day before study visits was self-reported which could impact the outcomes tested in this study. Furthermore, there was a relatively high contribution of polyunsaturated fats to the diet (21% of total energy), which may not be feasible to consume on a daily basis for most adults. Future studies are needed to examine different doses from polyunsaturated fats in order to see what amount and type of polyunsaturated fat is necessary to elicit a positive metabolic response.
Resources:
1 Stevenson JL, Miller MK, Skillman HE, et al. A PUFA‑rich diet improves fat oxidation following saturated fat‑rich meal [published online ahead of print May 18, 2016]. Eur J Nutr. doi:10.1007/s00394-016-1226-9.