September 13, 2016

expert reaction to conference poster (unpublished work) on fatty acids and type 2 diabetes in women

A poster presented at the European Association for the Study of Diabetes conference has reported an association between consumption of a particular fatty acid and risk for type 2 diabetes in women.

Catherine Collins, Registered Dietitian, said:

“This research suggests that dietary intake of one type of long chain omega-3 fat, DPA (docosopentanoic acid) is associated with a significant increase in the risk of type 2 diabetes in middle aged women. DPA is an omega-3 fat that has some similar properties to the more well-known EPA and DHA ‘fish oil’ omega-3 polyunsaturates, which are recommended to include as part of a healthy diet.  At higher intakes (above 800mg a day) DPA intake was associated with a 45% increased risk of type 2 diabetes in ideal weight women, increasing to 54% in overweight women.

“So do omega-3 fats increase a woman’s risk of developing Type 2 diabetes? The devil is in the dietary detail – and there’s really not enough detail on diet in this poster to be able to confirm DPA is a risk, although this study does confirm that EPA and DHA intake (the more well-known omega-3 fats) are definitely not a risk.

“First of all, diets in the UK don’t contain anywhere near the 800mg DPA which significantly increased type 2 diabetes risk in this population. Oily fish (salmon, tuna, mackerel and other dark-fleshed fish) provide around 100-300mg of DPA per 100g, along with other important omega-3 fats. But as the NDNS survey published last week shows, oily fish isn’t a regular in the UK diet and so our predicted intake of DPA is likely far below this 800mg threshold. Non-fish sources of DPA include red meat (beef and lamb), chicken, and dairy foods – but these contain far smaller amounts of DPA (for example, 20-50mg DPA per 100g of lean meat) than oily fish could provide.

“Secondly, the researchers overlooked their own evidence that arachidonic acid (AA) – a saturated fat – was far more implicated in type 2 diabetes risk than even the DPA omega-3 fat highlighted in this presentation. This suggests – without the dietary analysis available to back this up – that diet rich in fattier meat, and of a less Mediterranean style of eating is perhaps associated with an increased risk of type 2 diabetes.

“The bottom line? This research doesn’t change the healthy diet recommendation of the Eatwell Guide, which is to include oily fish as part of a healthy diet. It’s not clear from their data whether the study group had such a high intake of DPA from diet alone, or from supplements and diet combined. For those taking omega-3 supplements rich in DPA, it may be worthwhile choosing an alternative with a more balanced EPA and DHA omega-3 profile.”

Poster title: ‘Fatty acid consumption and incident type 2 diabetes: evidence from the French E3N cohort study’ by Courtney Dow et al. This is a conference poster discussed at the European Association for the Study of Diabetes conference.

Declared interests

Catherine Collins: “No conflict of interest.”