Lecture 13- N-3 fatty acids*, mood and cognition

Question 1

What are n-3 fatty acids?

Answer 1

Fatty acids are a hydrocarbon chain

Eicosapentaenoic acid (EPA) and Docosahexaenoic acid (DHA)

Oily fish

Question 2

N6 and N3 Fatty acids

Answer 2

The amount of N6 FA can influence the synthesis of N3 FA

Shorter chain N6 will SLOW down the synthesis of N3

Question 3

Modern diet change in fatty acids

Answer 3

Small decline in N3

Question 4

DHA- fatty acid

Answer 4

DHA is the most abundant n-3 fatty acid in the human brain

Concentration can affect neural membrane function (and thereby speed of signal transduction, and neurotransmission)

Question 5

The ‘Oxford-Durham’ study

Richardson & Montgomery (1999)

Answer 5

Some positive effects of fatty acid (omega-3 ) supplementation

Question 6

The ‘Oxford-Durham’ study

PROBLEMS

Answer 6

Should have controlled vitamin E (or interaction with fatty acid) as the placebo did not have vitamin E added to it

Generalization of the findings by those with commercial interests in fish oil products

Question 7

The ‘DOLAB’ study

Richardson et al. (2012)

Answer 7

First glance=
- The benefit gained over extended period of time (for reading ability)

Upon analysis of total child population:

Suggests that DHA supplementation harms reading development
in top-performing 80% of the population

Question 8

Systematic review of trials on effects of n-3 fatty acids on depressed mood

Answer 8

Small (just statistically significant) benefit to fish oil supplementation
WORRYING: biggest effects are shown in small trials

Thus, evidence for publication bias

Question 9

Primary Outcome measures

Answer 9

Measures of depressed mood

Question 10

Secondary Outcome measures

Answer 10

Beck Depression Inventory

Attentional bias for threat words

Mood diary