ALA Makes Vegetarians Happy

MESA, Ariz.While fish serves as the major dietary source of the long-chain omega-3s eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), which have been shown to be important in supporting brain health, low intake of EPA and DHA in vegetarians does not adversely affect mood, according to a new study (Nutr J. 2010;9:26. DOI:10.1186/1475-2891-9-26). A research team from Arizona State University (ASU) conducted a cross-sectional study to compare the mood of vegetarians who never eat fish with the mood of healthy omnivorous adults. A total of 138 healthy Seventh Day Adventist adults living in Arizona and California64 vegetarians and 79 non-vegetarianswere enrolled in the study and completed a health history questionnaire, food frequency questionnaire (FFQ) and two psychometric tests, the Depression Anxiety Stress Scale (DASS) and the Profile of Mood States (POMS).

Vegetarians had significantly lower mean intakes of EPA, DHA and the omega-6 arachidonic acid (AA); they had higher intakes of the omega-3 alpha-linolenic acid (ALA) and the omega-6 linoleic acid (LA). However, the vegetarians also reported significantly less negative emotion than omnivores in both psychometric tests. Mean total psychometric scores were positively related to the mean intakes of EPA, DHA and AA, and inversely related to ALA and LA intake.

The researchers noted previous studies have shown high intakes of LA and ALA can inhibit the formation of the longer-chain metabolites. Further, they cited a recent review that found high ALA intake helps to lower the LA/ALA ratio, regulating conversion of LA to the inflammatory AA. The research team noted a major limitation of the study was not measuring blood fatty acid concentrations or inflammatory markers; however, use of FFQ is generally considered effective in assessing omega-3 intake. They added there is also the possibility that vegetarians may make better dietary choices and may generally be healthier and happier.