Eur J Clin Nutr., 2009, Volume 63; Pages 1123-1129.

Bioavailability of alpha-linolenic acid from flaxseed diets as a function of the age of the subject.

Patenaude, A. Rodriguez-Leyva, D. Edel, AL. Dibrov, E. Dupasquier, CM. Austria, JA. Richard, MN. Chahine, MN.et al

Key Findings:

It is well established that ALA can be converted in the body to the longer chain omega 3, EPA and DHA to various extents and depending on a number of variables. Data on the capacity for conversion in the elderly is non-existent. This study showed equivalent levels of conversion in young and old subjects following supplementation with flaxseed oil within 4 weeks. There was little change in either cohort in levels of serum DHA. This study also demonstrated no adverse side with regard to the consumption of the test amount of 30 g of ground flaxseed or 6 g of flaxseed oil to this age range (18–69 years).

ABSTRACT:

BACKGROUND:  Dietary flaxseed may have beneficial cardiovascular effects. An aged population has a higher incidence of cardiovascular disease, but they may react differently to flaxseed in the diet. OBJECTIVE:  To investigate the response, over a period of 4 weeks, of subjects aged 18-29 or 45-69 years to a diet containing the same amount of alpha-linolenic acid (ALA) (6 g) introduced in the form of ground flaxseed (30 g) or flaxseed oil. RESULTS:  All subjects who received flaxseed oil showed a significant increase in plasma ALA and eicosapentaenoic acid (EPA) concentrations over the course of this study. Subjects who received ground flaxseed in the 18-29-year-old group showed a statistically significant increase in their plasma ALA levels, and although there was a trend in the same direction for the 45-69-year-old subjects, this did not achieve statistical significance. The diets induced no major changes in platelet aggregation, plasma total cholesterol, low-density lipoprotein or high-density lipoprotein cholesterol levels in any of the groups. Younger subjects showed a decrease in triglyceride (TG) values compared with older subjects. There were no significant side effects that caused compliancy issues. CONCLUSION:  Subject age does not seem to be a major determining factor in influencing ALA absorption from a flaxseed-supplemented diet nor in the metabolism of ALA to EPA in the groups fed flaxseed oil. Concerns about side effects in older subjects administered a higher fiber load in a flaxseed-supplemented diet are not justified. However, younger but not older subjects showed a beneficial decrease in circulating TGs due to flaxseed supplementation.

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