The effect of flaxseed supplementation in processed foods on serum fatty acids and enterolactone.
OBJECTIVE
The purpose was to study the effects of flaxseed supplementation as a part of daily diet on serum lipids, fatty acids and plasma enterolactone.


METHODS
Eighty volunteers participated in this clinical nutrition study which was carried out in a controlled, double-blind and cross-over manner. The subjects were randomized to diet sequences AB or BA. Diet A meals contained 1.3 g/100 g ground flaxseed and 5 g/100 g flaxseed oil. Also 3-4 g/100 of inulin and wheat fiber was added. AB diet with non-supplemented foods served as control. Test subjects were on both diets for 4 weeks separated by a 4-week wash-out period. Fifteen test subjects continued an open part of the study for 4 additional months.


METHODS
The dietary intake, basic blood values, serum lipids, fatty acids and enterolactone were measured at baseline, after both intervention periods and during the open study, at baseline and after 2 and 4 months. Serum thiocyanate and blood cadmium were controlled after both intervention periods.


RESULTS
The percentage of flaxseed supplemented test food out of total dietary intake was 20% of energy. The test food contained significantly higher amounts of fiber, polyunsaturated fatty acids (PUFAs) and especially alpha-linolenic acid than the control food. No significant changes were observed in the basic laboratory values or in blood lipids. There was a significant increase in serum alpha-linolenic acid, eicosapentaenoic acid and docosapentaenoic acid. Serum enterolactone concentration was doubled during flaxseed supplementation. Serum thiocyanate and blood cadmium values did not exceed reference values and there was no difference between the diets.


CONCLUSIONS
In this study we were able to show that, by adding ground flaxseed and flaxseed oil to one or two daily meals, it is possible to obtain significant effects on serum levels of enterolactone and alpha-linolenic acid.


BACKGROUND
The study was sponsored by the National Technology Agency of Finland (Tekes).
Tarpila
S
S
Department of Internal Medicine, The Mehiläinen Hospital, Helsinki, Finland. simo.tarpila@pp.fimnet.fi
Aro
A
A
Salminen
I
I
Tarpila
A
A
Kleemola
P
P
Akkila
J
J
Adlercreutz
H
H
D015107:4-Butyrolactone / Q000031:analogs & derivatives* / Q000097:blood*; D000328:Adult; D018592:Cross-Over Studies; D004043:Dietary Fiber / Q000008:administration & dosage / Q000378:metabolism; D019587:Dietary Supplements; D004311:Double-Blind Method; D005227:Fatty Acids / Q000097:blood*; D005260:Female; D019597:Flax / Q000378:metabolism*; D006801:Humans; D017705:Lignans / Q000097:blood*; D008297:Male; D008875:Middle Aged; D012639:Seeds / Q000378:metabolism*; D017962:alpha-Linolenic Acid / Q000008:administration & dosage / Q000097:blood*
D004043:Dietary Fiber; D005227:Fatty Acids; D017705:Lignans; D017962:alpha-Linolenic Acid; D015107:4-Butyrolactone; C029497:2,3-bis(3'-hydroxybenzyl)butyrolactone