Regular seaweed consumption among 3 to 6 year olds was associated with a significant reduction in blood pressure in both boys and girls, according to findings published in the open-access Nutrition Journal.
Japanese scientists from Gifu University and Aichi Bunkyo Women’s College proposed that the potential benefits may be linked to the dense nutrient profile of seaweed, including the minerals and alginate - a kind of dietary fiber – contained in the food.
“To our knowledge, this study is the first to demonstrate an association between seaweed intake and blood pressure in healthy children,” wrote the researchers.
“Although we cannot prove a causal relationship because of a cross-sectional design of this study, the finding suggests that seaweed might have beneficial effects on blood pressure among children.”
High blood pressure (hypertension), defined as having a systolic and diastolic blood pressure (BP) greater than 140 and 90 mmHg, is a major risk factor for cardiovascular disease (CVD) - a disease that causes almost 50 per cent of deaths in Europe, and reported to cost the EU economy an estimated $200 bn per year.
Blood pressure measurements were performed on 459 pre-school children in Aichi, Japan, and this was correlated with seaweed intake – predominantly nori - obtained from dietary records.
Results showed that seaweed intake was significantly associated with a reduction in systolic blood pressure in girls of about 3.5 mmHg. Boys with the highest average intakes of seaweed had 5.5 mmHg lower diastolic blood pressure.
Systolic function relates to the contraction of the heart, whereas diastolic relates to the filling of the heart with blood.
“Not only do our results suggest that seaweed intake may have beneficial effects on blood pressure in children, but they also provide the possibility of creating a new, earlier-in-life strategy for the prevention of hypertension in adults,” wrote the researchers.
Commenting on the potential mechanism, the researchers note that this “remains to be clarified”. However, they note that both the mineral content and the alginates in seaweed may be responsible.
“Alternatively, other ingredients may play a role in the control of blood pressure since alginate or each mineral in seaweed is lower than the effective dose needed to lower blood pressure. The whole diet pattern including seaweed intake is also possible to be responsible for the lower blood pressure.”
Source: Nutrition Journal
2011, 10:83 doi:10.1186/1475-2891-10-83
“Seaweed intake and blood pressure levels in healthy pre-school Japanese children”
Authors: K. Wada, K. Nakamura, Y. Tamai, M. Tsuji, Y. Sahashi, K. Watanabe, S. Ohtsuchi, K. Yamamoto, K. Ando, C. Nagata