The raison d'etre of this website is to provide you with hard scientific information which may help you make informed decisions in your quest for health (so far I have blogged concise summaries of over 1,500 scientific studies and have had three books published).

My research is mainly focused on the effects of cholesterol, saturated fat and statin drugs on health. If you know anyone who is worried about their cholesterol levels and heart disease, or has been told to take statin drugs you could send them a link to this website, and to my statin or cholesterol or heart disease books.

David Evans

Independent Health Researcher

Thursday, 16 August 2012

Soy may cause goiters in healthy people, especially the elderly

This study was published in Nihon Naibunpi Gakkai Zasshi 1991 May 20;67(5):622-9

Study title and authors:
The effects on the thyroid gland of soybeans administered experimentally in healthy subjects.
Ishizuki Y, Hirooka Y, Murata Y, Togashi K.
Ishizuki Thyroid Clinic.

This study can be accessed at:

This study investigated the effects of soy consumption on thyroid function. The study included 37 healthy subjects who were given 30g of soybeans everyday and divided into 3 groups.

(i) Group 1 were given soybeans for one month.
(ii) Group 2 (average age 29 years old) were given soybeans for three months.
(iii) Group 3 (average age 61 years old) were given soybeans for three months.

The study found:
(a) In all groups thyroid stimulating hormone (TSH) levels rose significantly (high TSH levels may indicate an underactive thyroid gland).
(b) TSH levels in group 3 increased more significantly than that in group 2.
(c) Symptoms such as malaise, constipation, sleepiness and goiters appeared in half the subjects in groups 2 and 3 after taking soybeans for 3 months, but they disappeared 1 month after the cessation of soybean ingestion.

The author of the study, Dr. Yoshimochi Ishizuki of Aichi Medical University in Japan, concludes: "These findings suggested that excessive soybean ingestion for a certain duration might suppress thyroid function and cause goiters in healthy people, especially elderly subjects".