The vegan diet advocacy film Forks Over Knives (2011) claims that in 1958, there were just 18 deaths from prostate cancer in Japan, but 14.000 such deaths in the United States, which had about twice Japan's population then.

The film goes on to present this as evidence that a certain diet is beneficial for human health, but here I am mostly interested in validity of the first claim: Did just 18 people die from prostate cancer in Japan in 1958?

  • Mortality data present here-ganjoho.jp/en/professional/statistics/table_download.html shows a combined value for Japan from prostate cancer as 177 for a time period of 1958-1967 and critical review of the film is present here-rawfoodsos.com/2011/09/22/…. – pericles316 Feb 16 '16 at 11:55
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    This may have more to do with health care and social issues than with any actual difference in causes of mortality. If cancer, especially in the reproductive system, is seen as socially embarrassing then doctors may have felt under pressure to put down something innocuous like "heart failure" instead. Also cancer is primarily a disease of old age, and its possible that something else was killing the Japanese at that time, so people were not getting old enough to die of prostate cancer. – Paul Johnson Feb 16 '16 at 17:42
  • @pericles316 I see the number "431" on line 2339 of the "number" tab in the "1. mortality" data. – DavePhD Feb 16 '16 at 18:05
  • @DavePhd-Good catch! – pericles316 Feb 17 '16 at 5:27


Other sources such as Vegan Bite By Bite (page 210) make clear that the number "18" is the number of autopsy proven deaths from prostate cancer, not the total number.

The source of the "18" number is An Epidemiological Survey of Prostatic Cancer from the Annual of the Pathological Autopsy Cases in Japan The Tohoku Journal of Experimental Medicine Vol. 130 (1980) pages 159-164. This article explains that only 5,798 men were autopsied in 1958, so only a fraction of deaths were studied.

An updated report on the trends in cancer incidence and mortality in Japan, 1958–2013 Jpn. J. Clin. Oncol. (2015) volume 45, pages 390-401, illustrates in Fig. 2 that 2 per 100,000 men died of prostate cancer in Japan in 1958.

See also Comparison of Prostate Cancer Mortality in Five Countries: France, Italy, Japan, UK and USA from the WHO Mortality Database (1960–2000) Jpn. J. Clin. Oncol. volume 35 pages, 690-691. which shows that the prostate cancer age-standardised death rate in the USA was about 10 times that of Japan (not the ridiculously exaggerated ratio in the OP).

Also, Cancer Statistics in Japan (mentioned in a comment by pericles316) says, in the "1. mortality" data, on line 2339 of the "number" tab, that 431 men died of prostate cancer in 1958 and, in the "asr" tab, that this corresponds an age adjusted death rate of 2.1 per 100,000.

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    +1 when you say "prostate death rate in the USA was about 10 times that of Japan", is that age standardised, or crude rate? – user56reinstatemonica8 Feb 16 '16 at 18:11
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    @user568458 Fig. 1 of the reference is "Age-standardized mortality rates for prostate cancer: age-standardized with 1985 Japanese standard population, rates per 100 000." and shows about 2 per 100,000 in Japan and about 20 per 100,00 in USA in 1960. Fig. 2 breaks the data down to specific age groups. – DavePhD Feb 16 '16 at 18:18

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