John Yudkin

Yudkin was raised in the East End of London in an Orthodox Jewish family that had fled the Russian pogroms of 1905.

His father's death left six-year-old Yudkin and his four brothers to be raised by their mother in considerable poverty.

He won scholarships to Hackney Downs School (formerly the Grocers' Company's School), and another from there to Chelsea Polytechnic.

John Yudkin FRSC (8 August 1910 – 12 July 1995) was a British physiologist and nutritionist, and the founding Professor of the Department of Nutrition at Queen Elizabeth College, London.

After gaining his BSc degree in 1929 he briefly considered a career in teaching, but then discovered that he could sit an examination for a scholarship to the University of Cambridge.

He matriculated at Christ's College, Cambridge as a scholar, and graduated in biochemistry at the age of 20 in 1931.

He worked for his PhD in the Department of Biochemistry at Cambridge under the supervision of Marjory Stephenson, a pioneer of research in bacterial metabolism, who funded his work.

His PhD thesis was on "adaptive enzymes" (subsequently termed "induced enzyme synthesis").

His account of the phenomenon inspired the research of Jacques Monod, who later worked out a detailed mechanism for the induction of enzymes in bacteria and was awarded the Nobel Prize for his work.

In 1933 Yudkin married Milly Himmelweit, who had recently left Berlin to escape the worsening political situation.

While pursuing his PhD research, Yudkin took up medical studies in 1934 and started teaching physiology and biochemistry to medical students, first at Christ's College, then also at other colleges in Cambridge.

He began clinical studies at The London Hospital in 1935, while continuing to teach in Cambridge one weekday and at weekends.

They had three sons, Michael (born 1938), Jonathan (1944–2012) and Jeremy (born 1948).

Yudkin completed his medical studies in 1938, and was appointed Director of Medical Studies at Christ's College.

The same year, he started research at the Dunn Nutritional Laboratory in Cambridge, working principally on the effects of dietary vitamins.

His studies of the nutritional status of school children in Cambridge showed that supplementation of the diet with vitamins had little effect on their general health.

The studies also showed serendipitously that children from a poorer area of Cambridge were shorter and lighter, and had lower haemoglobin levels and a weaker grip, than those from a wealthier area.

Moreover, children from three industrial towns in Scotland were, on average, inferior in the same four measurements to the average Cambridge child, and the children from the poorer families in the Scottish towns were inferior in these measurements to those from the wealthier families.

These findings probably helped to persuade Yudkin that nutrition was not only a biological science but also had important social and economic components and implications.

In 1942 he wrote an article in The Times (published anonymously, as was customary in those days) pointing out that there were a large number of organisations in the UK concerned in some way with nutrition – the Ministry of Food, the Ministry of Health, the Medical Research Council, the Cabinet Advisory Board on Food Policy, etc. – but no single body responsible for formulating a uniform plan for nutrition.

What was needed was a UK Nutrition Council with oversight of food policy.

The suggestion fell on deaf ears.

During the Second World War, Yudkin served in the Royal Army Medical Corps and was posted to Sierra Leone.

While there he studied a skin disease that was prevalent among local African soldiers and discovered that it was due not to an infection, as had been believed, but to riboflavin deficiency.

He found that the Army had devised a uniform diet for its soldiers in the four British West African colonies (Gambia, Sierra Leone, Gold Coast and Nigeria).

This diet was, on paper, adequate in all nutrients – including riboflavin, which was supplied predominantly from millet.

But it turned out that millet, although a staple in the Gold Coast and Nigeria, was loathed by soldiers from Sierra Leone, who would not eat it even if they were hungry.

This experience must have brought home to Yudkin the importance of custom and upbringing in determining a person's choice of foods.

In 1945, shortly after the end of the war, he was elected to the Chair of Physiology at Queen Elizabeth College in London (then the King's College of Household and Social Science).

Over the next several years, under his leadership, the college and the University of London established a BSc degree in nutrition (the first degree in nutrition in any European university).

Students were taught an integrated series of courses including not only chemistry, physics and biology but also relevant elements of demography, sociology, economics and psychology.

The first students were admitted in 1953, and in 1954 the Department of Nutrition was officially opened and Yudkin's Chair was converted into a Professorship of Nutrition.

Yudkin wrote several books recommending low-carbohydrate diets for weight loss, including This Slimming Business (1958).

He gained an international reputation for his book Pure, White and Deadly (1972), which warned that the consumption of sugar (sucrose, which consists of fructose and glucose) is dangerous to health, an argument he had made since at least 1957.

Specifically, he wrote that sugar consumption was a factor in the development of conditions such as dental caries, obesity, diabetes, and heart attack.

Yudkin's failure to incorporate possible confounding factors in his case-control designs was an area of heavy criticism at the time; apart from other unmeasured known risk factors that might affect cardiovascular disease (CVD), data had emerged soon after, suggesting that sugar intake was associated with smoking, a big risk factor for CVD.

Yudkin's failure to account for confounding factors led to harsh words from Ancel Keys at the time.

The marriage lasted until her death in March 1995.

From the late 2000s, there was a resurgence of interest in his work, following a 2009 YouTube video about sugar and high-fructose corn syrup by the pediatric endocrinologist Robert Lustig, and because of increasing concern about an obesity epidemic and metabolic syndrome.

Pure, White and Deadly was republished in 2012, with a foreword by Lustig.