Hi Lidan,
I’m not an expert in this issue, but I think that improvements in analytical methods should be taken in account. Could these minerals have been
overestimated in the past?
Best regards,
Andreu Farran-Codina
GRUP DE RECERCA EN ACTIVITAT FÍSICA I SALUT
Tel. 934031986 – 934031978
Fax. 934031967
Departament de Nutrició i Bromatologia –
Nutrition and Food Science Department
Facultat de Farmàcia
Universitat de Barcelona
Campus de l'Alimentació de Torribera
Edifici Verdaguer, despatx 19
Prat de la Riba 171
08921-Santa Coloma de Gramenet
De: Food Composition Discussion Group [mailto:[log in to unmask]]
En nom de Lidan Du
Enviat: dilluns, 25 / juliol / 2016 15:54
Per a: [log in to unmask]
Tema: Fwd: Have nutrient contents in our foods been declining over time?
Hi, all,
I have a question about nutrient contents of foods as shown in food composition tables. Do you think soil depletion and the single-focus on yield by the agriculture sector over the decades might have
caused the foods we consume now be less nutritious by unit weight than before? And if so, are the values in food composition tables in countries regularly updated? Are the current values reliable to support modeling exercises
A simple google search opened up a few discussions, and I would really appreciate your view on this.
"University of Texas (UT) at Austin’s Department of Chemistry and Biochemistry was published in December 2004 in theJournal of the American College of Nutrition.
They studied U.S. Department of Agriculture nutritional data from both 1950 and 1999 for 43 different vegetables and fruits, finding “reliable declines” in the amount of protein, calcium, phosphorus, iron, riboflavin (vitamin B2) and
vitamin C over the past half century. "
"David Thomas - a geologist turned chiropractor (who also happens to sell mineral supplements) - analysed data from McCance and Widdowson's epic work, The Composition of Foods (a reference manual republished
and updated by Government biochemists every few years). During that 51-year period, potatoes appeared to have lost 47 per cent of their copper, 45 per cent of their iron and 35 per cent of their calcium
while carrots showed even bigger declines. Broccoli - a 'superfood' rich in micronutrients and cancer-busting antioxidants - suffered an 80 per cent drop in copper while calcium content was a quarter of what it had been in 1940, a pattern repeated in
tomatoes. As Thomas pointed out: 'You would need to have eaten 10 tomatoes in 1991 to have obtained the same copper intake as from one tomato in 1940."
Thank you very much.
Best,
-Lidan
Lidan Du, PhD
Research Advisor
1616 N Ft Myer Drive, 16th Floor, Arlington, VA 22209
Tel: 703-310-5047 | Email:
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