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Tomatenketchup goed tegen kanker en hartproblemen.*
Ketchup bevat veel lycopeen, dat goed is tegen borst-,
pancreas-, prostaat en darmkanker. Onderzocht werd welke soorten ketchup de meeste
lycopeen, de stof die de tomaten rood doet kleuren, bevatten. Veruit de meeste
lycopeen werd aangetroffen in biologische ketchup en de minste in ketchup uit
een fastfood “restaurant”. In de biologische ketchup zat 5x meer dan in een
zelfde gewichtshoeveelheid tomaten.Omdat doorgaans onbekend is wat de
hoeveelheid lycopeen van een bepaalde ketchup is kan men het beste die ketchup
kopen met de meest donker rode kleur.
Organic varieties of tomato
ketchup contain three times as much of a cancer-fighting chemical called
lycopene as non-organic brands.
In the US, tomato ketchup
comes in purple and green varieties as well as the traditional red. Betty Ishida
and Mary Chapman at the Agricultural Research Service in Albany, California, US,
wondered if the colouring might be indicative of low levels of lycopene, the
pigment that makes tomatoes red.
The chemical has been shown to
help protect against breast, pancreatic, prostate and intestinal cancer,
especially when eaten with fatty foods. There is also evidence that lycopene can
reduce the risk of heart attacks (New Scientist print edition, 23 December
2000).
The researchers tested
lycopene levels and antioxidant activity in 13 ketchup brands: six popular ones,
three organic, two store brands and two from fast-food chains. Purple and green
ketchups had a similar lycopene content to their plain red counterparts.
But organic ketchups excelled,
with one brand containing 183 micrograms of lycopene per gram of ketchup, about
five times as much per weight as a tomato. Non-organic brands averaged 100
micrograms per gram, with one fast-food sample containing just 60 micrograms per
gram.
If you want high lycopene
levels, says Ishida, the rule of thumb is to pick the darkest red ketchup.
Journal reference: Journal
of Agricultural and Food Chemistry (DOI: 10.1021/jf0401540) (Jan. 2005)