In my previous article on
the advantages of organic food, I focused on the health risks involved with
pesticides. In order to be
organic, foods must also be free of chemical preservatives.
Many foods are prepackaged
and need to be able to sit on the grocery store shelf for long periods of
time. This has led to
manufacturers using preservatives to keep the food from going off before the
consumer buys the product. Some
natural preservatives include sugar, salt, vinegar, ascorbic acid (vitamin C), freezing
and pasteurizing (heat treating).
Others are not so natural and may be detrimental to your health.
The
recent health trend to help reduce cardiovascular disease (CVD) has been to cut
down on eating saturated fats and cholesterol by decreasing the intake of red
meat. This has led people to increase
their intake of ‘low fat’ processed meats. A study published this year in BMC Medicine found that there
was no link between unprocessed red meat and CVD. The link is only with processed meats due to the high sodium
and preservative content. [i] Another study found an increased risk of ovarian cancer from eating vegetables
and meat containing preservatives. [ii]
A study from the US
published this year found that kids who drank more soft drinks were more likely
to have asthma regardless of their weight. They only looked at kids who drank regular soft drink so
they were not consuming artificial sweeteners. The authors speculate this is most likely due to the
preservatives. [iii] So just
because you exercise and burn off the calories, soft drinks still have
detrimental effects on your health.
Certain
preservatives have been found to have a wide range of side effects. Sodium sulfite (221) and sorbic acid (200)
were found to suppress immune cells. [iv] Sodium
nitrate (251) and sodium benzoate (211) have been found to alter DNA, which is
how many cancers begin. [v] Sodium sulfite and sodium benzoate were found to
decrease the hormone leptin. [vi] Leptin
levels falling are a trigger for us to eat. Consumption of these preservatives can lead to overeating
which leads to weight gain. Sodium benzoate and artificial food colouring have
been linked to hyperactivity in children. [vii]
Sodium benzoate and potassium
benzoate (212) when combined with ascorbic acid (found in juice) creates
benzene, which is a known carcinogen.
Benzoates are slowly being phased out but they are still in circulation
so you need to watch out for them.
Sodium metabisulphite (223) has become more
popular as a preservative but it actually kills food contaminants as opposed to
the others, which just inhibit the growth. It is used to sterilize equipment for wine and beer
brewing. It is used during
processing and is present at levels lethal to bacteria when we consume the
products that contain it. As I
have mentioned in previous articles, having healthy gut bacteria is important
to our overall health status. Consuming
foods that contain lethal levels of preservatives is going to put your gut
bacteria out of balance potentially causing illness.
In Australia, as in many other countries, if an
ingredient is at a concentration of less than 10ppm it does not have to be
declared on the label. This has
led some companies to advertise their products as ‘preservative free’ despite
containing preservatives. This is
despite the fact that 10ppm is an effective level for killing bacteria.
Although it is important to
keep microbes off our food, the best thing is to eat your food fresh so you
don’t need to consume any chemicals.
If you do eat preserved food, make sure you check the labels carefully.
References
[i] Micha R, Michas G, Lajous M, Mozaffarian D. Processing
of meats and cardiovascular risk: time to focus on preservatives. BMC Med. 2013 May 23; 11:136.
[ii] Lee AH, Su D, Pasalich M, Binns CW. Preserved foods associated with increased risk of
ovarian cancer. Gynecol Oncol.
2013 Jun; 129(3): 570-3.
[iii] Park S, Blanck HM, Sherry B, Jones SE, Pan L. Regular-soda intake independent of weight status is
associated with asthma among US high school students. J Acad Nutr Diet. 2013 Jan; 113(1): 106-11.
[iv] Winkler C, Frick B, Schroecksnadel K, Schennach H,
Fuchs D. Food preservatives sodium
sulfite and sorbic acid suppress mitogen-stimulated peripheral blood
mononuclear cells. Food Chem Toxicol.
2006 Dec; 44(12): 2003-7.
[v] Loutsidou AC, Hatzi VI, Chasapis CT, Terzoudi GI,
Spiliopoulou CA, Stefanidou ME. DNA
content alterations in Tetrahymena pyriformis macronucleus after exposure to
food preservatives sodium nitrate and sodium benzoate. Acta Biol Hung. 2012 Dec; 63(4): 483-9.
[vi] Ciardi C, Jenny M, Tschoner A, Ueberall F, Patsch J,
Pedrini M, Ebenbichler C, Fuchs D. Food
additives such as sodium sulphite, sodium benzoate and curcumin inhibit leptin
release in lipopolysaccharide-treated murine adipocytes in vitro. Br J Nutr.
2012 Mar; 107(6): 826-33.
[vii] McCann D, Barrett A, Cooper A, Crumpler D, Dalen L,
Grimshaw K, Kitchin E, Lok K, Porteous L, Prince E, Sonuga-Barke E, Warner JO,
Stevenson J. Food additives and
hyperactive behaviour in 3-year-old and 8/9-year-old children in the community:
a randomised, double-blinded, placebo-controlled trial. Lancet. 2007 Nov 3; 370(9598):1560-7.