CARDIOVASCULAR JOURNAL OF AFRICA • Vol 24, No 8, September 2013
AFRICA
297
Cardiovascular Topics
Analysis of the omega-3 fatty acid content of South
African fish oil supplements: a follow-up study
MARETHA OPPERMAN, SPINNLER BENADE
Introduction:
Globally the omega-3 (n-3) fatty acid supple-
ment industry is expanding rapidly while consumers are
becoming more aware of the health benefits of n-3 fatty
acids. Our group conducted a survey in 2009 on 45 commer-
cially available fish oil supplements on the South African
market. The aim of the study was to determine the fatty acid
composition and content of supplements for comparison with
the claimed contents on the product label. The survey was
repeated in 2012 on 63 supplements.
Methods:
Sixty-three commercially available n-3 fatty acid
supplements were analysed using gas–liquid chromatogra-
phy to determine their fatty acid composition and content.
Results:
This analysis has shown an improvement in the accu-
racy of EPA content (44% in 2009) declared on supplement
labels compared to the 2012 (52%) survey. It was also evident
that a higher percentage of supplements (13% in 2009 vs
35% in 2012) contained DHA levels higher than declared.
In 2009, 64% of supplements cost R2.01 to R5.00 or more to
achieve a daily intake of 500 mg EPA + DHA, compared to
81% in 2012. Forty-four per cent of supplements were found
to be in the early stages of rancidity [conjugated diene (CD)
levels] compared to 73% in 2009. More than 80% of supple-
ments had peroxide levels higher than the recommended
content as specified by the Global Organisation for EPA and
DHA Omega-3 (GOED). The majority (81%;
n
=
51) of the
supplements under study in 2012 had a 1.1–1.5:1 EPA-to-
DHA ratio or less, compared to 56% in 2009. Almost a third
(32%) of the supplements in the 2012 survey contained ethyl
esters (EE) or a combination of ethyl esters and triglycerides.
Conclusion:
Although the results of the 2012 versus the 2009
analysis were encouraging in terms of the accuracy of EPA
declared on the supplement labels, the high peroxide levels
found in the supplement oils are of concern. High peroxide
levels are associated with potential health implications. EE
were present in some of the supplements, even though the
safety of EE has not been confirmed in vulnerable groups
such as pregnant women and children.
Keywords:
omega-3 fatty acids, supplement labels, conjugated
dienes, peroxides, ethyl esters
Submitted 26/9/12, accepted 16/4/13
Cardiovasc J Afr
2013;
24
: 297–302
DOI: 10.5830/CVJA-2013-074
Scientific research and media exposure as well as raising
health and nutritional awareness among consumers have led
to a substantial rise in fish oil supplementation over the past
five years. It is predicted that sales of omega-3 (n-3) fatty acid
products in the United States (US) will increase from $25.4
billion in 2011 to $34.7 billion in 2016 (pers commun).
Even though n-3 fatty acid supplements capture only 13%
of the US n-3 product market, the highest retail dollar value of
the supplements is in the fish oil as opposed to packaged food,
beverages and infant formulas where the n-3 content is relatively
small. The South African market for fish oil capsules over the
past 12 months is estimated to be worth about R65 million (pers
commun), however this figure only includes data from large
retail store groups and not from privately owned businesses.
A whole array of health benefits are attributed to the
long-chain polyunsaturated n-3 fatty acids found in fish oil.
The n-3 fatty acids of particular interest are eicosapentaenoic
acid (EPA) and docosahexaenoic acid (DHA). These fatty
acids are eminent as anti-thrombotic, anti-arrhythmic and anti-
aggregatory compounds.
1
Routine intake of oily fish and fish oil are now widely
acknowledged for their role in decreasing the risk of
cardiovascular diseases (CVD) such as fatal coronary heart
disease and stroke. N-3 fatty acids are also renowned for
their anti-inflammatory properties and may be beneficial in
reducing the risk of inflammatory-related conditions including
obesity, Crohn’s disease, ulcerative colitis, type 2 diabetes,
asthma, psoriasis, multiple sclerosis, cystic fibrosis and chronic
obstructive pulmonary disease.
2
The significance of EPA and
DHA in neural and visual development is also well documented.
3
In a typical Western diet there are only a few food sources
contributing to dietary n-3 fatty acid intake. Research indicates
that plant-derived n-3 fatty acids in the form of alpha-linolenic
acid (ALA) are poorly converted to EPA and DHA,
4
while
preformed EPA and DHA from fish oil is readily available for
metabolism. Several clinical trials have shown that baseline
EPA and DHA blood levels can be increased by means of good-
quality fish oil supplements.
Clinical trial results from our group indicated low dietary
EPA and DHA intakes, as reflected in the baseline blood
levels of healthy, normo-lipidaemic, non-smoking research
participants residing in Cape Town. Typical baseline red blood
Functional Foods Research Unit, Department of Agriculture
and Food Science, Cape Peninsula University of Technology,
Cape Town, South Africa
MARETHA OPPERMAN, PhD,
SPINNLER BENADE, DSc
