Milk-and-Dairy-Products-in-Human-Nutrition-FAO

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Milk and dairy products in human nutrition
Cow, buffalo, goat and sheep milks all contain similar quantities of SFAs,
65–75 g/100 g total FA. Mare and donkey milks contain the lowest amounts of
SFA, less than 40 g/100 g total FA in the case of mare milk. These two milks also
contain the highest amount of PUFA, on average 20 g/100 g total FA. In addition,
the indispensable FAs ALA and LA are present in equine milks.
Because of its high LA and ALA contents, mare milk has been suggested as ideal
for pre-term infants, as their livers are probably capable of transforming these FAs
into the n-3 FAs eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)
and the n-6 FA arachidonic acid (Orlandoi, Goracci and Curadi, 2003). However,
further studies are necessary, particularly with respect to effects on iron status
in infants. For populations with no access to n-3 FA from fish, e.g. landlocked
Mongolia, intake of mare milk is crucial for meeting requirements (adequate intake
of 100–150 mg EPA+DHA for a 2–4-year-old child; acceptable macronutrient
distribution range of 0.25–2 g/day for adults) (FAO and WHO, 2010a).
Trans-FA contents of up to 3–6 g/100 g total FA have been reported in cow,
buffalo, goat, sheep, goat, reindeer and llama milks (LeDoux et al., 2002; Rodríguez-
Alcalá, Harte and Fontecha, 2009). However, these values depend on the diet of the
animals, with values up to 10 g/100 g total FA (or 0.33 g/100 g milk, given an average
fat content of 3.5 g/100 g) being reported in cow milk under certain feeding regimes
(Briard-Bion et al., 2008). No trans-FAs have been reported in donkey milk, while
mare milk is reported to contain negligible amounts.
The most biologically active form of CLA is thought to be C18:2 cis-9, trans-11
(c9, t11-CLA) (Jensen, 2002), which represents more than 90 percent of CLA in
ruminant milk fat (Savoini et al., 2010). C18:1 trans-11 (vaccenic acid), the dominant
trans-FA in products of ruminant origin, can be desaturated in the body and
converted to CLA. 13
Cow milk is reported to contain between 0.1 and 2.2 g of CLA/100 g total FA, the
amount varying with various factors including feed, with values as high as 3.3 g/100 g
total FA reported in milk from grass fed cows (Jutzeler van Wijlen and Colombani,
2010). Sheep milk is reported to contain more CLA than cow and goat milks (Jahreis
et al., 1999; Tsiplakou et al., 2009), which may be partially attributed to the semiextensive
nature of sheep farming (Sanz Sampelayo et al., 2007). Buffalo milk contains
an amount of CLA similar to or greater than that in cow milk. Mare (monogastric),
llama and Bactrian camel (pseudo-ruminant) and yak (ruminant) milks have been
reported to contain only very small amounts of CLA. The CLA content in human
milk is reported to vary from 0.2 to 1.1 g/100 g total FA (Malacarne et al., 2002).
3.3 Treated liquid milks and dairy products
Very little raw milk (i.e., “milk which has not been heated beyond 40 °C or undergone
any treatment that has an equivalent effect”) is now drunk (FAO and WHO,
2009). The hazards and risks associated with the consumption of raw milk are
discussed in Chapter 6.
13 The health impact of CLA and trans-FA are considered in Chapter 5. Chapter 5 also highlights the
labelling classifications of CLA.