The Differences Between Cow and Goats Milk
Nutritionally very similar
Despite the numerous health benefits that cows' milk and cows' milk products can offer, (Ref 1) more and more of us are seeking alternatives due to a true or perceived allergy or intolerance - or other environmental, religious and health reasons (Ref 2). So if you are thinking of making the switch, have you considered goats' milk?
There are a number of theories…
A number of recent scientific research studies have focused on the differences between cows' and goats' milk (Ref 3, 4, 5, 6, 7). Disparities in their fat, protein and sugar composition may help to explain why many people report that goats' milk supports their digestive wellbeing. Some of the explanations can be quite complicated!
Differences in Fat
Fat levels in goats' milk vary depending upon the breed of goat, stage of lactation season and diet. Whilst the fat content of goats' milk is similar to cows' milk, goats' milk is naturally more homogenous than cow's milk i.e. it has a higher percentage of smaller fat globules (droplets) and this can make it easier to digest (Ref 3) . Fresh goats' milk you buy in the supermarket has had the fat standardised throughout the milk, so that the fat content can vary from about 3.6% to zero depending on whether you buy whole, semi-skimmed or skimmed.
Differences in Protein
Research has indicated that peoples' intolerance of cows' milk has much to do with the protein structure in the milk. Cows' milk contains more than 20 proteins (allergens) that can cause reactions (Ref 6). The main protein found in milk is called casein, of which there are four types. All four casein proteins are found in cows' milk, but goats' milk has a lower alpha-s1-casein content. Aplha-s1-casein is understood to be one of the main proteins responsible for most cows' milk allergies (Ref 3).
Goats' milk also contains more A2 beta-casein protein, rather than the allergenic A1 beta-casein found in most supermarket cows' milk (Ref 8).
This unique protein combination may assist with your digestive health and comfort by allowing the goats' milk to form a softer curd during digestion (Ref 9).
However, if you have been diagnosed with an allergy to cows' milk, never switch to goats' milk without first taking advice from your allergy consultant or State Registered Dietitian. Some of the proteins in goats' milk are still similar to those found in cows' milk, and those that react to cows' milk protein may also react to goats' milk protein.
Differences in Sugar
Goats' milk, like cows' milk, contains the milk sugar lactose. According to Allergy UK, (Ref 9) 5% of adults in the UK don't produce enough of the enzyme lactase to properly digest lactose.
Current advice for the treatment of lactose intolerance is to reduce or remove lactose from the diet (Ref 10). However, lactose tolerance levels vary from person to person. You should speak with your doctor and possibly experiment (through a food and symptom diary) how much lactose you can eat and determine your own personal tolerance level.
Goats' milk typically contains slightly less lactose than cows' milk (around 4.4g per 100g versus 4.5g per 100g in cows' milk), (Ref 11). This, together with goats' milks easier digestibility, may help to explain why some people with lactose intolerance are able to enjoy goats' milk without any repercussions (Ref 12,13). As usual, consult with your GP or relevant health professional before making any dietary changes.
A study has shown that goats' milk also has more oligosaccharides than cows' milk, with an amount similar to human milk. These act as prebiotics in the gut and help to maintain the health of the digestive tract by encouraging the growth of beneficial gut bacteria and preventing the growth of harmful bacteria (Ref 14).
References:
1. The Dairy Council. http://www.milk.co.uk/. Accessed 1/02/2012
2. Mintel (2010) Milk and Cream UK – May 2010 (online)
3. Tomotake H, Okuyama R, Katagiri M, Fuzita M, Yamato M, Ota F. Comparison between Holstein cow's milk and Japanese-Saanen goat's milk in fatty acid composition, lipid digestibility and protein profile. Biosci Biotechnol Biochem 2006; 70:2771-2774.
4. Alferez MJ, Barrionuevo M, Aliaga IL, Sanz-Sampelayo MR, Lisbona F, Robles JC, Campos MS. Digestive utilisation of goat and cow's milk fat in malabsorption syndrome. J Dairy Res 2001; 68:451-461.
5. Alonso L, Fontecha J, Lozada L, Fraga MJ, Juárez M. Fatty acid composition of caprine milk; major, branched-chain, and trans fatty acids. J Dairy Sci 1999; 82:878-84.
6. El-Agamy El. The challenge of cow's milk protein allergy. Small Rum Res 2007: 6864-72.
7. Lara-Villoslada F, Debras E, Nieto N, Concha A, Galvez J, Lopex-Huertas E, Boza J, Obled C, Xaus J. Oligosaccharides isolated from goat's milk reduced intestinal inflammation in a rat model of dextran sodium sulphate-induced colitis. Clin Nutr 2006; 25:477-488.
8. St Helen's Farm, general nutrition and processing information. 2011.
9. Allergy UK. http://www.allergyuk.org/.
10. Lactose intolerance_NHS Choices www.nhs.uk/conditions/Lactose-intolerance/Pages?introduction.aspx Accessed 26/06/2012
11. Food Standards Agency. McCance and Widdowson's. The Composition of Foods. Sixth Summary Edition Cambridge. Royal Society of Chemistry. 2002.
12. McBean LD, Miller GD. Allaying fears and fallacies about lactose intolerance. J Am Diet Assoc 1998; 98:671-76.
13. Pribila BA, Hertzler SR, Martin BR, Weaver BM, Savaiano DA. Improved lactose digestion and intolerance among African – American adolescent girls fed a dairy-rich diet. J Am Diet Assoc 2000; 100:524-28.
14. Lara-Villoslada F, Debras E, Nieto N, Concha A, Galvez J, Lopex-Huertas E, Boza J, Obled C, Xaus J. Oligosaccharides isolated from goat's milk reduced intestinal inflammation in a rat model of dextran sodium sulphate-induced colitis. Clin Nutr 2006; 25:477-488.
