With 18 of the 22 essential nutrients, cow’s milk really is a star staple. Nutritionist Jacqueline Birtwisle explains more
Did you know that one of the best recovery drinks you can have is low-fat chocolate milk made with cow’s milk? It’s an excellent, tasty and cheap option for a post-exercise recovery drink – and its ratio of carbohydrates to protein of 4:1 matches the more expensive commercial equivalents.
Cow’s milk
Not only has cow’s milk been shown to be of benefit as part of a healthy diet, there is plenty of evidence from a sporting perspective too. Cow’s milk consists of both whey (high in the key amino acid leucine) and casein, along with carbohydrate from the milk sugar lactose, fats and vitamins and minerals. The carbohydrate content is comparable to that of branded sports drinks and may be beneficial in glycogen synthesis – i.e. refuelling. The protein content and the ratio of whey to casein enhances post-exercise muscle protein synthesis – important in repairing damage done due to the exercise itself – while its high natural concentration of electrolytes, sodium and potassium means that it’s a highly effective post-exercise rehydration drink.
Milk also provides all nine essential amino acids and is therefore called a high quality protein
Calcium and bone growth
High in calcium and boasting a whole range of nutrients, cow’s milk is an important addition to a rower’s diet, particularly for younger athletes, as it is vital for the building of a strong skeleton. Bone grows denser throughout childhood and into the teenage years, finally peaking in density during the mid-twenties. Adolescence, though, is a critical time to build up bone – in fact during the two-year period across an adolescent growth spurt, up to 25% of the total peak bone mass is achieved, and up to 90% is acquired, by girls aged 18. It’s no surprise therefore that the requirement for calcium is at its highest during the teenage years.
Protein and essential nutrients
All in all, cow’s milk contains 18 of the 22 essential nutrients, including calcium, phosphorus, magnesium, zinc and manganese which are of special importance for bone health. Milk also provides all nine essential amino acids and is therefore called a high quality protein.
Low-fat chocolate milk has found to be an excellent, tasty and cheap option for a post-recovery drink
Iodine
UK cow’s milk is also rich in iodine and is the main dietary source of this nutrient. Contributing to the production of thyroid hormones and thyroid function, iodine is required for foetal brain development during pregnancy.
The recommended daily intake in the UK is 140 micrograms – a 200ml glass of non-organic milk would, on average, provide 64 micrograms, around 41% of daily requirements. Seafood and eggs are also sources of this nutrient and vegan sources would include seaweed and iodised salt – such as the brand Cerebos – or take a vegan-recognised supplement: check The Vegan Society guidance here.
Recommended daily amounts
In a 2000kcal daily diet, three servings of milk – or dairy such as yoghurt or cheese – have been shown to provide more than 70% of the recommended daily amount for calcium; 30-40% for vitamins A, B2 and B12 and 20-30% of protein, potassium, zinc and choline. One 200ml serving of milk is approximately 200-250 milligrams of calcium and is equivalent to 120 grams of yoghurt or 30 grams of hard cheese.
Alternative milk options
But what if you don’t like cow’s milk, or follow a vegan diet which eliminates all animal foods, or perhaps are diagnosed with a lactose intolerance?
There are a number of options available, but milk-like or plant-based drinks are not nutritionally comparable to cow’s milk, and so switching from cow to plant is not a decision to be taken lightly. This is because the protein content of most of the alternatives is low and the iodine content for most is negligible, so studying the nutrition label is essential to check if a product is fortified with calcium and vitamins B12 and D. The evidence that milk-like drinks possess health benefits, and indeed muscle-recovery benefits, above those of milk and dairy products is currently insufficient and more research needs to be done.
Soya milk
Soya milk is non-dairy and made from soya beans and water. Brands can be sweetened with added sugars or unsweetened. Each 200ml glass provides around six grams of protein which supplies all of the essential amino acids and so is a high-quality protein. Soya drinks are frequently fortified with calcium, vitamins B12 and D but, at the time of writing, it may be that only Alpro Soya Original chilled is fortified with iodine. Nutritionally, this could currently be the best choice for rowers requiring a lactose and non-dairy milk drink.
Oat milk
Oat milk is naturally sweet and a popular non-dairy milk option due to its taste. Often sugar is added in varying amounts, and this plant drink contains less than one gram of protein per glass. The Oatly brand has iodised salt in all but its organic variety.
Almond milk
Sales of this nut milk have overtaken sales of soya drinks in some UK supermarkets. It is made out of ground almonds and water. This non-dairy drink is also very low in protein, with just one gram per glass.
Check the label for added sugar, calcium, B vitamins and vitamin D as fortification will vary between brands. It has negligible iodine content and, at the time of writing, there were no brands available with added iodised salt or with added potassium iodide.
Coconut milk
Coconut milk’s composition can vary enormously – so study the label carefully for added sugars, fat content and calcium, vitamin D and B12. It has zero grams of protein per glass and negligible iodine, unless you can find one that is fortified. A good coconut drink that is fortified with everything including iodine, though still low in protein, is Koko Super.
Lactose-free milk
This is cow’s milk that has had the enzyme lactase added – this then helps break down lactose in the body. Nutritionally, lactose-free milk matches up with cow’s milk except that it is lower in carbohydrates. It provides seven grams of protein per 200ml glass and is the best alternative for health and performance for rowers requiring a lactose-free milk choice.
Take it further
Milk and dairy products: good or bad for human health? An assessment of the totality of scientific evidence by Tanja Kongerslev Thorning et al (2016) – read more here.
Vegan diets: practical advice for athletes and exercisers by David Rogerson (2017) – more information here.
Take home messages
1 Don’t switch to a plant drink without careful consideration and thinking about how you will replace the key nutrients that cow’s milk would otherwise provide.
2 Teenage girls and women of child-bearing age should choose an iodine-fortified milk drink and should pay attention to non-dairy sources of iodine in their diet, such as eggs and fish.
3 With the exception of soya drinks, the majority of the non-dairy alternatives are low in protein and would be a poor choice to aid muscle recovery and synthesis of protein.
4 Vegans would need to consider iodine supplementation, as per the Vegan Society’s guidance unless a brand with added iodine is chosen. With the exception of soya milk drinks, most non-dairy alternatives would not be a major source of protein for a vegan diet.
Illustrations: Jo Scales
