With so many milk options available in stores today, how can we even begin to make informed decisions about which type of milk to choose? Ritu Raizada talks to a Dubaibased nutritionist to find out how to maximise the health benefits of our daily dose of dairy.
Do you sometimes find yourself overwhelmed by your supermarket's milk selection? Dubai-based nutritionist Lovely Ranganath has some tips that will help you make the right choice on what to drink.
Milk varieties explained
"Fluid milk is broadly classified as whole milk, reduced fat, low fat or fat-free milk," explains Ranganath.
Whole milk contains around 3.25 per cent fat and not 8.25 per cent milk solids-not-fat (MSNF). Reduced fat milk contains 2 per cent milk fat, whereas low-fat milk contains 1 per cent milk fat. Fat free (non-fat) milk, the current designation for what was formerly skim milk, must have a fat content of 0 per cent and at least 8.25 per cent MSNF. All of these milks are usually homogenised, pasteurised and fortified with the addition of 2,000 units of vitamin A and 400 units of vitamin D.
Evaporated milk is a canned version of homogenised and vitamin D-fortified milk in which about half the water content is evaporated prior to canning. Sweetened condensed milk is a canned, homogenised and fortified (vitamin D) milk product in which about half the water has been evaporated prior to canning. A high percentage of sucrose and/or glucose (44 per cent) is added to help retard bacterial growth in order to increase flavour and viscosity.
Another form of fluid milk, ultra-high temperature processed milk (UHT), is heated at about 300 degrees Fahrenheit for two to six seconds. "Packaged aseptically into pre-sterilised containers to eliminate bacterial contamination, UHT milk can be stored for long periods of time," explains Ranganath, "Although after several months, ‘off-flavours' can develop (due to residual enzyme activity and chemical changes.")
Non-dry milk (NFDM) or instant milk powder is made from pasteurised skimmed milk by removing about two-thirds of the water content under a vacuum and then spray-drying the concentrated milk into a chamber of hot filtered air. Other varieties of milk include cultured milk, also known as fermented milk, which include yoghurt, buttermilk and sour cream.
"Different types of milk products are identified according to specific standards," Ranganath says. "These standards are required for labelling purposes and identify the product name, type and the amount of ingredients that a specific food type must contain, as well as the processing requirements."
Health benefits of milk
"We know that calcium-rich milk helps build strong bones," says Ranganath. "But milk is also loaded with eight other essential vitamins and minerals. These are calcium, protein, vitamin A, vitamin B 12, vitamin D, potassium, phosphorus, niacin and riboflavin."
In a study published in a recent issue of the Journal of the American Dietetic Association, milk intake of 50 children with histories of bone fractures was compared with that of other children of a similar age. "The researchers found that children with low dietary calcium intake (in other words, kids who consumed less milk) had lower bone density and documented more bone fractures. Additionally, the group who were not regularly exposed to dairy were generally overweight and exercised less."
Research shows that calcium is important for our health, and goes far beyond building strong teeth and bones. "Calcium even appears to help prevent hypertension, kidney stones, cardiovascular disease and colon cancer, and it may assist in weight management," says Ranganath. "Foods rich in calcium seem to provide the greatest benefit, although research is being conducted on the benefits of calcium supplements."
Milk is a fantastic hunger-supressant. "If you often feel ravenous by noon despite a good breakfast, try drinking some skimmed milk with your breakfast. You can't go wrong with a whole-grain cereal and berries with non-fat milk – this meal will cover your morning dose of fibre, folic acid and calcium. In a study conducted with overweight people, those who drank about 20 ounces of skim milk with breakfast ate less at lunch than the people who drank fruit juice in the morning.
According to Ranganath, milk drinkers also felt fuller and more satisfied after their morning meal. "The whey and casein proteins that are in milk are better at quelling hunger than the carbohydrates in fruit drinks," she says.
"Milk has received attention in the news recently. Although the research is still in its early stages, some studies are finding that people who consume more calcium, particularly in the form of milk and other dairy products, tend to weigh less as they age," says Ranganath. "This is good news for milk lovers and it may even get your teen to think about reaching for a glass of milk instead of a soda the next time he or she opens the fridge door."
The milk proteins: casein and whey
The major milk protein (roughly 80 per cent of total milk protein) is called casein. "The other milk proteins are called whey proteins," Ranganath says. "Two milk products that are high protein sources are whey protein concentrate (WPC) and whey protein isolate (WPI). WPC, roughly 75 per cent protein, is produced by heating milk and filtering it through a very fine membrane (a process called ultra-filtration). WPC is used as an additive in various food products. WPI, roughly 90 per cent protein, is a highly purified or concentrated form of protein. WPI is used in baked products, mixes, soups and in confections like a gelling agent."
Are today's kids in a calcium crisis?
"Yes," says Ranganath. "Growing children need more milk. Currently, more than half of the children between the age of two and eight, and three quarters of children aged nine to 19 do not get the recommended daily serving of milk products."
But the good news is that flavoured milk delivers the nutrients kids need. It provides the same nine essential nutrients as white milk and includes calcium, potassium, phosphorous, protein, vitamins A, D and B12 and riboflavin, as well as niacin equivalents.
"According to a study in the Journal of the American Dietetic Association, when compared to their peers, children who drink flavoured milk drink more milk overall and are more likely to meet their calcium needs without consuming more calories. It is a nutritious alternative to other beverages." But doesn't flavoured milk contain as much added sugar as fruit drinks or carbonated soft drinks?
"No," says Ranganath. "While flavoured milk contains both natural and added sugars, it contains less added sugar than other beverages (such as carbonated soft drinks). On average, a 220ml low-fat flavoured milk contains around four teaspoons of added sugar while the equivalent amount of fruit punch contains six teaspoons. The soda equivalent contains seven teaspoons. Researchers analysed food consumption data from the National Health and Nutrition Examination Survey (NHANES) and found that flavoured milks contributed to only 2 per cent of the total added sugar in children's diets, compared to the 50 per cent or more added by soft drinks and fruit drinks."
To help children consume milk while balancing added sugar intake, when selecting a low-fat flavoured milk, compare grams of added sugar per serving and select the option with the lowest amount of sugar.
Who needs which milk and how much?
During pregnancy: Three one-cup servings of milk or equivalent per day provide 24g of protein, close to the additional requirement during pregnancy of 25g per day. This amount also provides 900mg of calcium and 270 kcal (from skim milk) or 480kcal (from whole milk). If limited milk is consumed, a vitamin D supplement may be desirable, especially if exposure to sunlight is limited.
Many women are unable to digest lactose in milk unless consumed in small amounts. Commercial enzyme preparations such as Lactaid can be added to milk to improve lactose digestion. Expectant mothers can substitute milk with cheese or yoghurt, which contain small amounts of lactose as well as calcium-enriched soy milk (which is lactose-free). If necessary, physicians can prescribe preparations such as calcium lactate or calcium carbonate.
Infants: Although it is generally recommended that infants receive mother's milk or iron-fortified formula for the first year of life, many parents make the transition from formula to fresh cows' milk when the infant is between five and nine months of age.
"However," argues Ranganath, "Cows' milk is considered inappropriate during the first year because it provides insufficient vitamin C and iron, as well as excessive sodium and protein." If it's introduced too soon, cows' milk can hinder the uptake of iron-fortified formula or breast milk (this is referred to as the displacement of nutrients). "Low fat and non-fat milk is also inappropriate for infants during the first two years of life," continues Ranganath. "Additionally, substitute or imitation milks such as rice milk, oat milk or nut milks should not be fed to infants unless they are well supplemented."
She adds that zinc is a versatile trace element that supports the work of numerous proteins in the body, assists in immune function and growth and development.
"Cow's milk protein (casein) binds zinc and limits absorption. Infants absorb zinc better from breast milk. However, milk does not inhibit adult zinc absorption so long as one ingests adequate animal protein. At one year of age, whole cows' milk becomes the primary source of most of the nutrients that an infant needs. Two to three and half cups a day meet those needs sufficiently. More milk than this displaces foods necessary to provide iron and can lead to milk anaemia. Children from one to two years old should not drink low- or non-fat milk. If parents choose powdered milk, it should be a full-fat variety."
Children: "Because milk and other dairy products are the primary sources of calcium," says Ranganath, "children who consume limited amounts of these foods are at risk of poor bone mineralisation. A two- to three-year-old needs to be given four to five servings of milk and dairy products with one portion being about half a cup (120 grams). Children between four and six years old should have three to four servings of milk a day."
Teenagers and young adults: Adolescence is a crucial time for bone development, and the requirement for calcium reaches its peak during these years. "Low calcium intake during the adolescent growth spurt, especially when paired with physical inactivity, may compromise the development of peak bone mass. Attaining maximal bone mass is considered the best protection against age-related deterioration. Teenage girls are at the greatest risk. Three to four cups of non-fat or low-fat milk or yoghurt is recommended as a daily serving guide for adolescents."
Older adults: Some older adults have trouble digesting milk, even if they had no problem with it when younger. "With age, the small intestine may not produce as much lactase," explains Ranganath. "Lactase is the enzyme that digests the natural sugar lactose in milk. Without adequate lactase, consumption of milk can lead to gas, bloating and diarrhoea. The good news is that you don't have to eliminate milk – simply make a few alterations to your eating habits, such as drinking milk in small quantities. Usually the body can release enough lactase to digest a smaller amount of milk. Drinking milk with other foods will help to slow down digestion, making absorption of lactose easier. Also try other dairy foods that are lower in lactose such as yoghurt, cheese, buttermilk or special lactose-free milks."
What if I am lactose intolerant?
"This is a condition that results from an inability to digest the milk, sugar and lactose. It is characterised by bloating, gas, abdominal discomfort and diarrhoea. Lactose intolerance differs from a milk allergy, which is caused by an immune reaction to the protein in milk.
"About 30 per cent of people retain enough lactose to digest and absorb it efficiently throughout their adult lives. Fortunately, lactase-treated milks have been developed. The enzyme lactase is added to pasteurised milk and stored for 24 hours. The lactose content is reduced by 70 per cent (lactose reduced milk). Milk that has 99.9 per cent of its lactose hydrolysed is labelled ‘lactose-free'," says Ranganath.
What if I don't like skimmed milk?
"Contrary to popular belief, skimmed milk is not watered down whole milk. Skimmed milk has 99 per cent of the butter fat removed. Nutritionally, the only difference between these milks is the fat content. The blue colour of skim milk is from the riboflavin content, which is not camouflaged by the yellow cream that has been removed from 2 per cent milk."
Ranganath suggests that to help yourself wean off high-fat milk, try drinking 2 per cent milk for one week, then move on to 1 per cent milk for another week and finally start drinking skimmed milk. "Over time you will get used to the taste of skimmed milk and higher fat milk will taste like cream to you," she says.
