Is the sugar in milk bad for you?
When it comes to nutrition and health trends, and ways to lose weight, sugar has become scrutinised as something we must limit or avoid in recent years. However, not all sugars are created equal and some function as an integral part of a wide range of natural and nutritious foods. Here, we explore the facts on milk and sugar and, don’t worry – we promise not to ‘sugar-coat’ the truth!
Does milk have sugar in it?
The simple answer is yes – but the sugar in a cup of milk is a natural sugar which makes it very different to the sugar you might add to your cup of tea!
Some sugars may be added to foods to enhance sweetness and will provide additional calories, but no nutritional value. If eaten in excess, this could lead to negative health outcomes such as weight gain and tooth decay. Foods that contain these ‘added’ or ‘free’ sugars (e.g. sweets, chocolate, biscuits) should only be consumed in small amounts and on occasion, as recommended by the Department of Health’s healthy eating guidelines.
Both the Scientific Advisory Committee on Nutrition (SACN) and the World Health Organisation (WHO) have focused on restricting such ‘added’ or ‘free’ sugars, generally defined as ‘all monosaccharides and disaccharides added to foods by the manufacturer, cook or consumer, plus sugars naturally present in honey, syrups and unsweetened fruit juices’.
To note, some sugars are naturally found within nutritious foods (‘intrinsic’ sugars) and behave in a different way to the added sugars (‘extrinsic’ sugars) discussed above. Examples include the natural sugars found in fruit and vegetables; and lactose, which is the natural sugar in cow’s milk. In contrast to the guidelines to limit foods with added sugars, the Department of Health recommends 5-7 servings from the ‘Vegetables, salad and fruit’ food group per day. Three servings are recommended from the ‘milk, yogurt and cheese’ food group per day, with 5 daily servings recommended for those aged 9-18 years, due to the importance of calcium during this life stage. These recommendations also recognise the many nutritional benefits of milk and dairy foods and their role in contributing to normal health.
What are the lactose levels in milk and is milk high in sugar?
Checking the nutrition label of dairy products under ‘Carbohydrate – of which sugars’ will help you help you to determine how much naturally occurring sugar (or in other words, how much lactose) is in milk. The amount will vary very slightly depending on the brand and fat percentage of the milk, but the lactose content in milk is typically 4.5-5g /100mls (9-10g in a standard 200ml serving). It is important to remember that lactose does not fall into the category of ‘added’ or ‘free’ sugars – which we are advised to reduce – even though it is still represented as ‘sugar’ on nutrition labels.
Flavoured milks, however, may be sweetened with sugar and manufacturers will indicate this on the packaging by stating it in the ingredients list and as part of the nutritional information. Unlike most confectionary, flavoured or sugar-sweetened milks still provide the many nutritional benefits of milk and dairy foods, such as protein, calcium, vitamin B2, iodine and phosphorus. The main difference in composition is that flavoured products have a higher calorie and carbohydrate content due to the addition of sugar. As with all sweetened products, they should be consumed in moderation and as part of a healthy, balanced diet. The consumption of such products may also depend on a person’s lifestyle. For example, chocolate milk can be a popular option among sports people after an intense exercise session due to the additional carbohydrate (sugar) that can help to refuel muscles, as well as providing a form of hydration and protein to assist with muscle repair.
You can use the label of the product to decipher the sugar content. A food that is low in sugar will have 5g per 100g or less; while a food high in sugar will have 22.5g per 100g or more. The World Health Organisation (WHO) guidelines recommend that the intake of added sugars be less than 10% of total daily energy intake, and ideally below 5% (about 25g/6 teaspoons per day). Nutrition labels may be confusing as they generally do not differentiate between added or natural sugar, and combine both in the figure stated for ‘sugars’. If sugar has been added, the sugar amount per 100mls of milk will be >5 g (as 5g will be the natural sugar lactose). The ingredients list will also indicate added sugar by stating ingredients such as sucrose, glucose syrup, mannitol, maltose, molasses, dextrose, honey or corn syrup.
Because skimmed and semi-skimmed milk have some fat removed from them, a common question to ask is ‘Is there added sugar in skim milk to replace the fat removed?’. However, contrary to belief, plain skimmed, low-fat and whole milk all contain the same nutrients apart from their fat and calorie content and there is not more sugar in skim milk. When the fat is removed from whole milk, there is no sugar or sweeteners added in and all of these milk types remain a source of calcium, protein, iodine, phosphorus, potassium and B vitamins. The natural sugar (lactose) content ranges from 4.6-4.8% across whole, semi-skimmed and skimmed milk varieties.
What about milk and diabetes?
Over 850,000 adults over 40 years of age in Ireland are at increased risk of developing (or have) Type 2 diabetes. Type 2 diabetes mellitus (T2DM) occurs due to high levels of glucose being present in the blood (hyperglycemia). This is normally regulated by the hormone, insulin but in T2DM, this process becomes impaired. Significant health consequences are associated with diabetes including an increased risk of cardiovascular disease, as well as organ-specific complications.
The role of diet in the cause, prevention and management of type 2 diabetes is well established. Carbohydrate foods, which include complex (usually high fibre starches) and simple forms (usually low fibre starches and sugars), can be divided into ratings of between 0-100 based on how fast they cause our blood sugar to rise after eating. This rating is referred to as their ‘glycemic index’. Low GI foods (e.g. porridge, yogurt, apples, nuts) give a more gradual rise in blood sugar levels; with high GI foods (e.g. white bread, cereal bars, jellies) rapidly increasing levels. Low GI foods are important components of a healthy diet.
While those who are medically diagnosed with lactose intolerance may need to limit their lactose intake, those with diabetes generally do not need to worry about their intake of this sugar, once consumed within the recommended guidelines. Lactose is a ‘disaccharide’ sugar, meaning it is made up of two single sugar units (monosaccharides) – glucose and galactose. When lactose is broken down, these single sugars can be absorbed into the blood and used as energy. Because lactose has a moderate effect on GI; and as it is an intrinsic sugar, consumed alongside other components (e.g. protein), this gives milk and dairy foods an overall low GI score. Diabetes Ireland support the recommendations outlined in the Department of Health’s healthy eating guidelines, with 3 servings recommended per day for adults as part of a balanced diet. Serving examples include 200mls of milk, 125 g of yogurt or 25 g of cheese. Additionally, although more research is needed, the potential role of dairy and dairy components as part of a balanced diet for the reduction of type 2 diabetes risk has been indicated in a number of studies over recent years. Protective associations have been reported for total dairy consumption as well as for low-fat dairy, cheese and other fermented dairy products.