Nausea, abdominal pain, diarrhoea, bloating; lactose intolerance is certainly no bundle of fun for those who suffer from it. If you’re one of them, you may well go to great lengths to keep the symptoms at bay by avoiding milk and dairy products.
But having these symptoms of lactose malabsorption or intolerance doesn’t necessarily mean you have to totally give up the dairy foods, scientists say. In fact, the symptoms are often confused for other conditions. And cutting out dairy, a vital source of nutrients from your diet, could leave you more vulnerable to long-term disease – especially if you’re an older person (1).
What causes lactose intolerance?
Most people are born with an ability to absorb and digest lactose, a sugar found naturally in milk. To do this, babies have a plentiful supply in their gut of the enzyme lactase, which breaks down lactose into glucose and galactose. But after weaning, most of us are genetically programmed to become deficient in lactase, reducing our ability to absorb lactose. Hence, it’s normal to have lactose malabsorption.
As a result, more undigested lactose passes into the large intestine, where it may cause symptoms for some people. About one in three people with this lactase deficiency develop symptoms of lactose intolerance.
The terms ‘lactose malabsorption’ and ‘lactose intolerance’ are commonly muddled, even among doctors – with the result that studies of lactose intolerance can be misinterpreted.
Why is getting the diagnosis right so important for older people?
Until now, the common way of managing symptoms of lactose intolerance has been to cut out milk and dairy products from their diet.
But experts are calling this approach into question as dairy products are such an important source of nutrients that can’t always be obtained from other foods. This is particularly important for older people, for whom nutrients found in dairy products are essential for helping to keep us from becoming frail as we age.
According to a group of researchers who have reviewed the science, a large body of evidence has also linked dairy intake to the prevention of other long-term conditions in the elderly, such as heart disease (2-4). So restricting dairy product intake in older people can be harmful and should be the last resort when it comes to treating gastrointestinal symptoms, say the researchers.
This is all the more so because symptoms of lactose intolerance may overlap with other gut diseases that are common among older people, such as irritable bowel syndrome (IBS). Anxiety can also hamper the diagnosis, perhaps increasing the risk of symptoms after eating a food containing lactose. Anxiety arising from the fear that eating certain foods will trigger the symptoms can cause some people to restrict their food intake, leading to malnutrition.
That’s why, if you think you have lactose intolerance, a clinician should always take a careful medical history to assess symptoms and guide the correct diagnosis, the researchers stress. Lactose malabsorption should be at the bottom of the list of suspects, and treatment for IBS and other common conditions should be tried first, the researchers believe.
‘… a close temporal relationship between the ingestion of milk and dairy products and the onset of symptoms may suggest actual lactose intolerance.’ – Gallo A, et al. 2023
How should older people with lactose intolerance be treated?
The researchers advise that after the diagnosis has been made, treatment should start with a temporary avoidance of milk and dairy products so that the symptoms go away. Dairy products should then be gradually re-introduced to ensure you get sufficient nutrient intake.
To raise the threshold dose at which the symptoms are brought on, you may be advised to drink milk together with other foods, distribute the daily milk amount in small meals, or add a product containing lactase enzyme to milk at mealtime (5).
In studies, most people with lactose malabsorption found that their symptoms didn’t worsen after small doses of lactose (12-15 g/day, about 240 ml of milk).
Yogurt contains the enzyme lactase, produced by the bacteria used to make it, and which helps to digest the lactose contained in the product (6).
Why it’s important for older people to consume dairy products
Milk and dairy products are a vital source of several nutrients, and their consumption has been associated with multiple benefits for older people:
- Bones: Dairy products are rich in calcium and protein, which are essential for building and maintaining healthy bones. Cutting down on dairy product consumption due to lactose intolerance is particularly concerning among older people because of their risk of osteoporosis and bone fractures. A greater consumption of dairy products by older adults has been associated with a lower risk of loss of muscle mass and strength that occurs as we age. (7)
- Heart and blood vessels: Studies have shown that people who consume the most milk and dairy products have the lowest rate of cardiovascular disease (CVD) and lowest risk of type 2 diabetes. (2-4) Dairy products may play a role in maintaining a healthy blood pressure because of their calcium content.
- Colorectal cancer: Dairy product intake has been associated with a reduced risk of developing colorectal cancer; this could be due to its calcium and vitamin D content, regulators of cell growth. (8,9)
‘The approach to lactose malabsorption in older adults deserves careful considerations, starting from an accurate collection of medical history to avoid potentially misleading diagnostic tests. All confounding factors, including the psychological domain, should be thoroughly investigated to devise the best intervention strategy and limit dietary restriction to selected cases.’ – Gallo A, et al. 2023
