Question:
I make yoghurt from the commercial powdered varieties but wonder if the nutritional value matches that of yoghurt made from scratch at home?
Answer:
Yoghurt is one of the most popular fermented foods in the world, thanks to its taste, versatility and nutritional value. Since ancient times, the benefits of fermented foods have also been praised – with fermented milk recommended centuries ago for an upset stomach. But, is there a big difference in the nutritional benefits of a commercial powdered yoghurt compared with a yoghurt made at home from a live culture?
Yoghurt is a nutrient-dense food, providing a good source of calcium, phosphorus, potassium, vitamin A, vitamin B2 and vitamin B12. Yoghurt is also a beneficial source of high biological-value protein containing all the essential amino acids. All of which makes it a nutritional powerhouse.
The Ministry of Health recommends adults consume two or more servings of milk and milk products, such as yoghurt, each day. One serving equates to a small pottle of yoghurt (120-150g), a glass of milk (250ml) or two slices of cheese (40g).
Allegedly, yoghurt was accidentally discovered thousands of years ago when shepherds in the Middle East carried milk in sacks made from intestinal guts. The milk curdled as it came into contact with the intestinal secretions on the gut lining, effectively preserving it and enabling the shepherds to store it for longer.
Nowadays, most powdered commercial yoghurt sachets and fresh yoghurt are made from effectively the same ingredients: milk and lactic acid-producing bacteria. Lactic acid bacteria convert the lactose milk sugars in the milk into lactic acid, which then curdles the milk, forming yoghurt.
Consequently, whether yoghurt is store-bought, made from a commercial powder or a fresh culture, there are probably only minor nutritional differences (see table), given all yoghurts are made from curdled milk.
However, adding flavours and sweeteners to yoghurt can significantly alter the nutrition profile, as both often contain significant quantities of added sugars. The World Health Organisation recommends we limit added sugars to less than 10% of total energy intake (around 12 teaspoons of sugar per day), or ideally about half that, to reduce the risk of dental caries and serious conditions such as cancer, diabetes and cardiovascular disease. The lactose in yoghurt is not an added sugar, but flavourings and sweeteners typically added to yoghurt such as honey, syrups (eg, caramel) and fruit purees, do contain added sugars that we are best to limit.
The other key difference in yoghurts is the bacteria they contain. The starter cultures for yoghurt are not commonly probiotics; however, some yoghurts contain added probiotics – a subset of micro-organisms. Researchers have linked probiotics to various health benefits, such as reducing the severity and duration of antibiotic-associated diarrhoea, eczema associated with cow’s milk allergy, respiratory tract infections, infant colic, bacterial vaginosis and even urinary tract infections.
But although many different probiotic strains have been studied, showing a universal, consistent, cause-and-effect, positive health relationship for any single strain has been difficult.
Further, two studies investigating the impact of an 11-strain probiotic supplement on the human gut found many people’s digestive tracts prevent standard probiotics from successfully colonising them, and there was considerable individual variation in how they affected gut microflora.
So, even if one probiotic strain was unequivocally linked to a positive health effect, we can’t be sure that every person would benefit from consuming that probiotic, given the variation in individual responses to probiotics.
Ultimately, there is not likely to be a vast difference in nutritional composition between home-made, commercial powdered or store-bought plain yoghurts, as they are all made from milk and live cultures. But adding sweeteners and flavourings can negatively affect the nutritional profile.
So, enjoy your yoghurt – wherever you’ve sourced it from. It’s tasty and nutrient-dense, and it may also benefit your gut microflora and health, but nobody knows for sure.
