Yoghurt can be a nutritious food, though its potential is often exploited by companies who like to use yoghurt’s healthy halo as a marketing gimmick. There are so many options out there, when you look down the supermarket shelf you’ve actually probably got more chance picking something that resembles a dessert than a snack or breakfast. So, what makes a healthy choice when it comes to yoghurt?
(Note: this article deals with traditional, dairy yoghurt. I’ll put up a post on plant milk-based versions soon!)
What is yoghurt?
If you want to choose good yoghurt, it’s helpful to understand its production. Yoghurt is made by adding bacteria to milk and warming it, creating an environment where the bacteria ferment the milk. These specific bacteria are known as “starter cultures”, and have the ability to consume the lactose in milk and convert it to lactic acid, which is what gives yoghurt its characteristic tangy taste. (Lactose is the “sugar” in milk, and the bacteria like to eat it). Amazingly, the starter cultures also produce antimicrobial substances and create an environment where other (harmful) microorganisms cannot thrive, which is why although it’s kind of like off milk, yoghurt is an edible product and has quite a good shelf life!
The starter cultures that produce yoghurt are Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaris. You will usually see these names abbreviated to “S.thermophilus” and “L.bulgaris”. These bacteria are friendly to humans and also exist in our digestive tract (whether you eat yoghurt or not). For health and taste reasons, often more strains of friendly bacteria are added to yoghurt, making it a nourishing probiotic food. The most common strains you tend to see added are Lactobacillus acidophilus, Lactobacillus casei and Bifidobacterium. We like including multiple strains of these probiotic bacteria because research suggests they may help to keep our digestive systems functioning optimally, and may even possibly help to heal gut disorders and reduce the risk of other chronic diseases. So, on the ingredients list it’s healthy & normal to see a variety of bacteria species featured (and at a minimum, there should at least be the starter culture required for making the yoghurt!).
How to make a nutritious choice
Once you understand how yoghurt is made, it becomes pretty obvious what the golden rule is for selecting yoghurt. You want to choose one that has an ingredients list that does not include more than milk (and occasionally cream is used too, which is fine) + cultures. Everything else is added to make the yoghurt thicker, creamier, sweeter, etc., and is not actually necessary to the product. (If you can find a yoghurt that is made on a base of organic milk from pastured cows, even better; that way you know your yoghurt comes from a quality starting point, cows fed a natural diet.) Sounds so simple, right? Yet an overwhelming number of popular yoghurts have SO much more in them; this article would be a novel before I’d finished dissecting them all. Here are a couple of things in particular to watch for:
- Milk solids: a powdered milk product added in to yoghurt to give it a richer flavor (so you’ll see it often in lite or low-fat yoghurts). Skim milk is evaporated and dried into a powder at a high heat to make this. The heat-treating process may have toxic effects on the composition of the milk, in particular creating oxidized fats, which are linked to atherosclerosis (hardening of the arteries).
- Inulin: this is a type of dietary “fibre” (technically, it’s a carbohydrate, but indigestible) which is added to bump up the sweetness and texture. The main concern with inulin is that it’s pretty tough on our guts; our bodies don’t know how to break it down and it can cause gastrointestinal distress. I like this article from I Quit Sugar which gives you an easy-to-read breakdown on inulin.
- Numbers and other artificial ingredients: there are quite a few numbers that appear on yoghurt ingredient lists – remember, NONE of them actually are required to make yoghurt! They can cause digestive upset, may be derived from genetically modified ingredients, or be linked to other unpleasant health side effects, e.g. artificial colours have been associated with mood and attention disorders in children. This article by Pinkfarm has a great discussion on yoghurt including an analysis of some numbers they found in a commercial yoghurt.
And then there’s the sugar…
Milk contains lactose, which is chemically a type of sugar. Although the starter cultures break some of this down in to lactic acid, yoghurt will naturally contain some “sugar” which is lactose, approximately 4.7 grams for every 100 grams of yoghurt. But anything on top of this is ADDED sugar. A few points to get you super sugar-savvy:
- Sugar should be quite easy to spot on the ingredients list, but it might be hiding under a different name. To be sure you’re getting added-sugar-free yoghurt, scan the nutrition information panel, find the “per 100 grams” column and look for “total sugars”. Subtract 4.7 for the lactose, and there you go! (A teaspoon of sugar weighs approximately 4.2 grams, if you want a reference point).
- Fruity yoghurts are often big secret sugar bombs. Don’t get sucked in, thinking there’s no added sugar because they add “only fruit”. It’s not going to be fresh whole fruit; it’s highly processed fruit puree or fruit pieces, which are a concentrated source of sugar (and potentially with sugar added as well). You’re much better off buying plain yoghurt and adding fresh fruit.
- I’m not big on artificial sweeteners, especially the chemically produced types that end up in commercial yoghurts. They’re nutritionally empty and may cause some people digestive problems, as well as potentially being linked to more long-term negative health side effects. If you want to make your yoghurt sweet, add just a little of your favourite liquid sweetener e.g. rice malt syrup or honey, or try some ground cinnamon or vanilla extract. Even if you add a teaspoon of honey, you’re still probably consuming much less sugar and you also know you’re eating a simple, natural product.
Whole milk or low fat?
Personally, I love yoghurt that is made from whole milk, and find it much more delicious and satisfying than reduced fat or fat-free versions. Whole milk isn’t really very high in fat at all (it’s only 3.5% fat!) and I think that a lot of people have this misconception that it must be much higher, simply because there’s always a low-fat version on offer. Also, whole milk contains a range of beneficial nutrients, and many of these (including vitamins A, D, E and K and good fatty acids) are mainly in the fatty part of the milk.
An issue with many of the lower fat yoghurts is that because they remove some of the natural fats from milk, it’s difficult to achieve the thick consistency and creamy full flavour of traditional yoghurt, and so artificial ingredients need to be added to produce the right texture and taste. If you really do prefer lower fat versions of yoghurt and you can find one that is made of only milk + cultures, then I don’t think it’s necessarily a poor nutritional choice. Though I’d encourage you to try the whole milk versions if you’re just a little nervous about the fat content!
Key points to remember when you hit the shops
Now you’re all studied up on yoghurt and ready to make an informed, healthy choice next time you do the groceries. Just remember:
- keep the ingredients list short – milk + cultures;
- say no to milk solids, inulin and artificial additives;
- anything over 4.7g of sugar per 100g is extra sugar.
Do you have a favourite yoghurt that ticks all of the healthy boxes? Let me know where you live and what your recommended brands are, I’m always on the lookout for good local products!