I’ve been asked a few times recently whether smoothies are a better way to get vital nutrients and to promote good health, compared to eating well at each meal. The current blending trend with smoothies in bowls and toppings of ‘superfoods’ makes various claims such as improved digestion, increased vitamin and mineral absorption, quicker weight loss, better energy etc. The answer really comes down to several factors: what your health status is now, what you’re putting in your mouth every day, how active you are, and what’s in the smoothies you choose.
A couple of decades ago juicing was the rage, and the same sort of health claims were made for juices. A healthy person who generally makes good food choices is unlikely to notice any real benefit from adding a juice or smoothie every day. Pure fruit juices should only ever be an occasional choice, as fruit juice is high in fruit sugar (fructose) which is just as harmful to your health in high doses as other types of sugar. It’s best to eat, rather than drink, your fruits. And although pure vegetable juices can be a good choice for someone who needs to increase their daily vegetable intake, the juicing process removes all the fibre which is not a good thing – the fibre in plants is very important for our health. Also, vegetable juices can be high in naturally occurring minerals like sodium, which can create internal electrolyte imbalances if regularly consumed in high volumes.
Smoothies which are vegetable based are a better choice for two reasons:
- they contain less sugar and more vitamins and minerals overall than fruit, and
- they retain the plant fibre.
Fibre is essential for good health – it helps to reduce glucose (sugar) and cholesterol absorption, it gives the feeling of fullness when eating, and provides bulk and softness to digested food which enhances elimination of ‘number 2s’. A high fibre intake is proven to be important for heart health, cancer prevention and blood sugar regulation.
Its what’s in your smoothie that really matters
What ingredients your smoothie contains is significant. When I looked at recipes for these super-charged drinks, other than green vegetables (such as spinach and kale), they predominantly rely on fresh/frozen fruit, dried fruit, honey or sugar alternatives to make them palatable. Other common ingredients are nuts and seeds, dairy or dairy alternatives, protein powders, and oats.
Essentially these smoothies often resemble a meal rather than a snack, and some do contain a lot more sugar than you may realise. The average smoothie contains anywhere from 400 to 600 calories, and most of this is made up of fruit sugars. Smoothie bowls with lashings of extra toppings are more like a dessert than a healthy meal alternative. If you are having a smoothie regularly as a ‘healthy snack’ I suggest that you put all of the individual ingredients on a plate and decide if you would normally choose to eat all that food in one sitting for a snack. An apple or banana, a handful of nuts and seeds, hummus and carrot sticks, or a slice of toast with nut butter are healthier ‘fast food’ snacks in between meals.
What about athletes with higher nutrient needs?
A smoothie can be an excellent recovery meal for an athlete after a strenuous training session. By strenuous I mean spending a couple of hours running on hills or cycling with interval efforts – activities that deplete your reserves. That’s the time when sugars, fats and proteins are needed by your muscles for restocking glycogen supplies and repairing the damage from high intensity/volume exercise stress so that you can come back stronger.
Keep in mind though that fructose (fruit sugar) isn’t recommended before or during training as it commonly causes stomach upsets, especially when under stress. That’s why a lot of people avoid fluids and gels containing fructose in triathlons.
Are smoothies BETTER for nutrient uptake?
I particularly want to clarify that juices and smoothies do not enhance either the digestibility or absorption of nutrients. When you blend food, the blender is essentially doing the work of your mouth – that’s all. Healthy digestion relies on proper chewing of your food so that it becomes mush before you swallow (ie. baby food consistency). Chewing also promotes the release of certain enzymes and secretions which begin the digestion process in your mouth. If you don’t chew your food well enough then this puts additional load on the stomach and digestive tract, and that by itself can lead to indigestion, constipation and other problems. So, if you are drinking your food, you bypass this important first digestive step in your mouth as your smoothie will be going straight down your throat.
The optimal absorption of nutrients by your body from food eaten is reliant on many complex factors which I won’t touch on, other than to say that I am not aware of any robust scientific support for the idea that juices and smoothies provide enhanced nutrient absorption.
Personally, I’m a fan of forking – taking the time to sit down and really enjoy the taste, texture and pleasure in eating delicious freshly prepared food. Smoothies were a part of my training nutrition when I did Ironman, but only as a recovery meal when I had no appetite (for example after very long runs); or as a liquid meal in between training sessions on big mileage days, as they allowed me to easily consume the extra calories I needed.