Updated: Jun 19, 2019
As a naturopath who worked in a Thai wellness retreat specialising in detox for 2 years, you would expect me to be an advocate of the smoothie. But am I?
My parents recently decided to do a 3 week smoothie plan that is designed to load you up with lutein and zeaxanthin (2 of the major antioxidants that support eye health) from food sources. This morning mum was reading out the ingredients for their lunchtime smoothie (basically a mixed salad plus a few veg you'd normally cook blended with water) and she asked me why it was better to have this mix as a smoothie rather than just eating it.
I initially regurgitated the theory that blending breaks down the cell wall of things like kale which would otherwise be hard to completely break down via chewing, and so is supposed to provide you with easier to assimilate nutrients. And then a thought popped into my head.
If the point of blending is to make the nutrients more available so that you absorb more, the very act of glugging down a smoothie is leapfrogging through the digestive process without giving the body time to fully assimilate those nutrients. Drinking a dinner plate (or 2) worth of vegetables in a couple of minutes is a massive workload without much of a warm-up.
The yogic saying, “Eat your drink and drink your food.” came to mind. Now, this is not an ancient advocation for the smoothie. What it means is, for optimal digestion it is important to “eat” i.e. chew, or swirl around your drinks in your mouth to mix them with saliva and warm or cool them to body temperature before swallowing. To “drink” your food means it is optimal if your food is fully chewed, broken down to the smallest particles possible, and mixed with saliva into a liquid before swallowing. Both of these processes are about slowing down the speed of eating and being more present to the whole process.
On the surface, it seems that a smoothie is a perfect way to drink your food, but the way and speed that most of us consume smoothies is missing vital steps.
Now, I must add here that I am not a smoothie drinker in general. I may have one on a summer’s day just for the pleasure of the taste, or when I have been too busy at work for a proper snack break I might make a protein shake smoothie to tide me over. But I avoid them because I generally find that they don’t agree with me. I either end up feeling bloated like I have a stone in my stomach, or getting a blood sugar spike and crash, or both.
I put this down to the tendency of smoothies to contain more fruit or raw veg than I would normally eat in one sitting, plus ice, or some form of Damp* producing food like yoghurt, milk (cow or plant), or banana - none of which suit my digestion in a large, cold dose. But then, talking to my mum, I realised that it may also be to do with the method of delivery to the stomach.
The body is an amazing machine, perfectly designed to turn food and water into energy and our bodily tissues (you literally are what you eat). But our technology has speeded up to a degree that our evolution can rarely keep up with. The blender hadn’t even been invented when our grandparents were kids.
Digestion is a process that begins not in the stomach, but in the mind and involves all of our senses. Thinking about food, seeing food, touching and smelling food while we prepare it all sends messages to the brain to start preparing to receive it. All of these things trigger the digestive system to get to work.
Mechanically, digestion begins in the mouth, but chemical digestion starts here too. The process of tasting and chewing our food is not just important for breaking it down into smaller particles for easier digestion. It has a couple of other major actions. The act of chewing sends messages to the stomach to start producing acid, to the pancreas to start releasing digestive enzymes and to the liver and gallbladder to prepare to release bile.
Most smoothies, particularly of the green variety are mainly vegetables and fruit. The main macronutrient in plant foods is carbohydrate. Our saliva also contains enzymes that contribute to carbohydrate digestion. So the mastication process is also essential for mixing food with saliva as it is chewed to start the enzymatic break down of carbohydrates for energy.
Maybe part of the reason that my body reacts badly to smoothies is the fact that I drink them without chewing? - that this massive volume of plant matter and liquid reaches my stomach in record time, with very little warning and no predigestion from salivary enzymes?
So, next time you have a smoothie try improving your absorption by using room temperature ingredients, and activate your senses by slowing down even a little; think about how delicious it’s going to be and what it will taste like as you prepare it; take the time to sit down and savour the sight and smell of it; “chew” each mouthful; pause between sips; give your body time to realise that food is coming. Do you notice any difference? Your body will.
*In traditional Chinese medicine all foods have energetic qualities. Damp refers to a tendency of a food to be/and to create moisture, heaviness (Yin), or mucus in the body.