It seems to be a universal experience in developed countries: As children, our parents told us to eat our vegetables, and we resisted tooth and nail, sometimes literally. The end result is that many people in these countries do not consume enough fruits and vegetables, despite their many health benefits.
According to the recent FAO report, in 2017, some 3.9 million deaths worldwide were attributable to insufficient consumption of fruits and vegetables. WHO estimates that insufficient consumption of fruits and vegetables is responsible for about 14% of deaths from gastrointestinal cancer worldwide, about 11% of those from ischaemic heart disease and about 9% of those from stroke.
The WHO recommendation is to consume at least 400 g of fruits and vegetables every day. However, many people do not reach this amount. The benefits of eating more fruits and vegetables are due to the fact that they are sources of vitamins, minerals and antioxidants, substances that prevent the accumulation of damage in cells. In addition, they are a source of soluble and insoluble fiber. The general recommendation is to consume 30 grams of fiber per day, but again, almost everyone does not achieve this. In Spain, according to a report by ANIBES, we are in the middle. In this scenario, green powders have appeared.
What are smoothies? “Green”
One of the characteristics of fruits and vegetables is that they are mostly made up of water. The idea of concentrated green smoothies is to offer only the nutrients in powder form, to be mixed with water at home.
These “powdered greens,” available under names like Super Greens, AG1, Huel Daily Greens, or Superfood Mix, are a blend of freeze-dried fruits and vegetables ground into a very fine powder that can be easily mixed into water or other beverages. Some common ingredients include:
- Green leafy vegetables like spinach and kale
- Marine microalgae such as chlorella and spirulina
- Vegetables like broccoli, cabbage and beets
- Fruits like blueberries and açaí berries
- Herbs like basil and parsley
- Vitamins, minerals, probiotics or prebiotics
The market for these supplements is estimated to nearly double by 2030. The promise is very tempting: brands make us believe that we need these products to be healthy and promote cognitive function, gut health, energy and sleep quality. But scientific evidence indicates that in reality, insufficient consumption of fruits and vegetables is the cause of these ailments and that smoothies would therefore only partially cover a deficiency. On the contrary, if we eat a healthy and balanced diet, which includes a large amount of fruits and vegetables, we can obtain the same benefits at a much lower price.
A randomized, controlled study (of the highest quality) carried out in 2004 had already revealed that although these supplements offered slightly better results than placebo in terms of vitality and energy, a subjective measure of the participants, the difference was not significant.
Beneficial, but not enough
Experiments in mice have shown that feeding them broccoli, cabbage, and asparagus powder beneficially changes their gut microbiota. A more recent study in healthy people found a similar effect when given a plant supplement, which may help reduce the inflammatory response and increase antioxidant capacity.
Finally, a review of more than a dozen studies on the use of these concentrated plant supplements found that for people with metabolic syndrome and high blood pressure, the supplements may reduce the risk of cardiovascular disease.
How should we interpret these data? It must be taken into account that most of these studies come from the United States, where fruit and vegetable consumption is very low, where only 10% of the population consumes the recommended amount and where the prevalence of obesity, diabetes and cardiovascular diseases is very high. However, consumption in the United States is about as low as in Spain, about 50 kilos of vegetables per person per year. In comparison, the Chinese and Croatians eat about 350 kilos per year.
It is therefore not surprising that the situation of those people who do not consume enough fruits and vegetables improves slightly with the addition of these supplements, which offer a concentrated dose of the necessary minerals, vitamins and antioxidants. However, they are not a substitute for fresh fruits and vegetables, especially because they do not solve the problem of lack of dietary fiber.
In the daily portion corresponding to a measure of these supplements, there are about three grams of fiber. It is very far from reaching the 30 grams per day recommended if we do not also take other sources such as fruits, vegetables, legumes or seeds.
Additionally, you have to be consistent with these supplements. One study found that the beneficial effects of increased fruit and vegetable consumption for three months did not substantially improve the degree of DNA damage or the body’s antioxidant capacity. This is where the cost issue arises. An extra serving can cost $2 to $4 per day, or $60 to $120 per month. With this budget, you can buy many fruits and vegetables at the supermarket. Plus, its taste can be unpleasant for some people.
