Red plums, green kiwis, yellow bananas... Fruits exist in a multitude of colors.
But what in their evolution has pushed them to adorn themselves with such pigments?
A recent study questions the origin of the color of fruits.
According to the scientists, the main influencers are the animals that eat them.
A glance at the fruit shop is enough to illustrate this: there are many different colors of fruit.
As early as the 1800s, scientists hypothesized that fruit had evolved to attract the attention of certain species.
The interest for fruits is indeed consequent: by letting themselves be consumed.
The seeds and pits will be transported by the animal and the species will be able to spread on another territory.
An interesting theory, but it comes up against an obstacle: most animals do not perceive colors in the same way as humans.
"With the exception of some primates, no other animal on Earth perceives colors in the same way as we do" confirms Dr. Kim Valenta.
Humans and animals do not see the same colors
In the eyeballs, each of us has rods, which are sensitive to the amount of light and determine the clarity of what we see.
Colors, on the other hand, are detected by cones.
In humans, there are three types, some are sensitive in the red part of the spectrum, others in the green and the last in the blue.
Most other mammals have only two and birds have four. This allows them to detect a multitude of colors that we cannot see.
Fruit to the human eye may appear dark, where a bird will see ultraviolet light.
In a study published in the journal Scientific Reports, researchers wanted to test this theory and for this.
They collected data on the maturity of fruits and leaves of 97 plant species in Uganda and Madagascar.
According to the scientists, animal dispersal has indeed led to the evolution of fruit color in tropical trees.
Fruits color affected by environmental factors
They observed that fruits that are primarily eaten by mammals, such as monkeys, reflect more on the green spectrum.
Those eaten by birds reflect more in the red spectrum.
A likely explanation is that birds see more colors, and detect red more easily through the greenery.
Also, plants whose fruit reflect ultraviolet (UV) light tend to grow on trees whose leaves also reflect UV light.
This suggests that fruit color is also influenced by environmental factors affecting the entire plant - such as protection from sunlight.
In future studies, the researchers want to analyze other characteristics such as odor, size, and texture of the fruit.
"If color is important to make the fruit visible to birds, the smell may be more important to attract animals with a better sense of smell than sight."
Concludes study co-author Dr. Omer Nevo.
Why fruits are not all the same color
Have you ever wondered why fruits are not all the same color? The different color pigments they contain depend on what they contain in terms of nutrients.
It is important to eat a good amount of fruits and vegetables.
But it is also important to vary the colors as much as possible in order to get a wide spectrum of nutrients and antioxidants.
If you're in the average group of people who don't eat more kinds of fruits and vegetables than they have fingers…
It's time to broaden your horizons and have fun tasting new colors and discovering new vegetables.
Here is an overview of 2 large families of antioxidants that are behind these colors:
Purple and blue fruits: Anthocyanins
This family of antioxidants is found in your red, purple, and blue fruits.
The darker the color, the richer the fruit will be in antioxidants.
In addition to fighting free radicals in your body and thus protecting DNA, certain types of fruit also have certain properties of their own.
In this category, we find blueberries, which are known for their positive effects on memory and cognitive function and raspberries.
This can prevent arthrosclerosis and hyperglycemia.
Blackberries are said to protect against nerve degeneration and loss of bone density.
Also, it appears to play a role in the genes involved in suppressing tumors.
Pomegranate seems to be very effective in burning LDL (bad) cholesterol and may therefore also protect the body against arthrosclerosis.
Pomegranate is a topic that needs to be developed, so follow this link for more information on it.
Finally, cranberries, which have a very significant bioavailability, could improve cardiovascular condition in people.
Mannose which is the sugar contained in cranberries also has very strong anti-bacterial properties and is frequently-used against urinary tract infections.
Yellow, orange, and red fruits: Carotenoids
This family of antioxidants is found in your yellow, orange, and red fruits.
In this category are cantaloupe, tomatoes, grapefruit and oranges.
Beta-carotene, lycopene, lutein, and zeaxanthin are very interesting compounds.
These last 2 antioxidants accumulate in the retina of the eye and studies confirm their powerful effect in order to counter age-related macular degeneration.
It could also fight against the prevention of cataract.
Lycopene is well known for its protective effects on the skin against UV radiation from the sun.
Several studies are also beginning to show important links between lycopene and the prevention of cancerous tumors.
