There are many people around me who like to eat bananas, and I especially like them too. But I happen to be someone who values appearance, so I always reject bananas with spots when choosing them. I always thought most people were the same. But today, a colleague told me that spotted bananas are more nutritious. Is this true?
Why do bananas get spots?
Like other plants, bananas can also get diseases. For example, Yellow Sigatoka, Anthracnose, Black Tip Thrips, Fruit Cracking, and so on. Among these, Anthracnose causes bananas to develop black spots. Anthracnose is caused by the fungus *Colletotrichum musae*, and it is a fungal disease. This condition only appears when the banana is ripe.
However, eating these bananas is not harmful to the body. Because the anthracnose fungus only affects the banana and has no impact on humans. Besides, the anthracnose fungus that turns bananas black has nothing to do with the anthrax virus, of course, it cannot make people sick. But if the banana's flesh has turned black, do not eat it.
In fact, it's not just the anthracnose fungus that causes bananas to develop spots. Bananas also turn black if they are left for a long time. This is because the banana peel cells contain a polyphenol oxidase. Normally, the cell membrane tightly wraps and protects the polyphenol oxidase, just like human skin protects flesh and bones. But once it is bumped or frozen at low temperatures, the cell membrane breaks. The polyphenol oxidase inside then comes into contact with oxygen in the air, oxidizes and turns black, naturally forming some small spots.
Are spotted bananas better at fighting cancer?
There is a widely spread online claim that "bananas with many black spots can fight cancer." Is this true? Although this conclusion is not yet supported by theoretical evidence, spotted bananas are indeed better than unspotted ones. Because when bananas have spots, it means they are ripe. Their immune-activating effect is relatively mild, which is more beneficial to physical and mental health.
So in daily life, we might as well eat 1-2 bananas a day to prevent infections by enhancing the body's disease resistance, especially to prevent the invasion of viruses such as colds and flu.
Although eating spotted bananas is good, there are some precautions:
1. People with a weak or cold constitution should not eat bananas.
Bananas are considered "cold" in nature. People who are constitutionally cold-deficient, such as those with a cold stomach, cold-deficiency (diarrhea, dizziness), nephritis, or pregnant women with swollen feet, should avoid eating raw bananas.
2. Do not eat bananas on an empty stomach.
Bananas contain a large amount of magnesium. If you eat a large number of bananas on an empty stomach, it will cause a sharp increase in magnesium levels in the blood, disrupting the balance between magnesium and calcium in the body, which has an inhibitory effect on the cardiovascular system and is not good for your health.
3. Patients with arthritis, diabetes, nephritis, etc., should not eat bananas.
Bananas contain relatively high levels of certain components, such as sugar, potassium, and magnesium. Eating too many can worsen the condition.
4. People with excessive stomach acid should not eat them, and those with stomach pain, indigestion, or diarrhea should also eat fewer bananas.
5. If you want to achieve beauty and weight loss effects, it is recommended to eat slightly unripe bananas, because ripe bananas are very high in calories. On the contrary, unripe bananas can help burn excess fat.
6. Bananas can be preserved at 12~13°C and should not be stored in the refrigerator.