Banana contains plentiful potassium ions, dietary fiber, vitamins, and antioxidants. Delicious and nutritious, bananas aren’t only healthy snacks, but also great for preventing cancer, cardiovascular diseases, memory decline, and relieving anxiety.
What can a banana a day do for the human body?
1. Cancer Prevention
A report published in the International Journal of Cancer in January 2005 documents a 13-year study in Sweden of 61,000 women between the ages of 40 and 76, which found that women who ate at least four bananas a week had a 50 percent lower risk of kidney cancer.
Women who eat root vegetables such as carrots and beets also have a lower incidence of kidney cancer.
A Japanese study (pdf) discovered that ripe bananas can boost human immune cells to produce tumor necrosis factor (TNF), which can fight abnormal cells.
The darker the patches on the banana skin, the better the immune system enhancement. Yellow-skinned bananas with dark spots increase white blood cells eight times more than green-skinned bananas.
A research review published in Frontiers in Oncology in 2021 described how banana extracts prevent and fight various types of cancer by regulating different cell signal conduction pathways. The botanical chemicals in bananas can be used to develop multitarget drugs for cancer treatment.
2. Cardiovascular and Cerebrovascular Disease Prevention
Bananas are rich in magnesium. Magnesium helps reduce the risk of atherosclerosis by decreasing the plasma oxidized low-density lipoprotein, also known as bad cholesterol. They also have a lot of potassium, which controls blood pressure and regulates heart rate.
Arrhythmia and elevated blood pressure are symptoms of a lack of potassium. The right amount of potassium can stabilize the excitability of nerves and muscle cells within the normal range, keeping the heart functioning properly.
A report published in the European Heart Journal in 2022 describes a 19 1/2-year study of 11,267 men and 13,696 women, which found that those with the highest potassium intake had a 13 percent lower risk of cardiovascular disease than those with the lowest potassium intake.
Cardiovascular disease onset or recurrence risk was 11 percent lower in women and 7 percent in men.
The research indicated that eating more potassium-rich foods can prevent heart disease and stroke, especially in women.
Bananas also contain a lot of water-soluble dietary fiber, which is essential for heart disease prevention.
A study published in JAMA Internal Medicine in 2003 showed that eating high-fiber foods such as bananas can prevent heart disease. More than 9,700 U.S. adults participated in the study. During the years of follow-up, researchers discovered that the risk of coronary heart disease and cardiovascular disease was reduced by 12 percent and 11 percent, respectively, in those who consumed the most fiber per day (median of 20.7 grams) compared with those who ate the least (median of 5.9 grams).
People with the highest daily consumption of water-soluble fibers also saw a decreased risk of heart disease, by 15 percent. The mortality rate of coronary heart disease was reduced by 24 percent, and the chance of getting heart disease went down by 15 percent.
This particular group of participants was also 10 percent less likely to develop cardiovascular disease, with cardiovascular disease mortality rates also dropping by 12 percent.
3. Memory Loss Prevention
Bananas are a great source of vitamin B6. Vitamin B6 regulates the homocysteine level in the blood, improving cognitive ability.
In a study published in The American Journal of Clinical Nutrition in March 1996, researchers at Tufts University in Boston conducted cognitive tests on 70 men between the ages of 54 and 81.
They found that subjects with higher vitamin B6 levels performed better in two memory tests.
Research shows (pdf) that eating fruits rich in potassium helps students improve concentration and study more effectively. A school in England helped 200 students to pass an exam by giving them bananas at breakfast, break, and lunch to improve their brain power.
4. Emotional Regulation, Anxiety, and Depression Relief
Bananas contain tryptophan, which the human body can convert into serotonin. Serotonin can relax the body, relieve anxiety, and induce the feeling of joy.
Bananas also contain B vitamins, which play a vital role in the human nervous system, as coenzymes coordinate chemical reactions in the body.
A study published in the journal Human Psychopharmacology: Clinical & Experimental in 2022 documented the effects of high doses of vitamin B6 on 478 participants.
The clinical study found that high doses of vitamin B6 consumption can reduce anxiety and depression.
Another study, published in the Pakistan Journal of Pharmaceutical Sciences in 2017, pointed out that banana pulp and peel have anti-anxiety, anti-depression, and memory-enhancing functions, likely due to their antioxidant effects.
Some People Should Avoid Overeating Bananas
People With Kidney Disease
The metabolic function of potassium is abnormal in patients with acute and chronic nephritis, renal insufficiency, and other kidney diseases if they eat too much potassium-rich food.
Hyperkalemia and symptoms such as muscle weakness, drowsiness, and slow heart rate may arise as a result.
Therefore, the National Kidney Disease Foundation suggests that patients with kidney disease avoid bananas and have apples instead.
The sugar content of bananas is high. People with diabetes should be mindful of the amount they eat.
According to the U.S. Department of Agriculture, 100 grams of bananas contain about 15.8 grams of sugar.
However, since bananas contain more fiber and resistant starch that the human body can’t absorb, their glycemic index isn’t high, so they won’t cause a sharp spike in blood sugar.
According to the School of Public Health of Harvard University, the glycemic index of ripe bananas is 51. The glycemic index of semi-ripe bananas is only 42, but that’s still higher than that of apples, which is about 36.