Juice Health Insights
Many view fruits as nutritious and healthy, often considering fruit juice as a concentrated essence of these benefits.
However, what you may not realize is that when fruits are juiced, their calorie content skyrockets and their nutritional value diminishes. Today, let's delve into the truth behind freshly squeezed fruit juice.
1. Increased Sugar Content
Juicing fruits concentrates their sugar content, resulting in higher sugar levels compared to whole fruits. Take apple juice, for example; the sugar content in a cup of freshly squeezed apple juice may even exceed that of a can of cola.
2. Loss of Dietary Fiber
During the juicing process, almost all of the dietary fiber in fruits is discarded. Dietary fiber can increase satiety, promote bowel movements, and play a crucial role in preventing and alleviating constipation, promoting digestion, and controlling weight.
Although fruits contain sugar, the World Health Organization's "Guideline: Sugars Intake for Adults and Children" does not include fruits. This is mainly because components like dietary fiber can "offset" the negative effects of sugar in fruits. However, when fruits are juiced, the lack of dietary fiber highlights the issue of sugar in fruits, and juice (including freshly squeezed pure fruit juice) is also classified as free sugars.
3. Loss of Antioxidants
Vitamin C, β-carotene, and polyphenolic antioxidants in fruits are also lost during the juicing process. This is because, during juicing, fruits are chopped and stirred, allowing antioxidants like vitamin C to oxidize when exposed to oxygen from the air, resulting in a decrease in their content.
Taking vitamin C as an example, experimental data shows that the loss rates in freshly squeezed mango, and orange juices are 58.92%, and 32.76%, respectively.
Increased sugar content, and loss of key components like vitamin C and dietary fiber, are just some of the nutritional changes that occur when fruits are juiced. In fact, these changes can lead to differences in their health effects.
1. Rapid Blood Sugar Spike
After fruits are juiced, the properties of sugar change from endogenous sugar to free sugar, making it easier for the body to absorb. This is because most of the dietary fiber is removed during the juicing process, making the sugar in the juice more readily available.
As a result, the body absorbs sugar faster, and blood sugar levels rise faster compared to eating whole fruits. For example, oranges, when juiced, change from being low glycemic index (GI <55) foods to moderate glycemic index (GI between 55 and 70) foods, increasing their ability to raise blood sugar levels and causing greater fluctuations.
As mentioned earlier, the sugar in freshly squeezed fruit juice exists in the form of free sugars, which have no beneficial effects on the body. The World Health Organization recommends that adults limit their daily intake of free sugars to less than 10% of total energy intake, preferably further restricting it to less than 5%. However, the sugar content in a cup of freshly squeezed fruit juice may likely exceed this recommended intake.
2. High Caloric Content
It takes 3 to 5 apples to make a cup of apple juice. Eating three apples may take time, but drinking a cup of apple juice, even for a child, is effortless. However, this new way of consuming fruits silently leads us to consume too much sugar.
Moreover, fruit juice has low satiety, and refilling your glass is effortless, without interfering with meals, inadvertently increasing energy intake.
3. Increased Risk of Gout
Fruits are rich in fructose, and consuming fructose can increase uric acid production, leading to high levels of uric acid in the blood. It's important to note that hyperuricemia is a major cause of gout.
A study published in the prestigious medical journal "British Medical Journal" investigated over 50,000 American men and found that after consuming more than 2 cups of fruit juice daily, the risk of gout increased by 81%. Evidence from "Important dietary sources of fructose and risk of gout: a systematic review and meta-analysis of prospective cohort studies" suggests an adverse relationship between fruit juice consumption and the incidence of gout.
However, is fruit juice completely worthless?
A small amount of fruit juice may be beneficial. A large-scale study published in the "British Journal of Nutrition" in 2019 found that compared to non-juice drinkers, those who drank 5 ounces (approximately 150) or less of fruit juice per day had a 15% lower risk of cardiovascular disease.
So, we have no reason to completely reject fruit juice, but we need to control the quantity and frequency.
In conclusion, while freshly squeezed fruit juice offers flavor and convenience, it falls short as a healthful beverage compared to whole fruits. We should try to reduce our intake of fruit juice as much as possible and prioritize eating whole fruits to obtain fruit nutrition. Additionally, maintaining a balanced and diverse diet is essential for ensuring overall health.