Fruits have been hailed as nature’s best food over the past few decades, filled with nutrients, fiber, and antioxidants. Nutrition experts of all schools praise the advantages of eating fruits as part of an optimal regimen and national dietary guidelines across the globe recommend daily portions of fruits in their natural state. In a shocker that leaves a person agog in amazement, metabolic health expert Dr. Nick Norwitz certified that some fruits, mainly mangoes, grapes, and jackfruits might not be as healthy as people have believed them to be.
His problem? Too much fructose in those fruits and how he thinks this might cause metabolic damage and weight gain and an increased risk of cancer. People will take offense at this statement, but it is a legitimate argument: Is sugar in fruits bad for us, or another nutrition scare? Let us explore the science of fructose and how the human metabolism handles it and whether such a fruit deserves its newfound nutritional outcast status.
How to Know Fructose: Good, Bad and the Controversial
Fructose exists naturally as a sugar in fruits and vegetables as well as in honey. Fructose, unlike glucose and either being burned as energy immediately or stored in muscle in the form of glycogen, undergoes metabolism in the liver in most instances. Because of this singular metabolic process, it has been questioned whether excessive ingestion of fructose might have detrimental effects in the future.
Not all fructose is equal. Fructose in intact fruits comes with fiber and water along with an array of other health-promoting substances in contrast with very processed fructose in HFCS, a common ingredient in soft drinks and processed foods.
Dr. Norwitz refers us to a 2021 study in the journal Nature in which scientists learned that mice on a high-fructose diet had longer villi (small finger-like structures in the small intestine where the absorption of nutrients takes place). Longer villi equated to greater nutrient absorption, fats, fats most significantly with increased stored fat and weight gain.
The most egregious failure of this argument is that the study had used the processed high fructose corn syrup instead of naturally occurring fructose in fruits. HFCS contains the two sugars in a bound compound but contains none of the fiber, antioxidants, and micronutrients present in fruits. This argument holds up but gets lost in anti-fructose propaganda.
Mangoes: A Delicate Balance of Flavors or Metabolism Nightmare?
Mangoes are usually the most nutritious and flavorful fruits. They are now in the limelight as they have fructose in them. One mango contains approximately 30 grams of fructose, and this is twice as much as an apple contains (12.5 grams).
It is this excessive level of fructose present in mangoes that, according to Dr. Norwitz, holds the key as to why mangoes might be a contributing factor in metabolic disease in individuals who are obese and insulin resistant. Excessive consumption of fructose in some studies has been shown to lead to non-alcoholic fatty liver disease (NAFLD) through an accumulation of lipid in liver cells.
Nonetheless, this argument neglects some benefits of mango consumption such as:
Rich in vitamins A and C, essential in supporting immune function and eye and skin health
Rich in fiber to maintain intestinal health and block the absorption of sugar
Rich in antioxidants to combat oxidative stress and inflammation
It contains natural digestive enzymes such as amylase and this benefits digestive health.
It should also be mentioned at this point that only where there is excessive calorie intake, and less exercise will weight gain result it will not happen in the case of fructose by itself. Only mangoes in very huge amounts will hurt most people.
Jackfruit: Is This Meat Substitution Concealing Secret Risks?
Jackfruit also became popular as a meat substitute in the vegans’ circle due to its fibrous and chewy texture. Jackfruit naturally contains approximately 15.2 grams of fructose per cup, and this is relatively high compared to low-fructose fruits such as berries, according to Dr. Norwitz.
Of greater concern is the evidence that jackfruit upsets blood sugar balance. In 2021, a study published in the Scientific World Journal found that jackfruit extract had the power to increase insulin and reduce blood sugar levels significantly. While this would be beneficial to some, it harms those with unbalanced blood sugar and those who are at risk of hypoglycemia.
For all this, jackfruit is far from an unhealthy source of nutrition. Some of its most desirable benefits include:
Rich in vitamin C to support immunity and collagen production
It contains anticancer phytochemicals including flavonoids and tannins and
Rich in dietary fibre and with a positive influence on digestive health and regular bowels
One major disadvantage though, is that it contains very little protein. For all that the jackfruit can substitute for meat, it contains less than 3 grams of protein in a cup of it as opposed to a cup of chicken with 38 grams of it.
Grapes are Sneaky Heart-Healthy Nut
Grapes of any type contain around 12.3 grams of fructose per cup. Due to their very high sugar concentration, they cause bloating and production of gas and stomach upset upon overconsumption.
Grapes also have tannins in them, chemicals in them that irritate the stomach lining and make others feel uneasy. This does not make grapes unhealthy, however. In fact, grapes have been discovered to have many health benefits such as:
Enhancing heart health as a result of their rich polyphenol contents
Enhancing brain function through research linking the consumption of grapes to enhanced memory
It has resveratrol, an antioxidant linked with life extension and disease prevention.
It is true that overconsumption of grapes results in a buildup of sugar, yet a moderate consumption of grapes will very rarely present an immediate health threat.
Should You Cut These Fruits from Your Diet?
Though Dr. Norwitz does have some valid concerns to bring up concerning fructose, his arguments against such fruits seem to overlook the bigger picture. Fructose in fruits undergoes metabolization in the human organism differently than added sugar in processed foods and soft drinks. Fiber and water in fruits slow down sugar absorption and produce metabolic benefits.
The United States Department of Agriculture (USDA) and the American Heart Association continue to recommend 1.5 to 2 servings per day of fruits as part of an optimal meal. For those people who want to exclude fructose in their diets, some fruits low in fructose include:
Berries (strawberries, blueberries, blackberries)
Citrus fruits (oranges and lemons and
Kiwi
Low in carbs and non-sweet fruits are avocado, olives, and coconut.
Bottom Line: Everything in Moderation
Rather than demonizing fruits such as mangoes, grapes, and jackfruits, the message instead is moderation. These are healthy fruits in and of themselves, but excessive use, especially as part of an energy dense diet, results in metabolic disorders.
Worried about your sugar intake? Do the following:
Reduce the amount of 1. Combining fruit with protein and/or healthy fat to delay the absorption of sugar 2. Eating the fruit in a whole state rather than juice and fiber-free 3. Inclusion in the diet of a diversity of low- and high-fructose fruits Fruits are an incredibly healthy category of foods in the first place. Inasmuch as there have been all of the investigations on fructose, the health benefits of eating whole fruits far exceed any potential risk provided they are eaten in moderation in the context of the total diet.
