Fructose: The Most Harmful Sugar

by Mila McManus, MD

Fructose, especially high fructose corn sugar (HFCS), has earned its title as the most harmful sugar, causing a plethora of health problems. All sugars can be harmful, especially when eaten in excess. We always recommend reducing sugar intake as much as possible and limiting choices to real whole food, such as fresh fruit.

The negative effects of high fructose sugar intake include:

Fatty liver
High Triglycerides
Weight Gain
Leptin Resistance
Increased gut permeability, or leaky gut
Hunger and sugar cravings
Increases uric acid, which contributes to Cardiovascular Disease, cognitive decline, and kidney stones, to name a few
Is more addictive than cocaine
Causes insulin resistance

Fructose is a simple sugar found in fruit, vegetables, and some natural sweeteners. High fructose corn sugar [HFCS] is a manufactured sweetening additive derived from corn, a heavily subsidized [think cheap] crop. Over the last 50 years, HFCS use by the food industry has increased considerably worldwide. Other names are corn syrup, glucose-fructose syrup, isoglucose, or crystalline fructose. It is used to sweeten ultra processed food and beverages. Manufacturers love HFCS because, compared to regular sugar, it is sweeter, cheaper, and produced in abundance. However, it is a main culprit contributing to the dramatic rise in lifestyle diseases over the last several decades.

The body’s preferred source of fuel is glucose, the form of sugar we are “wired” to use. While fructose is a simple sugar, the liver must convert it to glucose. Once converted, it is used for energy if the blood needs glucose, or it will be stored in the liver, or fat cells. The process of converting fructose results in a waste product called uric acid, a key contributor to gout and heart disease. A good analogy would be to say that glucose is a clean fuel and fructose is a dirty fuel that pollutes your body.

High fructose corn sugar is a combination of fructose and glucose made from corn starch. It is cheaper and sweeter than cane sugar. It is found in soft drinks, bread, juices, ice cream, canned fruit, canned soup, ketchup, sweetened dairy products, cakes, cereal bars, salad dressings, and many other manufactured foods. We recommend eliminating these foods for a multitude of health reasons, notwithstanding the ones listed above.

We also recommend avoiding corn syrup, honey, and agave nectar as they are predominantly fructose. It is best to limit fresh fruit to no more than 2-3 servings a day. Grapes, watermelon, jackfruit, and dried fruits are intensified forms of fructose, so best avoided or limited. Small fresh fruit is a better choice and offers natural fructose. Fructose in fruit isn’t what’s causing disease in most people. Naturally occurring fructose in fruit is part of a complex web of nutrients and fiber and does not exhibit the same biological effects as the high fructose found in corn sugar. Along with the fructose in a piece of fruit you’re also getting fiber, hydration, vitamins, minerals, and other micronutrients your body needs. Good choices include apples, apricots, berries, melon, citrus fruit, kiwi, cherries, pear, plum, and peach. A portion is about the size of a tennis ball, or ½ to 1 cup of fresh bite-sized pieces.

If you need help eliminating harmful fructose from your diet, our staff nutritionist is available to guide you to healthier choices that are best for your unique body and health status.

Eat Well, Be Well.

References:

Dr. David Perlmutter, author of Drop Acid: The Surprising New Science of Uric Acid

https://www.livestrong.com/article/34054-list-foods-high-fructose/

https://drhyman.com/blogs/content/manufactureres-downsized-high-fructose-corn-syrup-still-concerned?_pos=3&_sid=ebacdeac0&_ss=r

By Mila McManus MD|2025-03-19T08:09:12-06:00March 19th, 2025|Articles, General|

Fructose: The Most Harmful Sugar

by Mila McManus, MD

Fructose is increasingly in the forefront as causing significant health problems and its use by the food industry has increased considerably.

All sugars are harmful for us, especially when eaten in excess. We always recommend reduction of sugar intake as far as you possibly can. Fructose is increasingly in the forefront as causing significant health problems.

The negative effects of fructose include:

Fatty liver
High Triglycerides
Weight Gain
Leptin Resistance
Keeps you feeling hungry
Increases uric acid which contributes to Cardiovascular Disease, cognitive decline, and kidney stones to name a few
Causes insulin resistance

Fructose is a simple sugar found in fruit, vegetables, and some natural sweeteners, and is also added to a wide variety of processed foods and beverages. Over the last 50 years, fructose use by the food industry has increased considerably.

The body’s preferred source of fuel is glucose, the form of sugar we are “wired” to use. While fructose is a simple sugar, the process of converting it to glucose must be done by the liver. Once converted, it will be used for energy if the blood needs glucose, or it will be stored in the liver, or in fat cells. The process of converting fructose results in a waste product called uric acid, a key contributor to gout and heart disease. A good analogy would be to say that glucose is a clean fuel and fructose is a dirty fuel that pollutes your body.

High fructose corn sugar is a combination of fructose and glucose and made from corn starch. It is cheaper and sweeter than cane sugar. It is found in soft drinks, bread, juices, ice cream, canned fruit, canned soup, ketchup, sweetened dairy products, cakes, cereal bars, salad dressings, and many other manufactured foods. We recommend elimination of these foods for a multitude of health reasons notwithstanding the ones listed above.

We also recommend avoiding corn syrup, honey, and agave nectar, and limiting fruit to no more than 2 servings a day. Grapes, watermelon, jackfruit, and dried fruit like cranberries, raisins, apricots, and apples are intensified forms of fructose, so best avoided or very limited. Small fresh fruit is a better choice and offers natural fructose. Fructose in fruit isn’t what’s causing disease in most people. Along with the fructose in a piece of fruit you’re also getting fiber, vitamins, minerals, and other micronutrients that your body needs. Good choices include apples, apricots, berries, melon, citrus fruit, kiwi, cherries, pear, plum, and peach. A portion is about the size of a tennis ball, or ½ to 1 cup of fresh bite sized pieces.

If you need help getting fructose out of the diet, our staff nutritionist is available to guide you to healthier choices that are best for your unique body and health status.

Eat Well, Be Well.

References:

Dr. David Perlmutter, author of Drop Acid: The Surprising New Science of Uric Acid

https://www.livestrong.com/article/34054-list-foods-high-fructose/

By Mila McManus MD|2023-05-15T15:55:34-06:00May 17th, 2023|Articles, General|

The Sugar that Never Satisfies

By Nancy Mehlert, MS

You most likely have heard about high fructose corn sugar (a.k.a. HFCS) which is the most processed form of fructose, a simple sugar, and the most damaging to your health. Manufacturers make HFCS with corn starch and add it to many processed foods such as fast foods, soda, ice creams and condiments like ketchup and pickle relish. On labels it may be called high fructose corn sugar, high fructose corn syrup, corn syrup or fructose.

This is one of the most harmful substances for human health and we encourage you to audit your pantry, refrigerator and grocery cart to ensure you and your family are not consuming it.

Here’s why:

Many scientists are suggesting that this processed fructose is a contributing factor to the obesity epidemic.
Processed fructose feeds pathogenic gut bacteria and disrupts a healthy microbial balance.
Fructose does not stimulate insulin production in the blood stream like other sugars, such as glucose, but goes directly to the liver for handling. As a result, leptin, an appetite suppressing hormone is never released to inform you that you are full. As a result, you remain hungry, craving and unsatisfied.
The output of fructose being processed in the liver is uric acid, known to be a contributor to gout and heart disease.

Step by step, be well and stay well by choosing well.

By Mila McManus MD|2019-03-04T06:30:29-06:00February 20th, 2019|General, NANCY’S NUTRITIONAL NUGGET|