Fructose, Fruit juice, and the Microbiome

The microbiome continues to dominate the research front.  That 5 pounds of microbial life that inhabits our digestive tract is far more responsible for our health, most people would ever guess.  It’s composition and how various populations of microbes relate to one’s risk of particular conditions is being intensely studied.  While some of the research surrounding specific microbiome profiles (diversity, presence of larger families of bacteria, or the numbers of potentially pathogenic strains for instance) is preliminary and limited to associations, many microbiologists and microbial experts believe that there is a great deal we can now say with confidence. Continue reading

Carbs and Sugars

Carbohydrates and Sugars 101

Carbs and Sugars

Sugar gets a bad rap, regardless of the type of sugar. What we forget is there is actually sugar that is not “bad.”

Sure, the monosaccharide glucose is the best common form of sugar.  It generally makes up the majority of starchy root vegetables carbohydrate content and is far more compatible with human physiology.  Although excess glucose from some sources can still produce high blood glucose levels and may create problems with our corresponding insulin production, this form of sugar is metabolized much more cleanly than fructose.  Fructose metabolism generates uric acid production and creates oxidative stress within our cells’ mitochondria.  Our liver has to clean up the metabolic clutter produced by fructose and this contributes to fatty liver deposits and ultimately non alcoholic fatty liver disease (NAFLD), which is now at unprecedented levels across all demographics, even young children, here in the US.  In addition, a significant number of people suffer from fructose intolerance and suffer significantly with even modest amounts of this sugar.

What is the difference between “good” vs “bad” sugars (or is that even a thing)?

The better sugars are those that are metabolized without significant harmful byproducts.  Glucose can be helpful to many organs in the body such as the thyroid gland, the brain, and our adrenals, when consumed in moderation.  These organs have higher needs for glucose and although any people can follow very low carb diets indefinitely with no observable side effects, others may see aberrations in their thyroid or adrenal function.  Glucose produces very few free radicals when it is converted to energy. In comparison, fructose generates a host of undesirable free radicals that in turn damage the mitochondrial membrane and create oxidative stress.

Carbs and Sugars

What are some sources/examples of “good sugar” and why are they on the ok list — why are they healthy (or at least not unhealthy)?

The best sources of sugar would be the starch found in most root vegetables, as well as a few grains or grain-like foods/ pseudo grains, which is almost entirely made up of glucose.  Examples would be potatoes, sweet potatoes, yams, carrots, and parsnips. Rice and buckwheat are also almost entirely glucose based with respect to their starch content.

The worst sources of sugar would be any sweetener with high fructose contents such as corn syrup, fruit juice concentrates, agave, and cane sugar (where half of the sugar will be in the form of fructose).  Fruit juice is typically very high in its fructose content and should be avoided. Even some fruits have very high fructose contents and should be eaten in limited quantities such as one piece or 1 cup per day and only when in season. Examples of these fruits are mangoes, pears, grapes/raisins, apples, bananas, and pineapple.  It is better to choose those fruits with very low fructose content most often. Examples of these better choices would be raspberries, blackberries, grapefruits, and tangerines.

~ John Bagnulo MPH, PhD.


1.  Lambertz J, Weiskirchen S, Landert S, Weiskirchen R. Fructose: A Dietary Sugar in Crosstalk with Microbiota Contributing to the Development and Progression of Non-Alcoholic Liver Disease. Frontiers in Immunology. 2017;8:1159. doi:10.3389/fimmu.2017.01159

2.  Jegatheesan P, De Bandt J-P. Fructose and NAFLD: The Multifaceted Aspects of Fructose Metabolism. Nutrients. 2017;9(3):230. doi:10.3390/nu9030230.

3.  Jensen T, Abdelmalek MF, Sullivan S, et al. Fructose and Sugar: A Major Mediator of Nonalcoholic Fatty Liver Disease. Journal of hepatology. 2018;68(5):1063-1075. doi:10.1016/j.jhep.2018.01.019.

4.  Siqueira JH et al. Sugar-Sweetened Soft Drinks and Fructose Consumption Are Associated with Hyperuricemia: Cross-Sectional Analysis from the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil). Nutrients. 2018 Jul 27;10(8). pii: E981. doi: 10.3390/nu10080981.

5.  Sara J White, Emma L Carran, Andrew N Reynolds, Jillian J Haszard, Bernard J Venn; The effects of apples and apple juice on acute plasma uric acid concentration: a randomized controlled trial, The American Journal of Clinical Nutrition, Volume 107, Issue 2, 1 February 2018, Pages 165–172

6.  Orlando A, Cazzaniga E, Giussani M, Palestini P, Genovesi S. Hypertension in Children: Role of Obesity, Simple Carbohydrates, and Uric Acid. Frontiers in Public Health. 2018;6:129. doi:10.3389/fpubh.2018.00129.


Obesogens: No safe limit for our food or our skin.

Functional Formularies hopes to raise awareness around a group of chemicals, ingredients, and common household toxins that are proven to contribute to obesity and insulin resistance.  Collectively described as obesogenic, these substances interfere with communication channels within our cells and alter our metabolism.  Some of these obesogens are well studied and have become more familiar to consumers as they appear in headlines.  Others are less known by most Americans but are often just as damaging to human health.  There are numerous mechanisms by which they disrupt normal processes in the body.  Many are also classified as endocrine disruptors because they create a very potent estrogen-like effect on cells and a few are also carcinogenic, with strong links to specific types of cancer.  All of them however, are proven to increase a child’s risk of becoming obese.  Of course sugar consumption and a lack of physical activity are major causes, but the addition of these molecules to an individual’s chemistry creates an even more likely pattern of metabolic disease. Continue reading

How Fructose Affects the Brain

How Fructose Affects the Brain and Why Fruit Shouldn’t Get a Pass When it comes to Sugar

How Fructose Affects the Brain

One of the biggest misunderstandings in the field of nutrition is the role of fruit in a healthy diet.  We have been told to eat more fruits and vegetables for so long, that the two are referred to almost synonymously.  There is definitely a problem with this association.  Vegetables are rich in fiber, minerals, and typically very low in sugar.  Fruit, on the other hand, is typically much lower in micronutrients and fiber, yet much higher in sugar.  The most notable sugar in fruit is fructose. Continue reading

Dirty Dozen

Be Wary of Enteral Formulas Built Around Dirty Dozen Ingredients

Organizations such as The Environmental Work Group,, that are essentially our only sentinels with respect to chemicals in our produce and other foods, have made it very clear.  There are certain foods that carry inordinately high pesticide and herbicide levels and they should only be consumed if organically grown.  These are labeled as Dirty Dozen fruits and vegetables.  The list is updated each year but the core members generally stay the same. Continue reading