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Let’s Talk About Smoothies!

Smoothies are all the rage these days, but are they really all they’re cracked up to be? From the green vegetable variety to the more-like-milkshake fare, we’ve got the skinny on smoothies here.


Do you want to boost your health, energy, and mood with a simple and delicious drink? If so, you might want to try smoothies! Smoothies are not only tasty, but also packed with benefits for your body and mind. In this column, you will learn how smoothies can help you improve your nutrition, digestion, immunity, cognition, and more. You will also discover how to avoid the common pitfalls of commercial smoothies that are loaded with sugar and artificial ingredients. And you will get some tips and resources from Dr. Bray, an expert in integrative nutrition and wellness coaching. Read on to find out why smoothies are the ultimate power drink for your health and happiness!

Smoothie Power: The Benefits of Blending

Smoothies are “all the rage” these days, and for good reason! They can:
  • Increase nutrient absorption.1-43
  • Prevent nutritional deficiencies.2-22
  • Supplement nutritional gaps.2-22
  • Enable nutritional gains.2-22
  • Maximize quality nutrition.2-22
  • Increase overall nutritional self-efficacy.2-5
  • And more!

This is especially true for those with snack or mealtime limitations. For individuals with:

  • Limited meal options.2-21
  • Limited time for meal preparation.2-21
  • Short mealtimes.2-5
  • Dietary Restrictions.2-21,23,24,30,38-40


But the benefits don’t stop there! A variety of research demonstrates smoothie consumption packs a punch of health benefits, including improvements in:

  • Antioxidant Status.6,9,11,14,16,19,22-39
  • Appetite/Satiety.40,43-48
  • Attention, Focus, & Concentration.22,49
  • Cardiovascular Health.12,13,36,40,50,51
  • Cognitive Function.22,49
  • Cholesterol.24,30,52,53
  • Diabetes Management.15,24,25,34,35,41,42,50,51,53-63
  • Digestion.11,19,23,24,30,38-40
  • Food Attitudes (e.g., in children,3,17,18,20,22 elderly,18,19 and disordered eating populations18).3,17-20,22
  • Glucose & Insulin Sensitivity.15,24,25,34,35,41,42,50,51,53-63
  • Hydration Status.64
  • Hyperlipidemia.6,56,65
  • Immune Function.8,26
  • Inflammation.8,23,28,36
  • Nutritional Status.2-21
  • Mental Health & Addiction Recovery!66
  • Metabolic Syndrome.26,46,63,67
  • Probiotic and Gut Microbiome Health.8,19,30,35,39,41-43
  • Sports Recovery & Muscle Repair.29,64
  • Supplementation.2-21
  • Vascular Function.28,40,67
  • Weight Optimization & Management.25,28,37,45,46,48,50,60,63,68
  • And More!

Sugary Scams & Milkshake Masquerades


The growing variety of content currently referred to as “a smoothie” severely jeopardizes the integrity of the word, causing many smoothies and smoothie powders to resemble little more than glorified milkshakes experienced by the body as “liquid sugar.”1,69-73

For example, many commercial smoothies these days are:

  • Void of fiber.1
  • Laden with artificial sugars or sweeteners.1,69-73
  • Closer to milkshakes than smoothies.1
  • Perceived by the body as “liquid sugar.”1

It can be tempting to associate this deadly combination with negative health outcomes, including

  • Blood glucose and insulin spikes (that can lead to):
    • Insulin resistance.74
    • Pre-diabetes and Diabetes.74
    • Inflammation.74
    • Weight gain.74
    • And a host of other ailments.74

A Glucometer Surrounded by Colorful Candies  orange heart decor  Woman in White Shirt Holding a Glucometer

The associations between low-fiber, high-sugar smoothies and negative health outcomes could occur from a combination of two main factors:

  1. High glycemic index (GI) ingredients (e.g., sugars or sugary ingredients that cause or enable a large load of sugar to rapidly enter the bloodstream).1,69-73
  2. Lack of fiber (which can act as a buffer for sugars, enabling slower release into the bloodstream15,41,42,51,53,54,56-58,61,75).1,69-73

This could theoretically cause many smoothies to act in the body as milkshakes or sugar, inducing insulin spikes that can lead ultimately to insulin resistance, diabetes/prediabetes, inflammation, weight gain, and host of other ailments.1,15,41,42,51,53,54,56-58,61,74,75

However, this possibility is not supported by existing research.

Research on Glycemic Index:


Vega-López et al. (2018) examined evidence from randomized controlled trials (RCT) and human observational studies for associations between different glycemic index (GI) diets and:

The strongest intervention studies typically found little relationship between GI/glycemic response (GR) and physiological measures of disease risk, including:

  • Body weight.74
  • Cardiometabolic disease risk,74 including:
    • Diabetes.74
    • Cardiovascular disease risk.74

Thus, the authors concluded “it is unlikely that the GI of a food or diet is linked to disease risk or health outcomes.”74 Rather, “other measures of dietary quality – such as fiber or whole grains – may be more likely to predict health outcomes.”74


Important Caveats:

Before you swear off smoothies altogether, there are some important caveats to consider. Most importantly, Vega-López’ 2018 data (described above) was funded by Mars Inc. (the candy bar manufacturing conglomerate) as part of a larger scope literature review into the science of the glycemic index.74 This potential conflict of interest could bias the findings.

Nevertheless, an abundance of research does show that high glycemic food options are not always bad. For example, many athletes will consume simple sugars (or straight glucose) during and directly after long bouts of exercise, when:

Happy Blending!



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Dr. Brenna Bray, a local health and wellness coach, stress researcher, associate professor, and avid ultra-marathon mountain runner, holds PhDs in Biomedical Science, Neuroscience, and Complementary and Integrative Health. Her journey through an eating disorder fuels her dedication to coaching, merging personal experiences with scientific expertise. Through her practice, Bray empowers clients to access and harness their innate healing abilities and achieve remarkable health and wellness transformations. Committed to community engagement and holistic well-being, Dr. Bray shapes a brighter, healthier future for all. Learn more about Dr. Bray at www.brennabray.com.

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