• Skip to primary navigation
  • Skip to main content
  • Skip to primary sidebar
Breaking Muscle

Breaking Muscle

Breaking Muscle

  • Fitness
  • Workouts
    • Best Shoulder Workouts
    • Best Chest Workouts
    • Best Leg Workouts
    • Best Leg Exercises
    • Best Biceps Exercises
    • Best Kettlebell Exercises
    • Best Back Workouts
    • Best HIIT Workouts
    • Best Triceps Exercises
    • Best Arm Workouts
  • Reviews
    • Supplements
      • Best Pre-Workout
      • Best BCAAs
      • Best Testosterone Boosters
      • Best Bodybuilding Supplements
      • Best Creatine
      • Best Supplements for Weight Loss
      • Best Multivitamins
      • Best Collagen Supplement
      • Best Probiotic
      • Best Non-Stim Pre-Workout
      • Best Greens Powder
      • Best Magnesium Supplements
    • Protein
      • Best Protein Powder
      • Best Whey Protein
      • Best Protein Powders for Muscle Gain
      • Best Tasting Protein Powder
      • Best Vegan Protein
      • Best Mass Gainer
      • Best Protein Shakes
      • Best Organic Protein Powder
      • Best Pea Protein Powder
      • Best Protein Bars
    • Strength Equipment
      • Best Home Gym Equipment
      • Best Squat Racks
      • Best Barbells
      • Best Weightlifting Belts
      • Best Weight Benches
      • Best Functional Trainers
      • Best Dumbbells
      • Best Adjustable Dumbbells
      • Best Kettlebells
      • Best Resistance Bands
      • Best Trap Bars
    • Cardio Equipment
      • Best Cardio Machines
      • Best Rowing Machines
      • Best Treadmills
      • Best Weighted Vests
      • Concept2 RowErg Review
      • Hydrow Wave Review
      • Best Jump Ropes
  • News
  • Exercise Guides
    • Legs
      • Back Squat
      • Bulgarian Split Squat
      • Goblet Squat
      • Zercher Squat
      • Standing Calf Raise
      • Hack Squat
    • Chest
      • Bench Press
      • Dumbbell Bench Press
      • Close-Grip Bench Press
      • Incline Bench Press
    • Shoulders
      • Overhead Dumbbell Press
      • Lateral Raise
    • Arms
      • Chin-Up
      • Weighted Pull-Up
      • Triceps Pushdown
    • Back
      • Deadlift
      • Trap Bar Deadlift
      • Lat Pulldown
      • Inverted Row
      • Bent-Over Barbell Row
      • Single-Arm Dumbbell Row
      • Pendlay Row
Fuel

How Do We Know If Supplements Work?

A recent research review sought to eliminate any confounding variables that create bias in supplement studies.

Doug Dupont

Written by Doug Dupont Last updated on Nov 22, 2021

Supplements occasionally get negative results when studied, and we end up questioning whether or not they actually are healthy. This leads to a quandary posed by many people, health professional and average Joe alike: “How do I know the truth, when there’s so much conflicting information?”

In a recent review published in the Nutrition Journal, researchers were interested in what supplement users do during their daily lives. On the surface this might seem confusing or unimportant, but when it comes to lending the support of statistics to science, this kind of study couldn’t be more necessary. Let me explain why.

One of the most important goals in the scientific process is to try to eliminate confounding variables. Without getting too deeply into statistics, a confounding variable is more or less a factor that is important to a study’s results, but is left out of the research because the variable is unknown or underestimated. If a confounding variable is present in a research study, it creates what is called an omitted-variable bias. This bias is exactly what it sounds like. The conclusion to the test is potentially flawed because of the missing variable.

In many studies about health, it is not uncommon to be concerned with confounding variables. Vitamins are a common example of this phenomenon. If people take vitamin supplements, they’re probably health conscious to begin with. If that’s true, perhaps reports of improved health from vitamin use are actually because of the otherwise healthy lives that the users live.

In the case of the Nutrition Journal study, the researchers were looking to find out about the behaviors of supplement users compared to non-users. Specifically, they were interested in variables known to affect health. If we know what regular activities supplement users do that are different from non-users, we also know the confounding variables. We can then review the existing literature or create new scientific studies that have greater statistical strength backing them.

Potentially confounding variables and other considerations were found in the review:

  • Supplement use was more common as people aged, and more common in women.
  • Supplement users also had slightly better diets, especially as they got older. That’s important because it’s possible for people to get too many nutrients, and could account for some negative results found from supplement use. However, the researchers found that supplement use nevertheless improved nutrient intake in general.
  • Supplement users were more likely to exercise and have a healthy body weight, and less likely to smoke.
  • The researchers also noted that heavy supplement users were healthier than non-users and users who took fewer supplements, even over a twenty-year span of time. However, this could be due to greater intensity of the confounding factors listed above.

When it’s all said and done, this review and others like it provide a springboard for examining the strength of past and future research. We can answer that oh-so-common question of “Who can we trust?” by seeing for ourselves how robust the research is. You have to love science.

References:

1. Annette Dickinson, et. al., “Health habits and other characteristics of dietary supplement users: a review,” Nutrition Journal 2014, 13:14

Photo courtesy of Shutterstock.

Doug Dupont

About Doug Dupont

Having grown up at the foot of a forest covered mountain in rural Vermont, Doug was active from a very young age. Hiking, running, and climbing were a part of everyday life in the Green Mountains. This culture of exercise led to dabbling in martial arts as a teen, and also getting work in a local powerlifting focused gym. Doug continued to pursue knowledge and training in exercise, becoming a certified personal trainer while still a teenager. Once in college he began his hand at the business side of fitness, taking a management position at a large local gym. During that time he became a founding member of the UVM Brazilian Jiu Jitsu club, and was the first among their competition team. After only a few months he was assisting in coaching, and ran conditioning program for the club.

Out of college Doug set up his own training center. He grew his list of clientele including several professional MMA athletes, eventually going so far as to corner a world title fight. He has continued ­­­to develop his business into today.

View All Articles

Related Posts

Three pre-workout supplements on a red background
Best Pre-Workouts for Building Muscle, Running, Taste, and More
supplementsarefake
Supplements, Seriously?
multivitaminsandrunning1
Do Runners Need a Multivitamin?
athleticwomantrxexercise
Can MCT Benefit Your Training

Primary Sidebar

Latest Articles

New Year’s Fitness Sales (2025)

XWERKS Motion BCAA Review (2025): A Registered Dietitian’s Honest Thoughts

Assault Fitness AssaultBike Pro X Review (2025): Assault’s Best Bike Yet?

13 Best Exercise Bikes for Home Gyms (2025)

Transparent Labs BCAA Glutamine Review (2025): The Key to Post-Workout Recovery?

Latest Reviews

Element 26 Hybrid Leather Weightlifting Belt

Element 26 Hybrid Leather Weightlifting Belt Review (2025)

Omre NMN + Resveratrol, Lifeforce Peak NMN, and partiQlar NMN on a red background

Best NMN Supplement: Fountain of Youth in a Bottle? (2025)

The Titan Series Adjustable Bench on a red background

Titan Series Adjustable Bench Review (2025)

A photo of the NordicTrack Select-a-Weight Dumbbells on a red background

NordicTrack Adjustable Dumbbell Review (2025): Are These Value Dumbbells Worth It?

woman lifting barbell

Be the smartest person in your gym

The Breaking Muscle newsletter is everything you need to know about strength in a 3 minute read.

I WANT IN!

Breaking Muscle is the fitness world’s preeminent destination for timely, high-quality information on exercise, fitness, health, and nutrition. Our audience encompasses the entire spectrum of the fitness community: consumers, aficionados, fitness professionals, and business owners. We seek to inform, educate and advocate for this community.

  • Reviews
  • Healthy Eating
  • Workouts
  • Fitness
  • News

Follow Us

  • Facebook
  • Twitter
  • Instagram
  • Pinterest
  • RSS Feed

© 2025 · Breaking Muscle · Terms of Use · Privacy Policy · Affiliate Disclaimer · Accessibility · About