According to research reviewed by Gram, daily fruit smoothies did not reduce stress or improve energy levels in 311 people recovering from opioid addiction over 16 weeks, with the smoothie group consuming only 4 of 7 recommended smoothies weekly on average, suggesting inconsistent adherence may limit nutritional interventions.
Researchers gave daily fruit smoothies to 311 people recovering from opioid addiction to see if better nutrition would help their mental health. After 16 weeks, those drinking smoothies didn’t feel less stressed or have more energy compared to those who didn’t get smoothies. While most participants had poor diets to start with, the smoothie group only drank about 4 out of 7 smoothies per week on average. The study suggests that simply adding fruit smoothies isn’t enough to improve mental health during addiction recovery, possibly because people didn’t drink them consistently enough.
Key Statistics
A randomized controlled trial of 311 adults receiving opioid replacement therapy found that the smoothie group’s stress levels dropped by 2.3 points compared to 2.1 points in the control group over 16 weeks, showing no meaningful difference between groups.
In the study of 311 participants, approximately 70% were eating very few fruits and vegetables at baseline, yet blood markers for fruit and vegetable intake did not increase in the smoothie group despite the intervention.
Participants in the smoothie intervention group consumed only 4 out of 7 recommended daily smoothies per week on average during the 16-week randomized controlled trial.
The Quick Take
- What they studied: Whether drinking daily fruit smoothies for 16 weeks would reduce stress and improve energy levels in people receiving treatment for opioid addiction
- Who participated: 311 adults receiving opioid replacement therapy, with about 70% eating very few fruits and vegetables at the start
- Key finding: Daily fruit smoothies made no difference in stress levels, energy, or fitness compared to standard treatment alone
- What it means for you: Simply adding fruit smoothies to your diet may not be enough to improve mental health, especially if you don’t drink them consistently
The Research Details
This was a randomized controlled trial, considered the gold standard for testing treatments. Researchers randomly assigned 311 people to either get daily fruit smoothies plus their regular addiction treatment, or just their regular treatment alone. The smoothie group got 250ml smoothies (about one cup) every day for 16 weeks. Researchers measured stress levels using a standard questionnaire, plus energy levels, fitness, and blood markers for nutrition.
This type of study design helps prove whether the smoothies actually caused any changes, rather than just showing a connection. By randomly assigning people to groups, researchers can be more confident that any differences were due to the smoothies, not other factors.
The study was well-designed with a good sample size and was registered beforehand. However, the main limitation was that people in the smoothie group only drank about 4 out of 7 smoothies per week, which may have affected the results.
What the Results Show
Both groups started with similar stress levels (around 44% on the stress scale) and both groups improved slightly by the end of 16 weeks (down to about 42%). However, there was no meaningful difference between the smoothie group and the control group. The smoothie group’s stress dropped by 2.3 points while the control group dropped by 2.1 points - essentially the same improvement. This suggests the smoothies didn’t provide any extra mental health benefits beyond what people got from their regular treatment.
The study also looked at energy levels, physical fitness, and blood markers that show fruit and vegetable intake. None of these showed any difference between the smoothie and control groups. Interestingly, even the blood markers for nutrients found in fruits didn’t increase in the smoothie group, suggesting people weren’t absorbing the nutrients as expected.
Previous research has shown that diets rich in fruits and vegetables can help with mental health in the general population. However, this study suggests that people recovering from opioid addiction may need different approaches, possibly because of their unique health challenges and medication effects.
The biggest limitation was that people only drank about 4 smoothies per week instead of the recommended 7. This poor adherence makes it hard to know if the smoothies would have worked if people drank them as directed. The study also only lasted 16 weeks, which might not be long enough to see major changes.
The Bottom Line
Based on this study, simply adding fruit smoothies to your routine is unlikely to significantly improve stress or energy levels, especially if you’re in addiction recovery. Focus on overall dietary improvements and consistent healthy habits rather than relying on single interventions like smoothies.
People in addiction recovery shouldn’t expect fruit smoothies alone to improve their mental health. Healthcare providers should consider more comprehensive nutrition interventions rather than single-food approaches.
If you do choose to add fruit smoothies to your diet, don’t expect immediate mental health benefits. Any nutritional changes typically take months of consistent intake to show effects.
Frequently Asked Questions
Do fruit smoothies help with stress and anxiety during addiction recovery?
No. A 16-week study of 311 people in opioid addiction treatment found smoothies produced no additional stress reduction beyond standard treatment alone, with both groups improving similarly by about 2 points on stress scales.
Why didn’t the fruit smoothies improve mental health in this study?
Participants drank only 4 of 7 recommended smoothies weekly, suggesting poor adherence limited effectiveness. Additionally, blood nutrient markers didn’t increase, indicating nutrients weren’t being absorbed as expected despite the intervention.
What should people in addiction recovery focus on instead of smoothies?
Research suggests comprehensive nutrition approaches work better than single interventions. Track daily fruit and vegetable servings aiming for 5-7 daily, gradually increase overall intake through varied foods, and monitor adherence to sustainable eating patterns.
How long does it take for dietary changes to improve mental health?
Nutritional changes typically require months of consistent intake to show effects. The 16-week study period may have been insufficient, and poor adherence (only 4 smoothies weekly) further limited the ability to detect benefits.
Want to Apply This Research?
- Track your daily fruit and vegetable servings rather than focusing on specific foods like smoothies, aiming for 5-7 servings per day
- Focus on gradually increasing overall fruit and vegetable intake through various foods rather than relying on smoothies alone
- Monitor your adherence to healthy eating patterns weekly, noting which approaches you can stick with consistently over time
This research applies specifically to people receiving opioid addiction treatment and should not replace professional medical advice. Consult your healthcare provider before making significant dietary changes, especially during addiction recovery.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.