This is a pretty poorly conducted study. First off, they make a causal claim that nutritional intervention induced reversal of CAD progression. This is an observational study so such a claim is inappropriate. This is also a very bold claim and yet this paper is published in a shit journal with an impact factor of < 1. That should be a huge red flag right off the bat.
Indeed, there are huge limitations in this study:
1. No control group
2. Self reported dietary adherence
3. Obvious possibility of the healthy adherer effect (people who voluntarily present for interventions and are adherent to dietary changes will probably also exhibit other healthy behaviors like exercise, mood control, better sleep etc which introduces confounders.
4. No monitoring of medication adherence. Perhaps these people simply started taking their medications more regularly while in this program. Medication adherence among patients with CAD is notoriously terrible.
5. Possibility of sick stopper effect in their non-adherers (sickest people also most likely not to take their meds, precipitating worse outcomes).
6. They note that on average their patients lost 18 lbs; perhaps weight loss alone was responsible for their improvements
7. They exclude some of their sickest patients
8. They report symptom relief in adherent patients but don't mention what that means. Do they report less angina? Did they see plaque size reduction? If the former, you have introduced potential for placebo effect.
Indeed, there are huge limitations in this study:
1. No control group
2. Self reported dietary adherence
3. Obvious possibility of the healthy adherer effect (people who voluntarily present for interventions and are adherent to dietary changes will probably also exhibit other healthy behaviors like exercise, mood control, better sleep etc which introduces confounders.
4. No monitoring of medication adherence. Perhaps these people simply started taking their medications more regularly while in this program. Medication adherence among patients with CAD is notoriously terrible.
5. Possibility of sick stopper effect in their non-adherers (sickest people also most likely not to take their meds, precipitating worse outcomes).
6. They note that on average their patients lost 18 lbs; perhaps weight loss alone was responsible for their improvements
7. They exclude some of their sickest patients
8. They report symptom relief in adherent patients but don't mention what that means. Do they report less angina? Did they see plaque size reduction? If the former, you have introduced potential for placebo effect.