A plant-based diet is associated with improved psychological health, a reduction in some of the known risk factors for type 2 diabetes, and possibly some of those linked to cardiovascular disease, according to new research published in the BMJ.
While a predominantly plant-based diet-rich in fruits, vegetables, nuts, legumes, and seeds with no (vegan) or few animal products-has been linked to a significantly lower risk of developing type 2 diabetes, it was not clear if it might also be linked to improved mood.
To try and find out, the researchers trawled through the available evidence and found 11 relevant English language clinical trials comparing plant-based diets with other types of diet. The studies involved a total of 433 people in their mid-50s, on average.
Eight of the trials assessed the impact of a vegan diet and six included patients being given information on optimal nutrition to help them better understand the benefits of a plant based diet. The trials lasted for an average of 23 weeks.
An analysis of the results showed that quality of life-both physical and emotional-improved only in those patients on a plant based diet. Similarly, depressive symptoms improved significantly only in these groups.
Nerve pain (neuropathy) eased in both the plant based and comparator diet groups, but more so in the former. And the loss of temperature control in the feet in those on the other diets suggests that eating predominantly plant based foods may have slowed the progressive nerve damage associated with diabetes, say the researchers.
The researchers point out several caveats to their findings, including the small sample sizes of the studies they reviewed and the reliance of the data on participant recall. But this review is the first to attempt to look at the psychological impact of a plant based diet in people with type 2 diabetes, and it draws on research from five different countries, they say.
Overall, the results indicated that even though the plant based diets were more difficult to follow, at least to begin with, participants stuck to them better than those in the comparison groups.
The researchers wrote: ‘Based on the evidence of the research analysis by this systematic review, it can be concluded that plant-based diets accompanied by educational interventions can significantly improve psychological health, quality of life, HbA1c levels and weight, and therefore the management of diabetes.’
‘Furthermore, plant-based diets could potentially improve diabetic neuropathic pain and the levels of total cholesterol, LDL cholesterol and triglycerides in type 2 diabetes.’