A study published in the Journal of the American Heart Association by Choi and others on 4th August 2021 explores this.
The association between diets that focus on plant foods and restrict animal products and cardiovascular disease is inconclusive.
This study investigated whether cumulative intake of a plant-centred diet and shifting towards such a diet was associated with a lower incidence of cardiovascular disease.
There were 4,946 adults followed in this prospective study. Initially they were aged 18 to 30 years old and free of cardiovascular disease. They were followed until 2018.
Diet was assessed by an interviewer administered validated diet history.
Plant centred diet quality was assessed using a priori diet quality score in which higher scores indicated higher consumption of nutritionally rich plant foods and limited consumption of high fat meat products and less healthy plant foods.
A proportional hazard model estimated hazard ratios of cardiovascular disease associated with both time varying average and a 13-year change in a priori diet quality score.
During the 30-year follow up, 289 cardiovascular cases were identified. Both long term consumption and a change towards such a diet were associated with a lower risk of cardiovascular disease.
In this 32-year prospective cohort study, which followed participants since young adulthood, long term consumption of a plant-centred high quality diet that also incorporated subsets of animal products was associated with a 52% lower risk of incidence of cardiovascular disease.
Furthermore, an increase in plant centred diet quality over 13 years was associated with a 61% lower risk of incidence of cardiovascular disease in the subsequent 12 years.
There is an increasing interest in understanding the association between diets that emphasise plant foods and limit most animal products and cardiovascular disease incidence, but the evidence is inconclusive.
A previous meta-analysis showed that vegetarians had a lower risk of ischaemic heart disease but not necessarily incident cardiovascular disease on all-cause mortality.
The noted limitations are narrow definitions of populations, uncertain accuracy of assessment of vegetarian status and inconsistent results across studies.
It is not fully understood how a plant-centred diet has a protective effect against the development of cardiovascular disease.
The concerted action of nutrients and bioactive compounds found in the combination of plant foods may lead to a favourable cardiovascular outcome. Numerous compounds, including ascorbic acid, tocopherols, carotenoids and phenolics are abundant in nuts and seeds, fruits, vegetables and whole grains. These compounds can trap free radicals and reduce the level of reactive oxygen molecules, thereby protecting against tissue damage.
Moreover, these substances may help inhibit plaque formation in the arteries by reducing low density lipoprotein oxidation, platelet activation and aggregation, and inflammatory markers.
Experimental studies have also reported that a mixture of compounds found in plant sourced foods had a synergistic effect on enhancing antioxidant activity.
Although the mechanism remains to be established, the findings from this study support a beneficial effect of plant-centred diet on cardiovascular disease prevention at the general population level.
The London General Practice, the leading London doctors’ clinic in Harley Street offers a full screening and medical service and works with leading nutritionists and dietitians to enhance the physical wellbeing of patients.
Dr Paul Ettlinger
BM, DRCOG, FRCGP, FRIPH, DOccMed