One of the most accepted truths in medicine is the benefits of the regular ingestion of fruit and vegetables. It has been the standard suggestion for many decades to have on a daily basis 2 to 3 pieces of fruit, along with three servings of vegetables. A serving is half a carrot, as an example. The regular ingestion of this dose of fruit and vegetables is associated with clear reductions in all forms of cardiovascular disease, cancer and many other chronic conditions. It is a sad fact that only 10% of modern society would consume this amount of fruit and vegetables on a regular basis.
There have been four recent studies which have reinforced this notion to an even greater level:
1. The regular ingestion of fruit and vegetables is associated with lower rates of lung disease. A study of 44,000 Swedish men aged between 45 to 79 who were followed up for 13 years showed over 60% had smoked at some stage in their life, 24% were current smokers and just under 40% had never smoked. During this time just over 1900 cases of chronic obstructive pulmonary disease were diagnosed. The rates of COPD in those who had less than two servings per day of fruit and vegetables were 1166 per hundred thousand cases in current smokers and 506 per hundred thousand in former smokers. When compared with those people who had five servings per day of fruit and vegetables, there was a 35% reduction in the risk of chronic obstructive pulmonary disease.
Interestingly, it appears that the best benefits come from leafy green vegetables, capsicum, apples and pears. Also of note, there was no effect in regard to COPD from the regular ingestion of berries, citrus fruits, bananas, roots and cruciferous vegetables, tomatoes, garlic, onions and green peas.
2. The second study looked at the relationship between fruit and vegetable intake and dementia. It is estimated that around 47.5 million people suffer dementia globally and this is expected to triple by 2050. Having the recommended two pieces of fruit and three servings vegetables per day has been demonstrated in the study to show a significant reduction in dementia. The study looked at 17,700 older Chinese adults who were followed up for six years. There was an even greater reduction in dementia seen with every extra three portions per day of fruit and vegetables. It is felt that the protection against dementia seen in the regular ingestion of fruit and vegetables is due to the high concentration of antioxidants, anti-inflammatories and B group vitamins.
3. The third study looked at the psychological well-being of young adults. This was a very short-term study performed on 171 students in New Zealand aged between 18 to 25. They divided the students into three groups. The first group was advised to continue eating their normal food without any change. The second group were given two additional servings of fruit and vegetables by the investigators. The third group were given prepaid produce vouchers with text messages sent to remind them to eat their fruit and vegetables.
A psychological assessment was performed at the start of the trial and two weeks later looking at the parameters of mood, vitality, motivation and the symptoms of depression and anxiety.
Only those physically given the two additional servings of fruit and vegetables showed any improvements and these were purely in mood vitality and motivation. There were no change in the indicators of depression and anxiety and in reality it would take much longer for the brain chemicals to change than the short two week period seen in this trial.
4. The final and probably most striking trial was a meta-analysis of 95 studies in 2 million people and showed clearly that the higher the intake of fruit and vegetables, the stronger the benefit. This study basically looked at double the recommended intake of fruit and vegetables i.e. 10 portions of fruit and vegetables on a daily basis which is the equivalent of 800 g or 10 servings. Those who ingested 10 portions per day had the lowest risk of death and premature disease. Of the 2 million people, there were 43,000 cases of ischaemic heart disease, 47,000 cases of stroke, 81,000 cases of cardiovascular disease and 94,000 deaths. Those who ingested 10 portions per day of fruit and vegetables had an overall 33% reduction in death and disease. It appears that apples, pears, leafy green vegetables and cruciferous vegetables such as broccoli and cabbage give the best benefits. The study also showed that even 2.5 portions of fruit & vegetables per day led to 18% reduction in stroke, 16% reduction in heart disease, 13% reduction in cardiovascular disease and a 4% reduction in cancer. With each 200 grams increase in fruit and vegetables i.e. 2.5 portions per day, there was a 15% reduction in death.
When you compare those people who had minimal fruit and vegetables versus those who had 10 portions per day, There was a 33% reduction in stroke, 28% reduction in cardiovascular disease, 24% reduction in heart disease, 13% reduction cancer and an overall 31% reduction in death.
It was suggested that if everyone on the planet had 10 portions per day of fruit and vegetables we would prevent 7.8 million deaths a year globally.
So the big question is which are the best? It appears that there was no benefits when separating raw and cooked vegetables. Apples, pears, citrus fruits and green leafy vegetables e.g. spinach, and cruciferous vegetables e.g. cabbage and broccoli are the best for reduction in stroke, cardiovascular disease, heart disease and premature death. The best reductions for cancer were leafy green vegetables and yellow or red/orange, vegetables such as capsicum and carrots.
The message is very clear — listen to what your grandmother said and eat your fruits and vegetables.