Consuming 10 portions of fruits and vegetable may prevent 7.8 million premature deaths each year.
Current dietary guidelines suggest that individuals consume 5 portions of fruits and vegetables per day as a part of a healthy diet. Unfortunately, many individuals fail to meet that goal.
Findings from a new study indicate that eating up to 10 portions of fruits and vegetables could significantly reduce the risk of heart attack, stroke, cancer, and premature death.
In the study, published by the International Journal of Epidemiology, the authors reviewed 95 previously conducted studies regarding fruit and vegetable intake. The analysis included up to 2 million patients, and examined 43,000 cases of heart disease, 47,000 cases of stroke, 81,000 cases of heart disease, 112,000 cases of cancer, and 94,000 deaths.
The authors found that although the recommended portions of fruits and vegetables reduced disease risk, the most significant benefits came from consuming 800g per day, which is equivalent to 10 portions per day if 1 portion is defined as 80g.
An 80g portion of fruit and vegetables is approximately 1 small banana, apple, pear, or large mandarin orange, or 3 tablespoons of cooked spinach, peas, broccoli, or other vegetables.
The study authors hypothesized that 7.8 million premature deaths could be avoided each year if individuals consumed 800g of fruit and vegetables per day, according to the study.
"We wanted to investigate how much fruit and vegetables you need to eat to gain the maximum protection against disease, and premature death,” said lead author Dagfinn Aune, PhD. “Our results suggest that although 5 portions of fruit and vegetables is good, 10 a day is even better."
Even a daily intake of 200g of fruits and vegetables was linked to a 16% reduced risk of heart disease, an 18% reduced risk of stroke, and a 13% reduced risk of heart disease, according to the study. The 2.5 portion of fruits and vegetables was also associated with a 4% reduced risk of cancer, and a 15% decline in the risk of premature death.
Fruit and vegetable intake of 800g was linked to a 24% decreased risk of heart disease, a 33% decreased risk of stroke, a 28% decreased risk of heart disease, a 13% decreased risk of cancer, and a 31% decreased risk of premature death, compared with consuming no fruits and vegetables, according to the study.
The authors were unable to determine the health associations from an intake of more than 800g per day, since this was the high range in the studies.
The investigators also examined which foods provided the best protection against various diseases. They discovered that heart disease, stroke, and premature death was prevented by consumption of apples, pears, citrus fruits, salad, leafy green vegetables, and cruciferous vegetables.
According to the study, green vegetables, yellow vegetables, and cruciferous vegetables may reduce the risk of developing cancer.
The study authors noted similar associations for raw and cooked vegetables in relation to premature death, but additional research is needed to determine the benefits of certain fruits and vegetables and cooking methods. Additional fruits and vegetables not included in the study may also offer health benefits.
The researchers believe that multiple mechanisms could be associated with the health benefits of fruits and vegetables.
"Fruit and vegetables have been shown to reduce cholesterol levels, blood pressure, and to boost the health of our blood vessels and immune system,” Dr Aune said. “This may be due to the complex network of nutrients they hold. For instance they contain many antioxidants, which may reduce DNA damage, and lead to a reduction in cancer risk."
Compounds in cruciferous vegetables, such as broccoli, are known to activate cancer-preventing enzymes, and fruits and vegetables may benefit our gut bacteria.
However, the significant health benefits of fruit and vegetable consumption cannot be easily translated into a dietary supplement.
"Most likely it is the whole package of beneficial nutrients you obtain by eating fruits and vegetables that is crucial is health,” Dr Aune said. “This is why it is important to eat whole plant foods to get the benefit, instead of taking antioxidant or vitamin supplements (which have not been shown to reduce disease risk)."
The authors accounted for weight, smoking, physical activity, and diet, but still discovered that high fruit and vegetable consumption was beneficial, according to the study. Future studies are needed to look specifically into the underlying mechanisms that elicit health benefits.
"We need further research into the effects of specific types of fruits and vegetables and preparation methods of fruit and vegetables,” Dr Aune concluded. “We also need more research on the relationship between fruit and vegetable intake with causes of death other than cancer and cardiovascular disease. However, it is clear from this work that a high intake of fruit and vegetables hold tremendous health benefits, and we should try to increase their intake in our diet."