Fruit & Vegetables–the more the better?
Headlines this week suggested that eating a whopping ten portions of fruit and vegetables a day reduced the risk of heart attack, stroke and cancer.
This week, the news headlines included a shocking revelation that many of us may need to double the government recommendation of 5-a-day to secure the benefits of long term health and old age. Some of us struggle to even make it to five, so why ten and would eight do or would eating even higher than ten bring even more benefits?
The number ten was based on a huge project conducted by Imperial College London, where researchers looked at 95 individual population studies on fruit and vegetable intake and collected together all those results and pooled them into a statistical test known as a meta analysis.
This study included up to 2million people who between them had 43,000 cases of heart disease, 47,000 cases of stroke, 81,000 cases of other cardiovascular disease, and 112,000 cases of cancer. They found that increasing fruit and vegetables reduced these risks by every 80-100g portion (up to 800g) we consumed. If we ate 800g (10 portions), we would experience:
- 24% reduction in the risk of heart disease
- 33% reduction in the risk of stroke
- 28% reduction in the risk of other cardiovascular diseases
- 13% reduction in the total risk of cancer (some cancers will come out higher than others)
- 31% reduction in the risk of a premature death
It is not known whether eating even more than 10 portions would further reduce the risk, since ten was the maximum any one study looked at.
The researchers also looked at whether specific fruits and vegetables had particular effects.
They found the following:
Reducing the risk of heart disease, stroke and cardiovascular diseases:
- Citrus fruits
- Salad vegetables
- Leafy greens such as spinach, chicory or lettuce
- Cruciferous vegetables such as cauliflower, broccoli, cabbage
Reducing the risk of cancer:
- Green vegetables (Spinach, green beans)
- Yellow vegetables (carrots, peppers)
- Cruciferous vegetables
It didn’t seem to matter whether fruits and vegetables were raw or cooked, although further studies are required on cooking methods and long term health benefits.
Precisely why fruits and vegetables reduce the risk of disease is most likely beyond that of their vitamin content. For example, reducing the risk of cardiovascular diseases and stroke could be due to the fibre which has shown in some studies to help the reduction of blood cholesterol and keep blood pressure in check.
Furthermore, most vegetables contain unique compounds known as phytochemicals, which include polyphenols and flavonoids. Many studies are now showing that different phytochemicals appear to have robust antioxidant properties, which can help the immune system fight off cancer.
Imperial College London news release: http://www3.imperial.ac.uk/newsandeventspggrp/imperialcollege/newssummary/news_22-2-2017-16-38-0
Gemini Research news: http://geminiresearchnews.com/2017/02/eight-day-clearly-best-heart/
From It’s About Nutrition:
Seb is a writer and blogger of food and nutrition. He holds a bachelors and a masters degree in nutrition science, and has studied sports and exercise nutrition at postgraduate level. He specialises in plant-based nutrition and believes passionately that we can all live with a little less meat.