So we established in Part 1 of this blog that the guidelines suggest that two or more serves is how much fruit we should consume. However, for some of us, it’s really easy to over consume. And this may well be having a negative impact on our health. Now I finished the previous blog with suggesting that somewhere between 2 to 3 serves is most ideal. But what if I have metabolic issues? Are there better and worse fruits to consume?
How much fruit should I consume to protect the heart?
Interestingly, many studies have looked into this question. However, they tend to combine fruit and vegetables together making it hard to conclude. One study by Lai et al (2015) looked into this and found that in a group of UK women the risk of death from a cardiovascular event decreased with more fruit even with over 4 serves per day. It’s would be easy from this to conclude that more is better right?
Another UK study looked at the risk of death from cardiovascular disease or cancer in both men and women (Oyebode et al 2013). What they found was that increased vegetable consumption was more protective than fruit. When they looked at just fruit intake the greatest benefit was at 3 serves per day. Depending on the model used, an increase in serves beyond this either had no further benefit or increased your risk.
How much fruit should I eat for metabolic health?
So we know that 3-4 serves of fruit is good for the heart. But what about people who are at risk of or want to prevent diabetes?
We have a good amount of evidence here that perhaps we shouldn’t be eating too much fruit. In fact a very large meta-analysis of 7 studies by Li et al (2015) concluded that those who had a fruit intake of around 200 grams per day (about 1.5 serves) were less at risk of developing diabetes. While it certainly is not good to have no fruit in a day, having 3-4 serves increased your risk comparatively. And from there, things tended to get worse with increased fruit consumption.
Furthermore, a study by Zhang & Jiang (2015) tended to corroborate this finding with two serves a day being the “sweet spot” for reducing the risk of developing diabetes in a study of over 200,000 individuals. And similar to the Li et al (2015) meta-analysis, they found a similar U shaped curve when consumption increased above 2 serves with 4 serves being as high a risk as having no fruit at all.
So there may be such thing as too much of a good thing. And like most things we need to consume fruit in moderation, especially if we’re at risk of diabetes and metabolic conditions.
But are some fruits better than others? Well the short answer to this question is “yes”
Fruits that when you consume more to have a health benefit
Interestingly, most studies will show that vegetables have a stronger association in reducing premature death than fruit (Oyebode et al 2013). However, some fruits, when you consume more tend to reduce your risk of either cardiovascular disease or diabetes.
Lai et al (2015) found that a greater intake of citrus was associated with a lower risk of fatal stroke in women. While grapes were seen to be more protective against a fatal cardiovascular event. When we look at the risk of diabetes, Alperet et al (2017) found that temperate fruit such as apples was associated with a loser risk of diabetes in women. Both citrus and grapes tended to lower the risk of diabetes for both men and women.
So it appears there are some common threads: citrus and grapes tend to reduce our risk. But what about fruits that perhaps aren’t so good for us to overconsume?
Fruits that may not be good for us when we over consume
Firstly, a common theme in most studies is that fruit juice is not fruit! Imamura et al (2015) found that while not quite as bad as soft drink (every serve a day increased your risk of diabetes by 18%), every serve of fruit juice increased your risk by 5%.
When it comes to increasing your risk of cardiovascular disease it seems that any canned fruit will do this (Oyebode et al, 2013). They found that every daily serve increased your risk by 17%.
Now there it appears that too much tropical fruits (bananas, mangoes, melons) will increase your risk of diabetes and these should be limited to less than one serve a day (Alperet et al 2017). Interesting Huang et al (2017) found that tropical fruit increased the risk of gestational diabetes.
Finally, Alperet et al (2017) also found that higher glycaemic index (GI) fruits had a greater risk than lower GI fruits. While these fruits tend to be more tropical in nature here’s a list of fruits with a GI greater than 50:
- Watermelon – 72
- Pineapple – 66
- Rock melon – 65
- Paw Paw – 60
- Canned Peaches – 58
- Banana – 56 (although increases with ripeness)
- Kiwi Fruit – 52
The take home message about how much fruit you should eat
- The amount of fruit you eat is important. 2-3 serves per day is probably best for your long term health but more than 4 may increase your your risk of metabolic conditions such as diabetes.
- Try and limit your consumption of high glycaemic fruits like tropical fruits and treat them as “treats”.
- Don’t count fruit juice as a fruit, if anything it should be treated more like soft drink
- Aim to get the bulk of your 2-3 serves of fruit a day from lower or moderate GI fruits. Fruits like grapes, apples and citrus all appear to reduce your risk of health conditions as you age.