Five a day is not an evidence based nutrition message. In this post I ask the question – is it still a good message – even though it’s not evidence based? I give five reasons as to why it is not a good message: the lost opportunity of making “eat real food” as well known as “five a day”; people having five a day ‘as well as’ not ‘instead of’; making bad choices to get five a day; the problem of fruit and starchy vegetables for carbohydrate sensitive/insulin resistant people; and the weight issue with fructose. As Gary Taubes says “If you’re overweight, fruit is not your friend.”
2015 has seen far greater awareness about sugar and there have been many newspaper articles showing how many teaspoons of sugar are in everything from pizza to prosecco. This post is about sugar in fruit.
Different forms of sugar
When we say sugar, we tend to mean sucrose – added white sugar – the stuff with no fat, no protein, no vitamins, no minerals – just empty carbohydrate calories. However, there are many other sugars in food:
- The simple sugars (monosaccharides) are: glucose; fructose; and galactose.
- The disaccharides (two sugars) are: sucrose (one molecule of glucose and one of fructose) – what we know as table sugar; lactose (one molecule of glucose and one of galactose) – what we tend to call milk sugar; and maltose (two molecules of glucose) – less familiarly known as malt sugar.
- Polysaccharides (many sugars) include digestible forms of carbohydrate…
– Glycogen – is the form in which animals (including humans) store energy – in the liver and muscles in the body;
– Starch – is the form in which plants store energy – as in grains, pulses, potatoes and root vegetables.
- … and indigestible forms of carbohydrate – collectively called fibre:
– Insoluble fibre – which does not dissolve in water e.g. cellulose, hemicellulose and lignin;
– Soluble fibre – which dissolves, or swells, in water e.g. pectins, mucilages, and gums.
Sugar in fruit
Sucrose, table sugar, is one part fructose and one part glucose. Fruit sugar is commonly assumed to be fructose, but this is incorrect. Fruit sugar is also part fructose/part glucose. Bananas and dates, as examples on this infographic, are almost equal balances of fructose and glucose – sucrose in effect. Apples have more than twice as much fructose as glucose, but don’t think of this as healthy. Read the work of Dr Robert Lustig and Dr Richard Johnson to see how fructose is not the halo sugar that fruit pushers would like to claim. It is particularly implicated in the obesity epidemic and Non Alcoholic Fatty Liver Disease (NAFLD).
In the following infographic, don’t be fooled by bananas seeming to be lower in sugar than apples and grapes. The medium banana with 14 grams (3.5 teaspoons) of sugar has 27 grams of carbohydrate in total. Even if we generously ignore the 3 grams of fibre, that leaves 10 grams of carbohydrate, which also breaks down into sugar.
The sugar in fruit is thus barely different to the sucrose in pizza or prosecco. The body does not know if glucose and fructose came from a banana or a chocolate bar. The body just registers the sugar – sucrose in effect – and has to deal with it.
The sources of information (US Department of Agriculture database) and the micro nutrients for the fruits and chocolate are in the table below. 100 grams of each product have been analysed to compare like with like. The highest provider of each vitamin and mineral has been highlighted in red and bold. Nutritionally, ‘junk’ milk chocolate provides more micro nutrients than any fruit comparator. (The chocolate should ‘win’ for vitamin A too, as it will contain some retinol – the form in which the body needs vitamin A). If you want to compare fruit with genuinely nutritious foods, check this.
|Per 100 grams||Large apple||Medium banana||Grapes||Medjool dates||Orange juice||Milk chocolate|
|B1 (Thiamin) (mg)||0.0||0.0||0.1||0.1||0.1||0.0|
|B2 (Riboflavin) (mg)||0.0||0.1||0.1||0.1||0.0||0.2|
|B3 (Niacin) (mg)||0.1||0.7||0.2||1.6||0.4||0.5|
|B5 (Pantothenic Acid) (mg)||0.1||0.3||0.1||0.8||0.2||0.5|
Some people don’t like it when I say that “fruit is sugar, with a few nutrients, and not as many as you’d think.” The truth hurts, no matter how softly spoken.