Should we be avoiding fruit?
It’s never as simple as the headlines suggest and, for most people, including local, seasonal fruit in the diet will serve to improve the diet, not detract from it.
Does it feel like all of the rules you’ve learned about what and how to eat are changing? What was once on the “forbidden” list is now a healthy food.
Bacon can be consumed as a food group in itself and not as an occasional treat. You might even be waiting for the day you wake up to discover the real reason for the health crises facing both individuals and the population as a whole is the increasing amounts of lettuce we’ve been eating.
Aside from that pesky little issue last year (you know, the lettuce carrying a bacteria causing gastrointestinal upset), I don’t think that will happen any time soon. But why are people suddenly up in arms about fruit? What once was hailed as a health food is suddenly on the forbidden list as being “too high in sugar” and — as you know — sugar is white death.
Is this just hyperbole or does the removal of fruit from your everyday diet have some merit? As with anything in nutrition, it’s a little more complicated than that and one recommendation does not suit all.
Fructose and glucose
Fruit is a carbohydrate, and the major carbohydrate molecule found in some fruit is fructose, which is digested differently to other carbohydrate molecules. Fructose bypasses the digestive tract and is delivered straight to the liver, it doesn’t raise blood sugar or cause an insulin spike the way that other carbohydrate foods do, hence why many fructose-containing foods can also say they have little effect on the blood sugar.
Glucose, however (the main carbohydrate molecule which carb-based foods are broken down into), is digested and released into the bloodstream, causing a rise in blood sugar and insulin levels. When this was discovered it was a real win in the health stakes.
Given what we know about blood sugar levels and insulin and the relationship with heart disease and diabetes, anything that contained less glucose and more fructose had to be a good thing. No rise in blood sugar, no issues, right?
Well, no, actually.
While it is good news that foods high in fructose don’t cause a massive increase in blood sugar and insulin (as this can lead to roller coaster energy levels, mood problems and inflammation), the appetite-regulating signals of insulin can be dampened when consuming foods high in fructose.
While too much insulin is not a good thing, not enough insulin to elicit appropriate appetite regulating signals can lead to overeating. There are other metabolic health effects of too much fructose.
Fructose is dealt with differently in the liver compared to glucose — it requires more energy to metabolise it in the liver and this process increases uric acid. Anyone who has suffered a bout of gout will understand the consequences of this inflammatory condition — while a high meat and shellfish intake are often touted as being wholly responsible for gout, a high fructose intake is another factor.
The differential way that fructose is broken down can also lead to increased fat storage from carbohydrate foods, as the breakdown of fructose creates by-products that cause an increase in fatty acid production in the liver, contributing to non-alcoholic fatty liver disease.
If the fat is not stored, it is released back into our bloodstream, packaged in very low-density lipoprotein (VLDL) molecules. VLDL is not often discussed in the public health domain and isn’t routinely measured when we get our cholesterol levels checked, but it is a type of cholesterol carrier that increases the risk of plaque build-up in our arteries, much more so than your standard low-density lipoprotein (LDL) molecules.
The interest in the effects of fructose has come about because we have far more fructose in the food supply than ever before. Fructose is the main “sugar” found in high-fructose corn syrup, which has a ratio of around 55 per cent fructose to 45 per cent glucose.
High-fructose corn syrup (HFCS) is a by-product of the grain industry and is a readily available, extremely cheap source of sweetener that is found in many processed food products adorning the supermarket shelves in North America. These include sugary beverages, peanut butter, breakfast cereals and the like.
Not in New Zealand though — the main sweetener that local food manufacturers use is sucrose, a carbohydrate you’ll know better as the white granulated stuff added to hot drinks (i.e. refined table sugar). However, sucrose isn’t too different from HFCS in terms of its carbohydrate make-up; it is 50 per cent fructose, 50 per cent glucose.
Therefore, consuming too many of the processed foods having a high sugar content (both “sweet” and “not so sweet”) has the potential to negatively impact our health in the ways I’ve described above.
Fructose in fruit
Does the fructose in fruit cause the same issues?
No. I’ve talked about the consequences of excessive fructose. However, it is extremely difficult to consume fruit in the amounts that would be considered excessive. The research conducted to show the deleterious effects of fructose has used amounts far exceeding that found in nature and in naturally occurring sources of fructose (such as fruit).
Whole pieces of fruit also contain fibre and water and require a certain amount of chewing — this is going to contribute to our feelings of satiety when we eat them. The fibre present in fruit helps slow down the digestion of the carbohydrate too, which can leave us feeling fuller both in the short and the long term.
Let’s not forget the antioxidants, vitamins and minerals that help with energy metabolism and the reparation of cell damage — far from creating inflammation, fruit can help protect us from this due to antioxidants present, acting as scavengers to the free radical damage that produces inflammation.
Many population studies show an association between reduced health risk and the consumption of fruit and vegetables. As a naturally occurring source of carbohydrates, including a variety of fruit in the diet contributes to an overall better quality of diet and an improvement in health, particularly when fruit is eaten in the place of more processed, refined food items.
There are some people though who do benefit from reducing fruit in their diet. Those who have problems with blood sugar regulation or who require a low-carbohydrate diet for therapeutic reasons are best to stick to a lower fruit intake, whereas healthy, more active people could eat three or four serves a day and be absolutely fine.
There are also fruits that are lower in overall sugar — berries, kiwifruit, citrus fruit, green apples and pears — which make a better choice than those that are higher in sugar (grapes, cherries, tropical fruits and ripe bananas).
Fruit is now so much bigger than it used to be also – some apples weigh in at 350g and grapes are the size of golf balls! To save you weighing your food items, use your fist as a guide, or what can fit into the palm of your hand. This is applicable to all people, young and old.
For bananas, use the length between your index finger and the tip of your thumb. Fruit juice, dried fruit and fruit leather are essentially just a concentrated source of sugar, with the fibre and/or the water removed. I would recommend only the very active individual could consider including these in their diet, but with no more than one serve a day (around a small handful of dried fruit).
And when you do eat fruit as a snack, regardless of the type of fruit, I always recommend that you eat it alongside of source of fat and protein. This will help you feel even more satisfied.
Fruity serving suggestions
- Add fruit (kiwifruit, watermelon, berries) to a salad.
- Sliced apple with peanut butter.
- Sliced pear spread with ricotta.
- Banana “coins” chopped into cottage cheese with a teaspoon of tahini dolloped on top.
- Half a slice of pineapple chopped and served with a couple of tablespoons of coconut cream.
- A small handful of berries served with a dollop of cream or greek yoghurt.
- A small handful of grapes with a slice of tasty cheese.
- Pan-fry sliced apple (in a little coconut oil) to serve with pan-fried halloumi.
- Sliced fresh apricot spread with cream cheese.
- Walnut halves, chopped apple and celery mixed with a teaspoon of good quality mayonnaise.
Through her subscription service of meal plans and nutritional support, nutritionist Mikki Williden helps people manage their diets in an interesting way, at a low cost. To find out more and to sign up, visit mikkiwilliden.com.