Fruit: to eat or not to eat?

We’re posing a simple question – fruit: to eat or not to eat? Could some fruits be throwing your healthy eating ambitions off track?

Patients are often surprised when I ask them to limit fruit to one piece a day, or to go a couple of days without fruit and then eat a couple of pieces. I particularly ask them to avoid dried fruit. They usually say, ‘But fruit is good for us, isn’t it?’ The answer is yes, and no.

Yes, fresh fruits do contain a number of vitamins, minerals, phytochemicals and fibre, which is nutritious. However, many of the common fruits we eat today are not the same as the fruits we would have consumed during evolution. Our fruits have been domesticated and bred to be bigger, sweeter and have less fibre than wild fruits.

The tricky thing about fruit is that it is high in a type of sugar called fructose. Now, fruit is not the only thing that contains fructose, some vegetables do, honey and agave nectar are high in fructose, and a man-made fructose (high fructose corn syrup) is found in many processed cakes, biscuits and carbonated drinks. The problem comes with the quantity of fructose that we are consuming, which has increased dramatically since humans were hunter gatherers. In the West, we can now buy fruits all year round rather than only eating seasonally. Fruits such as berries are being bred to be sweeter so that they are more palatable. Unfortunately evolution has not caught up and we don’t have the capacity to make physiologically healthy adaptations in the body in order to moderate the effect of fructose.

So what’s the problem with fructose?
As humans we are programmed to like sweet tastes. Sweet equals calories and during evolution calories were needed for survival. Fructose is sweet and when we came across it during evolution we would have stocked up, particularly as fruits, honey and some vegetables are only found at certain times during the year. The problem is that unlike glucose (our main energy source in the body), we don’t have a hormonal control (like insulin) to regulate intake and absorption of fructose. We also have no satiety system for fructose, meaning once we start eating we can’t stop, or we crave more!

Fructose is absorbed and processed mainly by the liver, which causes a depletion of energy in the liver. Added to our already hectic lifestyles and all the things we ask our liver to deal with (alcohol, hormones, prescription drugs, toxins), this can lead to liver overload symptoms such as: tiredness, increased hangovers, constipation, worsening of premenstrual symptoms, and hormonal conditions such as endometriosis. Fructose is also associated with metabolic syndrome, signs of which are poor blood sugar control, high blood pressure, weight gain, tummy fat, and gout. Gout is caused by increased uric acid levels, which is a byproduct of fructose metabolism. Achy joints in the morning can be a sign of increased uric acid levels even if it’s not high enough to register on a blood test.

If you’re tired or hungry, or craving something sweet, it’s actually our brain telling us we’re tired and need more energy. Our brains predominantly run on glucose. Therefore reaching for an apple, which is high in fructose is not what your body needs and it won’t make you less tired or less hungry! Try protein or fat first if you need energy, or at least fruit that is higher in glucose than fructose.

So what should I eat?
The best thing to do is to avoid sweet processed foods that will contain high-fructose corn syrup. Steer clear of sugar substitutes such as agave nectar as it’s very high in fructose. Avoid dried fruits as the sugar content makes them more like sweets than fruit and can be like a liver attack! A little natural honey or maple syrup is the best sweetener to use but only in small quantities. Try to include more vegetables than fruit in your diet (bearing in mind that some vegetables are also high in fructose). Always eat your fruit whole and avoid fruit juices. Juices are absorbed even more rapidly than whole fruit and usually contain much more sugar.

So yes, fruit is good for you, but just be aware that like most things you shouldn’t overdo it. If you have any of the symptoms of a sluggish liver, don’t go crazy on the fruit or use it as a crutch when you’re tired, bored or craving sugar!

For a list of fruits high in fructose check out http://fitnessprohealth.com/high-fructose-fruit/

For more information please contact Lucy Stephens (www.revaclinic.com, lucy@revaclinic.com).