According to reports, the WHO is soon to revise its sugar intake guidelines downwards.
This follows on from a growing body of research linking high sugar intakes to obesity and to the onset of serious metabolic diseases such as type II diabetes.
While there are many conflicting views in this area, and many gaps in our scientific knowledge concerning the health effects of sugar, there is also a lot of evidence which points to a problem with high sugar intakes, especially in liquid form.
Sugar (sucrose), is a small molecule made up of two units — one a glucose and the other a fructose — joined tightly together. This is the sugar commonly used in the sweet foods and drinks (apart from the diet varieties) we consume in this country. When we eat sucrose the link between its glucose and its fructose units is broken, allowing us to absorb these single units through the gut wall, at which point they’re sent to the liver.
From this point onwards, however, they’re handled quite differently by the body.
Glucose enters the liver and is built into its storage form glycogen. Once the liver’s stores are full, no additional glucose is allowed to enter and it will instead remain in the blood. As glucose concentrations in our blood rise, the hormone insulin gets released from the pancreas and stores this blood glucose away in our muscles.
The fate of fructose is very different, however. When it enters the liver it’s largely converted into glucose which then gets burned for energy or stored as glycogen. The real problem is our poor capacity to convert fructose to glucose in the liver. This means if we take large amounts of sugar at any one time, or if we take it in a quickly absorbed form (like a sugary drink) the rapid influx of fructose from the gut overwhelms the liver’s limited ability to convert it to glucose. This is when the real trouble begins, because it’s at this point that fructose starts to get converted to fat.
The destination of this fat is of major importance. In simple terms, much of it gets packaged into the small fat-rich particles which we know as cholesterol or its closely-related cousin triglyceride.
These are expelled from the liver and deposit their fat in two main locations — the lining of our arteries, directly increasing our risk of heart disease and stroke — or the fat cells within our abdomen, causing weight gain around the middle, high blood pressure, diabetes and raised blood fats, all of which also increase our risk of heart attack, stroke and certain cancers.
Obviously, these physical effects pose a serious risk to health.
So while some people contend that reducing sugar (and therefore fructose) intake, and developing public policy initiatives which support this objective aren’t the whole answer to our obesity problem, there is equally little doubt that they are at least part of the answer.
There has been much focus on fizzy drinks as a significant contributor of rapidly absorbed fructose, with the inference in some quarters that public health specialists are engaged in a witch-hunt against the manufacturers of these products.
This is not the case. Indeed, SafeFood, in an ongoing campaign, has highlighted the potential hazards associated with high consumption of sugary drinks, has been at pains to point out that natural fruit juices often contain equal or even greater amounts of these problematic sugars.
Considering all of the above, the need to take effective action to moderate our fructose intakes seems obvious. The health and economic rewards for achieving this goal are substantial — however, they will require creativity, forthright dialogue and cooperation between health policy and food industry stakeholders if they are to be realised.
¦ Dr Daniel McCartney is a lecturer in human nutrition and dietetics at DIT.
IN THE FRIDGE
Low in calories, with no added sugar, low-fat natural yoghurt is the perfect alternative to mayonnaise and other high-calorie dressings, especially if flavoured with herbs or garlic.
It’s also rich in calcium, potassium, and riboflavin, all of which help to control blood pressure, and protect against osteoporosis as we get older. Most studies examining the association of low fat dairy food intake with bodyweight have concluded that higher intakes are associated with lower risk of weight gain around the midriff.
Vitamin D boost
A study published in the January edition of the Journal of Clinical Endocrinology and Metabolism sheds further light on the benefits of vitamin D supplementation in pregnancy.
Researchers in Southampton University measured vitamin D levels in 678 expectant mothers during the late stages of pregnancy.
They subsequently followed up the children born to these women in early childhood, showing that higher maternal vitamin D levels during pregnancy were associated with better grip strength and muscle mass in their children at four years of age.
A QUICK FIX
Soak 300g of couscous in 500mls of vegetable stock. Add 100g of diced feta cheese, three cloves of crushed garlic, peppers, two diced courgettes, 25 grams of finely chopped parsley and 25 grams of finely chopped fresh mint. Pour in 25mls of lemon juice and a table spoon of olive oil and mix thoroughly. Serve cold for a delicious, refreshing snack.
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