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The Actuary The magazine of the Institute & Faculty of Actuaries

The sweetest taboo

Jean Eu looks at the effects sugar has on human health and how its consumption could be used as a rating factor in the underwriting process


The sweetest taboo
©Craig Zaduck
Sugar is everywhere. But, as actuaries, do we really understand the impact it has on our health, and how we can better allow for sugar intake in underwriting?
Let’s start with sugar consumption. If asked to name sugary foods, you may think of sweets, chocolate, fizzy drinks, table sugar, and perhaps even fruit. But sugar also appears in savoury foods such as ready meals, soups, salads and sauces; as well as ‘healthy’ foods such as breakfast cereals and yoghurt. Furthermore, starches such as bread, pasta, rice and potatoes also convert to sugar in our bloodstream, having the same impact on our bodies. These ‘hidden sugars’ can add a surprising amount to our daily intake.

Sugar is also used by food manufacturers to increase the attraction of their foods. Large brands focus on finding the ‘bliss point’ – the optimal level of sugar at which sensory pleasure is at its maximum – thus creating products that consumers will crave and return to buy.

The ‘low-fat’ food industry has also exploited the use of sugar. Researchers found that by removing fats from foods the taste deteriorated, so counter-balanced this by adding more sugar to make them more palatable.

According to the National Diet and Nutrition Survey, adults in the UK consume on average up to 58.8g, or 15 teaspoons, of sugar per day. Yet the World Health Organization recently published draft guidelines recommending that an average adult’s sugar intake should be below 5% of total energy intake. This roughly equates to no more than 25g, or six teaspoons, per day. This means that the average UK adult is currently consuming nearly three times more sugar than is healthy.

The dangers within

To understand why sugar consumption is such a problem, we first need to understand how our bodies process sugar. The sugars and starches we consume are digested in our intestines to form glucose, which is then transported around the body through our bloodstream. The glucose is absorbed by our body’s cells for energy.

To regulate the amount of glucose in our blood, the pancreas releases a hormone called insulin. The more sugar in our bloodstream, the more insulin is released to help lower it.

Equally, if blood sugar is low – say, between meals or during exercise – then a second hormone called glucagon is released by our pancreas to convert the stored sugar back into glucose and increase blood sugar levels.

Both insulin and glucagon work together to regulate blood sugar levels. Any excess sugar is stored first in the liver and muscles if glycogen levels are low. However, if glycogen levels in the liver or in the muscles do not need replenishing, the excess sugar is stored as triglycerides in fat cells around the body.

A problem occurs with the consumption of too much sugar. When we put a high level of sugar into our bodies too quickly, our body releases too much insulin in response to the sugar ‘flood’.

This causes our blood sugar to drop below normal levels, resulting in hypoglycaemia, or a sugar crash. There is a delay between this and when the body begins converting the stored sugars in our bodies back to glucose. This is when sugar cravings occur, in an attempt to replenish what our body thinks it has lost. So we take on even more sugar, and the process starts again.

A further complication is that the consumption of fructose or fruit sugars (the base of all table sugar) has been shown to increase the resistance of the brain to leptin, the protein which tells our body it is full and satiated.

Why we love sugar

Human beings are designed to crave sugar. If you consider the caveman, when humans had to hunt for or gather their food, sugar was hard to come by. Humans may have eaten fruit and recognised it as an instant energy source. As part of our evolution, we recognise sugar as a means of survival, and therefore naturally seek out sweet foods in times of need.

Sugar has also been shown to have a similar effect on our brains to any addictive substance.

Chemically speaking, dopamine is released when we consume drugs, nicotine or alcohol, giving individuals a ‘high’ that can lead to addiction. When eating food, dopamine is released in the brain; however, after repeatedly eating the same food, dopamine levels begin to plateau, and we no longer find the same foods as satisfying. This is an evolutionary tactic, to ensure we eat a variety of food so that our bodies receive the nutrition it requires.

Interestingly, no matter how much sugar a person consumes, dopamine levels never even out enough to discourage an individual from eating more sugar. Those who have tried to reduce their sugar intake have often reported withdrawal symptoms akin to drug withdrawal symptoms; for example, dizziness, headaches, fatigue, irritability, shakes and mood swings.

Apart from the impact on fat storage and subsequent obesity, sugar also has many other implications for our health. It can lead to tooth decay, non-alcoholic fatty liver disease, metabolic syndrome, cardiovascular disease, obesity and type 2 diabetes, and an increased risk of cancer.
For example, consider soft drinks which generally have high sugar content. Whether or not there is a direct link, it is interesting that consumption has risen along with the prevalence of obesity.

Consumption as a rating factor

Given that sugar has a clear impact on health, it might therefore be appropriate to use sugar consumption as a rating factor in the underwriting process. In theory, if we could measure the level of a person’s sugar consumption, we could calculate the risk of even a healthy individual developing a disease.

Current rating factors measure levels of cholesterol, blood glucose and abdominal obesity, however, these are measures of risks that have already occurred.

Healthy Chart 1 and 2

Furthermore, measures of blood glucose only provide a snapshot view at a specific point in time, rather than a measure of someone’s dietary habits. Individuals could answer questions about their food habits to indicate the amount of sugar they are consuming – but this is highly dependent on the individual’s memory, and on the questions being answered accurately and truthfully. We need to measure the amount of glucose being consumed by an individual over a prolonged period of time. Such a test would be a good indicator of future health before a disease advances.

Measuring sugar consumption may not be a too distant possibility. Wearable technology used by diabetics to monitor blood glucose levels is already in use. For example, a continuous glucose monitor (CGM) uses a tiny sensor under the skin of an individual’s stomach to measure blood glucose levels every five minutes, and sends a signal to a receiving device. The CGM sounds an alarm if blood sugar drops below a certain level, and can be connected to a number of smartphone apps.

There are also non-invasive methods of measuring blood glucose levels, such as GlucoWise, a device which measures blood sugar levels by squeezing the skin between the thumb and forefinger, or the earlobe, and connects wirelessly to a smartphone app, giving users a non-invasive and painfree method of continuously measuring their blood sugar.

An article published in the Journal of Nutrition (June 2013) reported that researchers in the United States have recently identified a biomarker for dietary sugar, which would enable detection of habitual sugar intake from a hair or blood sample. The methodology is still being developed, but it would appear that the test may become available in the near future.

While it is becoming more commonplace to measure sugar consumption with the aid of wearable technology, there are other considerations to investigate before sugar intake can be used as a rating factor. These include the impact of salt and fat consumption on an individual’s future health in conjunction with sugar intake; how much exercise the individual does, and how this may negate the impact of excess sugar intake; and the quantification of the exact level of risk associated with excess sugar consumption.

There are also socio-economic factors to consider. Traditionally, the less wealthy are associated with poorer health. However, these parts of the population may live off the land and consume less processed foods and sugar than their more affluent counterparts. In this scenario, it may actually lead to better health for them in the long run.

Jean Eu is a senior actuary at Correlation Risk Partners, specialising in life and health insurance