Dr Kevin McCarroll
Medical Matters
Reducing alcohol consumption in Ireland has become an important public health policy that has received much recent attention. A report conducted by the Health Research Board in 2013 showed that more than half (54.3%) of drinkers aged 18-75 in Ireland were classified as harmful drinkers, with approximately two fifths (37.3%) practising binge drinking and 6.7% having alcohol dependence.
‘At risk’ drinking based on current guidelines is so high that it has been suggested that the maximum safe level has been set too low”
What constitutes a safe level of alcohol intake has been subject to much questioning and even controversy over the years. Indeed, the prevalence of “at risk” drinking based on current guidelines is so high that it has been suggested that the maximum safe level has been set too low.
Definition
Hazardous or at risk drinking is defined as that which puts one at risk of future health problems due to drinking more than the recommended weekly or daily limit. Harmful drinking is said to happen when the pattern of drinking causes damage to physical or mental health.
Trying to define an exact cut-off point for safe alcohol consumption is not easily done and is largely based on evidence from epidemiological studies looking at the relationship between alcohol intake and several outcomes or diseases.
However, alcohol has been associated with up to 200 acute or chronic conditions and the level which poses a risk for cancer, cardiovascular disease and other health problems will vary.
Some would argue that there is no definable safe level of alcohol intake. Indeed, alcohol is classified as a group 1 carcinogen and has been causally implicated in at least eight cancers. The 2014 World Cancer report concluded that when it comes to cancer no level of alcohol consumption is safe and that increasing intake raises the risk in a dose dependent fashion.
On the other hand numerous studies consistently show that a low level of daily alcohol intake is beneficial against heart disease, however, this effect is not present for episodic and in particular heavy drinking.
Under reporting of alcohol consumption, difficulty in defining a reference or control group of non-drinkers, and lack of adjustment for other factors like smoking in those who drink make interpretation of studies difficult and mean that proving a definite cause and effect for any given level of intake is difficult.
Several professional bodies have established guidelines which have set maximum safe drinking levels for both female and males. Above these cut-offs there in an increasing risk of alcohol-related health problems. To confuse things, there is considerable variance in guidelines across countries with some referring to drinks as opposed to alcohol units consumed and with little attention being given to patterns of drinking behaviour.
In Ireland, the HSE recomendations which are broadly similar to Britain advise a maximum weekly consumption of 11 standard drinks for a female and 17 for a male (with a drink equating to half a pint of beer, a small glass of wine or a measure of spirits). Binge drinking is defined as taking six or more standard drinks in a short space of time. In addition, guidelines also advise not taking alcohol for at least two days of the week.
Having an alcohol intake just above this level puts one at an increased risk, but still in the relatively low risk category. As more studies emerge on the effects of alcohol, guidelines may become more fine tuned.
The World Health Organisation previously reported that drinking below 35 units per week in males and 17.5 units per week in females was low risk (one unit equates to approximately one standard drink). This is much higher than the safe drinking level now generally recommended.
Exceptions
Of course, guidelines apply to a typical person and cannot be applied in a one size fits all approach. In those with low body mass or liver disease a lower intake is advised.
Alcohol consumption should also be lower if you are taking certain medications, especially hypnotics or sedatives.
Studies also show that drinking behaviour changes throughout life and when younger tends be more irregular whereas with increasing age is more frequent though with overall consumption declining”
In addition, in older adults and in particular those with cognitive impairment alcohol may cause worsening confusion and falls and many guidelines now factor this in.
The evidence suggests that in terms of health risk patterns of drinking behaviour may be more important than total weekly alcohol consumption. Studies also show that drinking behaviour changes throughout life and when younger tends be more irregular, whereas with increasing age, it is more frequent though with overall consumption declining.
In summary, the guidelines reflect what constitutes for most a safe level of drinking. As always, a sensible approach should be taken to alcohol consumption which should factor in not just overall intake, but also importantly your pattern of drinking.