Alcohol may be a big part of how many people socialise and celebrate, but it can have a negative impact on our lives in a range of ways, as Alcohol Awareness Week (July 1st-7th), coordinated by Alcohol Change UK, highlights.

However, while some of the dangers associated with excessive drinking are obvious, what about the quieter or more surprising ways alcohol could be affecting your health?

Short and long-term eye symptoms

“Not only is blurred vision one of the main side effects, but drinking can also cause symptoms associated with dry eye,” says Stephen Hannan, clinical services director at Optical Express.

“These can include red eyes as a result of swollen blood vessels in the eyes, otherwise known as a bloodshot look, itchiness, irritation or discomfort, and fluctuation in vision.

“Although these are only minor issues, long-term alcohol abuse can actually permanently damage the optic nerves within our eyes, which are the connections responsible for sending visual information from the eyes to the brain,” Hannan adds.

“Cutting out alcohol, or drinking less, will allow your body to over time reverse and put the brakes on many of the short and long-term effects of drinking. For example, after just 24 hours of no alcohol, your blood sugar levels will normalise and blurred vision caused by alcohol intake will disappear.”

Impaired immunity

Carolina Goncalves, superintendent pharmacist at Pharmica, says: “Short-term alcohol consumption can hinder the activity of immune cells such as macrophages, T-cells, and B-cells, which are essential for identifying and combating pathogens. This impairment increases the body’s susceptibility to infections and diseases.

“Moreover, alcohol immediately affects the gastrointestinal system, the first point of contact before entering the bloodstream. The gut microbiome, a community of microorganisms aiding in gut function and immune system maturation, is altered by alcohol.

“Research shows that alcohol disrupts communication between gut microbes and the intestinal immune system,” she explains. “It also damages epithelial cells, T-cells, and neutrophils in the GI tract, compromising the gut barrier and allowing microbes to leak into the bloodstream.

“Finally, alcohol can impact cytokine production (proteins which control inflammation), leading to an imbalanced immune response.”

Menstrual cycle changes

Goncalves adds: “More research has found that the ethanol in alcohol can disrupt how the pituitary gland, which produces hormones, interacts with the hypothalamus, the region of the brain responsible for emotional regulation, and the ovaries. These interactions are collectively referred to as the ‘hypothalamic-pituitary-gonadal (HPG) axis’.

“Alcohol consumption can disrupt the secretion of luteinising hormone (LH) and follicle-stimulating hormone (FSH), both of which are part of the HPG axis. This can impact the maturation of ovarian follicles and how ovulation is triggered, resulting in hormonal and physiological changes that may cause irregularities in menstrual cycles.”

Fertility problems

Dr David McLaughlan, consultant psychiatrist specialising in addiction treatment at Priory Hospital Roehampton, and co-founder of Curb, an addictive behaviour change app, says: “Excess alcohol reduces testosterone production in men, as well as disrupting other hormones which in turn damages the number and quality of sperm produced by men.

“In women, alcohol disrupts ovulation and implantation of the fertilised egg. A recent study by The University of Louisville showed that even a moderate alcohol intake of just three to six alcoholic drinks per week reduced the chance of falling pregnant by 44 per cent.”

Cancer risk

While cancer can potentially affect anyone and isn’t always preventable, McLaughlan also notes that alcohol is a known risk factor for the disease.

“People might be surprised to learn that 10 per cent of all breast cancers are attributable to consumption of alcohol, which is one of the primary risk factors for developing the cancer, even at low volumes of consumption,” he says.

“The International Agency for Research on Cancer declared alcohol a group 1 carcinogen, which puts it in the same class as tobacco, radiation and asbestos.”

Absorption and blood issues

Long-term alcohol use also impairs absorption of vitamin B and folate, which is necessary for healthy red blood cells.

“Excess alcohol [can cause] macrocytic anaemia, where the red blood cells are enlarged but ineffective and break down quicker than healthy red blood cells,” says McLaughlan. “Symptoms can include tiredness, loss of balance, pins and needles, mood disturbance and stomach upsets.”

Low mood and anxiety

Alcohol is a depressant that can initially produce a calming effect. However, as Lisa Gunn, mental health prevention lead at Nuffield Health, explains: “When this wears off, we typically see a rebound effect where anxiety levels spike. This is partly because alcohol disrupts the balance of neurotransmitters and chemical messengers in the brain.

“There is also a social aspect to this. When we drink, we become inebriated and ‘carefree’, which can cause us to say and do things we wouldn’t do when we’re sober. If we go into ‘blackout’ (periods of alcohol-induced memory loss) during a period of acute intoxication, we are even more likely to wake up with feelings of anxiety, fear, worry, and dread.”

Raised blood pressure

Nathan Penman, clinical manager at Nuffield Health,  explains drinking alcohol can affect blood vessel too.

“This can cause them to become narrower. When your blood vessels are narrower, the heart has to work harder to push blood around your body, increasing your blood pressure,” says Penman. “High blood pressure can increase the risk of developing heart disease, making it more likely that a person would experience a heart attack or stroke.”

Sex drive changes

Alcohol may initially have a bolstering effect on hormones such as serotonin, dopamine and testosterone, which can seemingly boost our sex drive. “However, over time, these levels will reduce, which lowers the amount of sexual drive a person will experience and could potentially lead to incidences of depression or anxiety,” adds Penman.