Are you one of these people who loathes spending time outdoors at dusk as the weather warms and mosquitoes start biting?

Female mosquitoes need blood to develop their eggs. Even though they take a tiny amount of our blood, they can leave us with itchy red lumps that can last days. And sometimes something worse.

So why does our body react and itch after being bitten by a mosquito? And why are some people more affected than others?

What happens when a mosquito bites?

Mosquitoes are attracted to warm blooded animals, including us. They’re attracted to the carbon dioxide we exhale, our body temperatures and, most importantly, the smell of our skin.

The chemical cocktail of odours from bacteria and sweat on our skin sends out a signal to hungry mosquitoes.

Some people’s skin smells more appealing to mosquitoes, and they’re more likely to be bitten than others.

Once the mosquito has made its way to your skin, things get a little gross.

The mosquito pierces your skin with their “proboscis”, their feeding mouth part. But the proboscis isn’t a single, straight, needle-like tube. There are multiple tubes, some designed for sucking and some for spitting.

Once their mouth parts have been inserted into your skin, the mosquito will inject some saliva. This contains a mix of chemicals that gets the blood flowing better.

There has even been a suggestion that future medicines could be inspired by the anti-blood clotting properties of mosquito saliva.

It’s not the stabbing of our skin by the mosquito’s mouth parts that hurts, it’s the mozzie spit our bodies don’t like.

Are some people allergic to mosquito spit?

Once a mosquito has injected their saliva into our skin, a variety of reactions can follow. For the lucky few, nothing much happens at all.

For most people, and irrespective of the type of mosquito biting, there is some kind of reaction. Typically there is redness and swelling of the skin that appears within a few hours, but often more quickly, after just a few minutes.

Occasionally, the reaction can cause pain or discomfort. Then comes the itchiness.

Some people do suffer severe reactions to mosquito bites. It’s a condition often referred to as “skeeter syndrome” and is an allergic reaction caused by the protein in the mosquito’s saliva. This can cause large areas of swelling, blistering and fever.

The chemistry of mosquito spit hasn’t really been well studied. But it has been shown that, for those who do suffer allergic reactions to their bites, the reactions may differ depending on the type of mosquito biting.

We all probably get more tolerant of mosquito bites as we get older. Young children are certainly more likely to suffer more following mosquito bites. But as we get older, the reactions are less severe and may pass quickly without too much notice.

How best to treat the bites?

Research into treating bites has yet to provide a single easy solution.

There are many myths and home remedies about what works. But there is little scientific evidence supporting their use.

The best way to treat mosquito bites is by applying a cold pack to reduce swelling and to keep the skin clean to avoid any secondary infections. Antiseptic creams and lotions may also help.

There is some evidence that heat may alleviate some of the discomfort.

It’s particularly tough to keep young children from scratching at the bite and breaking the skin. This can form a nasty scab that may end up being worse than the bite itself.

Applying an anti-itch cream may help. If the reactions are severe, antihistamine medications may be required.

To save the scratching, stop the bites

Of course, it’s better not to be bitten by mosquitoes in the first place. Topical insect repellents are a safe, effective and affordable way to reduce mosquito bites.

Covering up with loose fitted long sleeved shirts, long pants and covered shoes also provides a physical barrier.

Mosquito coils and other devices can also assist, but should not be entirely relied on to stop bites.

There’s another important reason to avoid mosquito bites: millions of people around the world suffer from mosquito-borne diseases. More than half a million people die from malaria each year.

In Australia, Ross River virus infects more than 5,000 people every year. And in recent years, there have been cases of serious illnesses caused by Japanese encephalitis and Murray Valley encephalitis viruses.

Cameron Webb, Clinical Associate Professor and Principal Hospital Scientist, University of Sydney

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Humans have long been searching for a “magic elixir” to make us smarter, and improve our focus and memory. This includes traditional Chinese medicine used thousands of years ago to improve cognitive function.

Now we have nootropics, also known as smart drugs, brain boosters or cognitive enhancers.

You can buy these gummies, chewing gums, pills and skin patches online, or from supermarkets, pharmacies or petrol stations. You don’t need a prescription or to consult a health professional.

But do nootropics actually boost your brain? Here’s what the science says.

What are nootropics and how do they work?

Romanian psychologist and chemist Cornelius E. Giurgea coined the term nootropics in the early 1970s to describe compounds that may boost memory and learning. The term comes from the Greek words nӧos (thinking) and tropein (guide).

Nootropics may work in the brain by improving transmission of signals between nerve cells, maintaining the health of nerve cells, and helping in energy production. Some nootropics have antioxidant properties and may reduce damage to nerve cells in the brain caused by the accumulation of free radicals.

But how safe and effective are they? Let’s look at four of the most widely used nootropics.

1. Caffeine

You might be surprised to know caffeine is a nootropic. No wonder so many of us start our day with a coffee. It stimulates our nervous system.

Caffeine is rapidly absorbed into the blood and distributed in nearly all human tissues. This includes the brain where it increases our alertness, reaction time and mood, and we feel as if we have more energy.

For caffeine to have these effects, you need to consume 32-300 milligrams in a single dose. That’s equivalent to around two espressos (for the 300mg dose). So, why the wide range? Genetic variations in a particular gene (the CYP1A2 gene) can affect how fast you metabolise caffeine. So this can explain why some people need more caffeine than others to recognise any neurostimulant effect.

Unfortunately too much caffeine can lead to anxiety-like symptoms and panic attacks, sleep disturbances, hallucinations, gut disturbances and heart problems.

So it’s recommended adults drink no more than 400mg caffeine a day, the equivalent of up to three espressos.

2. L-theanine

L-theanine comes as a supplement, chewing gum or in a beverage. It’s also the most common amino acid in green tea.

Consuming L-theanine as a supplement may increase production of alpha waves in the brain. These are associated with increased alertness and perception of calmness.

However, it’s effect on cognitive functioning is still unclear. Various studies including those comparing a single dose with a daily dose for several weeks, and in different populations, show different outcomes.

But taking L-theanine with caffeine as a supplement improved cognitive performance and alertness in one study. Young adults who consumed L-theanine (97mg) plus caffeine (40mg) could more accurately switch between tasks after a single dose, and said they were more alert.

Another study of people who took L-theanine with caffeine at similar doses to the study above found improvements in several cognitive outcomes, including being less susceptible to distraction.

Although pure L-theanine is well tolerated, there are still relatively few human trials to show it works or is safe over a prolonged period of time. Larger and longer studies examining the optimal dose are also needed.

3. Ashwaghanda

Ashwaghanda is a plant extract commonly used in Indian Ayurvedic medicine for improving memory and cognitive function.

In one study, 225-400mg daily for 30 days improved cognitive performance in healthy males. There were significant improvements in cognitive flexibility (the ability to switch tasks), visual memory (recalling an image), reaction time (response to a stimulus) and executive functioning (recognising rules and categories, and managing rapid decision making).

There are similar effects in older adults with mild cognitive impairment.

But we should be cautious about results from studies using Ashwaghanda supplements; the studies are relatively small and only treated participants for a short time.

4. Creatine

Creatine is an organic compound involved in how the body generates energy and is used as a sports supplement. But it also has cognitive effects.

In a review of available evidence, healthy adults aged 66-76 who took creatine supplements had improved short-term memory.

Long-term supplementation may also have benefits. In another study, people with fatigue after COVID took 4g a day of creatine for six months and reported they were better able to concentrate, and were less fatigued. Creatine may reduce brain inflammation and oxidative stress, to improve cognitive performance and reduce fatigue.

Side effects of creatine supplements in studies are rarely reported. But they include weight gain, gastrointestinal upset and changes in the liver and kidneys.

Where to now?

There is good evidence for brain boosting effects of caffeine and creatine. But the jury is still out on the efficacy, optimal dose and safety of most other nootropics.

So until we have more evidence, consult your health professional before taking a nootropic.

But drinking your daily coffee isn’t likely to do much harm. Thank goodness, because for some of us, it is a magic elixir.

Nenad Naumovski, Professor in Food Science and Human Nutrition, University of Canberra; Amanda Bulman, PhD candidate studying the effects of nutrients on sleep, University of Canberra, and Andrew McKune, Professor, Exercise Science, University of Canberra

This article is republished from The Conversation under a Creative Commons license. Read the original article.