Chicken soup helps cure colds and flu

TRUE “When you’ve got a cold, the best thing you can eat is a hearty, nutritious soup,” says Rhiannon Lambert, a nutritionist and the author of Re-Nourish: A Simple Way to Eat Well. “Chicken contains vitamin B12, plus other antioxidants and vitamins which support the immune system and aid digestion. It’s also rich in protein, which is good for cellular repair. Adding more veg also increases the vitamins and minerals that are needed to aid recovery.”

Chocolate causes acne

FALSE “The skin is your largest organ and has its own microbiome – its own bacteria – so the better you eat, the better your skin,” says Lambert. “Small amounts of chocolate won’t hugely impact skin health but chocolate with less sugar and dairy is better. More important for skin health is hydration – you should drink a minimum of 1.5-2 litres (6-8 glasses) of water a day. Coffee is a diuretic, but the amount of fluid you take in outweighs what you lose in urine. Tea is also fine, but avoid drinking it with a meal, because tannins in tea block iron absorption.” (Iron deficiency can lead to symptoms such as itchy skin.)

An apple a day keeps the doctor away

FALSE “It’s untrue but it may keep you away from the pharmacy,” says Dr Hazel Wallace, nutritionist and author of The Female Factor. “One study looked at healthcare practices of daily apple eaters and found they used fewer prescription medications. This had more to do with them being healthier overall – apple eaters also had higher educational levels and were less likely to smoke – than specifically with eating apples. However, since apples are nutritious, one a day is not a bad idea.”

Going out with wet hair gives you a cold

FALSE “If wet hair makes you shivery, it’s an inflammatory response, so you probably already have a viral infection brewing,” says Punam Krishan, a GP and author of How To Be a Doctor and Other Life-Saving Jobs. “But if you’re otherwise healthy, you won’t catch a cold. Lack of sleep and stress affect your immune system, leaving you susceptible, but you only catch colds from other people, particularly in cold weather. Viruses and bacteria spread easily when we’re huddled indoors with no ventilation.”

Carrots help you to see in the dark

TRUE “Carrots contain vitamin A, which is important for healthy vision because it helps form a pigment in the retina called rhodopsin,” says Dr Ayan Panja, partner in an NHS surgery and author of The Health Fix: Transform Your Health in 8 Weeks. “This is necessary for low-light vision. Vitamin A deficiency can lead to difficulties seeing in low light, so getting enough – from foods such as carrots, leafy greens and sweet potatoes – is important for night vision.”

Spicy curry induces labour

FALSE “The theory is that spice stimulates the gut to work harder, and can stimulate the uterus at the same time,” says Krishan. “When you are about to go into labour the gut naturally gets irritated so most women will experience diarrhoea as a sign that the baby is coming. However, no food will bring on labour – it was probably imminent anyway.”

Feed a cold, starve a fever

TRUE “It is more accurate to say ‘feed a virus, starve bacteria’,” says Lambert. “Nutrition is important for recovery, hence feeding a cold, ideally with carbohydrates, to fuel immune responses against the virus. Conversely, bacterial infections benefit from fasting – the body’s response to bacteria can be extreme, so reducing carbs stops the immune system going into overdrive. Fluids are essential with both types of illness, however, and it’s better to eat little and often if possible.”

Turmeric helps prevent heart disease

TRUE “Turmeric has been shown to have anti-inflammatory and anti-oxidant properties, both of which help fight heart disease by reducing oxidative stress – a harmful biological process akin to rust on iron,” says Panja. “To absorb the active ingredient in turmeric – curcumin – you need fat such as olive oil, and a compound called piperine, found in black pepper, though it is unclear how much you would need to feel the benefit. Krishan adds: “High doses of turmeric can interfere with some blood thinning medication, so consult your GP first.”

Cracking your knuckles will give you arthritis

FALSE “That snapping sound of knuckle-cracking is caused by the rapid release of nitrogen gas from the fluid that lubricates our joints,” says Panja. “This is not actually harmful to joints and there is no evidence to suggest it can cause arthritis. However, some studies show that excessive knuckle cracking may be linked to swelling of the hands, reduced grip strength and damage to soft tissue.”

It takes up to seven years to digest swallowed chewing gum

FALSE “Chewing gum is made of sweeteners, preservatives and softeners, which your digestive system mostly breaks down,” says Lambert. “It also contains artificial polymers like waxes, which pass out in your poo in less than seven days. The bigger problems from chewing gum are bloating and acid reflux, caused by the stomach preparing to receive food, and producing saliva and unnecessary acid.”

Garlic under your pillow aids sleep

FALSE “Garlic contains minerals including vitamin B6 and selenium (plus several sulphur compounds, which may ward off insects) but it won’t have any impact on sleep,” says Panja. Consuming garlic can, however, help lower cholesterol and blood pressure and boost immunity. A better way to improve sleep is to avoid large meals before bed, keep the bedroom dark and go to bed and wake up at the same time each day.”

Peeing after sex can prevent UTIs

TRUE “Urinating after sex can help prevent a UTI by reducing the bacteria in the genital area,” says Panja. “Women are at higher risk because bacteria has a shorter distance to travel from the vagina to the bladder, and sex can trigger cystitis. The penile urethra is longer but it’s still a good idea to ‘void to avoid’ a UTI.”

Cinnamon helps balance hormones

FALSE “Some small trials showed that a natural chemical in cinnamon called cinnamaldehyde increased progesterone and decreased testosterone in women, helping to balance hormones,” says Lambert. “But the quality and amount of cinnamon you consume is unlikely to be enough. Hormones are part of your endocrine system and eating a balanced diet helps support that, but you can’t control hormones with food. You can, however, manage stress hormones cortisol and adrenaline with diaphragmatic breathing to switch your body from a sympathetic [fight or flight] to parasympathetic [relaxed] state.”

Urine relieves jellyfish stings

FALSE “Ammonia, being alkaline, is thought to neutralise the acid from bee stings, which is where this myth probably arose,” says Panja. “But it could actually make a jellyfish sting worse by causing the venom to release more toxins.” Water or urine can change the composition of the solution of any remaining stinging cells in the skin, so can encourage more venom release. “Also,” he adds, “introducing bacteria to the skin risks infection. It’s better to remove any tentacles with tweezers or scrape them off with a credit card then ask a doctor for oral pain relief and an anti-inflammatory cream.”

Oysters are aphrodisiacs

FALSE “Oysters are rich in zinc, which is important for reproductive health, but there are no studies to suggest that eating oysters will boost libido,” says Panja. “Zinc can increase dopamine, the brain’s pleasure chemical, but it’s a stretch to say a libido rise would occur instantly.” Krishan adds: “Treating low libido or erectile dysfunction is more about getting to the root cause, which for many is chronic insomnia, mental health issues, such as anxiety or depression, or perimenopause and menopause.”

You lose about half of your body heat through your head

FALSE “The amount of heat you lose from your head will be proportionate to its size in comparison with the rest of your body,” says Krishan. “You usually lose about 10-15%, largely because when you’re outside in the cold, most of you will be covered by clothes except for perhaps your head and face. If you went out in shorts, you would lose a similar amount of heat from your legs.”

Cheese gives you bad dreams

FALSE “There’s no robust evidence that cheese causes nightmares,” says Wallace. “In one 2015 study, 17% of people said they felt their dreams were influenced by what they ate, with dairy products most frequently blamed for disturbing dreams. However, this contradicts more substantial evidence that other dairy products, such as warm milk, before bed can help aid sleep, thanks to the amino acid tryptophan, which is used to make serotonin – ‘the happy hormone’ – and melatonin, a hormone that initiates sleep. However, for tryptophan to work, it needs to pass through the brain’s security system – the blood-brain barrier – to be converted into serotonin. Consuming carbohydrates alongside foods high in tryptophan may help this process, which is why malted milk or milk with honey are recommended for sleep.”

Sitting too close to a screen damages eyesight

FALSE “The world is becoming more myopic, and staring at our screens for too long is one theory for this,” says Panja. “However, sitting too close is more likely to cause eye strain than permanent damage. Taking regular screen breaks reducing blue light and glare and ensuring its brightness isn’t lighter or darker than your surroundings can help.”

Breakfast is the most important meal of the day

TRUE and FALSE “Skipping breakfast is not harmful, provided you can fit essential nutrients and daily calories into other meals,” says Wallace. “Those who consume most of their calories earlier in the day tend to eat less, be a healthier weight and have a lower risk of type 2 diabetes and heart disease. However, if you habitually skip breakfast and fit in healthy meals elsewhere, stick to what works for you.”

Probiotics support your gut health

FALSE “Probiotics are live beneficial bacteria and yeast that can be found in foods such as yoghurt [with live active cultures], kefir, kombucha, kimchi and natto [fermented bean], and you can find them in supplements,” says Wallace. “There is some evidence that probiotic supplements may be helpful in some cases, such as easing symptoms of irritable bowel syndrome but there’s little evidence to support the many other health claims made about them – and currently no convincing evidence to suggest that taking a probiotic will benefit healthy people who don’t have gut issues. There are also many different probiotic strains that can have different effects on the body, so it is case-by-case. Better to support your gut with food, aiming for 30 different plant-based foods, including nuts, seeds, wholegrains, pulses, herbs and spices, a week. The more diverse your diet, the healthier your gut microbiota, which will mean better immunity and bettter mental, cardiovascular and digestive health.”