Health myths have several sources. Some are ‘old wives tales’ passed down for generations. Others are based on poor studies that have since been scientifically disproven. Still others are spread by companies trying to push a product. Here are ten common examples of health advice you can safely ignore.
Eggs increase your risk for heart disease
In the past, health authorities warned the public against eating eggs for fear they would raise cholesterol levels. A national health and nutritional survey analyzed data from 27,378 participants and found that the opposite was true. Subjects who ate four or more eggs a week had a significantly lower cholesterol levels than those who none. A recent review of 17 different egg studies concluded that eating up to one egg per day is not associated with any increased risk of coronary heart disease or stroke.
You need to drink eight glasses of water a day
This oft repeated advice goes back to a 1945 report by the US Food and Nutrition Board which stated: ‘A suitable allowance [of water] for adults is 2.5 liters daily in most instances. Most of this quantity is contained in prepared foods’. The second sentence seems to have been forgotten. Many foods have a high water content which helps to keep us hydrated, and beverages aside from water can also quench our thirst. The amount of fluid we actually need varies with temperature and activity levels.
Cracking your knuckles causes arthritis
Osteoarthritis can be due to wear and tear on the joints, but the annoying knuckle cracking sound is not caused by bones rubbing together. It’s produced when the space between the bones is expanded and fluid is sucked into the gap. A study of 215 people found that a history of habitual knuckle cracking was not associated with any increased risk of osteoarthritis.
Abdominal exercises target belly fat
Crunches and sit ups will strengthen the abdominal muscles, but they won’t target fat in that area. Diet and exercise result in fat loss throughout the entire body. Most people have stubborn areas such as the waist, hips and thighs where the fat deposits are last to go. If you do want to lose belly fat, aerobic exercise is more effective than abdominal exercise because it burns more calories. For a flat tummy, focus on losing weight first, then do ab exercises to tone up.
You can catch up on sleep at the weekend
A lot of people sleep in late at the weekends to make up for a lack of sleep over the course of the working week. However, this may not be enough to combat the effects of sleep deprivation. In one study, participants were restricted to just four hours of sleep for five consecutive nights, then allowed to sleep for a full ten hours. After the extra rest, their reaction times and attention span were still below normal and their levels of fatigue remained high.
Eating greasy foods causes acne
Eating deep fried foods will not make your skin oilier or trigger an acne breakout. In fact, scientific studies have not found a link between acne and any type of food. (So chocolate is off the hook too.) Factors that cause acne or make acne worse include a genetic predisposition for acne, hormonal changes, taking certain medications and use of pore-clogging cosmetics.
Coffee and tea are dehydrating
A cup of tea or coffee will always hydrate you. Caffeine in very large doses can act as a diuretic, increasing urination. However, the amount of caffeine in tea or coffee is minimal, so the fluid intake more than makes up for any loss. One study compared men who drank four cups of coffee a day with a control group that drank only water. After analyzing volume of urine, kidney function and amount of water in the body, they concluded that the coffee drinkers were no more dehydrated than the water drinkers.
Coffee will sober you up
Alcohol is a depressant and caffeine is a stimulant, so it seems logical that one would counter the effects of the other. This might be true if alcohol only made you tired, but it also makes you intoxicated. Drinking relaxes inhibitions and affects motor skills, balance and reaction times. A study of mice given alcohol followed by caffeine found that while they did seem more alert, they were still much worse than sober mice at finding their way through a maze. Caffeine won’t sober you up. It will just make you a wide-awake drunk.
Chewing gum takes seven years to digest
Gum contains flavorings, sweeteners, softeners and gum base. The base is made up of indigestible natural or synthetic elastomers. A swallowed wad of gum is not broken down by the digestive system, but passes through the body and comes out in much the same shape as it went in. The process takes two or three days, not seven years. It’s still inadvisable to swallow gum. In rare occurrences, children have suffered from gum-based gastrointestinal blockages.
You can catch STDs from a toilet seat
It’s virtually impossible to catch a sexually transmitted disease like chlamydia or gonorrhea from a toilet seat. The disease causing organisms can only survive for a short time on the dry surface. Moreover, STD viruses cannot enter the body via the skin. Since your genitals are unlikely to be in contact with the toilet seat, you could only be infected through a cut or sore on your buttocks or thighs.