I’ve always been told to drink lots of water and that would help with wrinkles, dryness and even acne, is this true?
Unfortunately the short answer is, we don’t know.
While popular beauty advice says, “Yes”, newer articles have cited a British paper which indicated that drinking more water provided no skin benefits. However when we look at the study itself the authors indicate that there isn’t enough research on the topic.
Approximately 40-75% of your body is water, 1/3 of this being extracellular and the rest intracellular. A 1% reduction in your body’s water content can cause thirst, and a 10-20% reduction can lead to death.
Water is gained from drinking and eating and is lost through the skin, the lungs and excrement. It’s important in temperature regulation, cardiovascular function, transportation of nutrients, waste removal and other important functions.
The stratum corneum, or outer layer of skin, is about 20-30% water, and a 10-20% loss can result in skin dryness causing reduced elasticity and increased skin roughness. If one becomes dehydrated, water is pulled from the blood and tissues (including the skin) for more important functions.
A survey of studies trying to determine a recommended water intake showed results between 1.8 to 5 litres daily. The common adage of 8 glasses daily would provide 64 ounces or just under 1.9 litres. More water is recommended for those living in warmer climates as those living in hotter climates can sweat as much as 4-7 litres a day. The National Research Council of the National Academy of Sciences recommends a water intake based on your calorie intake, they recommend 1-1.5 ml per calorie of food. So someone consuming a diet of 2000 calories daily would (according to their recommendation) require between 2 to 3 litres of water.
Unfortunately there aren’t many studies that examine the effect of water consumption and the skin, however I will review the two that I was able to find.
The first study performed in Germany, took a group of 93 subjects and had them drink either 2.25 litres of mineral or tap water daily. They were first monitored for 2 weeks to determine their average water intake previous to the study. As a group they found no cosmetic changes in the skin, though some individuals did have improvement in the smoothness of their skin. Those who drank mineral water experienced a decrease in skin density, a slight increase in skin thickness, no change in skin surface pH and a decrease in the circumference of their ring finger (a marker for water retention). Those that previously drank very little water experienced a greater increase in skin thickness. Oddly enough the people that drank tap water experienced the opposite, their skin became denser, less thick, and the acidity of their skin increased. There was no noticeable change in the circumference of their fingers, however.
The second study comes from Japan and is very small with only 18 subjects. The study specifically looked at the effect that 500 ml of deep sea water had on the skin of those suffering from excema/dermatitis compared to 500 ml of tap water. Both groups of patients with excema or dermatitis showed elevated levels of magnesium to potassium and calcium to magnesium ratios. With the group drinking deep sea water, the ratios returned to normal levels. As well those drinking deep sea water produced less anti-podies and inflammatory cytokines. No visual assessment of improvement was performed.
From the studies it seems like the important factor isn’t so much the amount of water consumed, but the minerals that the water contains – mainly magnesium and calcium. A study has shown that topical application of magnesium ions increased skin barrier recovery, and that this effect was accelerated when the magnesium to calcium ratio was lower. As well studies have used magnesium deficient diets in rats to induce an eczema like skin condition.
The difference in effects between mineral water and tap water is a bit confusing, and it’s hard to determine which result is actually better. For example with the use of an ingredient like alpha hydroxy acids, the skin’s density of collagen increases as does thickness. It’s doubtful that mineral water is inducing production of collagen and tap water is destroying it. Like the researchers mentioned it might have to do with mineral water increasing the extracellular water in the skin.
So drink away, if you’re dehydrated you probably will notice some visual improvement in your skin, but it’s unlikely that it will lead to a large improvement in the quality of your skin – though it won’t hurt.