The Food we eat and its affect on scalp health There is a saying: "you are what you eat." This saying has been distilled from French to German to English, and has had numerous meaning through the ages, but taken at face value, what you put into your body can determine our health and well-being . Recently a study to be described in this article was able to quantify this concept and tie it to a very common skin condition that affects many areas of the body—seborrheic dermatitis. When thinking about the scalp and health we should start by defining two of the most common conditions that can go wrong with your scalp. The most common ailment is dandruff. Dandruff is the flaky, itchy condition that comes from excess sloughing of skin cells from the scalp. A more irritated state with more flakes, scales and redness is seborrheic dermatitis. Whereas dandruff is limited to the scalp, seborrheic dermatitis affects the scalp, eyebrows, behind the ears, on the folds between the cheeks and the nose, and in the folds of the armpits and the groin. This frustrating scalp condition, commonly referred to as 'Cradle Cap' when present on babies, is best treated by applying a medicated baby shampoo for cradle cap and seborrheic dermatitis. People of all ages, literally from infancy (every heard of "cradle cap") through to middle ages and the elderly, and both genders are affected by both of these conditions. Until recently the most commonly thought of factors contributing to dandruff and seborrheic dermatitis was: -hormones in infancy and puberty -yeast like fungus (Malassezia species) that lives on almost everyone's scalp, -diseases of immunodeficiency (HIV for example) -neurologic conditions like Parkinson disease. -food?... I always tell patients, in general, to be healthy you should always eat well balanced meals. A healthy plate of food includes fresh fruits and vegetables as well as protein and grains. Eating well does great things for all the organs in your body—remember skin is also an organ. Recently a group of authors (Sanders et. al.) were able to quantify the effects of a healthy diet and its effects on the scalp. These authors hailing from The Netherlands and the UK recently published an interesting article in The Journal of Investigative Dermatology that looked at diet and its relationship to seborrheic dermatitis . To conduct this study they looked at something called The Rotterdam Study, a study that looked at people in the Netherlands in real time over almost 2 decades to look at factors that may be determinants of disease . The Rotterdam study itself recruited over 15,000 subjects but for this study the authors looked at 4,379 of these subjects and 636 (14.5%) of them had seborrheic dermatitis. What they found was that those subjects with high fruit intake had a 25% lower risk of having seborrheic dermatitis and those having a "Western" fat-rich diet had a 47% increased risk of getting seborrheic dermatitis . Fascinating!! References: \t“You are what you eat.” The Phrase Finder. https://www.phrases.org.uk/meanings/you-are-what-you-eat.html Accessed 2 April 2020 \tSanders, MGH, et. al. Association between Diet and Seborrheic Dermatitis: A Cross-Sectional Study. J Invest Dermatol. 2019 Jan;139(1):108-114. doi: 10.1016/j.jid.2018.07.027. Epub 2018 Aug 18. \t“The Rotterdam Study.” University Medical Center Rotterdam. http://www.erasmus-epidemiology.nl/research/ergo.htm . Accessed 2 April 2020.