5 Things That Are Awful For Your Hair
Fish
Wait, what?! Aren’t fatty fish like salmon and tuna-rich in omega-3s and at the top every must-eat list? Only to a point. Some fish contain high levels of mercury, which can lead to hair loss– given in high doses. Mercury disrupts protein development and affects your absorption of zinc (which is essential to keratin formation)—all of this interferes with the growth process. Steer clear of swordfish and mackerel (both have high mercury levels), and don’t forget to choose the “light” varieties of canned tuna, salmon, and shrimp to keep your mercury consumption down. According to the FDA, as long as you eat no more than 12 ounces weekly and get your sushi fix fewer than four times a week, your health and your hair will stay out of trouble.

Processed Sugars
Processed sugars are bad for your skin and hair. No surprise there. Sugary foods like your favorite candy and cupcakes cause insulin levels to rise, which causes a male hormone to increase. Androgen, in high levels, produces unwanted hair growth in women. It also is known to irritate and shrink hair follicles. Irritated hair follicles do not produce long, strong hair.
Juice Cleanses
When you’re on a juice cleanse, you’re on an all-sugar, no-protein diet. In other words, you’re spiking your insulin and androgen levels (which usually leads to hair thinning and loss). All that sugar is creating a great deal of inflammation in your body—which isn’t good for anything, hair included.
Low-Protein Foods
Your hair is made of proteins, which is needed to grow healthy and long locks. Starches like white bread, pasta, and a lot of cereals can be low in protein, which will leave your hair limp and unhealthy. These foods also tend to be high on the glycemic index, and high sugar and low protein are not a good combo. That bounce and shine you want are impossible without a healthy dose of protein.
Vitamin A
Chances are your diet isn’t abnormally high in vitamin A, but if you’re taking multivitamins or a vitamin A supplement, you may want to rethink that. While generally a good nutritional addition, vitamin A is toxic to hair follicles in high doses. An overload of Vitamin A will shrink your oil glands to the point that they’re no longer producing the amount of oil necessary to nourish your strands, leading to hair loss.