When it comes to hair growth, nutrition plays a role that’s important but not exclusive.

Most people can improve their hair growth through better nutrition, although genetics plays an important role in regulating a variety of observable hair traits like color, length, and thickness. And underneath the skin it’s also deeply influenced by small differences in hormone regulation, which can be influenced but not completely controlled by nutrition.

But nonetheless, improvements to the diet can usually yield better hair for most people.

Let’s take a look at the mechanics of what your hair is, why it grows, and the foods you can eat to make it look better.

What Your Hair Is, And How It Grows

The hair you feel on your head and skin is an elongated piece of dead protein called Keratin that’s covered by an oily, waxy sheath made up of an fatty substance called sebum.

Since these substances are literally dead, anything you eat doesn’t influence the state of the hair directly. Underneath your skin is a biochemical complex called a follicle that’s responsible for scooping up nutrients from the bloodstream and packaging together the cells and proteins necessary to form your hair.

Providing your follicles with adequate starting materials for your hair is the key role in nutrition for hair growth.

Hormones And Your Hair: They’re Very Important

In addition to the follicle, the other key player affecting the growth of your hair is the balance of different hormones in your body. Different growth hormones are responsible for synthesizing different precursors for hair growth which are secreted in and around the follicles when hair is formed.

The balance of estrogen and testosterone is an important regulator for hair growth. Testosterone tends to slow hair growth, and estrogen stimulates it. The increased presence of testosterone in males is one of the reasons why men tend to have shorter hair and are more likely to suffer from baldness.

Part of the role nutrition plays in hair growth is supplying the body with the nutrients needed to convert and regulate hormone levels in th body as needed.

A Healthy Diet Means Healthy Hair

When you eat different nutrients, your body doesn’t immediately target it for a specific body part.

Instead, it pools its available nutrients together and based on its needs at that time appropriates nutrients where they’re most needed.

So if your diet is lacking in general, the iron, zinc, and biotin that it needs for hair growth will be used for more vital bodily functions, whether you want it to or not.

So eating for healthy hair and just plain “eating healthy” are practically one and the same. The biggest difference is that a “healthy hair” will place an emphasis on certain nutrients moreso than a reguar meal plan.

Exercise Is Crucial For Healthy Hair

The nutrients your body needs for hair growth are scooped up by your follicle from the bloodstream. Thus healthy circulation is essential for good hair growth. The most important determinant affecting your blood circulation is the amount of cardiovascular exercise you get on a regular basis.  For this reason anybody looking to improve their hair should also make it a point to exercise regularly.

High blood pressure, cholesterol, and diabetes are also impediments to healthy circulation.  Thus a diet that’s low in fat, high in fiber, and low calorie will help promote healthy hair, even though none of these qualities are directly responsible for hair growth itself.

Supplements, Nutrients and Hair Growth: Can You Over Do It?

If you stroll into GNC or another health food store you can usually find a supplement or two that are designed to promote healthy hair.

Should you consider buying one of these?

In my opinion it’s not necessary, although it wouldn’t hurt.

If you buy a supplement without making the necessary changes in your eating habits you are only avoiding the root causes (no pun intended) of your unhealthy hair, and probably spending more money than is necessary.

The same money you might spend on an expensive supplement would be better spent on a new pair of running shoes, a good cut of salmon, or some flaxseed oil to put on your salad.

The Six Essential Nutrients for Hair Growth

With all of that being said, let’s take a look at the six nutrients that your body uses most frequently for growing and nourishing your hair, and where they’re typically found.

Vitamins A and C: These two nutrients are important because they’re used as the building blocks of sebum, the substance that coats the outside of your hair follicles.

Food Sources: Most fresh vegetables provide an abundant supply of both vitamin A and C. Any you get at the grocery store will probably do.

Biotin: Also known as B7, biotin is used to synthesize Keratin Growth Factor, the hormone your body uses to synthesize Keratin, the protein that comprises the fibrous parts of your hair.

Food Sources:  beans, eggs, beef

Protein: Your hair is primarily a stick of protein with some hardened fatty acids coating it. Thus adequate protein is important for healthy hair. The amino acid lysine is particularly important, since it’s commonly found in keratin.

Food Sources: Any natural food source has to have protein in it, since it’s the building block of all cells. Fish, lean meats, legumes, and soy are all good sources.

Omega 3 and Omega 6 Fatty Acids: Your sebaceous gland uses a variety of fatty acids to create sebum, and Omega 3’s and Omega’s 6’s are the building blocks used to create the shiny coat that makes hair smooth.

In particular, alpha lonoleic acid is particularly robust for synthesizing the waxy sheath that coats the outer part of your hair.

Food Sources: flaxseed, salmon, hemp, canola oil, olive oil, brazilian nuts, walnuts

Iron: Iron is the mineral your body uses to convert testosterone to estrogen, which is an important hormonal regulator of hair growth. As I mentioned before, estrogen stimulates hair growth, while testosterone impedes it.

Iron deficiency is a common reason people start to get flaky hair that starts to shed.

Food Sources: Beef, poultry, nuts and legumes

Zinc: Zinc is an important regulator of a variety of different growth hormones which your body uses synthesize hair growth.

Food Sources: Nuts and legumes, seafood (especially oysters and shellfish), beef and chicken, dark leafy greens

Being Vegetarian

When it comes to eating for hair growth, a vegetarian has a little bit to worry about. While it’s very possible to get all the nutrients listed above with no meat or dairy in the diet, they tend to dovetail towards those less common than in omnivorous diets.

So it’s very possible to promote hair growth with your diet, but you have to plan well. A diet that’s poorly conceived might leave your hair lacking.

The most common elixir to this problem is to make sure you eat a lot of beans, as they’re regularly a good source of nutrients that aren’t typically found in other vegetables. Sea vegetables and plant oils are a good idea too.

References:

Anne-Randall, Valerie. “Androgens for Human Hair Growth” Clinical Endocrinology, 1994.
URL: http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2265.1994.tb02483.x/abstract

Schweikert, Hans, et. al. “Regulation of Human Hair Growth by Steroid Hormones. I. Testosterone Metabolism in Isolated Hairs”  Journal of Clinical Endocrinology.
URL: http://jcem.endojournals.org/content/38/5/811.short

Beach, Renee, et. al. “Sebum Transforming Growth Factor Beta1 Induced by Hair Products” Archives of Dermatology.

URL: http://archderm.jamanetwork.com/article.aspx?articleid=1184372

Dobbs, Joannie, et. al. “Hair Loss For Women Has Many Contributing Factors” University of Hawaii.

URL: http://www.nutritionatc.hawaii.edu/HO/2010/447.htm

Lowe, John, et. al. “Zinc Source Influences Zinc Retention In Hair and Hair Growth In Dog” Journal of Nutrition.

URL: http://jn.nutrition.org/content/124/12_Suppl/2575S.full.pdf

Walvarens, Philip, et. al. “Growth of Infants Fed A Zinc Supplemented Formula” American Journal of Clinical Nutrition.

URL: http://www.ajcn.org/content/29/10/1114.full.pdf