Macular Pigment and Diet

Where do we get macular pigment (MP) from?

Lutein (L) and zeaxanthin (Z), two of the three components of the macular pigment, can be found in a variety of fruits and vegetables (e.g spinach, corn, peppers and most leafy greens). Meso-zeaxanthin (MZ), the third component of the macular pigment, is found in slightly unusual foods (such as salmon and shrimp).  However, lutein can also be converted into meso-zeaxanthin at the back of the eye. 

The importance of the last sentence is paramount. The body converts L into MZ. The body must have a good reason to do so, and it is thought that the reason is this : 

MZ is a more powerful neutraliser of free radicals than either L or Z.  Furthermore, the presence of MZ results in the filtration of a wider range of damaging blue light.  Moreover, MZ is more closely related to vulnerable photoreceptors in the eye than either L or Z, and is therefore ideally located to afford protection against free radical damage of these important cells of vision.

How much MP is enough?

The components of the macular pigment, lutein, zeaxanthin and meso-zeaxanthin, do not have an established recommended daily allowance (RDA) but doses up to 30 milligrams per day are generally considered safe and effective.

On average we consume only around 1.7 mg per day of lutein and zeaxanthin from our diets, considerably less than the amount needed to protect against free radical and light damage. Meso-zeaxanthin is not commonly found in a typical diet.

A diet sheet containing various foodstuffs can be downloaded by clicking here.

Other Beneficial Nutrients

Other nutrients that are beneficial in the protection against AMD include Vitamins C and E, beta-carotene and Zinc.

Vitamin C has an RDA of 90mg for men and 75 mg for women (To this, add another 35mg if you are a smoker.) The amount of people getting just the RDA is less than half and a beneficial level is more 250 mg.

Vitamin C has an RDA of 22 IU, while a beneficial level is 100 IU. Less than ten percent of people get their RDA!

While L and Z have no RDA, a beneficial level of these carotenoids is 6 mg. The average daily intake is only 1.7mg.

Beta-carotene also has no RDA, but an average intake of 1.9mg is a long way from the beneficial level of 15 mg.

Zinc has an RDA of 11 mg for men and 8 mg for women. Nearly half of the population do not receive their RDA, while a beneficial amount is up to 80 mg.

As you can see from these figures, we really don't get enough of these hugely important anti-oxidants in our normal diets.

Most fruits and vegetables are excellent sources of vitamin C, including oranges, grapefruit, strawberries and papaya, as well as green peppers and tomatoes.

Vitamin E is more difficult to obtain from food sources alone, since it is found in very small quantities in foods, such as vegetable oils, nuts and seeds. Good food sources include vegetable oils (including sunflower and corn oil), almonds, pecans, wheat germ, and sunflower seeds.

Beta-carotene is present mostly in dark green leafy vegetables, deep orange or yellow fruits and vegetables, and fortified cereals.

Lutein and zeaxanthin are found together in many food sources. Egg yolks, corn, and dark green leafy vegetables are the primary sources of lutein and zeaxanthin, but they are also present in lesser amounts in other colourful fruits and vegetables, such as broccoli, orange peppers, peas, and tangerines.

Good food sources of zinc include meat, liver, shellfish, milk, whole grains, and wheat germ.