Lutein (and its companion zeaxanthin) is best known for promoting eye health. It is a “carotenoid” which is found in plants, and typically lacking in the standard American diet, as Americans only average one-sixth of the amount needed to reduce risk of certain eye conditions. Lutein is not synthesized in the body and must come from the diet.
For those who wish to avoid typical effects of aging, improving lutein intake is vital, as it accumulates in tissues, particularly the eye.
A Harvard Medical School study found a risk reduction for AMD (age-related macular degeneration) of 40% for both men and women ingesting high quantities of lutein/zeaxanthin. A Neurobiology of Aging study showed a direct correlation of low carotenoid concentration in the eye to lower cognitive (thinking) function.
Lutein appears to protect against a number of health issues:
- Atherosclerosis, the plaque buildup in blood vessels that can lead to heart attack or stroke
- Chronic inflammation
- Oxidative stress (free radical damage)
- Ultraviolet (UVB) skin damage
- “Blue light” (high frequency light) eye damage
- Poor cognitive function
- Cataracts and AMD (age-related macular degeneration)
The science behind the benefits
Lutein’s chemical structure is complex, and only synthesized by plants. It contains a long carbon chain of conjugated (alternating single and double) bonds — this bonding in carotenoids gives fruits and vegetables their color. Dark green leafy vegetables, such as spinach, swiss chard, and kale, are the best common sources of lutein. Lutein accumulates in the eye, and the conjugated bonds absorb high energy “blue light”, protecting the eye from damage that leads to cataracts and AMD. As an antioxidant, it grabs free radicals before they can attach to other molecules and set off a chain of free radicals that cause damage.
How to maximize lutein from food
Spinach is the most popular source of lutein, although kale and swiss chard are also good. A study at Linköping University considered the effects of various preparation techniques on the availability of lutein. The researchers found:
- Heating degrades the lutein, and high heat drastically reduces available lutein.
- Breaking/chopping the leaves releases more lutein and adding the amount one can absorb
- Added fat aids absorption
Lutein is fat-soluble, so combining it with a good fat such as avocado is beneficial. Creating a smoothie with raw ingredients in a commercial grade blender is the most effective combination. Only spinach was studied, but chard and kale are relatives and should release lutein similarly.
Shopping and growing
Spinach is particularly susceptible to degradation in stores. Leaves compressed together in packaging rot easily. Look for perfect dark green leaves throughout the package with no discoloration. Kale and swiss chard are less prone to rot because the leaves don’t compress as readily, but discoloration is a sign of poor quality. Of course, the best quality comes from picking it fresh, which is a good reason to grow it yourself. Spinach is a smaller plant and easily grown, especially in the spring, and along with kale and swiss chard it can withstand frost.
This study found that cooking the spinach denatures the proteins and causes a dramatic reduction in the bioavailability of the lutein. So to get the most active and useable amount of lutein into your cells you want to blend your spinach with avocado and eat it within 15 minutes from the time of blending. Food is your medicine. This is because it is a natural pharmacy of phytochemicals with no dangerous side effects. So blend your raw greens or juice them but definitely do not cook them.