Goji berries may help shield the brain from Alzheimer's disease, according to a recent study. In test-tube experiments, scientists found that extracts of the antioxidant-rich fruit could defend against brain-cell damage induced by homocysteine (an amino acid shown to increase Alzheimer's risk when it occurs at elevated levels in the blood).

Previously published test-tube studies show that goji berry extract may help prevent the growth of cancer cells, keep blood sugar in check, and lower cholesterol levels. However, very few studies have looked at goji berries' effects on human health.

It's too soon to tell whether eating goji berries could help protect against homocysteine's harmful effects on the human brain. To reduce your Alzheimer's risk and preserve your brain health as you age, focus on following a balanced diet, getting plenty of exercise, staying mentally active, and maintaining healthy blood pressure and cholesterol levels.

High levels of vitamin D may be linked to lower risk of colorectal cancer, the fourth most common cancer in the United States.

In a new study, researchers found that participants with the highest levels of vitamin D in their blood had up to a 40 percent reduced risk of colorectal cancer (compared to study members with the lowest vitamin D levels). The study included 1,248 people diagnosed with colorectal cancer, as well as 1,248 people who were free of the disease.

In previous research, scientists discovered that vitamin D may help prevent colon cancer by aiding the body in eliminating a highly toxic substance known as lithocholic acid. Since it's difficult to obtain your recommended daily intake of D solely through dietary sources, many medical experts recommend increasing your vitamin D levels by taking a dietary supplement.

Practicing Zen meditation may help thicken certain brain regions and lessen your sensitivity to pain, according to a new study.

For the study, researchers recruited 17 meditators and 18 non-meditators. To measure the participants' pain sensitivity, the researchers applied a heated plate to each individual's calf. In analyzing brain scans of the study members, they found that brain regions involved in regulating pain and emotion were significantly thicker in those who practiced meditation.

In past research, scientists have found that meditation could help improve pain management for people with coping with chronic pain. In particular, meditation has been found to lessen pain and reduce stress in people dealing with conditions like low back pain and fibromyalgia.

A number of other mind-body techniques (including tai chi, guided imagery, and yoga) may also benefit people struggling with chronic pain conditions.

Preliminary research suggests that green tea could help shield your eyes from the harmful effects of glaucoma. In a study on rats, researchers determined that green tea consumption helped defend the animals' eyes from free-radical-induced damage.

A leading cause of blindness in the U.S., glaucoma develops when fluid pressure builds up in the eyes and impairs the optic nerve. Past research shows that oxidative stress (a process that occurs when free radicals overwhelm the body's ability to neutralize them) may contribute to the onset of glaucoma. Known to knock out free radials, antioxidants are abundant in green tea.

In their new study, scientists demonstrated that drinking green tea can help deliver antioxidants to eye tissues and possibly protect against oxidative stress. However, it's too soon to tell whether green tea consumption could have the same effect on human eye health.

In previously published studies, investigators have found that the herb ginkgo biloba may also benefit people with glaucoma.