The study, published in the journal Annals of Neurology, confirmed that colorful carotenoids prevented the onset of ALS, while diets high in lycopene, beta-cryptoxanthin, and vitamin C did not decrease ALS risk.
Carotenoids are what make fruits and vegetables a bright red, orange, or yellow color, and are a dietary source of Vitamin A.
Earlier research reported that oxidative stress contributes to the development of ALS. Other research has shown that people with high antioxidant intake, such as vitamin E have a decreased risk of ALS. Carotenoids and vitamin C are antioxidants, therefore the researchers decided to analyze their link to ALS risk.
What is ALS?Around 20,000 to 30,000 Americans have ALS - commonly known as Lou Gehrig's Disease. Additionally, thousands of patients are diagnosed each year with the disease, according to the National Institutes of Neurological Disorders and Stroke (NINDS).
ALS is a progressive disease that attacks nerve cells (neurons) in the spinal cord and brain, which dictate the actions of voluntary muscles. When the lower and upper motor neurons deteriorate the muscles they influence slowly break down and waste away, resulting in paralysis.
Senior author Dr. Alberto Ascherio, Professor of Epidemiology and Nutrition at Harvard School of Public Health in Boston, Mass, said:
"ALS is a devastating degenerative disease that typically develops between the ages of 40 and 70, and affects more men than women. Understanding the impact of food consumption on ALS development is important. Our study is one of the largest to date to examine the role of dietary antioxidants in preventing ALS."The risk factors for ALS include:
- Age - after 40 years the risk is higher.
- Sex - men are at risk more than women.
- Military experience - studies have shown those with a military background are at a higher risk
- Professional football - studies show that professional football players are at a higher risk of dying from ALS and other neurodegenerative diseases.
Colorful Fruits and Vegetables Decrease ALS RiskThe researchers used data from five different groups:
- the National Institutes of Health (NIH) - AARP Diet and Health Study
- the Cancer Prevention Study II-Nutrition Cohort
- the Multiethnic Cohort
- the Health Professionals Follow-up Study
- the Nurses' Health Study
Researchers revealed a higher total carotenoid intake was associated with decreased risk of ALS. People with extra carotenoids in their diets were found more likely to exercise, have elevated vitamin C intake, take vitamin C and E supplements, and have an advanced degree.
They also found that participants with diets high in carotene and lutein - commonly present in dark green vegetables - had a decreased risk of ALS. Investigators did not however, find that lycopene, vitamin C and beta-cryptoxanthin reduced the risk of ALS. Vitamin C supplements taken over a long period of time were also not linked to reduced ALS risk.
Dr. Ascherio concludes, "Our findings suggest that consuming carotenoid-rich foods may help prevent or delay the onset of ALS. Further food-based analyses are needed to examine the impact of dietary nutrients on ALS."