In the news: Vitamins C & E and Parkinson’s; Flavonoids Tied to Lower PAD Risk

Vitamins C & E Tied to Lower Parkinson’s Risk

Parkinson's disease, characterized by progressive loss of coordination and movement, is a nervous system disorder that affects mostly dopamine-producing nerve cells in the substantia nigra area of the brain. Dopamine is a neurotransmitter that carries signals between nerve cells and is involved in regulating movement.

Oxidative stress plays an important role in the degeneration of dopamine-producing neurons in the substantia nigra. Antioxidants are believed to help counter oxidative stress that can lead to this loss of dopamine. A new study from Swedish researchers suggests that long-term intake of antioxidant vitamins C and E may lower the risk of developing Parkinson’s(1).

The researchers collected diet, health and lifestyle information from over 41,000 men and women who were free of Parkinson’s disease at the study’s start and were followed for an average of about 18 years. The participants intake of vitamins C and E and beta-carotene was assessed. The relationship between total (nonezymatic) antioxidant capacity (NEAC) of the diet and Parkinson’s risk was also analyzed.

Comparing participant groups with the lowest versus highest intake of C or E, they found that higher intake was associated with a 32% reduction in risk for Parkinson’s. Those who consumed the highest level of both vitamins together had a 38% risk reduction. No association with Parkinson’s risk was seen with dietary beta-carotene consumption or NEAC.

While the findings hold promise, one limitation of the study was that the dietary information was collected only at the beginning of the study. This does not ensure that people had not changed their diet over the course of the study. Nonetheless, it is possible that focusing on vitamin C and E-rich foods might help lower the risk of developing this disease later in life.

Sunflower seeds, almonds, spinach, avocados, squash, kiwifruit, trout, shrimp, olive oil, wheat germ oil, and broccoli are some of the foods high in vitamin E. Good sources of vitamin C include guavas, bell peppers, kiwifruit, strawberries, oranges, papayas, broccoli, tomatoes, kale, and snow peas.

Flavonoids May Help Protect Against PAD

Peripheral artery disease (PAD) is a common circulatory problem in which narrowed arteries reduce blood flow to the limbs – the arms, but most often the legs. Atherosclerosis is the most common cause of PAD, meaning that plaque has built up inside the artery walls.

Danish researchers recently analyzed data from 55,000 + participants of the Danish Diet, Cancer, and Health Study without PAD to see whether there is a relationship between intake of dietary flavonoids and hospitalizations for PAD(2).

The participants were followed for approximately 21 years, during which 2,131 had been hospitalized for the condition.

Compared with the lowest flavonoid intake (174 mg/day), an intake of 1000 mg/day was linked with a 32% lower risk of any PAD hospitalization, a 26% lower risk of atherosclerosis, a 28% lower risk of an aneurysm and a 47% lower risk of a hospitalization for other peripheral vascular disease.

While more research is necessary to determine whether flavonoids may help protect against PAD, these compounds have been shown to improve the function of the lining of arteries (endothelial function) and decrease inflammation and blood pressure. These healthy compounds are abundant in foods and beverages such as fruits, vegetables, dark chocolate, tea, and red wine.

References

1. Hantikainen E, et al. Dietary antioxidants and the risk of Parkinson Disease: The Swedish National March Cohort. Neurology. Epub Jan 6, 2021.
2. Bondonno P, et al. Higher habitual flavonoid intakes are associated with a lower risk of peripheral artery disease hospitalizations. Am J Clin Nutr. 113:187-199, 2021.