A new study published in the journal Atherosclerosis earlier this month indicates that Vitamin C supplementation benefits heart health, and that its positive effects are most helpful for those with type 2 diabetes, hypertension and high cholesterol (1).
The study, a meta-analysis carried out at Newcastle University, analysed data from 44 clinical trials, and concluded that Vitamin C has positive benefits on endothelial function.
The endothelium is the inner lining of blood vessels which, in a healthy body, works to assist the immune system and regulate blood clotting. It also expands and constricts, helping to regulate blood pressure.
Endothelial dysfunction is linked to diseases such as type 2 diabetes, hypertension and high cholesterol. Unfortunately these conditions are becoming increasingly common. Currently, around 30% of men and women in the UK have hypertension, and more than 50% have raised cholesterol levels.
The endothelium can be compromised by oxidative damage and inflammation as a result of infections, smoking, or an inflammatory diet loaded with sugar and trans fats. If the endothelium ceases to function properly, there can be serious health consequences, including atherosclerosis, stroke and heart attack.
There appear to be two ways that Vitamin C works to improve heart health. Firstly Vitamin C is an effective antioxidant, quenching oxidative damage to the endothelium. Secondly, this particular vitamin increases the availability of nitric oxide, a molecule that improves blood flow by causing blood vessels to relax.
The researchers found that higher doses of Vitamin C were linked with ‘significant improvement’ in endothelial function, with doses of 500mg and above showing the most benefit. The strongest benefits were seen in people with atherosclerosis, diabetes and heart failure.
For those interested in boosting Vitamin C levels, the best way to increase your vitamin C intake is by incorporating plenty of fresh fruit and vegetables throughout the day. While oranges can provide a reasonable dose of vitamin C, other fruits and vegetables contain far greater amounts. See below for the richest sources. You can also boost your nitric oxide levels by eating a large leafy green salad every day. Spinach, arugula and beetroot are particularly good sources. Finally a healthy lifestyle is essential in protecting cardiovascular health, as regular exercise, weight loss and smoking cessation can all help to improve endothelial function.
Top 10 sources of vitamin C
|Food (100g serving)||Vitamin C (mg)|
|Red bell pepper||280|
1. Ashor AW, Lara J, Mathers JC, Siervo M. Effect of vitamin C on endothelial function in health and disease: A systematic review and meta-analysis of randomised controlled trials. Atherosclerosis. 2014 Jul;235(1):9-20