 [ Symptoms ] how effective are natural remedies for colds such as zinc echinacea and vitamin c [ Disease ] some studies show that zinc nasal sprays help cut a cold is severity and duration but other studies show that zinc is no more effective than placebo recent well done studies on echinacea show that it is not effective in preventing colds researchers have found no evidence that vitamin c prevents colds however they did find evidence that vitamin c may shorten how long you suffer from a cold to prevent colds the natural way make sure you have got a well nourished immune system dark greens foods like spinach are loaded with vitamins a and c salmon is a great source of omega 3 fatty acids which fight inflammation low fat yogurt may help stimulate the immune system regular exercise    aerobics and walking    also boosts the immune system