So where are these key nutrients to be found?

Below is our guide to the plant-based food sources of these key nutrients and what are the best sources of them at Grape Tree.

Apricots Apricots are rich in carotenoids including lutein and zeaxanthin that protect the macular from excess blue and ultraviolet light. But they are also a good source of the antioxidant vitamins A and C. Three or four dried apricots (the recommended portion size) contains over a quarter of your daily requirement for Vitamin C and almost as much Vitamin A. And of course, they count as one of your five a day, widely recommended as a basic of eye health. Among their array of minerals is the important zinc. Fresh vegetable sources of lutein and zeaxanthin are kale, spinach and broccoli.

Blueberries Research continues into the wide-ranging health claims associated with the anthocyanins found in blueberries, nutrients linked to their purple colour. But there is no question that they have those carotenoids lutein and zeaxanthin as well as zinc and the crucial Vitamins C and E. Half a cup of blueberries (around 50g) delivers a tenth of your daily Vitamin C requirement. Other good Vitamin C sources are cranberries and prunes.

Sunflower Seeds One of the top food sources of vitamin E is sunflower seeds. A handful, around 35g, supplies well over three quarters of your daily requirement. Which means the seeds are rated alongside green vegetables like spinach and asparagus as a top E food. A handful of almonds will give you almost half your daily needs and peanuts and cranberries are also sources.

Pumpkin SeedsPumpkin seeds are so rich in zinc they are recommended as a source by the World Health Organisation. A quarter cup, around 30gs or a good handful, will give you around a quarter of your daily zinc requirements. They also have Vitamin E and while not in great quantities it is present in five different forms. Experts believe that this diversity magnifies its impact. Also, among the top zinc sources are sesame seeds, lentils, cashews, quinoa and oats.

Walnuts Walnuts are a top source of alpha-linoleic acid (ALA) the plant-based form of the Omega 3 fatty acids that are already linked with heart health and reducing cholesterol levels in the blood. The Macular Society suggests walnuts and linseed as sources of Omega 3s. The DHA (docosahexaenoic acid) form of Omega 3 is found in oily fish. ALA can be converted to DHA in the body but the effectiveness of this process is unclear. Walnuts also have lutein and zeaxanthin. But the outstanding nut source of carotenoids are pistachios.