Antony Hewish

In a Harvard University study, the diets of nearly 1,000 women were analysed before their morning melatonin levels were measured. Meat consumption was the only food significantly associated with lower melatonin production, for reasons that are as yet unknown.

Personally, I like to juice up several different kinds of fruit and vegetables - which may include various combinations of bananas, red bell peppers, apples, carrots, celery, broccoli, spinach, parsley, tomatoes, cucumbers, etc.