There are certain foods that are known to boost the downside area but I don't think just eating a lot of those foods are gonna make much of a difference. But without knowing exactly how bad your situation is I could be very well wrong here.
However what I would do is to aim to eat an overall healthy and balanced diet. There are also certain vitamins that are known to be beneficial for improving these symptoms like zinc and b vitamins. L-arginine which is an amino acid and a pretty popular supplement can help increasing blood flow.
And lastly lifestyle is another huge factor. Be active, try to minimize stress, get enough sleep and all that good stuff.