Intimacy is an essential social nourishment requirement for human beings. Trust, vulnerability, and a continual proportionate bidirectional flow of nourishing actions toward one another in the context of that intimate communal membrane are essential for intimacy to develop to full maturity. Except for developing children, relationships characterized by lopsided giving or taking cannot result in intimacy. This is why children who are not properly weaned or falsely believe their role is only to serve the needs of others are not able to cultivate fulfilling intimate relationships.
Here are some links to studies on the link between health and relational deprivation.
Social deprivation and premature mortality: regional comparison across England. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1679128/
Adding social deprivation and family history to cardiovascular risk assessment: the ASSIGN score from the Scottish Heart Health Extended Cohort (SHHEC) http://heart.bmj.com/content/93/2/172.short