(NaturalNews) Zinc and copper are considered trace minerals, which means that they're necessary for metabolic activity in smaller amounts than macro minerals such as magnesium, potassium and calcium. That doesn't negate the importance of trace minerals, though, which also include iron, iodine and selenium.
Any deficiency or excess of either zinc or copper creates problems that can be severe. And those two trace minerals in particular are expected to maintain a delicate blood serum balance with a zinc to copper ratio that favors zinc.
One source  claims that an ideal ratio would be 0.7 copper to 1 zinc, or slightly less copper than zinc. But the ratios should never exceed one to one or become top heavy with copper.
The health implications of excess or deficient copper and zinc are many. But excess copper or copper toxicity often leads to a zinc deficiency. Conversely, inadequate zinc blood levels can lead to copper toxicity. It appears to be that the easiest supplemental approach for maintaining this balance would be with zinc as the lever, since copper rises with lower zinc levels.
There are several tests, blood draw serum measurements, hair analyses and others that help determine your copper/zinc levels and ratios. 
A study linking low zinc and copper to heart disease
A 2007 Iranian study that linked lower copper and zinc levels to coronary arterial disease (CAD) measured serum copper, zinc, fasting lipid profiles and blood glucose levels of 114 patients (67 male and 47 female) undergoing routine coronary angiograms. An angiogram is an X-ray of blood vessels' blood flow to determine if there are any obstructions.
Actually, the researchers had already done their homework on clinical and study determinations with Western populations that linked copper/zinc metabolic issues to heart disease. But apparently they were curious to see if those issues affected Iranians similarly and if there were differences according to gender.
All the subjects, male and female, whose angiograms displayed some level of CAD had lower levels of both zinc and copper. The males who were examined had higher zinc to copper ratios, which is expected, since elevated or upwardly imbalanced copper induces estrogen production, and zinc is essential for testosterone production. 
Other health issues attributed to zinc deficiency and excess copper
Some studies have associated high copper and low zinc to dementia, Alzheimer's and other mental disorders. Though copper is vital for certain metabolic functions, levels too high or out of balance with zinc will produce copper toxicity.
According to nutritional and metabolic typing expert Michael McEvoy, zinc toxicity is possible, but copper toxicity is far more common. Excess copper will deplete zinc, as these two trace minerals are antagonistic.
That's why the balance is necessary, as copper is a pro-oxidant that will increase free radicals. Some recommend increasing glutathione production and vitamin C levels to counteract copper toxicity.
From McEvoy: Problems associated with copper toxicity include: pyrrole disorder, estrogen dominance, schizophrenia, depression, anxiety disorder, chronic fatigue, migraines, liver toxicity, thyroid conditions, chronic candida yeast infections, PMS, to name a few. Some research has even implicated copper toxicity with Alzheimer's Disease and with cardiovascular disease. More details from Michael McEvoy are in source .
Sources of excess copper can include copper piping in plumbing and tubing for refrigerator ice cube makers. Anything that contributes to excess estrogen can influence higher copper levels also. Birth control pills and copper IUDs (intrauterine birth control devices) can also induce copper toxicity.
Similar to macro-mineral magnesium deficiency, much of the population tends toward zinc deficiency. It's wise to supplement zinc and/or eat foods high in zinc. And there are several environmental factors and food factors that increase copper levels to excessively antagonize zinc levels. More in source .