The potential olive leaf toxicity is not well researched. It has been shown that Oleuropein, one of the medicinally active compounds found in the leaves, is non-toxic to mice at dose up to 1 gram per kilogram of body weight.
A kilogram is equivalent to a little more than two pounds. So, we might be able to extrapolate this and say that 75 grams would be non-toxic to a human weighing over 150 pounds, but that is probably stretching it. It has been shown that a concentrated extract of 1000mg reduces blood pressure. Thus, there are warnings concerning olive leaf toxicity to persons with chronic hypotension or low blood pressure.
Low blood pressure is not a very common ailment. High blood pressure or hypertension is much more common. High cholesterol is also a common problem, particularly in the US. About 20% of Americans over the age of 20 have unhealthy cholesterol levels. Typically, the problem is low levels of good cholesterols (HDL) when compared with LDL or bad cholesterol. HDL carries bad cholesterol away from the heart and arteries, transporting it back to the liver for excretion or reuse.
Extracts from olive leaves and other plants, such as green tea, have been shown to lower total cholesterol count and improve the ratio of HDL to LDL. Omega 3 fatty acids from fish oil have similar properties, but fish oil should not be taken before surgery or in people that have a tendency to bleed freely, as it reduces clotting.
Extracts form olive leaves have also been shown to reduce blood glucose levels. Extracts from green tea have been shown to promote insulin sensitivity. Many plants have been used historically to treat type II diabetes, including Banaba, gymnema sylvestre and bitter melon. Curcumin, found in turmeric, also has proven benefits for that purpose.
But, while the effects of these plants would be advantageous to some people, it could be a cause for concern for hypoglycemic people, because their blood sugar levels are already low. So, while there is no evidence of any olive leaf toxicity, even at high doses for a healthy individual, those with health problems should carefully monitor their condition and use these plants sparingly.
For those of you that would rather use natural extracts instead of prescription drugs (which are typically accompanied by an array of unwanted side effects), your best choice is to consult with a Doctor of Naturopathic Medicine or an ND. An ND is aware of, and in some areas can prescribe drugs, but he or she is also familiar with the health benefits of botanicals and would better be able to evaluate the olive leaf toxicity for your specific condition.
There is one health supplement on the market that was researched and developed with the help of an ND, a nutritionist and a team of scientists. The daily dosage that they have come up with is 50mg per day to help strengthen the immune system and contribute to good health. With a dosage like that, there would be no need to worry about olive leaf toxicity.