It may not be correct to generalise things so easily. Hypertension occurs primarily due to stiffening of arteries and functioning of kidneys. Plus there is a strong genetic predisposition in hypertension. Point is that an increased resistance to the flow of blood caused by stiffened arteries leads to back pressure on heart, which can lead to malfunction of heart over a long period of poorly monitored BP.
Unfortunately there is no way stiffened arteries can be again made soft so as to reduce BP. It’s an irreversible process just like white hair and freckles of skin are irreversible.
Medical science is a cumulative science based on gradual addition of evidence based understanding of human body. It may not be correct to say that herbal remedies (including mint leaves and black pepper) have not been evaluated by scientific organisations like Indian Council of Medical Research (ICMR) and their equivalents in various countries around the world. Only alkaloids that are found to consistently show beneficial effects are adopted in the medical practice. In fact a lot of allopathic medicines have been discovered through herbs and Ayurveda. When a herb is found to have a statistically proven beneficial effect in a certain medical condition, researchers study it’s alkaloids in lab, try to produce those alkaloids in lab in pure form in exact quantities (that is why allopathy talks about milligrams and micrograms).
While mint leaves and black pepper are healthy ingredients for food, there is no consistent scientific evidence that these can control BP on their own. Current medicines prescribed by doctors for BP are extremely safe. Rather leaving the BP unmonitored has side effects in the form of permanent changes in the heart, kidneys and other organs due to increased back pressure of stiffened arteries.
The bottom line is BP should be monitored and appropriate medication should be started so as to avoid permanent damage to heart.
Regular walking and reduced intake of salt definitely help in keeping the BP in check, but as age progresses, these measures alone are not enough. There is no point in denial to accept that I have BP or that I will first try all non medical therapies. This way unnecessarily you will end up wasting 2-3 years in trying unproven therapies and unnecessarily put your heart to risk. It’s like saying I need a mobile or a car, so first I will try to make one myself !