Is that statement inclusive of ALL supplements?
No, absolutely not. Supplements can range from superfoods (a class that can include things like chia seeds, which is a commonly eaten food in some cultures) to nutraceuticals (a class which includes isolated chemicals) to active hormones (e.g., melatonin, which is sold as a dietary supplement in some countries, including the USA). I believe the original statement was specifically qualified to apply to natural, full spectrum supplements only, and then it would still not apply to every single product in that class.
I have seen no research or papers that supported this statement.
As you pointed out, finding high quality peer reviewed papers on this subject is difficult. Not many medical scientists study hypotension management. (As a funny aside, the word hypotension was not even in my computer's default spell check dictionary, thus it showed as an error and hypertension was suggested as the correct spelling.) The main research focus is on hypertension management, and it leads to research that has a narrower perspective than this topic, which is how to normalize blood pressure that is either too low or too high.
Even though much published research has a specific narrow and directional focus, the fundamental concepts underlying this statement are present in all biology and physiology text books. See next comment.
What is the rationale for that statement?
Good question. The rational for the statement that some natural treatments can help the body normalize blood pressure when it is either too low or too high is based on the fundamental nature of how the body works: homeostasis.
Homeostasis is the self-regulating process by which living things regulate their internal environment to keep processes within the range necessary to sustain life. All living things do this and all living things have extensive mechanisms to facilitate it. It's very natural.
However, much research conducted from the perspective of allopathic medicine ignores this perspective. The allopathic approach is generally to look for a way to force a physiological system to move in a single direction. But entire medical systems (Traditional Chinese Medicine, Ayurveda, etc.) are built around the concept of supporting homeostasis (supporting the body's natural healing tendencies).
Disclaimer: all of this is written off the top of my head. If anyone finds peer reviewed publications that either support or refute anything here, please share the citations and I will edit this answer.
Can you also provide an analogy?
If you have a intelligently flexible pipe (imagine a blood vessel) that conducts a fluid of varying pressure, the pipe can increase in diameter when the pressure increases, thus offsetting that increased pressure. If the pressure drops, the pipe can contract to increase this pressure.
If the ability of this pipe to grow or shrink is compromised or lost, the pressure will tend to both go too high and too low. In physiological terms, homeostasis will be disrupted.
Also, if the pipe's ability to accurately sense the pressure inside is reduced or lost, homeostasis will be disrupted.
If the normal limits are disrupted (which chronic stress can do, for example), homeostasis will again be disrupted. (Normal limits are the end points of the normal range of any physiological process, and many lifestyle factors can disrupt them. In other words, the body can temporarily become confused or misled about what value equals abnormally low or high pressure.)
Think about your home thermostat. The settings on a home thermostat that control when the heat is turned on or when the air conditioning is turned on. If a someone alters those settings, the house will no longer stay at a comfortable temperature. That's an example of the normal limits being disrupted.
Moving beyond the analogy, there are multiple causes of hypotension which can include cardiac insufficiency, reduced intravascular volume (e.g., from dehydration or adrenal insufficiency), and inappropriate vasodilation.
Possible adrenal insufficiency is the rationale for adaptogenic herbs. Possible cardiacinsufficiency is the rationale for heart tonic herbs (e.g., hawthorn berry).
Examples of supplements that may help normalize blood pressure.
Given that all of this is based on limited evidence from traditional medical systems with very little controlled clinical research, be cautious in your use of these supplements for this purpose.
Note that qualifications apply to all these supplements and anything else that works by supporting the body's homeostasis. They work gently, they time time to show results, and they rarely (never?) push a physiological system outside of its normal limits, unlike pharmaceuticals. and some nutraceuticals. Also, a combination of treatments is generally necessary, and lifestyle factors, such as stress management and exercise, are usually essential. If the body is no longer maintaining normal blood pressure, the cause is likely not one simple thing. If you consider the analogy above, there is likely some loss of blood vessel elasticity / flexibility, some alteration of the definition of normal limits, and some disruption of the sensing accuracy, all present at the same time. It is likely to be a complex issue and resolving it naturally is likely to require a comprehensive approach.
ELEUTHERO: An adaptogenic herb that is used to increase circulation, among other things. It is said to raise blood pressure over time is some individuals. However, many experienced herbal practitioners report that it can lower or raise blood pressure, depending upon what the patient’s body needs.
GINSING: This herb can lower blood pressure with low to normal dosages, but it has been used in Chinese medicine (at higher doses) to increase blood pressure in specific situations. (Most experienced herbal practitioners will caution you not to experiment with high doses of any herb without professional training and experience.)
Almost any adaptogenic herb is worth further researching for this purpose. Some others include rhodiola, ashwaghanda and astragalus. There are many more.
HAWTHORN BERRY: Hawthorn is the premiere tonic herb in Western herbal medicine for the entire cardiovascular system. It is said to reduce inflammation in the blood vessels, protect against hardening of the arteries, reduce blood pressure if it is elevated, open blocked circulation, and protect against heart attacks. But it is often prescribed by herbal practitioners to manage hypotension (but evidence supporting that use is very limited). As stated above, its use would seem to be supported if the hypotension is related to cardiac insufficiency in some way, although hawthorn could potentially work by other mechanisms.
MAGNESIUM: this is a mineral, not an herb. But a number of experienced alternative medicine practitioners have reported that magnesium is able to normalize blood pressure. I am not aware of any peer reviewed study to support this claim, however.
BEETS: we have all heard about the benefits of consuming beets for high blood pressure, but some traditional medical systems tout them for their ability to correct hypotension too. I am aware of published studies that seem to contradict this statement. However, the studies I am familiar with all have design limitations that prevent us from being able to draw a solid conclusion about the effect of beets on normalizing hypotension.
Beets are one of the remedies I explored 15 years ago. I still consume beets today. I cannot offer proof that they help raise low blood pressure, but my subjective feeling is that they may help. They are also a healthy and tasty food, so there's little downside.
Managing My Blood Pressure and Eye Pressure While Sleeping | FitEyes.com
Beets are said to help circulatory problems, improve low blood pressure, and alleviate eye fatigue, among other things.
Which additional supplements would I personally further investigate (in addition to those listed at the link above)? You can find a list here:
Best Natural Glaucoma Dietary Supplements | FitEyes.com
Examples include:
Coleus forskolii: Coleus forskolii is a well known Ayurvedic herb that can help support overall vitality and well-being. This ancient medicinal plant has been used to treat diseases including hypothyroidism, heart disease and respiratory disorders. Forskolin is an active compound found in Coleus forskohlii which has been used in over 5000 research studies since 1981. There are numerous studies showing topical application lowers IOP. Oral efficacy for IOP reduction is still an open question, but a few FitEyes members have reported promising results; Forskolin increases cyclic AMP concentrations to enhance cardiac contractility and cause vascular dilation in vitro and in vivo. Increasing cyclic AMP is, in fact, Forskolin's basic mechanism of action. Cyclic AMP is perhaps the most important cell-regulating compound. Once formed it activates many other enzymes involved in diverse cellular functions.
Ginger: Ginger is used for improving poor peripheral circulation in Raynaud's disease (which may be related to NTG), and acts as a warming circulatory stimulant.
Ginkgo: Ginkgo has been found to support healthy circulation, help maintain the normal function and tone of blood vessels, support healthy oxygen and glucose metabolism in the brain, stabilize capillaries and make them less fragile, support normal coagulation of blood, and support healthy aging in the brain.
