There are many reasons to reverse and stop prediabetes to prevent full diabetes. One of them is that people with diabetes are more prone to cardiovascular disease and develop blood circulation problems at a younger age, including the poor blood flow to the feet and legs that can put diabetics at risk for amputation of the foot. Fruits and vegetables support good blood flow for a healthy cardiovascular system.
In this post, we will have a look at an important group of plant compounds plentiful in fruits and vegetables demonstrating a supportive role in the prevention and management of cardiovascular disease, including the cardiovascular disease to the feet and legs known as peripheral arterial disease (PAD), and how these “phytonutrients”found in fruits and vegetables support good blood flow and blood circulation.
In my last post about lifestyle and cardiovascular problems, I mentioned how vegetables can be like medicine. The polyphenol compounds in fruits and vegetables are a major factor in the benefits of certain plant foods for good cardiovascular health.
Polyphenol plant compounds are a highly varied group of plant nutrients (“phytonutrients”) that make up the most abundant anti-oxidants in our diets, however they can also play a healthy pro-oxidant role when required. They are categorized into different classes:
- phenolic acids
- and more
The diversity of their structure makes polyphenols different from other antioxidants. Their ability to be absorbed by the body, and their biologic properties, are quite different depending on their chemical structure.
The class of polyphenol compounds I will discuss in this post are the flavonoids. The flavonoids are the most common class of polyphenols in our diets, and because of their diverse nature, they have been further sub-divided into several groups; i.e., flavones, flavonols, isoflavones, flavanols, anthocyanins, proanthocyanidins, flavanones and more.
The flavonoid polyphenol compounds were first isolated from citrus fruit in 1936. And because they were first discovered to reduce the fragility and “leakiness” of tiny blood vessels know as capillaries, they were referred to as “vitamin P” (“P” for permeability, a.k.a. “leakiness” :-)).
Since then the involvement of flavonoids and related compounds on human health has become a major topic in human nutrition research. Numerous studies on many of the biological activities of flavonoids have been described, including in cardiovascular disease.
How do flavonoids found in fruits and vegetables support good blood flow for healthy blood circulation?
Research suggests that people who have higher flavonoid intake from fruits and vegetables tend to have a decreased risk for the development of cardiovascular diseases. There is a growing body of scientific evidence supporting a flavonoid rich diet from fruits and vegetables suuport good blood flow and promote healthy blood circulation.
In addition, some food derived flavonols have been reported to show various biological effects and “medicinal” properties such as antioxidant, anti-clotting, anti-inflammatory, anti-“hardening of arteries”, and heart-protective effects…food is medicine.
The walls of our blood vessels and the lining of our blood vessels appear to be a key target for flavonoid plant compounds – you may remember from the last post, the cells lining your blood vessels are known as the endothelium. It appears one way in which flavonoids may inhibit the development of vascular disease is through their interaction with the endothelial lining of arterial walls and influencing the production of signaling molecules that are made by your endothelial cells to help regulate blood flow.
One outcome of this interaction is reduced arterial stiffness, or to put it another way, increased pliability of your blood vessels. Stiff blood vessels are a sign of poor health and aging. The flexibility of your arteries can be tested with the use of a doppler machine in the doctor’s office with a “pulse wave velocity.”
Investigaton of the relationship between flavonoid consumption (how much vegetables and fruits you eat) and arterial pliability, or stiffness, suggests this can give a strong prediction of cardiovascular problems and lifespan.
In addition to supporting the good health of cells lining your blood vessels, other research suggests flavonoids influence cardiovascular health through the improvement of multiple risk factors including:
- reducing oxidative stress (acting as anti-oxidants)
- decreasing blood pressure
- improving dyslipidemia (bad cholesterol levels)
- improving blood sugar levels
- inhibiting low-density lipoprotein oxidation (just go with me on this one) source
Another common finding among many flavonoids is their ability to influence a chemical messenger in the blood associated with inflammation known as tumor-necrosis factor (TNF). TNF is a chemical messenger used by blood cells of your immune system to “talk” to one another. TNF has been shown to play a role in most chronic diseases such as cancer, rheumatoid arthritis, cardiovascular diseases, psoriasis, neurologic diseases, Crohn’s disease, and many metabolic diseases. In light of this, it is believed flavonoids that support regulation of the TNF-influenced inflammation pathways may have some potential against these inflammation associated diseases.
Common polyphenols that fall into this category of having some potential against disease associated inflammation include many compounds (with names that are hard to pronounce 🙂 ) including: curcumin, resveratrol, genistein, epigallocatechin gallate, flavopiridol, silymarin, emodin, morin isoliquiritigenin, naringenin, ellagic acid, apigenin, kaempferol, catechins, myricetin, xanthohumol, fisetin, vitexin, escin, mangostin and others. (2)
Another way in which it is believed the flavonoids found in fruits and vegetables support good blood flow and circulation is through the support of endothelium-derived nitric oxide (NO).
As I said at the beginning of this post, people with diabetes are especially prone to having poor blood flow and circulation, and there is some early evidence to suggest eating flavonoid rich foods may slow the onset and progression of circulation problems in diabetics.
Human studies on healthy participants show eating flavonoid-rich food improves blood circulation, but it also appears to provide this benefit to people at risk for cardiovascular disease like diabetics. The ability of flavonoids to counter cardiovascular disease in people with diabetes has been investigated.
Researchers have looked at blood circulation health and any worsening of “hardening of the arteries” in postmenopausal women with type 2 diabetes who ate flavonoids regularly for one year.
They looked at several different measures of blood circulation health and found while some measurements did not change, clinically relevant improvements in arterial stiffness were observed. They advised longer term studies and concluded,
Flavonoids may augment existing therapeutic strategies to reduce cardiovascular disease risk in postmenopausal T2DM patients…”
In addition, it is interesting to note that some flavonoids and/or their metabolites appear to be able to cross the blood-brain barrier and influence the brain.
Much of the research on flavonoid plant extracts has been conducted in the lab and on animals; there have been some human cell models used as well. I have provided links to some of this research at the end of this post.
Various flavonoid compounds that are available in plants show many effects that can potentially prevent the progression of atherosclerosis leading to poor blood flow and help reduce the severity of problems with metabolism like prediabetes-metabolic syndrome and full type 2 diabetes that can lead to early-onset cardiovascular disease, including the reduced blood flow to the feet and legs known as PAD.
Future research can be focused on the role of plant flavonoids in human health and metabolism and how they affect signaling pathways involved in the development of cardiovascular disease leading to poor blood circulation. This could help to determine ways for improving therapies for atherosclerosis and other related blood circulation problems.
There are flavonoid supplements available for those people who do not eat sufficient plant foods, but there’s nothing like real food. In the future, flavonoid-based medications may be utilized for the prevention and treatment of atherosclerosis and cardiovascular diseases, but I doubt they will be as good as the real thing. Try your best to include adequate plants in your diet. Some supplementation is available if needed, but do not overdo it with supplementation – more is not necessarily better.
The Nutrientology Store has great flavonoid supplements.
Good Review Article on Plant Flavonoids for Good Blood Flow
Antiartherosclerotic Effects of Plant Flavonoids – This article includes 156 references and a “Table 1” which is a summary of what the research suggests are potential health benefits of plant flavanoids.
Additional links to research on commonly studied flavonoids include:
- Does Quercetin Improve Cardiovascular Risk factors and Inflammatory Biomarkers in Women with Type 2 Diabetes: A Double-blind Randomized Controlled Clinical Trial…full text.
- Chronic intake of onion extract containing quercetin improved postprandial endothelial dysfunction in healthy men…abstract.
- Dietary fat increases quercetin bioavailability in overweight adults…abstract.
- Suppression of Nitric Oxide Production and Cardiovascular Risk Factors in Healthy Seniors and Hypercholesterolemic Subjects by a Combination of Polyphenols and Vitamins…full text.
- A review on the dietary flavonoid kaempferol…abstract.
- Protective effects of kaempferol against endothelial damage by an improvement in nitric oxide production and a decrease in asymmetric dimethylarginine level…abstract.
- Kaempferol stimulates large conductance Ca2+ -activated K+ (BKCa) channels in human umbilical vein endothelial cells via a cAMP/PKA-dependent pathway…full text.
- A review of the dietary flavonoid, kaempferol on human health and cancer chemoprevention…full text.
- Role of rutin on nitric oxide synthesis in human umbilical vein endothelial cells…full text.
- Rutin inhibits hydrogen peroxide-induced apoptosis through regulating reactive oxygen species mediated mitochondrial dysfunction pathway in human umbilical vein endothelial cells…abstract.
- Circulating endothelial cells in venous blood as a marker of endothelial damage in chronic venous insufficiency: improvement with venoruton…abstract.
- Distinct effects of naringenin and hesperetin on nitric oxide production from endothelial cells….abstract.
- Green tea polyphenol epigallocatechin-3-gallate inhibits TNF-α-induced production of monocyte chemoattractant protein-1 in human umbilical vein endothelial cells…abstract.
- Epicatechin attenuates atherosclerosis and exerts anti-inflammatory effects on diet-induced human-CRP and NFκB in vivo…abstract.
- (-)-Epigallocatechin gallate inhibits TNF-α-induced PAI-1 production in vascular endothelial cells…abstract.
- The flavanol (-)-epicatechin and its metabolites protect against oxidative stress in primary endothelial cells via a direct antioxidant effect…abstract.
- Epigallocatechin-3-gallate is a potent phytochemical inhibitor of intimal hyperplasia in the wire-injured carotid artery…full text.