Can You Grow New Veins and Arteries?

Your body grows new blood vessels throughout your entire life. It happens when you exercise, when you heal a wound, and when tissues get starved of oxygen. Adults have at least two major ways of expanding their vascular network: angiogenesis, which sprouts new capillaries from existing ones, and arteriogenesis, which remodels small pre-existing connections into full-sized arteries. These processes are powerful enough that, given the right signals, your circulatory system can reroute blood around a blocked artery or build a temporary capillary bed many times denser than normal tissue. But the same machinery also has a dark side, and understanding both is key to appreciating why researchers have spent decades trying to control it.

How Your Body Builds New Blood Vessels

There are two fundamentally different ways adult blood vessels grow, and they respond to different triggers. Angiogenesis is driven by low oxygen levels in tissue. When cells are starved of oxygen, they release signaling molecules, most famously vascular endothelial growth factor (VEGF), that coax nearby capillaries to sprout new branches toward the oxygen-deprived area. These new capillaries are small and thin-walled, built for gas exchange rather than carrying large volumes of blood.

Arteriogenesis works differently. It doesn’t create vessels from scratch. Instead, it enlarges tiny arterial connections that already exist in your body but normally carry very little flow. When a major artery narrows or gets blocked, blood pressure drops downstream. That pressure difference forces more blood through these small bypass routes, increasing the physical shear stress on their inner walls. The endothelial cells lining the vessels sense that shear stress and kick off a remodeling process: immune cells invade the vessel wall, smooth muscle cells proliferate, and over weeks to months the tiny connection grows into a proper artery capable of carrying meaningful blood flow.¹ This is the process that cardiologists are talking about when they refer to “collateral circulation” developing around a blocked coronary artery.

The success of arteriogenesis depends on several conditions lining up: a pre-existing network of tiny connections has to be there in the first place, the endothelium has to be activated by shear stress, bone marrow-derived cells have to invade (though they don’t become part of the vessel wall), and both endothelial and smooth muscle cells have to proliferate.² If any of those steps falters, the collateral doesn’t develop fully.

Exercise Is the Strongest Natural Trigger

If you want to grow new blood vessels on purpose, the most proven stimulus is regular physical activity. Exercise creates exactly the conditions that drive both angiogenesis and arteriogenesis. Contracting muscles demand more oxygen, creating local hypoxia that triggers capillary sprouting. At the same time, the increased cardiac output pushes more blood through your arterial tree, raising shear stress on vessel walls and prompting larger conduit vessels to remodel and enlarge.³

The enlargement of conduit arteries in response to repeated shear stress is an endothelium-dependent process that relies on nitric oxide. Meanwhile, inside working muscles, capillary density increases through a process called intussusceptive angiogenesis, where existing capillaries essentially split lengthwise to create two vessels where there was one.³ This is a less dramatic process than sprouting angiogenesis but it’s efficient and fast, which makes sense for meeting the repetitive oxygen demands of training.

The practical upshot: endurance exercise over weeks and months genuinely increases the density of your capillary network in trained muscles and enlarges the arteries feeding them. This is one reason why athletes have lower resting heart rates. Their cardiovascular plumbing has literally expanded to move blood more efficiently.

Wound Healing Shows the Process in Action

Every time you cut yourself, you witness a miniature demonstration of blood vessel growth. Within days of injury, angiogenic capillary sprouts invade the wound clot and organize into a dense microvascular network throughout the healing tissue. This new vascular bed is far denser than what the tissue normally needs. Growth factors including VEGF, fibroblast growth factor, and others orchestrate the process, recruiting endothelial cells to migrate, proliferate, and form tubes.⁴

What’s interesting is that the body doesn’t keep all of those vessels. As collagen accumulates and scar tissue forms, most of the newly formed capillaries regress, leaving a final vascular density close to what the skin had before the injury.⁵ The body builds far more than it needs, then prunes back. This overshoot-and-trim approach is part of why wounds heal as well as they do, but it also hints at the sophistication required to get vascular growth right. Too little vessel growth and the wound doesn’t heal. Too much and you can end up with chronic, poorly organized tissue.

When New Vessel Growth Works Against You

The same angiogenic machinery that heals wounds and feeds exercising muscle can also fuel disease. Tumors are the most well-known example. A solid tumor cannot grow beyond a few millimeters without recruiting its own blood supply, and it does this by hijacking the body’s angiogenic signaling, releasing VEGF and other factors that trick nearby vessels into sprouting toward and into the tumor mass.⁶ The researcher Judah Folkman first proposed this idea more than 30 years ago: that starving a tumor of its blood supply could be a viable cancer treatment.⁷ That concept led to an entire class of anti-angiogenic drugs now used in oncology.

The eyes are another site where unwanted vessel growth causes serious problems. In age-related macular degeneration, abnormal blood vessels grow beneath the retina in a process called choroidal neovascularization. These vessels are leaky and fragile, and they eventually detach the retinal pigmented epithelium, leading to vision loss.⁸ The current standard treatment uses drugs that block VEGF, injected directly into the eye. These have been a genuine breakthrough for many patients, but they don’t restore long-term visual acuity in everyone, and a subset of patients don’t respond well, suggesting that VEGF-independent pathways also contribute.⁸ Anti-VEGF injections aim to block abnormal blood vessel growth in the eye and can prevent further vision loss.⁹

The tension is clear: the same growth factor pathway that you’d want to enhance after a heart attack to build collaterals is the one you need to suppress in cancer and macular degeneration. This is why blanket approaches to turning angiogenesis “on” or “off” have proven so tricky.

Why Aging and Diabetes Make It Harder

Your ability to grow new blood vessels declines with age and deteriorates faster if you have diabetes. Research in mice has shown that stromal cells from young animals secrete significantly more VEGF under both normal and low-oxygen conditions compared to cells from aged or diabetic animals. Aged and diabetic cells can still ramp up their VEGF production in response to hypoxia, but the response is blunted. They also proliferate more slowly and are less able to form tube-like structures, the earliest step in building a new vessel.¹⁰

This double hit, from aging and from metabolic disease, helps explain why older adults and people with diabetes heal wounds slowly and develop fewer collateral arteries around blocked vessels. It’s also why peripheral artery disease, where arteries in the legs narrow and restrict blood flow, becomes increasingly dangerous in these populations. The body’s natural backup plan of growing collateral vessels simply doesn’t work as well.

The brain provides another sobering example. Studies in aged mice have found significant capillary loss across multiple brain regions, with the white matter losing roughly a third of its capillary density and the hippocampus losing about a quarter.¹¹ Not only do you lose vessels with age, but the remaining tissue becomes less capable of replacing them.

Therapeutic Angiogenesis and Why It Has Been Disappointing

Given that the body can grow new vessels naturally, a logical medical strategy would be to boost that process in people whose arteries are blocked. This idea, called therapeutic angiogenesis, has been pursued since the 1990s. The approach typically involves delivering growth factors like VEGF directly to ischemic tissue, either as purified proteins or via gene therapy vectors that instruct the patient’s own cells to produce them.

Animal studies were very promising. Pre-clinical work showed impressive new vessel growth in response to VEGF gene therapy and related strategies. But clinical trials in humans have been largely disappointing. Results in actual patients have not matched the animal data.¹² The reasons are debated. Human atherosclerotic disease is more complex than the clean arterial blockages created in lab animals. Many of the patients enrolled in trials are elderly, diabetic, or both, meaning their angiogenic machinery is already compromised. And delivering the right dose of growth factor to the right tissue at the right time has proven far harder in humans than in a controlled lab setting.¹³

One promising newer approach targets the HIF pathway, the master oxygen-sensing system inside cells. Under normal oxygen, an enzyme called prolyl hydroxylase tags the HIF protein for destruction. If you inhibit that enzyme, HIF accumulates and switches on dozens of genes related to surviving low oxygen, including VEGF. Small molecules that block prolyl hydroxylase have been tested in animal models and show significant effects. In one mouse study of limb ischemia, silencing certain forms of prolyl hydroxylase increased vessel density by roughly two-fold and capillary density by about double as well, compared to controls.¹⁴ In fracture models, locally injected prolyl hydroxylase inhibitors increased vascularity at the fracture site and improved bone healing.¹⁵ These are still mostly pre-clinical findings, but the approach of stabilizing HIF pharmacologically rather than injecting growth factors directly has attracted considerable interest.

Building Vessels in the Lab

An entirely different approach sidesteps the body’s own vessel-growing machinery and tries to build blood vessels from scratch using tissue engineering. Since the first lab-constructed blood vessel was made using collagen and cultured vascular cells, the field has progressed substantially. Tissue-engineered blood vessels have been successfully constructed in the lab and used to repair vascular defects in animals.¹⁶ The more recent push involves combining stem cell biology with advanced fabrication techniques to create vessels that not only withstand blood pressure but also perform the biological functions of natural arteries and veins.¹⁷

A related challenge sits at the frontier of organ engineering. Lab-grown organoids (miniature organ-like structures grown from stem cells) need their own blood supply to survive and mature. Without functional vascular networks, organoids can’t grow past a certain size because their cores become oxygen-starved. Current limitations in establishing those internal vascular networks remain a major bottleneck for growing replacement tissues and organs.¹⁸ The irony is clear: the same problem that drives therapeutic angiogenesis research in patients (getting blood to oxygen-starved tissue) also limits what tissue engineers can build in the lab.

Lymphatic Vessels Can Regenerate Too

Blood vessels get most of the attention, but the lymphatic system, the parallel network that drains fluid and immune cells from tissues, also has regenerative capacity. When lymphatic vessels are injured, for instance during cancer surgery that removes lymph nodes, the resulting damage can cause lymphedema, a chronic and debilitating swelling. Research has shown that lymphatic regeneration after tissue transfer occurs through a combination of new lymphatic vessel ingrowth and spontaneous reconnection of existing lymphatics, processes driven by VEGF-C signaling and macrophage infiltration.¹⁹

Recent work in mice has shown that implanting an optimized fibrin gel at the site of lymphatic injury can promote the reconnection of severed lymphatic vessels and restore lymph flow to the draining node. The gel appears to work by elevating levels of a chemokine called CCL5 that recruits macrophages to the injury site. Mice engineered to lack CCL5 had a reduced ability to reconnect their lymphatic vessels after the same treatment.²⁰ These findings are still in animal models, but they suggest that stimulating lymphatic regeneration could eventually become a real therapy for people suffering from lymphedema after cancer treatment.

What Zebrafish Can Do That Mammals Can’t

Humans are not the most talented species when it comes to growing new vessels. Zebrafish can regenerate their hearts after injury, and coronary revascularization begins within hours of damage. The process involves a coordinated response across multiple tissues: the epicardium and endocardium guide new coronary vessels to sprout into the injured area, forming a vascular scaffold that cardiomyocytes then repopulate.²¹

Mammalian hearts don’t do this. After a heart attack, the damaged area scars rather than regenerating, and the vascular network in the scar zone remains inadequate. Understanding how zebrafish coordinate their rapid revascularization is an active area of research, with the hope that some of those signals might eventually be harnessed to improve vessel growth in injured human hearts. The gap between what a zebrafish heart can do and what a human heart can do remains enormous, but it proves that the biological machinery for rapid, high-quality vascular regeneration exists in vertebrates. The challenge is figuring out why mammals have lost most of that capacity and whether it can be reawakened.

Diet and the Angiogenic Balance

Dietary compounds, particularly polyphenols found in fruits, vegetables, tea, and wine, interact with angiogenic signaling in complex ways. Depending on the context and concentration, polyphenols can either promote or inhibit vessel growth. Some have been shown to increase endothelial cell proliferation and migration, nudging the process toward new capillary formation. Others interfere with the signaling cascades that drive angiogenesis and may help suppress unwanted vessel growth.²²

This dual nature makes dietary polyphenols hard to pin down as simply “good” or “bad” for vessel growth. The effects depend on which polyphenol, at what dose, and in what tissue context. The research is largely observational and cell-culture based. Nobody has shown in a controlled human trial that eating more blueberries meaningfully improves collateral artery development after a blockage, or that green tea prevents tumor angiogenesis at achievable dietary doses. The biological plausibility is there, but the clinical proof remains thin. Antioxidant vitamins like C, D, and E have shown some ability to promote re-endothelialization (the regrowth of the endothelial cell layer) after vascular injury in experimental settings, contributing to vascular repair through increased cell growth and proliferation. But again, these findings come from controlled lab conditions, not from people taking supplements and seeing measurable improvements in their blood vessel networks.

What can be said with more confidence is that the lifestyle factors with the strongest evidence for promoting healthy vascular growth are the boring ones: regular aerobic exercise, not smoking, and managing blood sugar. These directly affect the signaling pathways and cellular health that underpin angiogenesis and arteriogenesis, which is more than can be said for any specific food or supplement.