Why Inflammation Matters for Heart Health

When we talk about heart disease, cholesterol often dominates the conversation. But over the last two decades, research has increasingly pointed to another important piece of the puzzle: chronic inflammation.

Inflammation is not inherently harmful. It is a vital part of the immune response. The issue arises when inflammation becomes long-term, low-grade and persistent. This type of chronic inflammation is now recognised as a key contributor to cardiovascular disease, acting alongside cholesterol, blood pressure, blood sugar balance and lifestyle factors.

In this blog, I will explain what chronic inflammation is, how it affects the heart and blood vessels, and what the current evidence shows us about diet and lifestyle changes that may help reduce cardiovascular risk.

What is chronic inflammation?

Inflammation is the body’s natural defence mechanism. When you cut your finger or catch an infection, inflammatory signals help recruit immune cells and promote healing. This short-term response is known as acute inflammation and is both necessary and protective.

Chronic inflammation is different. It refers to a persistent, low-level inflammatory state that can continue for months or years. It often develops quietly, without obvious symptoms, and is influenced by factors such as excess body fat, insulin resistance, smoking, poor sleep, chronic stress, physical inactivity, ultra-processed diets and some long-term health conditions.

In research settings, chronic inflammation is commonly assessed using blood markers such as C-reactive protein (CRP), particularly high-sensitivity CRP (hs-CRP). Elevated hs-CRP has been consistently associated with increased cardiovascular risk, even when cholesterol levels are not markedly raised.

How inflammation affects blood vessels and the heart

The cardiovascular system is lined with a delicate layer of cells called the endothelium. This lining helps regulate blood flow, blood pressure and clotting. Chronic inflammation disrupts normal endothelial function, making blood vessels less flexible and more prone to damage.

Inflammatory signals also play a direct role in the development of atherosclerosis. Rather than cholesterol simply building up passively in artery walls, we now understand that atherosclerosis is an inflammatory process. Cholesterol-containing particles that enter the artery wall trigger an immune response. Over time, this leads to the formation of plaques that can narrow arteries or become unstable and rupture.

Large genetic, observational and interventional studies over the last five years have strengthened the link between inflammation and cardiovascular events. Importantly, these associations persist even after adjusting for traditional risk factors such as LDL cholesterol.

Links with cholesterol and blood pressure

Unsurprisingly, inflammation and cholesterol are closely intertwined.  Inflammation increases the likelihood that cholesterol-containing particles will penetrate and be retained in the artery wall. Plus, it impairs the body’s ability to clear these particles effectively. This may explain why some people experience cardiovascular events despite having LDL cholesterol levels that are not dramatically elevated.

Blood pressure is also affected by inflammatory processes. Chronic inflammation contributes to endothelial dysfunction and arterial stiffness, both of which increase vascular resistance and raise blood pressure over time. Elevated blood pressure, in turn, further damages the vessel wall, creating a reinforcing cycle.

This is why cardiovascular risk assessment increasingly focuses on the broader picture rather than a single number.

Nutritional strategies supported by research

Nutrition cannot remove cardiovascular risk entirely, and it should never be positioned as a replacement for medical care where that is needed. However, a growing body of peer-reviewed evidence shows that diet plays a meaningful role in modulating inflammatory pathways linked to heart disease.

Dietary patterns matter more than individual foods

Recent systematic reviews and meta-analyses consistently show that overall dietary patterns are more predictive of cardiovascular outcomes than individual nutrients in isolation.

Mediterranean-style dietary patterns are associated with lower inflammatory markers, reduced cardiovascular events and improved endothelial function. These benefits appear to be driven by a combination of factors including higher intakes of vegetables, fruit, legumes, wholegrains, nuts, seeds and olive oil, alongside regular fish intake and lower consumption of ultra-processed foods.

Importantly, these effects are observed even when weight loss is modest or absent, suggesting benefits beyond calorie reduction alone.

The role of fats in inflammation

The type of fat consumed influences inflammatory signalling. Replacing saturated fats with unsaturated fats, particularly monounsaturated and omega-3 fats, has been shown to reduce inflammatory markers and improve lipid profiles in controlled trials. Extra virgin olive oil, oily fish, nuts and seeds are key contributors within dietary patterns associated with lower cardiovascular risk.

Omega-3 fatty acids from oily fish appear to have modest anti-inflammatory effects, partly through the production of specialised pro-resolving mediators that help switch off inflammatory responses once they are no longer needed.

Fibre and the gut–inflammation link

Dietary fibre, particularly soluble and fermentable fibre, plays an important role in inflammation regulation.

Fibre supports gut microbiota diversity and the production of short-chain fatty acids, such as butyrate. These compounds help maintain gut barrier integrity and modulate immune activity. Poor gut barrier function has been linked to increased systemic inflammation and cardiometabolic risk.

Higher fibre intakes are consistently associated with lower CRP levels and reduced cardiovascular events in large prospective studies, with benefits seen across a range of populations.

Ultra-processed foods and inflammatory load

Diets high in ultra-processed foods are associated with higher inflammatory markers and increased cardiovascular risk. These foods often combine refined carbohydrates, industrial fats, additives and excess sodium, while displacing fibre-rich, nutrient-dense foods.

Reducing ultra-processed food intake does not require perfection. Even partial replacement with whole or minimally processed foods has been shown to improve inflammatory profiles in controlled feeding studies.

Alcohol, stress and sleep also matter

Inflammation does not arise from diet alone. Alcohol intake, chronic psychological stress and poor sleep quality all influence inflammatory pathways that directly affect cardiovascular risk.

Alcohol and inflammation

Alcohol has a complex relationship with cardiovascular health, but recent evidence has shifted the conversation away from the idea that alcohol is protective.

Large observational studies and Mendelian randomisation analyses published in the last five years suggest that lower alcohol intake is associated with lower cardiovascular risk, with no clear threshold at which alcohol becomes beneficial. Alcohol consumption is linked to higher blood pressure, raised triglycerides and increased systemic inflammation, even at moderate intakes.

Alcohol can increase gut permeability, sometimes referred to as “leaky gut”. This allows inflammatory compounds to pass into the bloodstream more easily, activating immune responses that contribute to chronic low-grade inflammation. Alcohol metabolism also generates oxidative stress, further amplifying inflammatory signalling.

From a practical perspective, people concerned about heart health may benefit from:

• Having regular alcohol-free days each week
• Reducing portion sizes and frequency rather than aiming for perfection
• Being mindful that alcohol can worsen sleep quality and blood pressure even when intake feels modest

Stress, the nervous system and inflammation

Chronic stress is a powerful but often underestimated driver of inflammation.

Persistent activation of the stress response leads to dysregulation of cortisol and other stress hormones. Over time, this can promote insulin resistance, abdominal fat accumulation and increased production of pro-inflammatory cytokines. Chronic stress is also associated with higher CRP levels and increased cardiovascular event risk, independent of traditional risk factors.

Stress influences cardiovascular health through both biological and behavioural pathways. It can directly affect blood vessels and immune signalling, while also increasing the likelihood of poor sleep, irregular eating patterns, higher alcohol intake and reduced physical activity.

Supportive strategies do not need to be complicated. Evidence suggests that even modest, regular practices can help reduce inflammatory load, including:

• Daily movement, particularly walking, which has been shown to lower inflammatory markers
• Breathing practices or mindfulness-based approaches that support parasympathetic nervous system activity
• Creating predictable meal patterns, which can reduce stress-related blood sugar fluctuations

Importantly, stress reduction is not about removing stress entirely, but about improving the body’s ability to recover after stress.

Sleep and cardiovascular inflammation

Sleep plays a central role in regulating immune and inflammatory processes.

Short sleep duration and poor sleep quality are both associated with higher CRP levels, increased blood pressure, impaired glucose regulation and greater cardiovascular risk. Experimental studies show that even a few nights of restricted sleep can raise inflammatory markers and impair endothelial function.

Sleep disruption also alters appetite-regulating hormones, increasing hunger and cravings for ultra-processed foods, which can further exacerbate inflammation.

From a heart health perspective, supportive sleep strategies include:

• Aiming for consistent sleep and wake times, even at weekends
• Reducing alcohol intake in the evening, as alcohol fragments sleep architecture
• Prioritising exposure to natural daylight earlier in the day to support circadian rhythm
• Ensuring evening meals are balanced and not overly late or heavy, which can disrupt sleep and blood pressure regulation

For individuals experiencing ongoing sleep problems, addressing sleep quality can be just as important as dietary changes when aiming to reduce cardiovascular risk.

Why this matters in practice

When alcohol intake, stress and sleep are overlooked, people can do everything “right” nutritionally and still see limited improvement in inflammatory markers or cardiovascular risk factors.

The most effective approach to heart health recognises that inflammation sits at the intersection of diet, lifestyle and physiology. Supporting recovery, regulation and resilience is often what allows nutritional strategies to work more effectively.

Bringing it together

Chronic inflammation is not a vague or theoretical concept. It is a measurable biological process that plays a central role in cardiovascular disease development.

For individuals concerned about heart health, the most effective approach is rarely about eliminating a single food or chasing one marker. Instead, it involves supporting the body’s inflammatory balance through consistent, sustainable changes that address diet quality, metabolic health, lifestyle stressors and overall cardiovascular risk.

If you would like support translating this evidence into a personalised plan that fits your health history, preferences and test results, why not get in touch?