• Your diet and gut health can impact your risk of developing heart disease. (Getty Images)Source: Getty Images
Although the link between your gut and heart seems unusual, research shows that a poor diet and an imbalance in your gut microbiome could actually lead to heart disease.
By
Yasmin Noone

26 Nov 2020 - 1:48 PM  UPDATED 27 Nov 2020 - 12:54 PM

Most of us know there’s a link between heart disease, high blood pressure and high cholesterol. But there’s one possible silent precursor to heart disease that might be flying under the radar: an imbalance in your gut microbiome (or gut dysbiosis).

Dr Catherine Itsiopoulos – an accredited practising dietitian and Pro Vice-Chancellor of the College of Science, Health, Engineering and Education at Murdoch University – tells SBS that gut research conducted over the last five-to-10 years has revolutionised the way we think about heart health, the gut microbiome and chronic disease.

In her new book, The Heart Health Guide, she discusses how gut dysbiosis can be a precursor to heart disease.

“The gut contains trillions of bacteria called the microbiome: a combination of friendly healthy and unfriendly bacteria,” Dr Itsiopoulos says.

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“The friendly bacteria in your gut are retained and grow when we have a diet that is full of fibre and carbohydrates. Think of fibre as a fertiliser for these bacteria. When you feed these friendly bacteria with fibre, you help to retain the lining of the bowel.”

Meanwhile, a diet that is high in processed foods and saturated fats will favour the unfriendly bacteria in your gut. Fewer beneficial bacteria and more unfriendly bacteria in your gut could cause the barrier between the gut and the body to become ‘leaky’ or permeable.

“What happens then is that toxins produced by the unfriendly bacteria, which also reside in the bowel, will enter the bloodstream and cause chronic disease. This can affect all of the organs in your body, including your heart.”

“What happens then is that toxins produced by the unfriendly bacteria, which also reside in the bowel, will enter the bloodstream and cause chronic disease. This can affect all of the organs in your body, including your heart.”

Gut microbiota and heart disease

As explained in written in Dr Itsiopoulos’s new book, emerging research also suggests that a disturbed or ‘dysbiotic’ gut microbiome can create inflammation in the body. Inflammation can lead to the development of obesity and insulin resistance – both of are common contributors to cardiovascular disease and type 2 diabetes.

A 2020 review of current scientific literature led by Chinese researchers, which examines the relationship between the gut and cardiovascular disease (CVD), details the link between the gut microbiota and CVD.

The study published in Microbial Biotechnology states that bacteria can relocate from the gut to the heart, causing gut bacterial DNA in the plaques (artery walls). This indicates that “the intestine is a potential reservoir of pathogenic microorganisms and that the gut microbiota is involved in the development of atherosclerosis [a build-up of fats and cholesterol in and on your artery walls, which can restrict blood flow]”.

“Complex correlations exist between the gut microbiota and CVD, as they mutually influence each other via microbiota‐associated products, the circulatory system, immune responses and metabolic changes,” the study reads.

The Mediterranean diet and a healthy gut

Dr Itsiopoulos explains that more research is needed to really understand the specific mechanisms of our gut microbiota and its impact on heart health. However, one thing is known for certain – we can maintain a healthy gut by adopting a diet that’s rich in plants, low in processed foods and high in fibre.

She says that by following a fibre-rich Mediterranean diet, complete with a range of fruit, vegetables, wholegrains and legumes, we can reduce cholesterol levels, inflammation and blood pressure while improving overall heart health and promoting weight loss. 

“A healthy Mediterranean diet has, in general, double the amount of fibre that we normally consume in Australia,” she tells SBS. “The Nutrition Survey (National) shows that Australians eat around 20-25 grams of fibre a day but the Mediterranean diet has around 40-45 grams.”

A moderately low intake of eggs, dairy and meat are also advised, as well as lots of nuts and legumes.

The Heart Foundation also advises that dietary patterns based on the Mediterranean diet have been protective against CVD.

Dr Itsiopoulos recommends having lots of prebiotic foods (dark leafy greens, lentils, chickpeas, olives and extra virgin olive oil) and probiotic-rich foods (feta and goats cheese, Greek-style yoghurt and sourdough bread) as part of a Mediterranean diet to benefit your gut microbiome. A moderately low intake of eggs, dairy and meat are also advised, as well as lots of nuts and legumes.

But remember, following a balanced Mediterranean diet to promote gut and heart health is as much to do with what you eat as it is about how much you eat.

“Rebalance your plate by piling up the vegetables so your meals reflect the Mediterranean plant to animal food ratio of 4:1,” the book states. “[This will] ensure you pack in the nutrition benefits of all the anti-inflammatory and cardio-protective ingredients of the Mediterranean diet.”

The Heart Health Guide, created by Dr Catherine Itsiopoulos and published by Pan Macmillian, features 80 recipes and an expert guide on how the Mediterranean diet lowers cholesterol and blood pressure, improves overall heart health and promotes weight loss. 

cook the book
Skordalia: purple-skinned white sweet potato and garlic mash

This is a variation on the Greek mashed potato dish skordalia, which goes perfectly well with fish, meatballs or baked vegetables (especially beetroot). Sweet potato has a lower GI than potato and is better for people with diabetes.

Baklava clusters

This take on the baklava is made into delicious little clusters that can be eaten with yoghurt and fresh berries for a filling breakfast, or as a snack on their own.

Village-style sourdough bread

A gorgeous golden loaf of sourdough with a hint of honey and a sprinkle of sesame seeds with an easy cheat's sourdough starter.

Pork and fennel polpette

Fennel seeds have a sweet liquorice-like taste and are rich in anti-inflammatory nutrients. They go well with pork meatballs, and here I have also used some fennel bulb, which gives a softer flavour and moister meatball.

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