Married At First Sight star John Shepherd is a gym lover who has never smoked or drunk heavily. But a health check ahead of his 40th birthday revealed a hidden type of cholesterol, known to quadruple the risk of heart attack and strokes in young people, and he had experienced no symptoms at all.

Referred to as lipoprotein(a) or Lp(a), this substance is similar to bad cholesterol that builds up in artery walls. However, it is stickier, meaning it can clog the vessels up more quickly and severely. It can strike those who seem healthy and fit, and is also harder to manage, as specific Lp(a) lowering treatments are not yet available. Plus, this type of cholesterol often does not respond to diet and lifestyle changes, as the amount of Lp(a) in your blood is determined by your genes.

What Is Lipoprotein(a) and Why Is It Dangerous?

Around one in five people are thought to have elevated Lp(a), including Inbetweeners actor James Buckley, 38, who revealed he gave up alcohol and cut down on takeaways since his diagnosis. However, it is not routinely tested for on the National Health Service, meaning many people may be unaware their levels are high.

The British Heart Foundation describes lipoproteins as little groups of proteins and fats that help carry fats around the body. Lp(a) is made up of a lipoprotein, similar to low-density lipoprotein, and two proteins called ApoB and Apo(a), the latter of which makes Lp(a) stickier. Unlike standard cholesterol measurements, Lp(a) levels are only measured at specialist lipid clinics.

John, who married Abi, 35, on Married At First Sight UK in 2025, says finding out about his diagnosis was bittersweet. He notes that knowing about it gives him a chance to take action that could help him live a longer, healthier life. At the same time, it makes him sad for his mum, who lost her dad and her big brother to heart disease far too young, wondering whether they might still be here with the same opportunity.

Rising Heart Attack Risks in Younger People

Society tends to consider heart attacks and strokes as events that strike people at least over 40 years old. But Dr Adam Staten, from One Day Tests, says evidence suggests that rates of ischaemic heart disease and death from heart attacks are slowly rising in younger, working-age people.

Overall progress has been made in reducing death from heart disease, but most of the progress is in older people, while progress has stalled and even seems to be reversing in younger people. This is likely due to sedentary lifestyles and poorer diets that are high in processed foods. This leads to obesity and higher rates of type 2 diabetes which, in turn, increase the risks of heart disease.

Some people, like John, may have a genetic predisposition, meaning their risk is not entirely within their control. Problems with cholesterol and blood pressure can be down to genetics so there may be an issue despite a healthy lifestyle, according to Dr Staten. If these problems are tackled early then the long term outlook is good, whereas if left undetected, they can be life-threatening.

Family History and the Search for Answers

John lives in Southbourne, Dorset, with Abi, and his family has been plagued by a devastating history of heart disease. Since finding out he has high Lp(a) levels, he wonders whether the hidden risk factor played a role in the premature deaths of his grandfather and uncle. His maternal grandfather, Giovanni, died from a heart attack in 1978, at the age of 47.

In 2019, the family suffered another loss when his mum's brother, Uncle Angelo, who John idolised, died suddenly from a heart attack at 59. Another of his mum's brothers, Uncle Johnny, survived a heart attack in 2024, at 58. John points out that despite his uncle's fitness and gym routine, he still suffered a cardiac event.

John had a health check at the One Day Tests clinic in Southampton on July 14. The most significant finding was his raised Lp(a) level at 0.85 g/L, which put him at high risk of heart disease. With findings of slightly raised low-density lipoprotein and raised blood pressure, he was slightly above recommended levels for a healthy adult.

How to Get Lp(a) Levels Checked

Lp(a) is not routinely measured in general practice when you undergo a standard cholesterol test. In the United Kingdom, it can be measured by a specialist lipid clinic, which a general practitioner can refer patients to.

HEART UK recommends getting levels measured if an individual has developed cardiovascular disease before the age of 60, or if people in the family have developed cardiovascular disease before that age. Testing is also advised for those with first-degree relatives with raised Lp(a) levels, individuals with familial hypercholesterolaemia or other inherited lipid conditions, and anyone with calcific aortic valve disease or family history of it.

John cut back on highly processed foods, refined carbohydrates, chocolate, and cake in favour of whole foods, including chicken, salads, vegetables, and fruit. Within two weeks, he lost 3kg, going from 13stone 7lb to 13stone 2lbs, and had another test done. His blood pressure showed a marked improvement, though there was less change to his cholesterol levels.

Lifestyle Changes and Medical Next Steps

There is currently no approved treatment specifically to lower Lp(a). Because these levels are largely determined by genetics, diet and exercise do not make much of a dent on the level itself. However, keeping cholesterol, blood pressure, and weight in check is still advised to reduce the overall risk of heart disease and stroke.

After discussing his raised Lp(a) levels and family history with his general practitioner, John is now on a prevent plan to lower his disease risk long term. He continues to exercise and improve his diet, particularly around saturated fats to help overall heart health. His doctor agreed that no medication is needed right now, but referred him to a specialist cholesterol clinic.

Dr Staten advises that anyone worried about their heart health should exercise regularly, maintain a healthy weight, eat healthily, and avoid smoking and vaping. It is also important to get checked for issues that are invisible without testing, including cholesterol, blood sugar levels, and blood pressure. The National Health Service recommends having these things tested at the age of 40 and every five years from then, or more regularly if a problem is identified.