Heart disease: I'm a cardiologist. Here are 10 science-based ways to prevent it

NZ Herald

29-07-2025

1. Do both aerobic and resistance exercise
Aerobic and resistance exercise help reduce heart disease risk. Photo / 123RF
This is considered the single most effective medical intervention to protect against atherosclerosis and promote healthy ageing. Physical activity lowers inflammation in the body. Evidence has shown that both aerobic and strength training forms of exercise are important. But only one in four Americans meet the two activity guidelines from the American Heart Association: aerobic exercise of 150 minutes per week of at least moderate physical activity, such as walking, bicycling on level ground, dancing or gardening, and strength training for at least two sessions per week, which typically translates to 60 minutes weekly.
The protective benefit of exercise is seen with even relatively low levels of activity, such as around 2500 steps per day (via sustained physical activity, not starting and stopping), and generally increases proportionately with more activity. It used to be thought that people who exercise only on the weekend – known as 'weekend warriors' – put themselves in danger, but recent data shows the benefits of exercise can be derived from weekend-only workouts, too.
2. Follow an anti-inflammatory diet
A plant-based diet, like the Mediterranean diet, reduces inflammation significantly. Photo / 123RF
A predominantly plant-based diet – high in fibre and rich in vegetables, fruits and whole grains, as seen with the Mediterranean diet – has considerable evidence from large-scale observational and randomised trials for reducing body-wide inflammation and improving cardiovascular outcomes.
Foods rich in omega-3 fatty acids, such as salmon, also form part of a diet that suppresses inflammation. On the other hand, red meat and ultra-processed foods are pro-inflammatory, and you should limit your consumption. High protein intake of more than 1.4g per kg of body weight per day – around 95g for someone who is 68kg – has also been linked to promoting inflammation and to atherosclerosis in experimental models. That is particularly related to animal-based proteins and the role of leucine, an essential amino acid that is obtained only by diet.
3. Maintain a healthy weight
A lean body weight helps reduce heart disease risk.
Being overweight or obese indicates an excess of white adipose tissue. This kind of tissue can increase the risk of heart disease because it stores fat cells, known as adipocytes, which release substances that contribute to inflammation.
In studies, we've seen that glucagon-like peptide (GLP-1) drugs can reduce inflammation with weight loss, and a significant reduction of heart attacks and strokes among high-risk patients treated for obesity. Lean body weight also helps protect against atrial fibrillation, the most common heart rhythm abnormality.
4. Know and avoid metabolic syndrome and prediabetes
There are a variety of ways you can help protect yourself from heart disease. Photo / Getty Images
Tied into obesity, in part, is the problem of insulin resistance and metabolic syndrome. Two out of three people with obesity have this syndrome, which is defined as having three out of five features: high fasting blood glucose, high fasting triglycerides, high blood pressure, low high-density lipoprotein (HDL) and central adiposity (waist circumference of more than 40 inches in men, 35 inches in women).
Metabolic syndrome is also present in a high proportion of people without obesity, about 50 million Americans. Prediabetes often overlaps with it. Prediabetes is defined as a haemoglobin A1c (a measure of how much glucose is stuck to your red blood cells) between 5.7 and 6.4%, or a fasting glucose between 100 and 125 milligrams per decilitre.
Both metabolic syndrome and prediabetes carry an increased risk of heart disease and can be prevented – and countered – by weight loss, exercise and an optimal diet.
As the glucagon-like peptide drug family moves to pills and less expense in the future, these medications may prove helpful for reducing risk in people with metabolic syndrome and prediabetes. For those with Type 2 diabetes, the goal is optimising glucose management and maximal attention to lifestyle factors.
5. Keep your blood pressure in a healthy range
Lifestyle changes can help combat heart disease. Photo / 123RF
Hypertension is an important risk factor for heart disease and is exceptionally common as we age. The optimal blood pressure is 120/80mm Hg or lower. But with ageing, there is often an elevation of systolic blood pressure to about 130mm Hg, related to stiffening of arteries. While common, it is still considered elevated.
Ideally, everyone should monitor their blood pressure with a home device to make sure they haven't developed hypertension. A mild abnormality of blood pressure will typically improve with lifestyle changes, but more substantial elevations will probably require medications.
6. Find out your genetic risk
There are ways to test your heart health and risk factors. Photo / 123RF
We now have the means of determining your genetic risk of coronary artery disease with what is known as a polygenic risk score, derived from a gene chip. The term polygenic refers to hundreds of DNA variants in the genome that are linked to risk of heart disease. This is very different from a family history, because we're a product of both our mother's and father's genomes, and the way the DNA variants come together in each of us can vary considerably for combinations of variants.
That means you could have high or low risk for heart disease that is different from your familial pattern. People with a high polygenic risk score benefit the most from medications to lower cholesterol, such as statins. A polygenic risk score can be obtained from a number of commercial companies, though it isn't typically covered by insurance.
I don't recommend getting a calcium score of your coronary arteries via a computed tomography (CT) scan. This test is overused and often induces overwhelming anxiety in patients with a high calcium score but without symptoms or bona fide risk. If you have symptoms suggestive of coronary artery disease, such as chest discomfort with exercise, then a CT angiogram may be helpful to map the coronary arteries. It is much more informative than a calcium score.
7. Check your blood lipids
Protect your heart with lifestyle changes.
The main lipid abnormality that requires attention is low-density cholesterol (LDL), which is often high and for people with increased risk of heart disease should certainly be addressed. While lifestyle improvements can help, significant elevation typically requires medications such as a statin; ezetimibe; bempedoic acid; or injectables such as evolocumab (Repatha), alirocumab (Praluent) or inclisiran (Leqvio). The higher the risk, the more aggressive LDL lowering may be considered.
It should be noted that the use of potent statins, such as rosuvastatin or atorvastatin, especially at high doses, is linked to inducing glucose intolerance and risk of Type 2 diabetes. While this is not a common side effect, it requires attention since it is often missed from lack of awareness.
A low high-density lipoprotein (HDL) cholesterol often responds to weight loss and exercise. We used to think that high HDL was indicative of 'good cholesterol', but more recent evidence suggests that is not the case and it may reflect increased risk when very high.
To get a comprehensive assessment of risk via your blood lipids, it's important to get the apolipoprotein B (apoB) test at least once because about 20% of people have abnormal LDL and a high apoB.
Like low HDL, high fasting triglycerides may indicate insulin resistance as part of the metabolic syndrome and will often respond to lifestyle factors.
The lipoprotein known as Lp(a) should also be assessed at least once because it indicates risk when elevated. The good news is scientists are on the cusp of finally having medications to lower it, with five different drugs in late-stage clinical trials.
8. Reduce exposure to environmental pollutants
Air pollution, microplastics and chemicals can cause inflammation, affecting heart health. Photo / 123RF
In recent years, we've learned a lot about the substantial pro-inflammatory effects of air pollution, microplastics and forever chemicals, all of which have been linked to a higher risk of heart disease. In one study, microplastics or nanoplastics in the artery wall were found in about 60% of more than 300 people. Researchers found a vicious inflammatory response around the plastics, and a four- to fivefold risk of heart attacks or strokes during three years of follow-up.
While we need policy changes to address these toxic substances in the environment, risk can be reduced by paying attention to air and water quality using filtration or purification devices, less use of plastic water bottles and plastic storage, and, in general, being much more aware and wary of our pervasive use of plastics.
9. Don't smoke
Research shows repeated attempts to quit smoking improve the odds of eventual success. Photo / 123RF
By this point, it should be well known that cigarette smoking is a potent risk factor for coronary artery disease and should be completely avoided.
10. Get good sleep
Testing for sleep apnea can involve checking for good oxygen saturation throughout one's sleep. Photo / 123RF
Although we tend to connect sleep health with brain and cognitive function, there's evidence that sleep regularity and quality are associated with less risk of heart disease. Regularity means adhering to a routine schedule as much as possible, and its benefit may be because of our body's preference for maintaining its circadian rhythm. Sleep quality – meaning with fewer interruptions – and maximal deep sleep can be tracked with smartwatches, fitness bands, rings or mattress sensors.
Sleep apnea, when breathing stops and starts during sleep, is fairly common and often unsuspected. So if you're having trouble sleeping or you snore loudly, talk to your doctor about ruling out the condition. Testing for sleep apnea can involve checking for good oxygen saturation throughout one's sleep. That can be done through a sleep study or at home using rings or smartwatches that include oxygen saturation in their sensors and body movement algorithms that pick up disturbed breathing.