In the digital age, all the wildly conflicting medical advice on eating for heart health is enough to give you indigestion. Not just figuratively, but, potentially, also literally.
So, is there really such a thing as a heart-healthy diet? That depends on whom you ask.
The digital medical and scientific discourse on heart-health habits is contradictory enough for informed minds. Pervasive myths about good or bad foods for hearts compound the confusion.
The humble egg is just one example. Once slandered as a heart breaker for its yolk’s cholesterol content, it has undergone a huge reputational shift. It is back on its scientific pedestal as a hearty superfood.
Cholesterol has had a similarly scientific facelift. Research shows that lowering cholesterol isn’t always a smart move for hearts.
Cholesterol comprises LDL (low-density, formerly called “bad” lipoprotein) and HDL (high-density, “good” lipoprotein) cholesterol. You have to have both LDL and HDL cholesterol coursing through your bloodstream because without it, you’d be dead.
It is a crucial component of cell membranes, providing stability and fluidity. Without cholesterol, your cells couldn’t function properly. It is the precursor for the synthesis of steroid hormones, including sex hormones (oestrogen and testosterone) and adrenal hormones (cortisol and aldosterone).
It is also essential for brain health. Despite comprising only 2% of body weight, your brain carries your body’s highest concentration of total cholesterol. Most of it is present in the myelin sheath, which insulates nerve fibres, assisting optimum cognition (thinking).
Along with cholesterol-rich animal foods, saturated fat is another rehabilitated, former health demon. If not exactly an angel, saturated fat has a restored health halo as a good energy source and essential for brain function. Your brain requires it for proper myelination, which is crucial for nerve signal transmission.
Controversy around saturated fat is mostly a function of mixed research, some of it showing an increased risk of cardiovascular disease (CVD — heart attack or stroke) and because dietary fats are not all created equal. Most foods containing fats contain a blend of different types of fats — saturated, monounsaturated, and polyunsaturated. Proportions, benefits and risks vary widely, depending on food sources.
Animal foods are generally higher in saturated fats than plant foods. An exception is coconut oil, which is close to 90% saturated fat. Olive oil and avocados are predominantly monounsaturated fats with small amounts of saturated and polyunsaturated fats.
If there is consensus among doctors and dietitians, it’s that in small doses, saturated fat is unlikely to kill most people. Emphasis has shifted towards overall dietary patterns, food sources of saturated fat, what replaces it when reduced and individual health conditions and risk factors.
There is also consensus that conventional low-fat, high-carbohydrate diets deserve their bad press. Once the darling of heart foundations globally, these diets advocated reducing all fats, good and bad. The focus has shifted to dietary quality, emphasising whole foods, healthy fats and high-quality carbohydrates within “balanced” eating patterns.
The current reigning “king” of healthy-heart diets is the Mediterranean diet. It takes inspiration from traditional eating patterns of people in countries bordering the Mediterranean Sea, particularly southern Italy, Greece and Spain.
The diet promotes vegetables, wholegrains, nuts and olive oil, moderate consumption of fish and poultry, red meat and dairy kept to a minimum. Science supports it.
The Spanish Prevention with Mediterranean Diet (Predimed) trial is a landmark, randomised, controlled study — the gold standard of modern medical science — conducted from 2003 to 2011. Researchers investigated the diet’s effects on cardiovascular health. Data showed a significant reduction in cardiovascular events. Challenges include adopting it in cultures where olive oil and fresh produce may not be dietary staples or may be prohibitively expensive.
Pretenders to the heart-healthy diet throne include:
- The dietary approaches to stop hypertension (Dash) diet — if not the king, then can claim to be the current princely heir to the throne of heart-healthy diets. Dash involves reduced sodium (salt) intake and focuses on fruits, vegetables and lean proteins. With endorsement from the US National Institute of Health (NIH), it is shown to improve blood lipid (blood fats, including cholesterol) and lower blood pressure. Hypertension (raised blood pressure) is a major risk factor for CVD. Concerns include benefits versus risks of reduced salt intake for general populations, compliance issues and cultural adaptability.
- Low-carb, including ketogenic (very low-carb), diets — as the name implies, these diets focus on restricting carbohydrate foods and increasing protein and foods high in healthy fats (including saturated). Low-carb diets have shown effectiveness for weight loss. However, their long-term cardiovascular effect is not yet clear. Research suggests a complex picture of potential benefits and risks.
- Paleo diets — these mimic the presumed eating habits of Paleolithic humans. The diets include lean meats, fish, fruits, vegetables, nuts and seeds while excluding dairy, grains and processed foods. Some studies suggest metabolic benefits, but researchers debate long-term cardiovascular effects.
- Plant-based diets — these range from vegetarian to vegan and emphasise fruits, vegetables, whole grains, nuts and seeds, while reducing or eliminating animal products. Research supports cardiovascular benefits of plant-based eating. Concerns include nutrient deficiencies if these diets are not carefully managed. They may be impractical for people with specific dietary needs, cultural preferences or geographic constraints.
There is some consensus among doctors and dietitians on fundamental principles for a heart-healthy diet. Ironically, Johannesburg cardiologist Dr Riaz Motara sees the “major problem” that people are supposedly “eating healthier”. “Unfortunately, the food we consume lacks the right amount and quality of micronutrients,” says Motara. “We are starving in the face of plenty. Foods that many people regularly consume are pro-inflammatory.”
Research suggests that 70% of all deaths related to chronic lifestyle illnesses is related to chronic low-grade inflammation. “It is almost always the inflamed plaque in our arteries that ruptures to cause the heart attack and not the chronic stable plaque,” Motara says.
In the US, research shows that about 60% of the population has high inflammation levels, he says. Research on the prevalence of chronic inflammation in SA is limited. However, given the country’s high burden of heart disease, South Africans are likely to have high inflammation levels.
Motara’s advice on heart-healthy eating:
- Cut out refined sugar and starch.
- Follow an anti-inflammatory diet by consuming omega 3-rich fats and reducing pro-inflammatory omega 6-rich fats.
- Avoid omega 6-rich cooking oils; favour ghee, olive oil and coconut oil.
- Reduce the amount of animal protein but eat better quality (grass-fed where possible).
- Go green — consume more vegetables and green leaves.
SA-born, Israeli clinical dietitian Justine Friedman, a graduate of Wits University and the University of Cape Town, agrees that inflammation is a major contributing factor to heart disease and that cholesterol levels alone are not reliable indicators of cardiovascular disease.
“Elevated blood sugar levels also contribute to plaque build-up in the arteries,” Friedman says. “We all have plaque build-up as a natural result of ageing. It’s only when this causes narrowing and blockages that risk to life is greater.”
Friedman’s top tips for a heart-healthy diet include balance, moderation and a wide range of nutrient-dense foods that provide essential vitamins, minerals, and antioxidants to support overall cardiovascular health.
“Health depends not only on the food we eat,” she says. “It is impacted by genetic and lifestyle factors, such as whether people smoke and stress and physical activity levels.”
To that end, Friedman adds “mindset mentoring” to her practice. She uses research and a “mindful” approach to food to help clients “shift mindsets, manage triggers, reduce daily stress and intuitively understand their bodies’ needs”.
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