A heart attack that nearly killed his father when he was 47 changed the life of Dr Dariush Mozaffarian, inspiring him to dedicate his career to understanding how food affects human health.
Mozaffarian was 17 when his father suffered a massive heart attack in his sleep, followed by two cardiac arrests. Doctors performed an emergency quintuple bypass to restore blood flow through five severely blocked arteries.
His father spent weeks on a ventilator in intensive care, barely alive, before surviving and returning to work as an endocrinologist after months of rehabilitation.
The experience shaped Mozaffarian’s approach to medicine and public health. He went on to study at Stanford and Columbia universities in the United States before earning a doctorate in public health from Harvard University.
Now a leading cardiologist and public health scientist, Mozaffarian advocates better nutrition as a way to prevent disease.
In his book, Food Is Medicine, he challenges common assumptions about diet, arguing that people should focus less on eating fewer calories and more on consuming foods that protect and support the body.
“We are growing sick and dying young because of what we eat,” he says.
Mozaffarian maintains that changing dietary habits can improve health at any age.
“We have done many studies in people who are over 70 and dietary habits still matter at older ages,” he says. “It’s never too late to start and any time you change your diet – for better or for ill – you’re going to affect your health. I’m already 10 years past my father’s heart attack.”
Stop counting calories
Excess weight forces the heart to work harder and can alter its structure, increasing the risk of heart failure, heart attacks and irregular heart rhythms. However, Mozaffarian argues that conventional calorie-counting approaches do not adequately explain why people gain weight.
Although the principle of energy intake and expenditure remains valid, he says the calories listed on food packaging do not necessarily reflect how the body processes and absorbs energy.
He notes that obesity rates have continued to rise despite reported declines in calorie consumption and increases in physical activity. He also points to a reduction in the energy the body burns at rest as a possible contributing factor.
Mozaffarian said the type of food consumed also affects how the body absorbs calories.
He explained that the gut microbiome processes food differently depending on dietary patterns.
People who eat traditional diets rich in minimally processed foods may absorb a different proportion of calories than those who consume highly processed foods.
Research by Mozaffarian has also challenged the assumption that calorie-dense foods necessarily cause weight gain.
He found that higher consumption of nuts, whole grains, fruit, vegetables, seafood and yoghurt was associated with greater weight loss.
“This is the primary principle of Food Is Medicine,” he says. “I tell people not to count calories but instead track the quality of what you eat. We need to be focusing on eating more of the good foods, not less of the ‘bad’ ones.”
Rethinking saturated fat
Mozaffarian also questions the long-standing emphasis on avoiding saturated fat to prevent heart disease.
He says dietary guidelines began advising people to limit fat around 1980, based on concerns about saturated fat and dietary cholesterol.
However, he argues that research published since then has found no consistent overall relationship between saturated fat intake and heart disease risk.
“More than 20 subsequent studies have since looked at saturated fat and heart disease risk…and identified no overall relationship,” Mozaffarian writes. “While saturated fat raises LDL cholesterol, it also produces a multitude of other, offsetting effects.”
In his own research examining the relationship between nutrients and the progression of arterial plaque in women, higher saturated fat intake was associated with less plaque progression, while higher carbohydrate consumption was associated with more.
He attributes some of the potential harm from refined carbohydrates to their rapid digestion, which can cause sharp rises in blood sugar and insulin levels.
Mozaffarian says foods such as cheese and milk can form part of a healthy diet, while eggs, poultry and butter appear neutral in his assessment. He considers unprocessed red meat acceptable in moderation, recommending one or two servings a week.
He cautions that consuming larger amounts of red meat may increase inflammation and cancer risk.
Choose an anti-inflammatory diet
Mozaffarian points to a clinical trial conducted in Lyon, France, in 1994 that examined the effects of a Mediterranean-style diet on about 600 people recovering from a heart attack.
Participants followed a diet rich in fruit, vegetables, fish and grains. They replaced red meat with poultry and butter and cream with a canola oil spread containing omega-3 and omega-6 fats.
After five years, the group following the dietary plan experienced 70 per cent fewer cardiovascular events than the control group, despite only minimal differences in cholesterol levels, blood pressure and body weight.
The findings support the argument that cardiovascular health depends on more than cholesterol levels alone.
Mozaffarian explains that inflammation within artery walls plays a key role in the development and instability of plaque, which can contribute to heart attacks and other serious cardiovascular events.
Poor dietary habits can contribute to persistent, low-level inflammation, increasing the risk of complications.
“If [arterial] plaque is not inflamed, it’s not actually likely to cause you any problems,” he says. “The plaques that are more problematic are those which are inflamed – these are more unstable and increase the risk of serious cardiovascular events.”
He adds that nutrition can influence both the amount of plaque that develops and whether it becomes unstable.
Replace refined carbohydrates with whole foods
Mozaffarian divides foods into three broad categories, prioritising minimally processed foods that support health.
The first category includes fruit, nuts, seeds, vegetables, beans, fish, plant oils and yoghurt. These foods provide nutrients, fibre and other compounds that support the gut microbiome and overall health.
He highlights foods rich in unsaturated fats, including walnuts, peanuts, pistachios, sesame seeds, pumpkin seeds and sunflower seeds. Soybean, rapeseed, corn and sunflower oils are also sources of omega-6 fats.
Olive and avocado oils, along with nuts such as almonds, hazelnuts, macadamias, pecans and cashews, provide plant-derived monounsaturated fats.
Fish supplies omega-3 fats, while yoghurt provides beneficial bacteria associated with fermented foods.
The second category comprises minimally processed animal foods. Highly processed packaged foods rich in refined starches and sugars fall at the least healthy end of his classification.
“We know now that rapidly digested carbohydrates – refined grains, flours, starches and sugars – are more important to avoid than saturated fat,” Mozaffarian writes.
He explains that rapidly digested carbohydrates can cause sharp increases in blood sugar, while the liver can convert excess energy from these foods into fat. Fat accumulation around abdominal organs, known as visceral fat, is associated with increased health risks.
Mozaffarian acknowledges that avoiding packaged foods entirely is not always practical. However, he encourages people to choose foods that are as close to their natural state as possible.
“I don’t want to make people feel guilty, obviously sometimes we have to buy packaged food, but ultimately we should be buying food as close to nature as possible.”
The Telegraph
