Exactly how good are plant-based diets?

Many of us are cutting back on our meat consumption, and for many different reasons. But what does it really mean for our health and our planet? Here’s what the research says.

While around one in 10 people in Australia and New Zealand are vegetarian or vegan, many more have recently decided simply to eat less meat. Going plant based, it seems, is more popular than ever.

A range of factors from health and environmental concerns to cost-of-living pressures can provide the motivation to reduce meat consumption, but how effective is making the change in addressing those issues? And does it only provide benefits if you go plant based full time? The latest research is revealing.

How healthy are plant-based diets?

In the past decade, research has linked plant-based diets with improved heart and gut health, immunity, mood and even dental health.

The results of a study published in 2022 has more good news. Investigating the characteristics of the best diet for longevity, researchers reviewed hundreds of studies and discovered that the optimal eating pattern for a long healthy life appeared to be one that’s largely – but not solely – plant based. Recent research has also shown that healthy plant-based diets are associated with a lower risk of developing type 2 diabetes and dementia. Another 2022 study showed that plant-based omega-3s, found in walnuts and flaxseeds, can reduce the risk of heart disease for people who don’t eat seafood.

However, plant-based diets aren’t always – or automatically – healthy. Research suggests those based around less nutritious foods can increase the risk of some health problems. For example, researchers at Australia’s Bond University found that low-quality plant-based diets, high in processed foods, may bump up the risk of depression.

There’s also research showing that without professional advice or careful planning, healthy vegan and even vegetarian diets may lead to deficiencies in a number of important micronutrients including zinc, calcium and vitamin B12.

A review study published late last year suggests it may be flexitarian diets that include large quantities of plant-based food, moderate amounts of fish, poultry, eggs and dairy and very low amounts of red meat, that strike the ideal balance for health, compared with strict, exclusively plant-based diets.

Are plant-based meat substitutes good for you?

There’s at least three times the amount of these products on the market today compared with a decade ago, and 45 per cent of people believe they’re healthier and more nutritious than meat. So are they? According to new Australian research, the answer is yes … and no.

While they are healthier than their processed meat-based equivalents like sausages, bacon and burgers, they’re still a highly processed food. Plus, of the 132 plant-based meat products analysed, only 12 per cent were fortified with key micronutrients like zinc, iron and vitamin B12, that are found in meat.

“Both plant-based and processed meats mostly fall into the ultra-processed category, so this raises concerns about their role in a healthy diet,” lead author of the study, Maria Shahid, said when the results were released earlier this year.

“While we found plant-based meat products were generally healthier than their processed meat equivalents, healthier alternatives would still be lean unprocessed meats and legumes, beans and falafel,” she explained.

Does plant based pay off for the planet?

A 2019 United Nations report declared that the Western world’s high consumption of meat and dairy was fuelling global warming. In June this year, a UK study went further, revealing that any action we took to protect the planet against climate change would fall short unless we reduced greenhouse gas emissions from the global food system. Then, just a month later, new research reaffirmed how important plant-based diets were if we hoped to achieve that, showing that vegan diets resulted in 75 per cent fewer climate-heating emissions compared with diets where 100g of meat is consumed daily.

The power of plant-based diets for the planet aren’t all equal though. Research also shows healthy plant-based diets are significantly better for the environment than less-healthy ones.

You don’t need to commit to plant based full time to make a difference either. Last year, Australian researchers said that eating a flexitarian diet, comprising predominantly plant-based foods while not cutting out any food groups entirely, can drastically reduce greenhouse emissions too.

What about your bank balance?

Ten years ago, plant-based diets were declared some of the most budget friendly, and a study published recently shows that, in countries like Australia, eating sustainably is still the cheaper option. While vegan diets can reduce food costs by up to a third, vegetarian diets aren’t far behind. Even flexitarian diets can lower your food bill by about 14 per cent. Remember though, these figures are based on buying whole foods rather than those highly-processed foods, including meat replacements.

What a healthy plant-based diet looks like

A healthy plant-based diet is rich in whole, rather than processed foods.

Nuts, seeds and legumes are an important source of zinc in plant-based diets, as it’s otherwise sourced from meat, poultry and seafood, while brassicas like kale and broccoli are good non-dairy sources of calcium. Plant sources of vitamin B12 include nori seaweed, mushrooms and fermented foods, or use supplements.

Research shows flexitarian diets modelled on eating patterns like the Mediterranean diet, prioritising plant-based foods but including animal products, may strike the ideal balance between health and environmental benefits and can be easier to follow too.

5 budget-friendly plant-based staples

• Canned chickpeas: Whip up hummus with garlic, tahini and lemon
• Canned tomatoes: Use these for pasta sauces and pizza bases
• Brown rice: A perfect wholegrain base for a speedy weeknight stir-fry.
• Raw mixed nuts: Save $ on value packs. Portion out and bag for snacks on the go.
• Frozen veg: The freezer is your friend! Frozen veg are just as nutritious as fresh at a fraction of the price.