‘Meat’ of plant-based diets: really best for people and planet?

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By Marika Sboros

Plant-based foods are a global trend. They are also blooming marvellous for bottom lines of companies producing these foods, as a Bloomberg Intelligence report shows.

The trend is from vested interests vigorously pushing for a “global transition to sustainable diets”. In a recent UK study, researchers make that call. They also use “sustainable’ as a synonym for diets “typically high in plant-based and whole foods and low in animal-sourced foods”.

The ‘meat’ of their claim is that plant-based diets have “co-benefits for human health and environmental sustainability”.

That claim is the trend’s beating heart.

Among those promoting it are nutrition professors at Harvard’s TH Chan School of Public Health in the US and Oxford and Nottingham universities in the UK. Down Under, academics at  Sydney and Adelaide universities are prime movers.

In November 2020, the University of Adelaide announced a $2.5 million joint-venture with Nottingham  “to take on the challenge of getting more sustainable, healthy, plant-based food into people’s diet”.

But are plant-based foods really healthier than animal foods for people and the planet ? Do plant foods deserve the health “halo” many appropriate to them? Is it easy to replace meat with plant alternatives and not lose out on natural nutrient density of animal foods?

That depends on who you talk to.

The scientific debate is ongoing with both sides claiming strong evidence in support of their views. And replacing animal foods with plant alternatives safely is proving much more complex than most people might think.

Changing Plant-Based Landscape

Advances in food science and technology have changed the landscape rapidly.  Plant-based foods have moved from a “niche pursuit” and “moderately off-putting experience” in the 1980s to 1990s to “de rigueur in many settings”, as Australia-based epidemiologist Dr Gideon Meyerowitz-Katz has noted. From a coffee shop serving five types of plant-based milk, supermarket shelves are now stocked with non-meat alternatives, he writes.

One problem plaguing the plant-based foods industry is nutritional content that differs widely – and wildly. An aggravating factor is over-enthusiastic marketing hype, at best. At worst, it’s flagrantly dishonest (aka false) advertising.

Dr Nicola Guess

A recent major study by UK, US and Canadian researchers highlights these issues. The lead author is Dr Nicola Guess, an associate professor at the University of Westminster and a research fellow at King’s College London. She makes a special study of food to treat and reverse symptoms of diabetes.

Guess and co-authors say their pre-print study is probably the “broadest analysis of the plant-based landscape to date”. They have assessed the nutritional content of commercial, plant-based products across multiple sectors  – supermarkets, fast-food and sit-down restaurants, food delivery companies and manufacturers. They have built a database of close to 4000 products and identified 3488 as unique.

The authors show marketers of these products often deliberately claim them as “healthy alternatives”. Plant-based products, particularly meat alternatives, also undergo processing whereas meat counterparts do not. However, for many plant-based products, meat-based counterparts may also be processed.

The authors acknowledge study limitations, including relying on nutrition information available online for products. However, they have deliberately performed their data collection “through the lens of a person without expert nutritional knowledge”.

Nutrition Snapshot

Thus, their focus was items “visible for (those) seeking to consume more plant-based products … in the supermarket, ordering food at home or eating out”. The sector providing meals and products with optimal nutritional content in their analysis was meal-delivery services.

However, the study design makes information about the foods “potentially incomplete”, Meyerowitz-Katz writes. It’s a “snapshot taken at a specific point (mid-late 2020)”, he says. Given the speed of the market’s growth, “it will probably not be representative of these foods forever”.

The data also show significant variation in protein and sodium content of plant-based foods. Supermarkets products labelled as “meat alternatives”, for example, contain less than 5g of protein per serving. They are also higher in sodium. In contrast, protein-rich plant-based products available in supermarkets are not signposted on packaging or supermarket websites.

They say that dairy alternatives, in general, offer “poor nutritional quality”. As well, the researchers conclude that plant-based foods “tend to be lower in saturated fat and sodium than their meat-based counterparts”. They present that conclusion as if it’s settled science as necessarily a good thing. It isn’t.

Robust scientific research over decades shows that both saturated fat and sodium (salt) are not the health demons that conventional dietary advice suggests.

A good book on the subject of salt is The Salt Fix by US cardiovascular (CVD) researcher Dr James DiNicolantonio.

There’s also the issue of the currently unproven “diet-heart hypothesis”  – that fat in your diet equals fat in your arteries. In other words, eating saturated fat significantly increases your risk of premature death or disability from heart attack or stroke.

A seminal book on that topic is The Big Fat Surprise, Why Butter, Eggs And Cheese Belong In A Healthy Diet, by Nina Teicholz, a US-based science journalist and author of a ground-breaking book.

Perils Of Plant-Based Foods

Teicholz has relayed her concerns about plant-based replacements to me via email.

“Firstly, their carbohydrate content is significantly higher,” she says. This is “problematic for people with diabetes, obesity and other diet-related diseases”. High-carbohydrate consumption will worsen these conditions.

The plant-based diets that Guess and co-authors have assessed also do not provide sufficient protein for basic health, Teicholz says. “The average adult needs at least 30 grams of protein per meal to sustain muscle mass and other health aspects. The plant-based meals consistently fell short of this target,”

The study also reported on 18 times more meat-based restaurant meals than vegan meals. And eight times more than vegetarian meals, Teicholz says. This will “inevitably distort the data”, she says. “Smaller sample sizes lead to less reliable results.”

University of Hull researcher Craig Scott has noted that chronic diseases and obesity rates have risen in correlation with a reduced intake of dietary fat (including saturated).

He writes on the topic in The Conversation, titled We’re so indoctrinated that saturated fat is bad that we don’t listen to the science. He says that the science on dietary fat has moved on but conventional nutritional advice lags behind.

UK interventional cardiologist Rahul Bahl is also deputy editor of the BMJ Open Heart journal. He has noted an over-reliance in public health on saturated fat as the “main dietary villain for cardiovascular disease”. In an editorial, he sees this as  distracting from the risks posed by other nutrients, such as carbohydrates.

However, “replacing one caricature with another does not feel like a solution”, he writes.  It is plausible that “both can be harmful”. Or that the relationship between diet and cardiovascular (CVD) risk is “more complex than a series of simple relationships with  proportions of individual macronutrients”.

Dietary Guidelines Can Help

There remain “reasons to postulate a causal connection between fat consumption and coronary heart disease”. However, it’s also “reasonable to expect that RCTs might produce negative results”.

Individual sessions of dietary advice are unlikely to alter actual human behaviour over long periods, he writes. Despite this, nutritional guidelines can be beneficial. They can alter the content and packaging of available food and set  normative standards for what is considered healthy.

Others say that the choice between plant and animal foods for health need not be binary. In a Harvard study in the Journal of the American College of Cardiology in 2017, Dr Ambika Satija says just that. Data are “encouraging in the sense that you don’t have to completely eliminate animal foods from your diet … to get a heart benefit”.

Similarly, the authors of an editorial on the Harvard study refer to the real “meat” of the issue. It is the “mindset” that healthful eating is an “all-or-none phenomenon”.

Healthy plant-based diet indices represent both a challenge and an opportunity for cardiology, they say. Heart specialists too often simply “treat CVD’s downstream effects” Rather than obliterating its roots, they leave “primary and secondary prevention opportunities on the table”. Cardiologists must educate themselves on dietary patterns, risk, and outcomes. They should focus more on “turning off the faucet”, not “mopping up the floor”, the authors say.

They recommend starting with smaller dietary tweaks rather than major changes. This would be “more encouraging and sustainable for those finding it difficult to make a complete, precipitous change in dietary habits”. They favour the simple approach that UK science and environmental journalist Michael Pollan coined: “Eat food. Not too much. Mostly plants”.

Feeding A ‘Ferocious Biological Drive’

A confounding variable in the plant-versus-animal foods debate is the reasons people give for their choices. These are many, varied and often have nothing whatsoever to do with health.

Eating is rightly described as a “ferocious biological drive”. It is as emotional, and social as it is hedonic.

One driver of the plant-based trend is the desire for more “clean” or “ethical” eating. Experts define ethical eating as “the consideration of economic, social and environmental impacts of purchasing or consuming foods and beverages”.

The biggest problem with the health “halo” that hangs over plant-based foods is not just that it’s unscientific. It’s also highly politicised. A brilliant new book on that vexed topic is The Great Plant-Based Con by Jayne Buxton.

The sub-title of Buxton’s book speaks volumes: Why eating a plants-only diet won’t improve your health or save the planet. It’s an essential riveting read for anyone concerned with personal and planetary health.

Along with religious and spiritual imperatives, the plant-based movement is often also a front for militant animal rights activism. Some people don’t want to eat anything that “once had a face”. Or that involves killing anything high on the scale of “sentient beings”. That scale is the subject of contentious debate on its own.

In May 2021, the UK government introduced a first-of-its-kind bill to recognise animals (vertebrates only) as sentient beings. Press releases heralded an action plan to  “revolutionise the treatment of animals in the UK”. It also aimed to introduce measures to protect the welfare of animals abroad.

Tips To Get Your Diet Right

For consumers wanting to meet their protein needs with animal or plant proteins, or a mix of both, US cardiologist Bret Sher has some tips:

  • Gram for gram, animal protein sources are more complete and have better absorption and muscle-building effects compared to plant-only foods. They have more additional nutrients, and contain fewer calories and carbohydrates.
  • It’s possible to meet all of your protein needs with plant-only sources. That’s if you choose soy or mix and match your plant sources to get a full amino-acid profile.
  • No high-quality data exist to support the concern that eating more animal products comes with adverse health effects. If you lead an otherwise healthy lifestyle, you should be able to enjoy your favourite protein sources.
  • Like my Facebook Page
  • Follow me on Twitter @MarikaSboros

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