It’s no secret our diet can have a major impact on our health. But our new umbrella review, published this week in Advances in Nutrition, provides compelling evidence that pro-inflammatory diets increase the risk of 27 chronic diseases and premature death. An umbrella review is a review of multiple reviews, and is among the highest levels of evidence.
What’s more, reducing inflammation by eating better could cut our risk of developing certain chronic diseases.
A pro-inflammatory diet is one that, over the long-term, may lead to increased inflammation in the body. Such a diet often includes high amounts of commercially baked goods, fried foods and fatty meats, and at the same time is low in fruits, vegetables and other healthy foods.
We reviewed and pooled data from 15 meta-analyses, which is a type of study that summarises data from lots of individual studies. All up, we looked at 38 health outcomes from four million people from across the world.
We found strong evidence for a link between pro-inflammatory diets and heart attacks, premature death and certain cancers including bowel cancer, pancreatic cancer, respiratory cancers and oral cancers. There was also evidence pro-inflammatory diets were linked with depression.
By bringing together data from populations all over the world, we were able to provide a comprehensive and reliable overview of the research to date. We also looked at the strength of the evidence of studies and found that for most outcomes, evidence was limited, highlighting the need for more research.
Because of the type of study we did, we were unable to determine cause and effect, so we can’t conclusively say pro-inflammatory diets cause these chronic diseases yet. But we found clear evidence a pro-inflammatory diet is linked with an increased risk of developing certain chronic diseases and premature death.
But what is inflammation, and what role does our diet play?
Inflammation is part of our body’s natural defence processes. It’s our immune system’s response to an irritant, be that an infection or injury, and is often a welcome sign our body is working to protect us. For example, swelling when you roll your ankle delivers resources to help repair the damage.
But when inflammation can’t be turned off, this process may start to work against us.
Persistent low levels of inflammation (known as chronic inflammation) can be problematic and is linked to premature death and conditions including coronary heart disease and depression, to name a few.
We can detect whether chronic inflammation exists by a simple blood test that looks at levels of inflammatory markers in the blood. Our diet is one factor that influences levels of these inflammatory markers, among many.
Take the “Western diet”, for example, which consists of calorie-dense, ultra-processed foods and is low in fruits, vegetables and other plant-foods. This type of dietary pattern has been linked to higher levels of inflammation.
Conversely, healthy dietary patterns have been linked to lower inflammatory markers. This includes the Mediterranean diet, which is high in fruits, vegetables, legumes, olive oil and oily fish, and low in ultra-processed, refined foods.
The potential for diets to be pro- or anti-inflammatory can be measured using a tool known as the Dietary Inflammatory Index.
The index takes into account a number of nutrients, compounds, and foods that have been identified in research as having either anti- or pro-inflammatory properties.
Using foods to fight inflammation
Despite promising marketing claims you might see online, there’s no magic supplement or superfood to combat all our inflammation woes.
Instead, you should focus on improving your overall diet quality, rather than on a single food or nutrient. This is because many nutrients and foods interact with one another and can work together to improve inflammation.
As for what to eat?
- Load up your plate with a wide variety of plant foods such as fruits, vegetables, wholegrains and legumes, like chickpeas and lentils. These foods are high in anti-inflammatory nutrients, such as fibre and a range of vitamins. They also contain unique “phytochemicals”, such as polyphenols which are plant compounds that have potential antioxidant and anti-inflammatory effects
- Flavour your food liberally with herbs and spices, and sip on tea and coffee regularly. These are also great sources of polyphenols
- Enjoy oily fish regularly, such as salmon, sardines and mackerel, which are rich in anti-inflammatory omega-3 fatty acids
- Reduce your intake of foods that may fuel inflammation. These include foods high in trans and saturated fats, found in commercially baked goods, fried foods and fatty meats.
Given almost half of us live with a chronic disease, and many more are likely at risk, adopting an anti-inflammatory diet could be very beneficial for your health, and may help you live longer too.
As the new year starts, you may be planning to tackle COVID-related weight gain. Before you do, consider that it may be better to focus on your eating patterns, rather than looking to the latest fad diet.
Emotional eating and weight gain
A survey of 13,829 Australian adults found one in five reported drinking more alcohol during COVID. In a survey of over 22,000 drinkers in the United Kingdom, one-quarter reported drinking more than usual over the previous week.
In Italy, of 602 people surveyed about changes in their eating habits during isolation, almost half said they sought “comfort foods” and ate more to feel better.
Eating and drinking alcohol boosts the release of “feel good” chemicals in your brain, making you feel better in the short term.
According to a global WebMD poll on self-reported weight gain during the pandemic, about one-quarter of people in Hong Kong and Germany reported gaining weight, roughly 45% in Australia, Canada and the UK, and over 60% in Brazil and Italy.
United States respondents who reported putting on weight were asked to estimate how much weight they thought they had gained. Some 49% said less than 3 kilograms, 26% said 3-4kg, and 25% reported more than 4.5kg.
Participants believed a lack of exercise, stress eating and drinking more alcohol were contributing factors.
It’s not just about weight
While weight gain can increase your risk of health problems, recent research suggests having healthy eating patterns is more important than weight.
A US study of 210,000 adults followed for up to 32 years found that irrespective of body weight, having a high diet quality was associated with lower risk of heart disease and stroke compared to having low diet quality.
A “high-quality” diet includes lots of variety within the basic food groups of vegetables, fruit and wholegrains, and includes limited junk food. A “low-quality diet” is the opposite.
Similarly, a Swedish study followed 79,000 adults over 21 years and found that among people with a higher body weight, also having a high-quality diet was protective against dying from any cause. But having a body weight in the healthy range was not protective among those who had a low-quality diet.
4 tips to improve your diet and beat COVID kilos
Home cooking and eating together
If you spent more time cooking and eating meals at home during the pandemic, keep doing it. As well as being better for you than eating take-away foods and ready-made meals, it promotes well-being.
A study of 160 adults found people who ate healthy foods cooked at home experienced more intense positive emotions and worried less, compared to people who ate away from home.
For adolescents, a review found frequent family meals were associated higher self-esteem and other indicators of better mental health.
Eat more vegetables and fruit
A US study of 133,468 adults found those who increased their vegetable and fruit intakes lost weight. Every extra daily serve of fruit was associated with a weight loss of 250 grams over a four-year period, and every extra daily serve of vegetables with a loss of 110 grams. People who ate more berries, apples, pears, cauliflower, green leafy vegetables and carrots experienced greater weight loss.
This has well-being benefits too. For example, an Australian study which followed 12,385 adults from 2007 to 2013 and found greater life satisfaction, happiness and well-being among those who increased their intake of vegetables and fruit.
Try buying bigger quantities and a greater variety of vegetables and fruit when you do your grocery shopping.
Keep a food diary
Recording what you eat and drink and then checking the kilojoule and nutrient content helps boost your knowledge of what’s in various foods and drinks. It also increases awareness of your eating habits, especially snacking. You can use an app or pen and paper.
Once you’ve recorded your food and drink intake for a few days, you will notice areas to target for improvement.
You might also consider keeping a mood diary. This can help you identify other ways to improve your diet quality. The mood you’re in affects your food choices and your food choices affect your mood. Keeping track of both food and mood helps to identify triggers for eating.
Plan meals and snacks ahead
Check what ingredients you already have and plan meals and snacks to use these up. Next write a grocery list, just for what you need. Even if you’re staying home, prepare your lunch and snacks for the day in advance. This saves you time, money, limits food waste and reduces the number of times you have to think about food.
Visit the No Money No Time website to check your diet quality score using our free healthy eating quiz and find simple, inexpensive and healthy recipes.
If you’d like to learn more about food, nutrition and weight management, enrol in our free online course, The Science of Weight Loss – Dispelling Diet Myths, which starts on January 27.
Humans (and our ancestors) have been processing food for at least 1.8 million years. Roasting, drying, grinding and other techniques made food more nutritious, durable and tasty. This helped our ancestors to colonise diverse habitats, and then develop settlements and civilisations.
Many traditional foods used in cooking today are processed in some way, such as grains, cheeses, dried fish and fermented vegetables. Processing itself is not the problem.
Only much more recently has a different type of food processing emerged: one that is more extensive, and uses new chemical and physical techniques. This is called ultra-processing, and the resulting products ultra-processed foods.
To make these foods, cheap ingredients such as starches, vegetable oils and sugars, are combined with cosmetic additives like colours, flavours and emulsifiers. Think sugary drinks, confectionery, mass-produced breads, snack foods, sweetened dairy products and frozen desserts.
Unfortunately, these foods are terrible for our health. And we’re eating more of them than ever before, partially because of aggressive marketing and lobbying by “Big Food”.
Ultra-processed foods are harming our health
So concludes our recent literature review. We found that more ultra-processed foods in the diet associates with higher risks of obesity, heart disease and stroke, type-2 diabetes, cancer, frailty, depression and death.
These harms can be caused by the foods’ poor nutritional profile, as many are high in added sugars, salt and trans-fats. Also, if you tend to eat more ultra-processed foods, it means you probably eat fewer fresh and less-processed foods.
Industrial processing itself can also be harmful. For example, certain food additives can disrupt our gut bacteria and trigger inflammation, while plasticisers in packaging can interfere with our hormonal system.
Certain features of ultra-processed foods also promote over-consumption. Product flavours, aromas and mouthfeel are designed to make these foods ultra-tasty, and perhaps even addictive.
Ultra-processed foods also harm the environment. For example, food packaging generates much of the plastic waste that enters marine ecosystems.
And yet, we’re eating more and more of them
In our latest study, published in August, we found ultra-processed food sales are booming nearly everywhere in the world.
Sales are highest in rich countries like Australia, the United States and Canada. They are rising rapidly in middle-income countries like China, South Africa and Brazil, which are highly populated. The scale of dietary change and harms to health are therefore likely immense.
‘Big Food’ is driving consumption
We also asked: what explains the global rise in ultra-processed food sales? Growing incomes, more people living in cities, and working families seeking convenience are a few factors that contribute.
However, it’s also clear “Big Food” corporations are driving ultra-processed food consumption globally — think Coca-Cola, Nestlé and McDonald’s. Sales growth is lower in countries where such corporations have a limited presence.
Globalisation has allowed these corporations to make huge investments in their overseas operations. The Coca-Cola System, for example, now includes 900 bottling plants worldwide, distributing 2 billion servings every day.
As Big Food globalises, their advertising and promotion becomes widespread. New digital technologies, such as gaming, are used to target children. By collecting large amounts of personal data online, companies can even target their advertising at us as individuals.
Supermarkets are now spreading throughout the developing world, provisioning ultra-processed foods at scale, and at low prices. Where supermarkets don’t exist, other distribution strategies are used. For example, Nestlé uses its “door-to-door” salesforce to reach thousands of poor households in Brazil’s urban slums.
Rising consumption also reflects Big Food’s political power to undermine public health policies. This includes lobbying policymakers, making political donations, funding favourable research, and partnerships with community organisations.
Here’s how things can change
The evidence that ultra-processed foods are harming our health and the planet is clear. We must now consider using a variety of strategies to decrease consumption. This includes adopting new laws and regulations, for example by using taxation, marketing restrictions and removing these products from schools.
We cannot rely on industry-preferred responses such as product reformulation alone. After all, reformulated ultra-processed foods are usually still ultra-processed.
Further, simply telling individuals to “be more responsible” is unlikely to work, when Big Food spends billions every year marketing unhealthy products to undermine that responsibility.
Should dietary guidelines now strongly advise people to avoid ultra-processed foods? Brazil and other Latin American countries are already doing this.
And for us as individuals the advice is simple — avoid ultra-processed foods altogether.
Phillip Baker, Research Fellow, Institute for Physical Activity and Nutrition, Deakin University, Deakin University; Mark Lawrence, Professor of Public Health Nutrition, Institute for Physical Activity and Nutrition, Deakin University, and Priscila Machado, Research Fellow, School of Exercise & Nutrition Science, Faculty of Health, Deakin University
Eating about five servings of fruit and vegetables a day is widely promoted as a key part of a healthy diet. This is because consuming fruit and vegetables is linked to lowering the risk of health problems such as coronary heart disease, stroke and some types of cancer.
But there’s still confusion about the role that fruit and vegetables have in preventing type 2 diabetes. Evidence from research has been inconsistent, partly because most studies have relied on participants remembering what they ate – which can be inaccurate. But our latest research found that people who regularly ate more fruit and vegetables in their diet had half the risk of developing type 2 diabetes compared to those who ate less.
Since research shows that type 2 diabetes can be prevented through a healthy diet, we wanted to know just how important eating fruit and vegetables is as part of that. We conducted the world’s largest study that measured blood levels of vitamins linked to fruit and vegetable consumption in a population. This method of using objective nutritional biomarkers – indicators of dietary intake, metabolism or nutritional status that are present in our blood – cuts out the errors and inaccuracies that affected previous studies. We also asked people to report what specific foods they ate to compare with the biomarker data.
We followed a group of 340,234 people from eight European countries. We specifically studied biomarkers in 10,000 people who developed type 2 diabetes during follow-up and compared them with 13,500 people who didn’t.
The biomarkers we measured were levels of vitamin C and six different carotenoids or plant pigments in the blood. These biomarkers tell us about the fruit and vegetables a person gets in their diet. We then calculated the total sum of these seven nutrient biomarkers as a composite score, then split scores into five categories ranging from lowest consumption to highest.
We found that the higher the biomarker score level, the lower the risk of future type 2 diabetes. People whose biomarker score was in the top 20% of the population had a 50% lower risk of developing type 2 diabetes compared to those with lower scores. We also found that eating around 66 grams of fruit and vegetables daily could potentially cut risk of type 2 diabetes by a quarter.
Our findings build upon the results of a smaller study of 21,831 people living in England, 735 of whom developed type 2 diabetes. This study showed a strong link between higher blood vitamin C level and lower risk of diabetes. But the link was weaker when examining fruit and vegetable intake as reported by the participants. By repeating this work on a larger scale and in several countries, our results further strengthen evidence that these results are likely to be repeated in other populations, too.
Five a day
Since UK dietary guidelines consider each portion of fruit or vegetable to be 80 grams, our study shows eating even one portion per day could have health benefits. For instance, seven cherry tomatoes, two broccoli spears, or one banana would all roughly equal one portion.
Although “five a day” has been around for decades, fruit and vegetable consumption remains low. Only one in seven people over 15 eat at least five portions everyday – and one in three people don’t eat any daily. Encouragingly, our results show there are large potential benefits from making small changes to our diets.
Our research highlights that reduced risk isn’t just because of certain nutrients or vitamins. Rather, the benefits we observed are because of the combination of multiple beneficial components found in fruits and vegetables. Alongside vitamin C and carotenoids, other components including fibre, potassium and polyphenols, which have beneficial effects on weight, body inflammation, blood sugar levels, and keep gut bacteria healthy. And a diverse variety of fruit and vegetables has the greatest health benefits, as you consume more of these beneficial components.
We also took into account how several factors – including age, gender, body mass index, education level, occupation, smoking, alcohol intake, physical activity and use of vitamin supplements – all affected the risk of type 2 diabetes. We found that the biomarker results linked to fruit and vegetables were independent of these other factors – so regardless of whether a person smoked or was physically active, eating a diet rich in more fruit and vegetables is relevant for lowering the risk of developing type 2 diabetes.
Our research doesn’t establish cause and effect, because we did not intervene with dietary change – rather we observed what happened over time to participants with different blood biomarker levels. But, by using these objective measures and a large sample size in different countries with varying diets, our confidence in these findings is increased. We still don’t yet know whether our findings would be different among different ethnic groups, which should be a focus of future research.
It’s well known that fruit and vegetables are an important part of maintaining good health throughout life, but we also know that in reality the majority of people do not eat enough of them. Our study shows that even just a small increase in the amount of fruits or vegetables you get in your diet can significantly reduce your risk of developing type 2 diabetes.
Nita Forouhi, Programme Leader, MRC Epidemiology Unit, University of Cambridge; Ju-Sheng Zheng, Principal Investigator, Human Nutrition and Epidemiology, Westlake University, and Nick Wareham, Director of the MRC Epidemiology Unit, University of Cambridge
Home cooks have been trying out their skills during isolation. But the way food tastes depends on more than your ability to follow a recipe.
For example, eating from a heavier bowl can make you feel food is more filling and tastes better than eating from a lighter one.
Contrast this with fast food, which is most commonly served in lightweight disposable containers, which encourages fast eating, underestimating how much food you’re eating, and has even been linked to becoming impatient.
These are just some examples of the vital, but largely unconscious, relationship between the design of our tableware – including size, shape, weight and colour – and how we eat.
In design, this relationship is referred to as an object’s “affordances”. Affordances guide interactions between objects and people.
As Australian sociologist Jenny Davis writes, affordances:
…push, pull, enable, and constrain. Affordances are how objects shape behaviour for socially situated subjects.
Designed objects don’t make us do things.
The colour of your crockery
When you visit a restaurant, the chances are your dinner will be served on a plain white plate.
But French chef Sebastien Lepinoy has staff paint the plates to match the daily menu and “entice the appetite”.
Research seems to back him up. Coloured plates can enhance flavours to actually change the dining experience.
This association between colour and taste seems to apply to people from Germany to China.
A review of multiple studies conducted in many countries over 30 years finds people consistently associated particular colours with specific tastes.
Red, orange or pink is most often associated with sweetness, black with bitterness, yellow or green with sourness, and white and blue with saltiness.
The size of your plate
The influence of plate size on meal portions depends on the dining experience and whether you are serving yourself. In a buffet, for example, people armed with a small plate may eat more because they can go back for multiple helpings.
Nonetheless, average plate and portion sizes have increased over the years. Back in her day, grandma used to serve meals on plates 25cm in diameter. Now, the average dinner plate is 28cm, and many restaurant dinner plates have expanded to 30cm.
Our waistlines have also expanded. Research confirms we tend to eat more calories when our plates are larger, because a larger capacity plate affords a greater portion size.
Plastic is too often ignored
The pace of our busy lives has led many people to rely on those handy takeaways in disposable plastic food containers just ready to pop into the microwave. And it’s tempting to use plastic cutlery and cups at barbecues, picnics and kids’ birthday parties.
In contrast to heavy, fragile ceramic tableware, plastic tableware is designed to be ignored. It is so lightweight, ubiquitous and cheap we don’t notice it and pay little mind to its disposal.
Plastics have also changed how we eat and drink. An aversion to the strong smell of plastic containers that once might have caused people to wrap their sandwiches before placing them in Tupperware seems to have disappeared. We drink hot coffee though plastic lids.
Australian economic sociologist Gay Hawkins and her colleagues argue lightweight, plastic water bottles have created entirely new habits, such as “constant sipping” on the go. New products are then designed to fit and reinforce this habit.
Healthy eating is not only characterised by what we eat but how we eat.
And the Japanese cuisine Kaiseki values this mindful, slower approach to eating. It consists of small portions of beautifully arranged food presented in a grouping of small, attractive, individual plates and bowls.
This encourages the diner to eat more slowly and mindfully while appreciating not only the food but the variety and setting of the tableware.
Japanese people’s slower eating practices even apply to “fast food”.
One study found Japanese people were more likely to eat in groups, to stay at fast food restaurants for longer and to share fast food, compared with their North American counterparts.
Affordance theory is only now starting to account for cultural diversity in the ways in which designed objects shape practices and experiences.
The studies we have reviewed show tableware influences how we eat. Size, shape, weight, colour and aesthetics all play a part in our experience of eating.
This has wide implications for how we design for healthier eating – whether that’s to encourage eating well when we are out and about, or so we can better appreciate a tastier, healthier and more convivial meal at home.
This can feel like we have little control, but there are several evidence-based protective measures we can take in the interim to ensure we are as healthy as possible to fight off infection and prevent mental health problems that escalate with uncertainty and stress.
Coronavirus and underlying medical conditions
There is recent evidence that some younger people suffer strokes after contracting the virus, but the majority of people who end up hospitalised, in intensive care or dying from COVID-19 have an underlying medical condition. One study showed 89% of those hospitalised in the US had at least one.
These underlying medical conditions include high blood pressure, high blood sugar (especially type 2 diabetes), excessive weight and lung conditions. An analysis of data from the UK National Health Service shows that of the first 2,204 COVID-19 patients admitted to intensive care units, 72.7% were either overweight or obese.
All of these health issues have been associated with our lifestyle including poor diet, lack of exercise, smoking, excessive alcohol and high stress.
It’s obvious we have created a society where being active, eating healthily, drinking less and keeping our stress under control is difficult. Perhaps it’s time to push back. This may be important for major conditions like heart disease and diabetes as well as the added threat we face from emerging infectious diseases.
One study shows only 12% of Americans are in optimal metabolic health, which means their blood pressure, blood glucose, weight and cholesterol are within a healthy range. This rate is likely similar in many Western countries.
There is now a body of evidence linking our unhealthy lifestyle with viral, especially respiratory diseases. High blood sugar reduces and impairs immune function. Excessive body fat is known to disrupt immune regulation and lead to chronic inflammation. Insulin resistance and pre-diabetes can delay and weaken the immune response to respiratory viruses.
Improving immunity through lifestyle choices
If we are going to restrict and change our lifestyles for 12 to 18 months while we wait for a vaccine, and if we want to protect ourselves better now and in the future, we could address these lifestyle factors. They not only affect our recovery from viruses and respiratory infections, but are also the biggest cost to the quality of life in most countries.
Optimising the health of the nation must be at the forefront. And this is long overdue. There has been a substantial under-investment by most developed countries in preventive medicine to reduce chronic diseases and improve both longevity and quality of life through healthy lifestyles.
We identify three modifiable risk factors:
Research shows better nourished people are less likely to develop both mental and physical problems. Certain nutrients, such as vitamins C and D and zinc have been identified as essential for improving immunity across the lifespan. A better diet is associated with a lower chance of developing mental health problems in both children and adults. Low levels of specific nutrients, such as vitamin D, have been recognised as risk factors for COVID-19. These nutrients are easy (and cheap) to replenish.
What does it mean to be better nourished? Eating real whole foods – fruits and vegetables, nuts, legumes, fish and healthy fats and reducing the intake of ultra-processed foods.
Being physically fit adds years to your life – and quality of life. High cardiorespiratory (lung and heart) fitness is also associated with less respiratory illness, and better survival from such illnesses.
How do you get fit? Set aside time and prioritise walking at a minimum, and more vigorous activity if possible, every day. Ideally, you would get outside and be with important others. The more the better, as long as you are not overdoing it for your individual fitness level.
Stress impairs our immunity. It disrupts the regulation of the cortisol response which can suppress immune function. Chronic stress can decrease the body’s lymphocytes (white blood cells that help fight off infection). The lower your lymphocyte count, the more at risk you are of catching a virus.
How do we lower stress? Meditation, yoga, mindfulness, cognitive-behaviour therapy, optimising sleep and eating well can all help in mitigating the negative impact of stress on our lives. Taking additional nutrients, such as the B vitamins, and the full breadth of minerals like magnesium, iron and zinc, during times of stress has a positive impact on overall stress levels.
Modifying lifestyle factors won’t eliminate COVID-19 but it can reduce the risk of death and help people to recover. And these factors can be in our control if we and our governments take the initiative.
Jesse Beasley, University of Melbourne; Kate Howell, University of Melbourne; Nathan M D’Cunha, University of Canberra; Nenad Naumovski, University of Canberra, and Senaka Ranadheera, University of Melbourne
If you’re trying to reduce your trips to the shops as you practise social distancing and contribute to “flattening the curve” of the coronavirus spread, you might be wondering what it means for your vegetable crisper.
Fresh vegetables need replacing often and, thanks to panic buying, there’s no guarantee you’ll find your favourite fresh foods in your local supermarket.
The good news is there are some really nutritious alternatives to fresh vegetables, and the old adage that “fresh is best” isn’t always true.
Even before coronavirus, vegetables were getting pricier
Fresh vegetable prices have been increasing on average 2% per year over the past decade.
In Australia, vegetable prices are expected to increase 20-50% over the coming months due to drought and the recent bushfires.
Cauliflower, broccoli, green leafy vegetables, and root vegetables such as potatoes and pumpkins are expected to be hardest hit.
We should therefore all be thinking of ways to maximise the shelf life of our fresh veggies. In addition, it’s important not to forget the value of frozen, canned and fermented alternatives.
Don’t skip the veggies, even in a pandemic
Australian dietary guidelines recommend daily consumption of different types and colours of vegetables. However, these guidelines don’t say in what form these veggies should be eaten.
Fresh vegetables are at their most nutritious (and often cheapest) when they are recently harvested and in season, which is not always the case on supermarket shelves.
Long transport times and poor storage conditions can also reduce the nutritional quality of fresh vegetables.
The upshot is that frozen and fermented vegetables can provide the same nutrition as fresh alternatives, especially as they’re often harvested in season and snap-frozen or fermented soon after picking.
Whatever you choose, it’s important to remember vegetables are not only nutritious – they can also reduce the risk of cancer and improve your gut microbiome.
Fresh vs frozen vegetables
The shelf life of fresh vegetables is generally short (3-14 days) even when refrigerated. Freezing, on the other hand, can preserve the nutritional quality of vegetables and increase their shelf life to up to 12 months.
In some cases, frozen vegetables have a higher nutritional quality than fresh vegetables, particularly if there is a short time between harvesting and freezing.
Nevertheless, some nutrients such as B vitamins and vitamin C are vulnerable to the freezing process. One study found higher levels of vitamin C in fresh capsicum, carrot, parsley and spinach relative to frozen alternatives.
Variation in the freezing process, storage conditions and temperature can also change the quality of vegetables.
For example, ice crystals that form during freezing can damage the internal cell structure of potatoes and negatively affect their texture.
If you want to freeze vegetables yourself, select those that are fresh, undamaged and in season and blanch them quickly before freezing. This helps retain colour, flavour and nutritional quality.
Some vegetables such as tomato, capsicum and corn do not need to be blanched before freezing.
Canned and fermented vegetables
Canning and/or fermentation can extend the shelf life of vegetables to between one and five years.
Canned vegetables generally have a similar nutritional profile to fresh vegetables, particularly when it comes to minerals and fibre. However, certain steps in the process (such as peeling) may lead to some nutritional loss.
Just remember that once opened, canned vegetables should be stored in a separate container and consumed within three days.
During fermentation, microorganisms convert the carbohydrates in veggies into alcohol and/or acids that act as natural preservatives (extending shelf life) and can improve the digestibility of starch and protein.
Fermented vegetables are also full of antioxidants and adding extra ingredients like ginger, chilli and garlic can make them an even more nutritious choice.
To reap the full benefits, ferment veggies yourself or choose refrigerated fermented vegetables at the shops (unrefrigerated versions are pasteurised and can have lower probiotic benefits).
Keep calm and eat veggies
Vegetables are a great source of essential nutrients and Australians should aim to eat a wide variety of them each day.
By including fresh, frozen, canned and fermented vegetables in our diet, we not only give our bodies a boost, but help to take pressure off Australian growers to produce high quality and seasonal vegetables all year round.
The vast majority of Australians don’t eat enough vegetables, and these nutritious and tasty alternatives could be the key to improving our overall health – at a time when we need it most.
Jesse Beasley, PhD Student in BioSciences, University of Melbourne; Kate Howell, Senior Lecturer Food Chemistry, University of Melbourne; Nathan M D’Cunha, PhD Candidate, University of Canberra; Nenad Naumovski, Associate Professor in Food Science and Human Nutrition, University of Canberra, and Senaka Ranadheera, Lecturer, University of Melbourne
The coronavirus presents many uncertainties, and none of us can completely eliminate our risk of getting COVID-19. But one thing we can do is eat as healthily as possible.
If we do catch COVID-19, our immune system is responsible for fighting it. Research shows improving nutrition helps support optimal immune function.
Micronutrients essential to fight infection include vitamins A, B, C, D, and E, and the minerals iron, selenium, and zinc.
Here’s what we know about how these nutrients support our immune system and the foods we can eat to get them.
What is a balanced diet anyway?
1. Vitamin A
Vitamin A maintains the structure of the cells in the skin, respiratory tract and gut. This forms a barrier and is your body’s first line of defence. If fighting infection was like a football game, vitamin A would be your forward line.
We also need vitamin A to help make antibodies which neutralise the pathogens that cause infection. This is like assigning more of your team to target an opposition player who has the ball, to prevent them scoring.
Vitamin A is found in oily fish, egg yolks, cheese, tofu, nuts, seeds, whole grains and legumes.
Further, vegetables contain beta-carotene, which your body can convert into vitamin A. Beta-carotene is found in leafy green vegetables and yellow and orange vegetables like pumpkin and carrots.
2. B vitamins
B vitamins, particularly B6, B9 and B12, contribute to your body’s first response once it has recognised a pathogen.
At a football match, this role would be like security guards intercepting wayward spectators trying to run onto the field and disrupt play.
B6 is found in cereals, legumes, green leafy vegetables, fruit, nuts, fish, chicken and meat.
B9 (folate) is abundant in green leafy vegetables, legumes, nuts and seeds and is added to commercial bread-making flour.
B12 (cyanocobalamin) is found in animal products, including eggs, meat and dairy, and also in fortified soy milk (check the nutrition information panel).
3. Vitamins C and E
When your body is fighting an infection, it experiences what’s called oxidative stress. Oxidative stress leads to the production of free radicals which can pierce cell walls, causing the contents to leak into tissues and exacerbating inflammation.
So the role of vitamin C here is a bit like cleaning up the football ground after the game.
Good sources of vitamin C include oranges, lemons, limes, berries, kiwifruit, broccoli, tomatoes and capsicum.
Vitamin E is found in nuts, green leafy vegetables and vegetables oils.
4. Vitamin D
Some immune cells need vitamin D to help destroy pathogens that cause infection.
Although sun exposure allows the body to produce vitamin D, food sources including eggs, fish and some milks and margarine brands may be fortified with Vitamin D (meaning extra has been added).
Most people need just a few minutes outdoors most days.
People with vitamin D deficiency may need supplements. A review of 25 studies found vitamin D supplements can help protect against acute respiratory infections, particularly among people who are deficient.
5. Iron, zinc, selenium
We need iron, zinc and selenium for immune cell growth, among other functions.
Iron is found in meat, chicken and fish. Vegetarian sources include legumes, whole grains and iron-fortified breakfast cereals.
Zinc is found in oysters and other seafood, meat, chicken, dried beans and nuts.
Nuts (especially Brazil nuts), meat, cereals and mushrooms are good food sources of selenium.
Putting it all together
It’s true some supermarkets are out of certain products at the moment. But as much as possible, focus on eating a variety of foods within each of the basic food groups to boost your intake of vitamins and minerals.
While vitamin and mineral supplements are not recommended for the general population, there are some exceptions.
Pregnant women, some people with chronic health conditions, and people with conditions that mean they can’t eat properly or are on very restrictive diets, may need specific supplements. Talk to your doctor, Accredited Practising Dietitian or pharmacist.
And beyond diet, there are other measures you can take to stay as healthy as possible in the face of coronavirus.
Stop smoking to improve your lung’s ability to fight infection, perform moderate intensity exercise like brisk walking, get enough sleep, practise social distancing and wash your hands with soap regularly.
As a parent, I find it so frustrating to take my children shopping, reusable bags in hand, only to be offered plastic toys at the checkout. It’s an incredibly confusing message to be sending kids. And it seems Coles is confused too.
Last year the company stated it wants to be “Australia’s most sustainable supermarket”. But with last week’s relaunch of “Stikeez” – yet another plastic collectables range off the back of their Little Shop promotion – Coles is showing dogged commitment to unsustainable marketing.
Stikeez are 24 plastic characters (plus four rare ones) in the shape of fruit and vegetables, aimed at encouraging kids to eat healthy food.
After petitions against previous plastic “mini” campaigns by Coles and Woolworths, Coles will make the Stikeez characters returnable in store for recycling.
But this misses the point. Coles is generating waste needlessly in the first place. Surely it’s time to move beyond plastic freebies as a way of boosting sales?
We have a waste problem in this country. Australians are the third highest producers of waste per person, after the US and Canada. Some councils are having to stockpile plastic, there’s a federal plan to phase out exporting waste overseas and we have high rates of contamination of recyclables.
And Coles, one of Australia’s supermarket giants, sent almost 100,000 tonnes of waste to landfill in 2019. That’s 274 tonnes per day.
But after their Little Shop collection provoked a consumer backlash, Coles took steps to reduce waste generated from their latest campaign. Stikeez wrapping contains partially recycled content, and Coles is providing in-store collection points where Stikeez can be returned and repurposed into shoe soles, in partnership with Save Our Soles.
Certainly this is preferable to throwing the items into the rubbish, but repurposing the plastic is not without environmental cost. Fuel is required to transport the waste and the process of repurposing plastic uses energy.
What’s more, asking shoppers to bring back their Stikeez puts the onus on consumers, rather than the company, to dispose of the items responsibly. And as we’ve seen by the low rates of recycling of soft plastics on a national level – recycling soft plastics is also offered in store – it’s far more convenient to throw items in the bin.
Coles is also missing the point of the consumer backlash. When a company already generates huge quantities of waste in its core business and says it wants to be Australia’s most sustainable supermarket, it cannot generate additional waste on plastic marketing.
Boosting the bottom line
Last year Coles’ Little Shop put many parents offside. But Coles earned around A$200 million in extra revenue as a result of the original promotion.
Coles reported an increase in the first quarter of 2019 in sales of 5% and gained a competitive advantage over rival Woolworths, which managed only 1.5% in the same period. Obviously the bump in sales was too hard for Coles to resist.
It’s difficult to get an accurate figure on what waste this latest Stikeez campaign will generate. Coles haven’t publicised data about how many collectables they will produce. And waste contractors to Coles haven’t revealed how many collectables ended up in landfill last year, though there have been reports of Little Shop items ending up on beaches in Bali.
Last year, Coles said 94% of Little Shop collectables were either kept or given to family or friends. But University of Tasmania marketing expert Louise Grimmer discredited this data, saying it was not based on any meaningful longitudinal research that would allow such claims.
Stikeez undermines Coles’ sustainability efforts
If organisations produce plastic for marketing purposes, it’s difficult to see how we can achieve plastic recycling rates of 70% by 2025. This target – set by federal and state governments and which Coles has signed on to meet – also stipulates the removal of “problematic and unnecessary” single use plastic packaging.
Federal Assistant Minister for Waste, Trevor Evans, said finding a sustainable way to manage plastics was a major challenge and requires a coordinated effort. As a powerful household brand, Coles must unequivocally be part of this effort.
Coles’ environmental policy says it’s “committed to doing business in an environmentally responsible manner”. But plastic freebies fly in the face of this policy.
Better waste regulation
Voluntary initiatives for companies to reduce packaging and plastic waste, which Coles have signed on to, have not produced meaningful results.
Currently only one-third of all plastic packaging in Australia is recycled.
Overseas countries have moved away from voluntary frameworks to more structured and enforceable regulations to reduce plastic production and waste. In fact, Europe voted to ban single use plastics last year.
As long as Australia lags on waste regulation, organisations such as Coles will continue to contravene their own environmental policies.
The Conversation contacted Coles for comment. Its response is as follows:
Customers have told us that they use Stikeez as a fun tool to encourage kids to eat more types of fresh foods. The collectibles form part of the Coles Fresh 5 Challenge which encourages kids to eat all the Five Food Groups daily. We made changes to the Stikeez campaign this year to ensure it’s more environmentally sustainable.
Stikeez collectibles, including those customers have from last year, can now be recycled at all Coles supermarkets. We have partnered with Australian recycling group Save our Soles so that Stikeez can be recycled through the same process that is used to recycle footwear in Australia since 2010 to create useful products like anti-fatigue mats, gym matting, retail flooring and carpet underlay.