Issues Magazine

Hidden Hunger: Food Security Means Balanced Diets

By Dyno Keatinge and Warwick Easdown

Vegetables are often overlooked in the global debate on hunger. What solutions can they bring to the current food crisis?

Food security is fundamentally about securing a balanced diet, and most diets in the world today are imbalanced due to inadequate consumption of vegetables. Recent price increases for staple crops, which form the bulk of the diets of the world’s poor, have hit millions of people very hard, but many of their diets were already of low quality well before this recent “food crisis”.

Food security is more than just the means for bare survival. A well-balanced diet is essential to good health and human development, and malnutrition occurs when this is not the case. Malnutrition is a problem affecting not just poor people. Obesity is an extreme result of malnourish­ment just as much as starvation, and rich and poor alike suffer from diets that are missing vegetables.

The Importance of Vegetables

Vegetables are our most important dietary source of essential micronutrients such as iron and vitamin A, as well as antioxidants, which can help prevent cancers. Some are also major sources of protein and carbohydrates. World vegetable production does not even meet the basic nutritional needs of most countries, and the resulting imbalanced diets are one of the world’s most serious health problems. Figure 1 shows that many countries in the Asia–Pacific region do not produce enough fruit and vegetables to meet even half of their population’s nutritional needs.

Figure 1

The results of a lack of vegetable consumption are insidious more than spectacular. There are no news images of starving children to raise public awareness of the problem. The “hidden hunger” of micronutrient and vitamin deficiencies increases the risk of illness or death from infectious diseases, and children may not develop to their full physical or mental potential. The correlation between low national production of vegetables and the incidence of micronutrient deficiencies is strong. In much of South Asia and Africa, vitamin A deficiency is a major health problem, resulting in millions of deaths each year.

Even before the recent food crisis, the diets of poor people were already monotonous and imbalanced because cheap staples are all they can afford. One measure of this is how much energy in the diet is provided by a staple food. Table 1 shows that in seven countries in our region more than 70% of energy is provided by staple foods, and this hasn’t changed much in the past 10 years. Recent steep increases in the price of staples have worsened already monotonous diets.

Table 1

Poor households have little room to move when they are under financial stress. Food accounts for 50–70% of total household expenditures in South and South–East Asia, and most of that is spent on staple foods like meat or vegetables. When poor households face financial stress they first cut down on non-staples, then on the total number of meals.

But it is not just poor people in developing countries who have imbalanced diets that lack vegetables. A global epidemic of excess weight and obesity is linked to less physical activity and overconsumption of poor-quality food with diluted nutrients and dense energy. Obesity is now a serious public health issue in Australia, predisposing individuals to serious chronic diseases, including Type 2 diabetes, cardiovascular disease, hypertension and stroke, as well as certain forms of cancer. This is not only a problem for developed countries, but also for countries in transition including China and India, where Type 2 diabetes in children is increasing at an alarming rate.

Which Vegetables to Eat?

Different vegetables and even varieties of the same vegetable can have quite different nutritional contents, and some of the world’s most nutritious vegetables are actually little-known indigenous ones.

Our bodies are able to absorb just the right amounts of micronutrients and vitamins from the vegetables we eat so long as we eat enough and a wide variety. A simple guide is to eat a variety of colours or plant parts: green leafy vegetables, red and orange vegetables like tomatoes or capsicums, and white stems or roots such as onions or potatoes.

Plant breeding can improve the nutritional value of vegetables. The joint Australia and New Zealand Vital Vegetables initiative is breeding more nutritious varieties of crops such as broccoli with enhanced levels of anti-cancer compounds and other nutrients. AVRDC – The World Vegetable Center has bred tomatoes with three to six times the beta-carotene of normal tomatoes. Eating just one of these orange-coloured tomatoes can provide all of a person’s daily vitamin A requirements.

Some of the most nutritious vegetables are those that are the least widely known. Indigenous vegetables have all sorts of names and shapes, and can give national cuisines like that of Thailand their unique flavours. Many indigenous vegetables are so easy to grow that they may be regarded as weeds, but can be a particularly important source of food for poor people. In rural Tanzania, researchers from AVRDC – The World Vegetable Center found that almost half of the vitamin A and one-quarter of all the iron in the diets of the poorest rural people was provided by indigenous vegetables.

Ironically, the weeds in many Australian paddocks can be more nutritious than the crops they’re competing with! Amaranth is a common Australian weed but an important indigenous vegetable in Africa. It is extremely nutritious, with almost three times the protein, 12 times the iron and a whopping 57 times more beta-carotene (a vitamin A precursor) than cabbage.

But indigenous vegetables have been a victim of their own success, often stigmatised and ignored as just “food for the poor” so very little breeding work has been done on these remarkable crops or their marketing and promotion.

With the right marketing, indigenous vegetables can become an important addition to national diets. In Kenya we worked with partners to promote several indigenous leafy vegetables including amaranth, African nightshade and spider plant in supermarkets in Nairobi, and the results were spectacular. The media highlighted them as “heritage vegetables” and they even became a feature in the parliamentary canteen. Many older urban consumers knew them from their childhoods in rural villages, but were unable to buy them in town, so they were delighted to find them on their supermarket shelves. Within two years of introducing the program, the consumption of leafy vegetables had increased from less than 50 tonnes per year to more than 9000 tonnes in Nairobi alone.

In Australia, indigenous fruits and vegetables have been recently marketed as “bush foods” in many exclusive restaurants. Many better adapted and more nutritious vegetables are available than those we are currently used to eating. We need to think differently about the range of vegetables that we grow and eat.

Safer Vegetable Production

Producing more vegetables starts with plant breeding drawing on genes from the wild relatives of vegetables. AVRDC – The World Vegetable Center maintains the world’s largest public vegetable gene bank, a living repository of more than 57,000 different vegetable seed samples. The characteristics of the parent plants are recorded in the gene bank database and website, and samples of their seed are dried and stored in sealed containers in giant freezers kept at –15ºC. Such seed can stay alive for decades, but eventually all samples must be regenerated by sowing in the field and harvesting fresh seed. Plant breeders from around the world have free access to request any seed lines from the gene bank to use to develop new varieties.

Plant breeders aim to improve the disease resistance, yields and nutritional content of vegetables. New varieties are needed because we are engaged in a global arms race with pests and diseases. With more international travel and a changing climate, pests or diseases that used to be restricted to limited parts of the world are spreading. Recently, Australian tomato crops were devastated by the introduction of a new disease – tomato yellow leaf curl virus. Breeding resistant varieties to this disease has proved particularly hard because the disease exists in so many strains around the world.

Both public and private breeding organisations produce new vegetable varieties, but concern is growing that the world’s investment in public plant breeding has been seriously declining. This is particularly important for the development of new vegetable varieties for poor farmers, and to deal with regional pests and diseases that are not economic for private plant breeders to address. Because so little public vegetable breeding is currently being done in Sub-Saharan Africa, most farmers there are forced to rely on poor-yielding varieties, sometimes up to 80 years old.

Vegetable production in many countries is well below its potential, not just because of poor varieties but also due to poor production practices. Vegetable production requires more fertilisers and pesticides than staple crops as well as more skills. Most vegetables are also highly perishable once harvested, so getting them to market quickly is important to reduce losses.

Many developing countries have major problems with misuse of fertilisers and pesticides in vegetable production. In Sub-Saharan Africa, the main problem is extremely low fertiliser use. Factors such as poor transport infrastructure mean that nitrogen fertiliser prices are up to four times the world price and well beyond the means of poor farmers. An estimated 75% of Africa’s soils are now run down due to overcropping and a lack of fertiliser use.

In developed countries in Asia, the opposite problem occurs, with excessive use of fertilisers leading to contamination of groundwater and eutrophication of waterways. The recent financial crisis saw the global price of phosphate fertilisers rise sevenfold between 2007 and 2008. While this may reduce excessive use, in Africa it makes a poor situation much, much worse.

Farmers often rely on pesticides to control insects and diseases, particularly in Asia where many cheap pesticides are available, but misuse is a serious environmental and health issue. India produces the largest quantities of basic pesticides in Asia and accounts for one-third of all pesticide poisoning cases in the world. Excessive use of cheap pesticides by poorly educated farmers is a growing global problem affecting the health of farmers and consumers alike and causing major environmental damage. In India, surveys show that pesticide residues in vegetables are extraordinarily high, with 50–70% of marketed crops contaminated.

Producing more vegetables must not be done at high environmental cost and the risk of poisoning farmers and consumers alike. There is a serious need for increased farmer training and better tracking of pesticide residues in many developing countries.

One of the easiest means of increasing vegetable supplies is to reduce losses after harvest. On average, about 15–20% of all vegetables are lost before they reach consumers, mainly due to high rates of bruising, water loss and subsequent decay. The solutions are often very simple: harvesting during the coolest part of the day, better packing methods, basic cool storage or processing by drying. Yet over the past 30 years less than 5% of horticultural development funding has gone into postharvest management, while more than 95% has gone into increasing production. A simple refocusing of research and development efforts could have a big payoff.

Cooking methods can also have a large impact on the nutritional value of vegetables. We found that slight modifications to traditional recipes for African indigenous vegetables, such as adding oil, tomato, lemon or soybean, could increase iron and vitamin A bioavailability by two- to threefold. Extending such innovations can have a large impact on community nutrition.

A Balanced Diet for Everyone

Vegetables have to be more affordable, available and accessible to improve the world’s diets. This is quite achievable, but different strategies are needed for rich and poor countries where the causes of low vegetable consumption vary.

In countries with high vegetable production but low vegetable consumption and rapidly growing problems of obesity, public health programs to promote healthy eating and improve nutritional literacy need to be expanded. Vegetables need to be as affordable, accessible and socially acceptable as the high fat and sugar foods that contribute to obesity.

Worldwide there is a need to expand public breeding programs for vegetables, and to increase research and extension efforts to improve production methods, reduce harvest losses and promote improved recipes. As supplies are increased, vegetables will become more affordable.

In all countries, policies are needed to ensure the availability and accessibility of vegetables in rural and urban markets. When this happens we will be making a difference to the real food crisis – one of imbalanced diets.