Should you eat more superfoods, eat less to stay slim and avoid the sun to stay healthy? A new book by Norwich nutritional therapist Glen Matten says not. By Emma Harrowing.

Did you know that antioxidants can be harmful to your body even though they are said to protect us from diseases such as cancer or delay the ageing process? Or that being slim doesn't actually mean that you are healthier?

The more advanced we become in society the unhealthier we get. That's the paradox debated in a new book by Norwich nutritional therapist Glen Matten.

'We might be living longer but can we honestly say we're living healthier?' says Glen. 'Despite all the amazing advances of modern medicine and health advice at every turn, chronic ailments such as obesity, diabetes, cancer, heart disease, osteoporosis, depression and dementia are rife, and in most cases things are getting worse, not better. In fact, if you're a healthy adult in today's society, you're in the minority.'

Glen teamed up with pharmacist and nutritionist Aidan Goggins to write his new book The Health Delusion. The book tackles some of the food and diet myths that have developed over the last few years.

'The book provides a detailed plan of the foods, supplements and lifestyle changes needed for total wellness at every stage of life,' says Glen. 'All of our findings are backed up by the latest scientific discoveries.'

Here are just some of the myths busted in the new book:

Myth one: We're overweight because we eat too much

Glen says: 'Research shows that we're not eating any more now than we did three or four decades ago. What has changed is our level of physical activity. We're much less active in our day to day lives than we used to be. The difference between our activity levels today and those 50 years ago is the equivalent of running a marathon a week! To avert the obesity crisis we should be looking to increase our activity levels, not turn to dieting.'

Myth two: You get all you need from a well-balanced diet

Glen says: 'Even if you eat a good diet it's very likely that you will be deficient in selenium. This important trace mineral is critical to our health as it's required for a strong immune system, thyroid health, fertility, and most importantly of all for reducing cancer risk. To reap selenium's health benefits a modest supplement of 50-60mcg per day is required or up to 100mcg for men concerned about the risk of prostate cancer.'

Myth three: Antioxidants are 'good' and free radicals are 'bad'

Glen says: 'We have been led to believe that free-radical busting antioxidants are the best thing ever and will protect us from diseases such as heart disease and cancer, and even stave off the ageing process itself. This has led many people to take high dose antioxidant supplements (such as vitamins A, C and E, and beta carotene). The reality is that there is a delicate balance in the body between antioxidants and free radicals. Having some free radicals is actually critical to our health. Consequently by upsetting this delicate balance by taking high dose antioxidant vitamin pills is now shown to increase the very illnesses people take them to prevent.'

Myth four: We should eat more 'superfoods'

Glen says: 'The word 'superfood' is a meaningless marketing slogan. You should never take it seriously nor spend a lot of money on them. Instead stick with eating a broad range of plant-based foods. There is a lot of research to show striking health benefits from common-or-garden everyday plant foods, encompassing everything from broccoli, kale and tomatoes, to tea, cocoa and even coffee.'

Myth five: Being slim automatically means you are healthy

Glen says: 'Our weight and even our BMI can only tell us so much. It's actually where we store fat in the body that affects our risk of disease. The dangerous type is visceral fat, the noxious fat that gets packed around our organs and releases a host of inflammatory chemicals. This crucial factor means we may look trim and healthy on the outside but harbour dangerous levels of visceral fat on the inside exposing us to obesity related disease. Conversely it is possible to be overweight and in good metabolic health, what we might term 'fat and fit'. It is our physical activity levels that have a major bearing on how much visceral fat the body stores.'

Myth six: Avoid the sun to stay healthy

Glen says: 'Our main source of vitamin D has always been and still is the sun. Yet in Britain we can't make any vitamin D when we are outside from October to March even on a sunny day. Come summertime, due to valid concerns about skin cancer, many of us now avoid the sun altogether or apply strong sun block. The result is that we've become a nation starved of vitamin D, which research is now linking to many chronic health problems including osteoporosis, common cancers, heart disease, diabetes, multiple sclerosis, arthritis (both osteoarthritis and rheumatoid), depression, dementia, and more besides. It is a mounting public health predicament that can be addressed by small amounts of 'safe' sun exposure in the summer – little and often and never getting sun burn – and an appropriately dosed vitamin D supplement in the winter months.'

Myth seven: Saturated fat causes heart disease

Glen says: 'Saturated fat has long been public enemy number one when it comes to our risk of heart disease, but there is actually no real evidence directly linking the two. In fact what you replace it with could be doing you more harm. Cutting down your intake of saturated fat and replacing it with high 'Glycaemic Index' carbohydrates (such as white bread, white rice, white pasta, sugary breakfast cereals or potato products) will actually dramatically increase your risk of heart disease.'

Myth eight: There's no such thing as 'brain food'

Glen says: 'The evidence grows stronger and stronger to support the idea that fish is 'brain food', notably the omega-3 fats found in oily fish. In one famous study, eating fish once per week or more was linked to a 60pc reduced risk of Alzheimer's disease compared to those who rarely or never ate fish. It doesn't end there as a lack of omega-3 fish oils is linked to increased risk of depression and a particular type of omega-3 fat, called EPA, is even showing promise in treating depression.'

The Health Delusion: How to achieve exceptional health in the 21st century is published by Hay House (�12.99).