Meat and Cancer: The Carnivore's Conundrum

The media are abuzz with conflicting reports about the possible cancer risks of eating red meat, reinforcing already widespread confusion among consumers. However, safe meat consumption is possible, provided you steer clear of processed meat and eat moderate amounts of red meat that's been carefully prepared, experts say.

A review published last week by the British Nutrition Foundation (and funded by the UK meat industry) found no evidence that eating moderate amounts of lean red meat has negative health effects. "Hurrah - eating red meat is good for you!" Britain's Daily Mail cheered.

At the other end of the spectrum, the British Vegan and Vegetarian Foundation issued a press release saying that women wishing to lower their risk of breast cancer "should reduce the amount of meat they eat and cut down - or even cut out - dairy produce."

The World Cancer Research Fund on its blog responded by pointing out that this recommendation was based on research that had not actually investigated the link between animal foods and breast cancer. "This press release is likely to hinder, rather than help, people's ability to make informed choices," it concluded.

In-between these poles, the British government said in its Iron & Health Report that while red meat is a valuable source of iron, eating too much could lead to cancer and heart disease. It recommended that people consuming more than 90g (3.2 oz) per day of red and processed meat should reduce intakes to 70g (2.5 oz) per day or less. (This is equivalent to two standard beef burgers; one lamb chop; two slices of roast lamb, beef or pork; or three slices of ham.)

This tallies with the WCRF's recommendation that adults should eat no more than 500g (1.1 lb; cooked weight) red meat per week, though the cancer research and education charity makes a clear distinction between "red" and "processed" meat, advising people to avoid the latter wherever possible.

Where does this leave the confused carnivore? Should we avoid red meat and only eat poultry and fish? Should we stop eating meat altogether? Or is there a safe way of enjoying red meat?

I asked Denis Corpet, Professor of Food Hygiene and Human Nutrition at the University of Toulouse, for his views on the matter. Professor Corpet heads the "Prevention and Promotion of Carcinogenesis by Foods" research team at the ToxAlim center of France's public agriculture research agency INRA.

CMW: What is the colon-cancer risk of eating red and processed meat?

DC: Meat is not carcinogenic, but people eating lots of meat develop cancer more often than those who eat it less. In Europe, twenty percent of people eat more than 80g beef per day, and they are more likely to develop colon cancer than those eating meat rarely. The risk increase is modest, between +20% and +30%. The same risk is observed in people eating more than 50g deli (cured meat) per day.

From an individual perspective, this is not a huge increase. It means that one person out of 20 will get colorectal cancer, and in big meat eaters this value becomes 1.2 person out of 20. But from a public health perspective, each day one hundred people in France are told they have colorectal cancer. The excess risk associated with a daily steak, +25%, now translates to an extra 25 people each day with cancer!

CMW : Is red meat implicated in any other cancers?

DC: The link between meat and cancer was discovered with stomach and colorectal cancer. The link seems much weaker with breast and prostate cancers, and did not show up even in the very large European EPIC study of half a million persons. In an American study of similar size, elevated risks (from 20% to 60%) were evident for esophageal, colorectal, liver, and lung cancer, but not breast or prostate.

CMW: What are the cancer risks inherent in red meat?

DC: Nobody knows exactly why red meat is (slightly) toxic, but we have "hypotheses," that is, various paths to track down the villain. A tasty BBQ steak could be bad for you because it's fatty, grilled, or "red."

Yes, too much fat increases our risk of obesity, which is a cause of cancer. But dietary fat in itself is not carcinogenic.

Yes, the black-brown part of a grilled steak contains potent carcinogens (named, for instance, PhIP, MeIQx, BaP), but the doses are very low and it is hard to believe they could give us cancer.

Yes, beef is red because it contains heminic iron, which our body needs to make our own red blood and red muscles. In my laboratory we found that that rats given heminic iron (or beef meat) after being injected with carcinogens had more tumors than controls given the shot but not the iron-rich diet. Thus "the red" in red meat clearly promotes cancer.

CMW : What are the cancer risks inherent in processed meat?

DC: Most processed meats are made from red meat (pork is red, even if it has less iron than beef), and ham and sausages are often fatty and grilled; thus the same risks are present in beef and in cured meat.

In addition, cured meat is made by adding salt (no effect on the colon, but bad for the stomach) and nitrites. Nitrites provide four benefits: fewer bacteria (particularly the killer botulism), less oxidation (no rancidity), better color (red instead of brown, pink instead of grey when cooked) and better flavor (the "deli" taste). But nitrites may form carcinogenic substances called nitrosamines, or related toxic compounds we call NOCs, and my lab has shown that these promote tumors in rats.

CMW : Are there risks in not eating red or processed meat?

DC: Meat is good for you. We need protein, and meat provides excellent proteins, though we can also get protein from other foods. We need iron, zinc and vitamin B12, and it is very hard to find those elsewhere than in meat. This is why I would not advise people to give up red meat, but to eat at least one steak a week. Many young women dislike red meat and become anemic: as the iron stores in their bodies decline they cannot make enough red blood cells and this can lead to constant tiredness and a pale complexion.

In contrast we do not NEED to eat cured meat. Its benefits are the same as those of red meat, but because it seems twice as toxic, it's better to eat fresh than processed meat.

CMW: Observational studies show that red meat consumption is associated with a higher risk of cancer; are these studies reliable? What experimental evidence is there for the meat/cancer link?

DC: Epidemiological observations do not "prove" the cause and effect link. This is why I chose to work experimentally on this question about ten years ago. The problem is that this type of research cannot be done on humans. We thus provide strong evidence that red meat, cured meat, and heminic iron, promote tumors in rats and mice. This does not translate directly to humans, but bringing together observations in people and experiments in rodents seems to provide a compelling picture.

CMW: How can people who eat red meat regularly cut their cancer risk?

DC: It is wise not to eat red meat too often, and to have small portions in line with the WCRF's guidelines. In addition, people who are afraid of fat should choose lean meat. And people who worry about carcinogens should not fry, grill or barbeque their steak, but eat slowly cooked red meat instead.

For those who think, as I do, that heminic iron could be the villain, a good way to reduce their risk is by consuming calcium with an iron-rich meal (calcium lowers the absorption of iron from food); for instance, by eating a yogurt or a piece of cheese after a steak.

CMW : Is there a way of lowering the risks from processed meat?

DC: In my laboratory we are testing specific substances that could be added during the curing process to "protect" meat so it does not promote tumors in rats. We already have shown, but not yet published, that added calcium and vitamin E can block the toxic process. We are now investigating the possible protective effects of natural polyphenols, like those that lend red wine and green tea their color and flavor.

I would advise against eating processed meat without nitrites (preservatives) because the deadly botulism bacterium remains a risk. Overall, it's enough to eat cured meat rarely: For instance I never buy ham or sausage, nor do I chose it at the cafeteria. But when I am invited to dinner at a friend's house, I eat whatever they serve me, most often with delectation (I just love the French "saucisson").

Professor Corpet's personal website provides articles he has published about his work (http://fcorpet.free.fr/Denis/Science.html), lecture notes and some of his favourite healthy recipes (http://fcorpet.free.fr/SalmonRecipe.html).

World Cancer Day 2011: Cancer can be prevented

In case you didn't know it yet: Cancer can be prevented.

As every year on February 4, known since 2005 as World Cancer Day, the Geneva-based Union for International Cancer Control (UICC) is shouting it from the rooftops. "So many of my patients have said to me that they wish they had acted on cancer prevention advice earlier in their lives," says UICC President Dr. Eduardo Cazap. "I would like to ... recommend that you learn about the very simple ways you can reduce your own cancer risk, take action and also spread this advice to those you love."

More than a third of the most common cancers can be prevented by eating a varied and healthy diet, maintaining a healthy body weight, getting regular physical activity and limiting alcohol intake.

Some common cancers are especially influenced by lifestyle: according to data released today by the World Cancer Research Fund (WCRF), in the US alone 70% of endometrial cancers, 69% of esophageal cancers, 47% of stomach cancers, 45% of colorectal cancers, 39% of pancreatic cancers and 38% of breast cancers could be prevented if people ate a healthy diet, exercised and had a healthy body weight. Avoiding tobacco, carefully managing sun exposure and protecting ourselves against cancer-causing infections further lowers our risk.

Alas, the prevention message is struggling to get through. At a talk I gave last night about cancer prevention, one lady said: "I wish I could get my daughter to listen to your advice. But you know what young people are like - they don't worry until it's too late."

One reason why many people don't practice cancer-prevention is that they're confused. A UK survey conducted last summer by the WCRF showed that about half the people polled thought scientists were always changing their minds about what increases and decreases cancer risk. And about a quarter of people thought that because the advice was always changing, the best approach was to ignore it all. (This is despite the fact that cancer prevention advice has not changed substantially over the last 10 years!)

Another reason why people ignore prevention advice is fear. Nearly all of us have seen family members or friends endure the prolonged agony of cancer. Cancer is often referred to as an "enemy," like an insidious alien invader against which we are defenseless and that we need to "fight," "battle," "crush" or "declare war" on.

Indeed, many people find cancer so scary that they dare not pronounce its name; it is often referred to in hushed tones as "The Big C." Some behave as though the mere mention of "the C-word" might increase their risk of "catching" the dreaded disease. Many cancer patients experience that their friends and family struggle to even talk with them about their disease - as though it were all too terrifying to put in words.

I think one reason for this fear is that many people don't understand that many types of cancer can be prevented, nor how. For while most of us now realize that the risk of heart disease or diabetes can be lowered through lifestyle measures, many still see cancer as some kind of act of fate that hits people out of the blue, regardless of whether they are living healthily or not. In which case, they conclude, they might as well eat, drink and be merry!

Don't get me wrong - I'm all for merry-making. But I don't think a "healthy lifestyle" has to mean boring food, tedious exercise routines and an altogether fun-free existence.

Indeed, with regard to healthy eating habits, a diet can only be effective if you truly enjoy it - no sacrifice, no hunger, no suffering. This will motivate you to eat it every day. Even children, adolescents and young adults - easily dismissed as the "junk-food generation" - will eat an anti-cancer diet (without knowingly doing so) if it is presented to them in the form of exciting textures, vibrant colors and stimulating tastes - all of which healthy food can deliver.

Exercise, too, doesn't have to be mind-numbingly boring or expensive. A brisk walk in the park with a two- or four-legged friend, a few flights of stairs bounded up energetically, a half-hour bike ride to work or for errands, an occasional jog around the neighborhood - these cheap, simple activities are not just healthy but can be enjoyable and convivial.

Rest and relaxation are important too, and cost nothing: getting adequate sleep regularly and leaving some ‘empty spaces' in our busy lives for moments of quiet contemplation can have powerful stress-reducing and immune-boosting effects.

Being the hedonist I am, I believe that the most effective way to integrate cancer prevention into our daily lives is to enjoy it, and focusing not on the dreaded fate we wish to avoid, but on the many other immediate rewards a healthier lifestyle brings: more energy, fewer colds, stronger muscles and a slimmer silhouette, clearer skin and brighter thoughts.

Of course, cancer prevention shouldn't just be down to individual effort; policy-makers should do their bit too. Off the top of my mind, I can think of at least eight ways in which government, schools, the media, the food industry, health professionals and employers can help cut cancer incidence, such as

• making fresh, healthy food accessible to economically disadvantaged citizens,
• providing nutrition and cookery classes in schools,
• credibly publicizing the benefits of healthy food and the risks of unhealthy food,
• serving unprocessed, fresh food in school and workplace cafeterias,
• building bicycle paths and inexpensive sports facilities,
• encouraging new mothers to breastfeed their babies,
• providing clearer information about the risks inherent in convenience food,
• curbing advertising by junk food manufacturers.

And many, many more. The WCRF's 2009 Policy Report offers an excellent analysis of the need for public cancer-prevention policy with a multitude of realistic recommendations. Public actors would do well to read it.

More pressure on public policy makers is set to come from the UICC. In an effort to move cancer prevention to the top of government agendas, it is collecting signatures that will be presented to the world's leaders at the first UN Summit on Non-Communicable Diseases in September 2011. 

"We want to show them that you care and demand that they use this meeting to set the momentum for effective measures to be implemented in all countries to reduce the global cancer burden," says UICC chief executive Cary Adams. If you want your government to get serious about cancer prevention, sign the UICC's declaration here.

Should we swap aspirin for vegetables? Not just yet.

Two cancer studies grabbed the headlines this week, causing nutritionists' hearts to sink and pharmacists to cheer. One suggested that vegetables and fruits offer scant protection against cancer; the other indicated that taking low daily doses of aspirin may cut our risk of dying of this dreaded disease. So, should we simply give up on vegetables and fruits, and pop the little white pill instead? I think not.

In the first article published in the British Journal of Cancer, Oxford University Professor Tim Key summarized evidence from several dozen long-term research projects looking at the amount of fruit and vegetables people eat and their overall cancer risk. He found little, if any, connection between eating lots of fruits and vegetables and the likelihood of developing cancer.

Meanwhile, the Lancet published a study showing that people who took a low dose of aspirin daily to lower their risk of cardiovascular disease were 20% less likely after 20 years to die of solid tumor cancers than those who had been taking placebo pills during the clinical trials, and their risk of gastrointestinal cancer death was 35% lower. The risk of lung cancer death was 30% lower, that of colorectal cancer death was 40% lower and that of esophageal cancer death was 60% lower.

The inflammation connection

Aspirin is thought to act on cancer through its ability to reduce inflammation, which plays a role in the development and spread of cancer cells. In animal studies, aspirin has been shown to block the synthesis of prostaglandins, chemicals that mediate inflammation and promote early tumors.

Whether aspirin systematically protects humans from cancer is uncertain, however. Indeed, the study notes that the results of observational studies in humans "have been conflicting, with more rigorous studies yielding weaker associations." Since few women took part in the trials studied, it is also unknown whether aspirin protects against breast or uterine cancer.

What we do know is that prolonged aspirin use can have negative side-effects, including gastrointestinal bleeding and bleeding in the brain. Non-steroidal anti-inflammatory drugs (NSAIDs) like aspirin can also disrupt the gut flora and increase intestinal permeability, thereby in fact increasing the body's inflammatory burden. (See this paper, this and this). So don't start a regimen of aspirin without first weighing up the potential benefits and risks of such a treatment with a doctor.

Those who can't or won't take a daily dose of aspirin may wish to turn their attention to ways in which food can be used to regulate inflammation. Many of those much-maligned vegetables and fruits, as well as spices, herbs and fats with a healthy omega-3-to-6 ratio, are thought to help cool inflammation, as well as providing antioxidants and a plethora of other compounds that work in different ways to protect the body against cancer.

Alas, these foods are woefully lacking in our western convenience-food diets, which are characterized by inflammation-promoting sugar and refined carbohydrates, trans fats in processed foods, oils with a high proportion of omega-6 fatty acids (e.g. corn, soy, safflower) and meat, eggs and milk from intensively-reared animals fed corn, rather than grass and hay.These should be replaced by foods that can reduce inflammation, such as:

• Vegetables like peppers, broccoli and broccoli sprouts, Brussels sprouts, cabbage, cauliflower, chard, collards, fennel, garlic, onions, kale, leeks, spinach, sweet potatoes
• Fruits such as acerola cherries, apples, avocados, black currants, blueberries, kiwifruit, lemons, limes, mulberries, oranges, raspberries and strawberries
• Herbs and spices like ginger, turmeric, curry mix, basil, cayenne and chili peppers, cinnamon, cloves, cocoa, mint, oregano, parsley, rosemary and thyme
• Nuts and seeds containing healthy fats, like olives, almonds, flaxseed, hazelnuts and walnuts (olive oil has been found to contain a compound called oleocanthal that acts similarly to the NSAID ibuprofen)
• Oily fish, such as sardines, mackerel, herring, anchovies and wild salmon which are rich in soothing omega-3 fats, and a healthy omega-3-to-6 ratio in the overall diet

In addition to containing natural anti-inflammatory compounds, vegetables and fruits do act in some indirect and hard-to-measure ways on cancer risk.

"People who eat a large proportion of fruit and vegetables are less likely to be overweight or obese, which is a major cancer risk factor," notes Dr Rachel Thompson, deputy head of science at the World Cancer Research Fund. Most fruits and vegetables are low in calories and contain fiber which helps to make us feel full and hence stops us eating too much and gaining weight, she explains. The World Cancer Research Fund has issued a list of ten recommendations to reduce cancer risk.

Even cigarette smokers, the most at-risk from cancer, are protected if they eat vegetables and fruits. A recent study (which I wrote about here) showed smokers who ate the greatest variety of fruits and vegetables were 27% less likely to get squamous cell lung cancer than those with the least variety. (Of course, not smoking at all confers much greater protection!)

So before you rush to the drug store to stock up on aspirin, may I suggest you head into the kitchen and cook yourself a nice vegetable-and-fish curry. I made one last night that contained red onions, leeks, carrots, broccoli, mushrooms and salmon, swimming in a coconut-milk sauce spiced with turmeric, ginger, garlic, ground coriander, pepper and chili flakes. It was warming, quick and easy to prepare.

Amazing Grace: The digestive and emotional benefits of mealtime grace

When our eldest son was five, we started to say grace at mealtime. Untrained in matters of gastronomic spirituality, we began by rolling a wooden cube inscribed with six child-friendly, non-denominational prayers: whichever verse landed face-up was recited.

Soon we got bored of rattling off the same six prayers and decided to wing it. Now we no longer call it grace and we don't couch it in religious terms (though the children like to finish with a rousing 'Amen!' every now and then), but we find it hard to begin a meal without a brief moment of calm.

Grace and gratitude are closely related (the Latin gratia means 'good will' or 'gratitude'). At home, we now refer to mealtime grace as the 'Thankfulness Moment.' Much like a Thanksgiving dinner, every person at the table expresses his or her gratitude for something.

When we are eating meat or fish, for instance, our 8-year-old son always thanks the animal for giving its life for us. His twin sister often gives thanks for family and friends. Our teenage son is often grateful for the fact that we are all together at the table, or that it's Friday. My husband and I give thanks for children, health and a comfortable home. Occasionally, someone thanks the cook for prepWhen children are jittery or parents tired, we sometimes hold a 'silent grace' where we link hands and sit quietly for as long as the children can bear (about one or two minutes). A note of caution: when young children are present, make sure you your food warm; their thanks-giving can go on for quite a while as they express gratitude for teachers, friends, the weather, pets, a snuggly pyjama or a favourite soft toy.

When we are eating meat or fish, for instance, our 8-year-old son always thanks the animal for giving its life for us. His twin sister often gives thanks for family and friends. Our teenage son is often grateful for the fact that we are all together at the table, or that it's Friday. My husband and I give thanks for children, health and a comfortable home.

When children are jittery or parents tired, we sometimes hold a 'silent grace' where we link hands and sit quietly for as long as the children can bear (about one or two minutes). A note of caution: when young children are present, make sure you keep your food warm during grace; their thanksgiving can go on for quite a while as they express gratitude for teachers, friends, the weather, pets, a snuggly pyjama or a favourite soft toy.

Mealtime grace doesn't have to be a religious act. If for no other reason, saying grace - some would prefer to call it 'meditating/relaxing before a meal' - is worth adopting because it has a strong bearing on nutritional health. For as we settle for the moment of calm that precedes the meal, our body relaxes and our organs prepare to digest and absorb the food we are about to eat.

At the thought, sight and smell of food, gastric juices start flowing, enzymes are secreted, and the body stops whatever it is doing to relax and welcome the incoming nourishment. Our in-built fight-or-flight stress response, which dates back to our hunter-gatherer days and which halts digestive processes at times of stress, is suspended, making way for digestion and absorption.

Indeed, scientists have found that eating in a relaxed state may be even more healthful than chewing one's food thoroughly! In one study, subjects who ate complex carbohydrates under stressful conditions secreted less of the carbohydrate-digesting enzyme amylase than those eating under relaxed conditions. The study's authors conclude that "deep relaxation was significantly more important than thorough chewing in the oral digestion of complex carbohydrates." Stress has also been shown to cause trouble further down the digestive tract, disrupting the gut flora and contributing to the development of food allergies (see this study).

Grace doesn't just boost your digestive system though. In recent years, psychologists have turned their attention to the study of gratitude, and not surprisingly, they have found that our ability to experience and express gratitude is a key determinant of our overall health and happiness.

"Gratitude leads people to act in virtuous or more selfless ways," according to Northeastern University psychologist David de Steno. "And it builds social support, which we know is tied to both physical and psychological well being."

But there's a catch: gratitude only ‘works' if you express it on a regular basis. "If you don't do it regularly you're not going to get the benefits," notes Sonja Lyubomirsky, a psychology professor at the University of California, Riverside. "It's kind of like if you went to the gym once a year. What would be the good of that?"

According to Robert Emmons, a psychology professor at the University of California, Davis, people who express gratitude are less resentful, experience longer and better-quality sleep, exercise more and report a drop in blood pressure. "The practice of gratitude can increase happiness levels by around 25%," he estimates.

For many people I know, the past few years have been difficult. Some have experienced economic hardship and employment worries, others have endured ill health and troubled personal relationships.

When life is tough, it's hard to feel grateful. But it's precisely when we feel down that it may be most helpful to tap into feelings of gratitude. When I sit down and focus on things to be grateful for (people who are more organised than me keep a 'gratitude diary,' something I may start in the New Year...), I usually begin by being thankful for small blessings: the purring of the cat on my lap or the comforting warmth of my sweater.

This quickly brings me to big blessings: the food on my table, the chatter of my children, my husband who shares my burdens, hopes and dreams, friends who will listen on the phone or over a cup of tea. As I consider these gifts, I feel suffused by a warm glow of gratitude, and feelings of sadness, hurt and anger recede.

For this is the beauty of gratitude: you can't be simultaneously angry and grateful, or depressed and grateful, or selfish and grateful. Gratitude is the most potent counterforce to egoism, ruthlessness, greed and the many other masks behind which unhappiness hides. By forcing ourselves to experience, and to express, gratitude -- if only once a day, at mealtimes -- we can rise above the darker side of human nature.

So why can't we all show a little more gratitude? According Emmons, "some people feel uncomfortable talking about these topics, since they may sound too spiritual, or religious. Others simply don't want to feel obligated to the person who helped them, and never come to realize the boost in energy, enthusiasm, and social benefits that come from a more grateful, connected life."

Here's wishing you a Thanksgiving filled with light, peace and a healthy digestion!

Mediterranean diet gets UNESCO's stamp of approval

Increasingly under threat from mass-produced fast-food, the Mediterranean diet received a boost this week when the United Nations' culture and education agency UNESCO added it to its list of cultural heritage worth preserving and promoting.

A press release issued after the meeting of UNESCO's Intergovernmental Committee for the Safeguarding of the Intangible Cultural Heritage highlights the Mediterranean diet's widely-accepted healthfulness. But to me, at least as important is the agency's emphasis on the socio-cultural elements of the Mediterranean diet.

"The Mediterranean diet (from the Greek diaita, or way of life) encompasses more than just food. It promotes social interaction, since communal meals are the cornerstone of social customs and festive events. It has given rise to a considerable body of knowledge, songs, maxims, tales and legends. The system is rooted in respect for the territory and biodiversity, and ensures the conservation and development of traditional activities and crafts linked to fishing."

The UNESCO also notes that women play "a particularly vital role in the transmission of expertise, as well as knowledge of rituals, traditional gestures and celebrations, and the safeguarding of techniques."

This is an interesting point, for one reason why home-cooked family meals are in decline in the Mediterranean region is the increased number of women who work outside the home. (See this article about the sharp rise in obesity around the Mediterranean following the marked shift in nutritional habits and demographic trends.) Of course I do not 'blame women' for abandoning home-cooking; I blame social structures that make it very difficult for women and men to both work and prepare healthy, natural food for their families.

The request for recognition of the diet was made by the governments of Italy, Spain, Greece and Morocco. Each of these countries is now committed to undertaking a series of safeguarding efforts, together with a plan for transnational measures aimed at ensuring transmission to younger generations and promoting awareness of the Mediterranean diet.

Some commentators have dismissed the Mediterranean diet's inclusion on the UNESCO's heritage list as PR gimmickry, or, more cynically still, as part of a marketing ploy to boost Mediterranean olive-oil sales. Citing varied cuisines around the Mediterranean basin, they also claim that there is no such thing as a distinct 'Mediterranean diet' and therefore no cultural heritage to preserve.

These cynics are missing the point. Cuisines vary around the Mediteranean because of the different climatic, geological, historical and cultural environments that shaped them. Yet, despite superficial differences, there is more that unites than divides them. For the traditional pre-industrial diets eaten in the whole region were, almost without exception, characterised by a high intake of vegetables, fruits, pulses, whole grains, nuts, seeds, herbs and spices, a moderate intake of fish, dairy and meat and accompanied by red wine (religious practices permitting).

Incidentally, anyone who is familiar with Mediterranean cuisines knows that many countries have similar dishes that go by different names: for example, Italy's pesto is virtually the same as the pistou of French Provence, which closely resembles the romesco sauce of Spain's Catalunya region or north African chermoula.

Meanwhile, to those who accuse the olive oil growers of dark and scheming motives, I say: the Mediterranean diet is precious precisely because, apart from olive oil and perhaps red wine, it is largely anti-commercial, being based on unprocessed, fresh food that offers slim profit margins to producers. It is the exact antithesis of the sort of diet the industrial food giants would have us eat, one that consists almost entirely of processed and denatured 'food-like edible substances' that are making us sick and fat.

Indeed, if everyone started eating a Mediterranean diet - fresh fruit and vegetables from farmers' markets, homemade whole-grain bread, eggs from chickens scratching in the back yard, meat and milk from animals raised on nearby meadows, etc. - the industrial food giants would soon be out of business.

Luckily for them, this isn't going to happen anytime soon, because, among others, many people below the age of 30 don't know how to produce or prepare food from scratch, nor do they remember the taste of fresh, natural, unadulterated food. Long working hours, competitive labor markets, uninspired school and workplace cafeterias and the ever-present lure of tasty but unnutritious convenience fare will ensure that young palates remain undemanding, even to the point of preferring a factory-made poultry nugget to a home-roasted chicken!

So while putting the Mediterranean diet on a list of threatened lifestyles is probably not enough to restore an ailing food culture, I think every effort is worth undertaking it if it means raising public awareness just that teeny little bit. Call me a hopeless romantic, but I believe that if more people ate a Mediterranean diet and enjoyed the life-affirming lifestyle that goes with it, the world could be a healthier and happier place.

Humble fruits that pack a powerful punch

For too long, plums, and especially their dried incarnations, prunes, have gotten a bum rap. This is mostly because of their unfortunate association with constipation, which they relieve quickly and naturally thanks to their high fiber content.

However, as we feast on this year's crop of this delicious stone fruit, it's time to stop snickering and start appreciating this humble stone fruit's many other health benefits. For in addition to their laxative qualities, plums, and their cousins, peaches and nectarines, appear to have cancer-fighting properties.

Animal and test-tube experiments have yielded promising results. Most recently, scientists at Texas A&M University discovered that breast cancer cells died after being treated with peach and plum extracts. The researchers treated healthy cells and breast cancer cells (including an aggressive non-hormone-dependent strain) with extracts from yellow-fleshed ‘Rich Lady' peaches and red-fleshed ‘Black Splendor' plums - both commercially available varieties.

"These extracts killed the cancer cells but not the normal cells," reports Luis Cisneros-Zevallos, Food Scientist and Associate Professor at Texas A&M University. "Our studies in vitro show the potential for selective killing of cancer cells, and our studies with mice have confirmed that these compounds inhibit metastasis," he adds. (Metastasis is the spread of cancer cells to other parts of the body.) Indeed, the effect of the fruit extract was strongest on the aggressive, non-hormone dependent cancer cells that most commonly metastasize, he notes. The research was published in the Journal of Agricultural and Food Chemistry.

 

The two phenolic compounds largely responsible for plums' anti-cancer effect, chlorogenic acid and neo-chlorogenic acid, occur in many fruits and vegetables but are more prevalent in stone fruits than anywhere else - including blueberries with their impressive array of cancer-preventive phytonutrients. Whether these phenolic acids have similarly beneficial effects on other types of cancer is unclear. "We intend to study other types of cancers including prostate, colon and pancreatic," says Dr Cisneros-Zevallos.

What makes plums and prunes (coyly renamed ‘dried plums' by American prune marketers wishing to shake the stigma of geriatric constipation...) even more appealing is their low glycemic index (GI) ranking. (Anything below 55 is considered low.) According to the University of Sydney's Glycemic Index Database, prunes have a GI of 29, even below low-GI apricots (around 31) and half that of raisins (between 54 and 66). Foods with a high GI-value are thought to contribute to weight gain - a cancer risk factor - and the secretion of hormones such as insulin that can fuel cancer-cell growth.

Also in their favour, plums, prunes and peaches (ideally organically grown, to avoid pesticides: peaches and nectarines have among the hesviest pesticide residues, according to the Environmental Working Group's Shopper's Guide to Pesticides; plums fare better) are less expensive than many other fruits - especially imported tropical fruits or exiotic 'miracle foods' such as goji berries and acai fruit. This makes it easy to eat them on a daily basis, even for people with a tight food budget.

So what's the healthiest way to enjoy stone fruits? Straight off the tree. That's because phenolic compounds may be lost during processing, especially when subjected to heat, as in high-temperature canning and pasteurization for juice.

Alas, the plum season is short, so what can we do to get year-long protection from plum and peach compounds? Dried fruit is an option, as drying preserves a larger proportion of phenols than canning. "How much is lost will depend on the conditions of processing being used including temperature, air humidity and processing time," says Dr Cisneros-Zevallos. If you have a dehydrator, you may wish to experiment with fresh peaches and plums. Another option is frozen fruit - either bought fresh, pitted and frozen yourself, or bought ready-frozen.

Prune puree - which some call ‘prune butter' because of its thick, shiny texture - is quick and easy to make at home. Simply empty a packet of soft dried prunes into a bowl (making sure there's no stray pits left in any of them), pour warm water over them and leave to soak for an hour (or longer if they are very dry). Puree in a kitchen blender (you can add ginger or cinnamon for extra flavor) and transfer to a tightly sealed jar. This should keep for 3-4 weeks in the refrigerator.

In my house, we spread prune butter on toast, pancakes and waffles, mix it with plain yogurt and porridge or add it into fruit smoothies. We even serve it alongside roast meat (especially duck) as a sort of relish or chutney (adding a little salt, pepper and other spices). Lastly, one of my favorite recipes in Zest for Life is a chocolate-hazelnut spread that contains prune puree and tastes a lot like Nutella.

One excellent use of prune butter - which you can also buy in jars - is as fat replacement in baking. According to researchers at New York's Hunter College, pureed prunes can replace as much as 30 per cent of the fat by weight in chocolate cupcakes. The American Institute for Cancer Research's ‘Healthy Substitutions' page suggests replacing ½ cup of butter with ¼ cup prune purée and ¼ cup butter. As prune puree is dark and has a distinct flavor, this works best in spicy fruit cakes or chocolate cake (for example, Martha Stewart's ‘guilt-free' brownies - though I would reduce sugar content slightly and use whole grain flour). You can find dozens of other delicious prune recipes on the website of the California Dried Plums website.

Try it now: The Sit-Down Diet

Do you want to know about a diet that requires neither calorie-counting nor deprivation and doesn't involve weight-loss books, punishing exercise routines or expensive supplements? It's free, it's simple and anyone can do it. In fact, there's only one simple rule to follow: you may only eat when you are sitting down. Not in a car, not at a desk or in a subway train, but at a table designed for eating. I think I'll call it the Sit-Down Diet.

The idea was born from a passing comment my husband made last weekend when he saw me standing in the kitchen, eating leftovers off our children's plates before loading them in the dishwasher. "Have you noticed how often you eat standing up?" he observed, grinning. "I wonder what would happen if you only ever ate when sitting at the dining table." Thud went the gauntlet.

The Sit-Down Diet is based on the idea that when we sit down to eat, we consume fewer calories and more nutritious food than when we're standing up or walking. As an added bonus, when we sit down to eat and chew our food properly, we're more likely to digest and assimilate it well than when eating while rushing around.

Like most diets, the Sit-Down Diet may not work for everyone. But if, like me, you have a busy life and regularly snack on tasty tidbits while standing in front of your fridge, shopping, preparing a meal or travelling, it may work for you! And while the Sit-Down Diet is not (yet) scientifically proven, it is based on hard evidence.

For one, mindless eating is fattening. As Cornell University consumer behaviour professor Brian Wansink shows in his excellent book, ‘Mindless Eating,' many of us over-eat because we eat in response to external cues and distractions rather than a genuine physical need for food. I believe that sitting down to eat (without a TV, computer or book to distract us) focuses our mind on eating and makes us more attuned to physical cues for hunger and satiety.

Moreover, scientists have shown that most of the foods we eat standing up are low in nutritional value and high in empty calories. A study published last year in the Journal of the American Dietetic Association showed that young adults who eat on the run consume more fast foods and soft drinks and less healthy food than their peers who make time to sit down to dinner, eating more fruit and vegetables in the process.

Another investigation conducted by Cornell University researchers showed that time-starved working parents struggle to find the time to sit down to a home-cooked meal. Instead, many of them grab quick foods at work or opt for fast food and take-out meals of inferior nutritional quality.

That sit-down eating can favor healthy weight was shown in a study published recently in the Journal of Pediatrics. Researchers studying children in Greece found that those who regularly sat down to family meals ate more vegetables and fewer snack foods and were thinner than their peers who did not have these eating habits.

How might sitting at a table translate into healthy weight? In part it is because we slow down when we sit down. And slowing down means consuming fewer calories; for when we eat slowly we feel fuller and more satisfied than when we wolf down our food.

Previously considered an old wives' tale, the link between eating quickly and weight gain was recently confirmed by a clever intervention study where healthy adult male volunteers were served a large cup (300 ml) of ice cream on two different occasions. One time, the men were given five minutes to eat the ice cream; the other time, 30 minutes were allotted. Same volunteers, same amount of ice cream - but when people took a half hour to eat the food, their rating of ‘fullness' rose and two gut hormones related to appetite satisfaction increased markedly.

How does any of this relate to cancer prevention? The link is obesity, for excess weight is a key cancer risk factor. The World Cancer Research Fund (WCRF) in its 2009 Policy Report estimates that nearly a fifth of all cancers of the esophagus, pancreas, gallbladder, colon, rectum, breast, endometrium and kidney in the US could be prevented if people had a healthy body weight. (For a global perspective on obesity and cancer, please watch this excellent talk by Professor Philip James, the President of the International Association for the Study of Obesity, given at a WCRF conference I recently attended).

Seen in this light, almost anything we can do to prevent obesity is worth a try - even sitting down to eat!

To practice what I preach, I will spend the next week only eating when seated; then I will report my findings here. Won't you join me? There's room at the table!