Eating purple fruits such as blueberries and drinking green tea can help ward off diseases including Alzheimer’s, Multiple Sclerosis and Parkinson’s, a University of Manchester report claims. New research from Professor Douglas Kell, published in the journal Archives of Toxicology, has found that the majority of debilitating illnesses are in part caused by poorly-bound iron which causes the production of dangerous toxins that can react with the components of living systems. These toxins, called hydroxyl radicals, cause degenerative diseases of many kinds in different parts of the body. In order to protect the body from these dangerous varieties of poorly-bound iron, it is vital to take on nutrients, known as iron chelators, which can bind the iron tightly.
Brightly-coloured fruits and vegetables are excellent sources of chelators, as is green tea, with purple fruits considered to have the best chance of binding the iron effectively. However, despite conflicting reports, the widely-publicised benefits of red wine seem to work in a different way, and have no similar benefits, Professor Kell’s paper noted.
This new paper is the first time the link has been made between so many different diseases and the presence of the wrong form of iron, and gives a crucial clue as to how to prevent them or at least slow them down. Professor Kell argues that the means by which poorly-liganded iron accelerates the onset of debilitating diseases shows up areas in which current, traditional thinking is flawed and can be dangerous. For instance, Vitamin C is thought to be of great benefit to the body’s ability to defend itself against toxins and diseases. However Professor Kell, who is Professor of Bioanalytical Science at the University, indicates that excess vitamin C can in fact have the opposite effect to that intended if unliganded iron is present.
Only when iron is suitably and safely bound (“chelated”) will vitamin C work effectively. Professor Kell said: “Much of modern biology has been concerned with the role of different genes in human disease. “The importance of iron may have been missed because there is no gene for iron as such. What I have highlighted in this work is therefore a crucial area for further investigation, as many simple predictions follow from my analysis.
“If true they might change greatly the means by which we seek to prevent and even cure such diseases.”
Women who eat more than three servings of fish per week are less likely to experience a stroke, a new study suggests. Specifically, fish-lovers in Sweden were 16 percent less likely to experience a stroke over a 10-year-period, relative to women who ate fish less than once a week. “Fish consumption in many countries, including the U.S., is far too low, and increased fish consumption would likely result in substantial benefits in the population,” said Dr. Dariush Mozaffarian of the Harvard School of Public Health. When choosing fish to eat, it’s best to opt for fish that are rich in omega-3 fatty acids, found most abundantly in fatty fish like salmon, mackerel and albacore tuna. “But any fish is better than none,” Mozaffarian noted.
“Indeed, these fatty acids likely underlie the benefits of fish on stroke risk”, said study author Dr. Susanna Larsson of the Karolinska Institute in Stockholm. “These fatty acids may reduce the risk of stroke by reducing blood pressure and blood (fat) concentrations.”
This is not the first study to suggest that people who eat more fish have a lower risk of stroke, and experts already recommend a fishy diet to reduce the risk of cardiovascular problems, Mozaffarian added. “This study supports current recommendations.” Earlier this year, for instance, a study showed that middle-aged and older men who eat fish every day are less likely than infrequent fish eaters to develop a suite of risk factors for heart disease, diabetes and stroke.
In the current study, published in the American Journal of Clinical Nutrition, Larsson and her colleagues looked at 34,670 women 49 to 83 years old. All were free of cardiovascular disease and cancer at the beginning of the study, in 1997. During 10 years of follow-up, 1,680 of the women (4 percent) had a stroke. Stroke caused by blockage of an artery that supplies blood to the brain — also known as a “cerebral infarction” or “ischemic stroke” — was the most common event, representing 78 percent of all strokes in the study. Other types of strokes were due to bleeding in the brain, or unspecified causes.
Women who ate more than three servings of fish per week had a 16 percent lower risk of stroke than women who ate less than one serving a week. “Not a small effect,” Mozaffarian said, noting that it was roughly equivalent to the effect of statin drugs on stroke risk. Furthermore, the researchers asked women about their diets only once, using a questionnaire, which might have caused errors that would underestimate the link between a fishy diet and stroke risk, he explained. “So, the true risk reduction may be larger.”
Interestingly, women appeared to benefit most from eating lean fish, when other research shows fatty fish is better for health. This finding may stem from the fact that most fatty fish, such as herring and salmon, is eaten salted in Sweden, Larsson explained. “A high intake of salt increases blood pressure and thus may increase the risk of stroke,” she said. “So the protective effects of fatty acids in fatty fish may be attenuated because of the salt.”
Indeed, when it comes to fish, not all have equal benefits, Mozaffarian noted – for instance, he said, research has not shown any cardiovascular benefits from eating fast food fish burgers or fish sticks. In addition, women of childbearing age should avoid certain types of fish known to carry relatively high levels of pollutants, such as shark and swordfish, Mozaffarian cautioned. “This is a very, very short list of fish to avoid or minimize — there are many, many other types of fish to consume,” he said. “Women at risk of stroke are generally beyond their child-bearing years, and so for these women, all types of fish can be consumed.”
Larsson and her team speculate that certain nutrients in fish, such as fatty acids and vitamin D, might explain its apparent benefits. The Swedish study cannot prove cause and effect for high fish consumption and lowered stroke risk, however. For instance, fish consumption could be a sign of a generally healthier lifestyle or some other mechanism at work. Last December, Larsson and colleagues published data from the same group of women in the journal Stroke showing that those who eat a lot of red meat may also be putting themselves at increased risk of stroke.
SOURCE: bit.ly/dKunk8 American Journal of Clinical Nutrition, online December 29, 2010.
A new study has found that the leading causes of death are no more infectious diseases but chronic diseases such as cardiovascular disease and cancer – which may be affected by food habits. Researchers investigated eating patterns of over 2500 adults between the ages of 70 and 79 over a ten-year period and found that certain diets were associated with reduced mortality.
By determining the consumption frequency of 108 different food items, researchers were able to group the participants into six different groups as per their food choices:
- Healthy foods- 374 participants
- High-fat dairy products- 332
- Meat, fried foods, and alcohol- 693
- Breakfast cereal-386
- Refined grains-458
- Sweets and desserts-339
‘Healthy foods’ group ate more low-fat dairy products, fruit, whole grains, poultry, fish, and vegetables, and lower consumption of meat, fried foods, sweets, high-calorie drinks, and added fat. ‘High-fat dairy products’ group had higher intake of foods such as ice cream, cheese, and 2 per cent and whole milk and yoghurt, and lower intake of poultry, low-fat dairy products, rice, and pasta.
End results indicated that ‘High-fat dairy products’ group had a 40 per cent higher risk of mortality than the Healthy foods cluster and the ‘Sweets and desserts’ group had a 37 per cent higher risk. No significant differences in risk of mortality were seen between the ‘Healthy foods’ cluster and the ‘Breakfast cereal’ or ‘Refined grains’ clusters.
The “results of this study suggest that older adults who follow a dietary pattern consistent with current guidelines to consume relatively high amounts of vegetables, fruit, whole grains, low-fat dairy products, poultry and fish, may have a lower risk of mortality,” said Amy L. Anderson at Department of Nutrition and Food Science, University of Maryland.
“Because a substantial percentage of older adults in this study followed the ”Healthy foods” dietary pattern, adherence to such a diet appears a feasible and realistic recommendation for potentially improved survival and quality of life in the growing older adult population.” The study will be published in the January 2011 issue of the Journal of the American Dietetic Association .
Recent studies show that grapefruit and diabetes may share a close link. Researchers concluded that naringenin found in grapefruit may increase the body's sensitivity to insulin. This research was conducted only in the laboratory, and further studies are still needed. Grapefruit and diabetes may share a close link given some recent studies suggesting that eating of the fruit can help in controlling the disease. One recent report suggests that grapefruit may become an effective part of the treatment for type 2 diabetes as it contains the antioxidant Naringenin that can break down fats and increase a person's sensitivity to insulin.
The study also concluded that grapefruit is also capable of treating abnormal levels of cholesterol, warding off metabolic syndrome and improving a person's tolerance to glucose, factors that are all associated with diabetes. The study was conducted by scientists from the Massachusetts General Hospital Center for Engineering in Medicine and Hebrew University of Jerusalem. Although more research needs to be completed, grapefruit is a safe source of vitamins for diabetics. One-half of a grapefruit contains 52 calories and 13g of carbohydrates, and the fruit has a low rating on the glycemic index, indicating a lower propensity to drive up blood sugar levels.
The antioxidant Naringenin is found in grapefruit and has been largely credited for its ability in heping to treat type 2 diabetes. Naringenin is specifically noted for being able to break down fatty acids in the liver, similar to what happens when a person undergoes fasting. Yaakov Nahmias, PhD of the Hebrew University of Jerusalem reports that the results of their study indicate that Naringenin antioxidant was found to be capable of breaking down fatty acids similar to those induced by significant amounts of fasting. It does so by activating nuclear receptors, a family of proteins that can cause the liver to break down fatty acids instead of storing them.
Another study conducted by researchers at the University of Western Ontario showed that Naringenin can correct increases in triglyceride and cholesterol levels, while resisting insulin resistance and normalizing glucose metabolism. The said study showed that Naringenin genetically reprograms the liver to burn up more excess fat, instead of storing it. The said study also showed that Naringenin is able to suppress appetite and decrease food intake, which are common strategies in controlling diabetes.
The study of MGH and Hebrew University scientists also noted that Naringenin can lower bad cholesterol called vLDL while able to cure several symptoms of type 2 diabetes.
Research on grapefruit and diabetes, however, has not yet been conducted on humans, and were only done in the laboratory on the liver cells of humans and rats. Until further studies are done to confirm the effects of grapefruit in the treatment of diabetes type 2 in humans, it is still not safe to conclude that the naringenin in grapefruits can indeed cure diabetes. Further studies are still needed to establish its efficacy as well as its overall effects in the body, including the negative effects it might have.
Thus, many health experts do not encourage patients with diabetes to increase their consumption of grapefruits or increase grape juice intake, especially if they are also taking medications. There are patients prescribed with some type of drugs to lower their cholesterol level who are advised not to drink grapefruit juice as it can increase risk of side effects.
Eating almonds could help prevent diabetes and heart disease, according to a study.
The research found incorporating the nuts into our diets may help treat type 2 diabetes, which accounts for 90 to 95 per cent of all cases.
As well as combating the condition, linked to obesity and physical inactivity, it could tackle cardiovascular disease, the report published in the Journal of the American College of Nutrition said.
Diabetes is one of the fastest growing diseases in the world, and sufferers have a shortage of insulin or a decreased ability to use the hormone that allows glucose (sugar) to enter cells and be converted to energy.
When diabetes is not controlled, glucose and fats remain in the blood and over time, damage vital organs.
The study found consuming a diet rich in almonds may help improve insulin sensitivity and decrease LDL-cholesterol levels in those with pre-diabetes, a condition in which people have blood glucose levels higher than normal but not high enough to be classified as diabetes.
Researchers looked at the effects of consuming an almond-enriched diet on 65 adults with pre-diabetes (48 women and 17 men) with an average age in the mid-50s.
The participants were split up, and the group on the almond-enriched diet showed greater improvements in insulin sensitivity and clinically significant reductions in LDL-cholesterol compared with the nut-free group.
Dr Michelle Wien, assistant research professor in nutrition at Loma Linda University's School of Public Health, said, “We have made great strides in chronic disease research from evidence of effective treatment to evidence of effective prevention.”
The principal researcher for the study, conducted at the University of Medicine and Dentistry of New Jersey, added, “It is promising for those with risk factors for chronic diseases, such as type 2 diabetes and cardiovascular disease, that dietary changes may help to improve factors that play a potential role in the disease development.”
An estimated 55 million people in Europe have been diagnosed with diabetes, and the figure is expected to rise to 66 million by 2030.
There is no known way to prevent type 1 diabetes, which may be autoimmune, genetic, or environmental. It accounts for five per cent of all cases. Type 2 diabetes most often occurs in people older than 40.
Around 60 million people in Europe have pre-diabetes. People with the condition have an increased risk of developing type 2 diabetes, heart disease and strokes.
Almonds are cholesterol-free and compared with other nuts, they are the highest in six essential nutrients – fibre, magnesium, protein, potassium, copper and vitamin E.
The steep rate of death from stroke in a swath of Southern states often referred to as America's “stroke belt” may be linked to a higher consumption of fried fish in that region, new research suggests. A study published in the journal Neurology shows people living in the stroke belt — which comprises North Carolina, South Carolina, Georgia, Alabama, Mississippi, Tennessee, Arkansas and Louisiana — eat more fried fish and less non-fried fish than people living in the rest of the country, and African-Americans eat more fried fish than Caucasians. “Differences in dietary fish consumption, specifically in cooking methods, may be contributing to higher rates of stroke in the stroke belt and also among African Americans,” says study author Fadi Nahab, medical director for the Stroke Program at Emory University Hospital in Atlanta.
The research, part of a large government-funded study, Reasons for Geographic and Racial Differences in Stroke (REGARDS), involved 21,675 participants from across the country; the average age was 65. Of the participants, 21% were from the “stroke buckle,” the coastal plain region of North Carolina, South Carolina and Georgia where stroke mortality rates are even higher than they are in the rest of the stroke belt. Another 34% were from the rest of the stroke belt and 44% were from the other states.
Participants were interviewed by phone and then given an in-home physical exam. The questionnaire asked how often they ate oysters, shellfish, tuna, fried fish and non-fried fish. The American Heart Association recommends people eat fish high in omega-3 fatty acids—essential fatty acids humans get through their diet—at least twice a week, baked or grilled but not fried. Fewer than one in four overall ate two or more servings of non-fried fish a week. Stroke belt residents were 32% more likely to eat two or more servings of fried fish each week than those in the rest of the country.
African-Americans were more than 3.5 times more likely to eat two or more servings of fried fish each week than Caucasians, with an overall average of about one serving per week of fried fish compared with about half a serving for Caucasians. When it came to eating non-fried fish meals, stroke belt residents ate an average of 1.45 servings per week, compared with 1.63 servings eaten by people elsewhere.
“This is good stuff. It's a well-done study, but I think one thing to bear in mind is that it's not specifically a study of stroke risk. You're looking at a community and seeing how it's behaving on the whole,” says Daniel Labovitz, a stroke neurologist at Montefiore Medical Center in the Bronx. “This study can't tell you causation. It can't tell you there's a direct link between one thing and another, it just tells you they're associated,” says stroke neurologist Victor Urrutia, an assistant professor at Johns Hopkins University School of Medicine.
How might eating fried fish impact stroke?
It could be that frying the fish leaches out the omega-3s, says Jeremy Lanford, stroke director at Scott & White Healthcare in Roundrock, Texas. Or the increased fat calorie content from the frying oil may contribute to stroke, says author Nahab. He also notes that fish used for frying, such as cod and haddock, tend to be the types lower in healthy fats. More research is needed to tease out whether cooking methods affect stroke risk, Labovitz says. “In other words, is fried fish a problem, or is it another red herring?” he says.
The study was supported by the National Institute of Neurological Disorders and Stroke, the National Institutes of Health, and the Department of Health and Human Services. Funding was provided by General Mills for coding of the food frequency questionnaire.
Scientists have upgraded their opinion of Neanderthal cuisine after spotting traces of cooked food on the fossilised teeth of our long-extinct cousins. The researchers found remnants of date palms, seeds and legumes – which include peas and beans – on the teeth of three Neanderthals uncovered in caves in Iraq and Belgium. Among the scraps of food embedded in the plaque on the Neanderthals' teeth were particles of starch from barley and water lilies that showed tell-tale signs of having been cooked. The Ice Age leftovers are believed to be the first direct evidence that the Neanderthal diet included cooked plants as well as meat obtained by hunting wild animals.
Dolores Piperno, who led the study at the archaeobiology laboratory at the Smithsonian National Museum of Natural History in Washington, said the work showed Neanderthals were more sophisticated diners than many academics gave them credit for. Piperno said the discoveries even raised the possibility that male and female Neanderthals had different roles in acquiring and preparing food. “The plants we found are all foods associated with early modern human diets, but we now know Neanderthals were exploiting those plants and cooking them, too. When you cook grains it increases their digestibility and nutritional value,” she added.
The findings bring fresh evidence to the long debate over why Neanderthals and not our direct ancestors, the early modern humans, went extinct. The last of the Neanderthals are thought to have died out around 28,000 years ago, but it is unclear what role – if any – modern humans played in their demise. “The whole question of why Neanderthals went extinct has been controversial for a long time and dietary issues play a significant part in that,” Piperno said. “Some scholars claim the Neanderthals were specialised carnivores hunting large game and weren't able to exploit a diversity of plant foods. “As far as we know, there has been until now no direct evidence that Neanderthals cooked their foods and very little evidence they were consuming plants routinely.”
Piperno's team was given permission to study the remains of three Neanderthal skeletons. One was unearthed at the Shanidar cave in Iraq and lived 46,000 years ago. The other two were recovered from the Cave of Spy in Belgium, and date to around 36,000 years ago. The scientists examined three teeth from the Iraqi Neanderthal and two from each of the Belgium specimens. To look for traces of food on them, they scraped fossilised plaque from each tooth and looked at it under a microscope. Grains from plants are tiny, but have distinct shapes that the scientists identified by comparing them with a collection at the Smithsonian's herbarium. The researchers also cooked a range of plants to see how their appearance changed.
They collected 73 starch grains from the Iraqi Neanderthal's teeth. Some of these belonged to barley or a close relative, and appeared to have been boiled in water. “The evidence for cooking is strong. The starch grains are gelatinised, and that can only come from heat associated with cooking,” Piperno said. Similar tests on the Belgian Neanderthals' teeth revealed traces of cooked starch that probably came from parts of water lilies that store carbohydrates. Other cooked starch grains were traced back to sorghum, a kind of grass.
The study is published in the Proceedings of the National Academy of Sciences journal.
In Piperno's opinion, the research undermines one theory that suggests early modern humans drove the Neanderthals to extinction by having a more sophisticated and robust diet. The work also raises questions about whether Neanderthals organised themselves in a similar way to early hunter-gatherer groups, she said. “When you start routinely to exploit plants in your diet, you can arrange your settlements according to the season. In two months' time you want to be where the cereals are maturing, and later where the date palms are ready to pick. It sounds simplistic, but this is important in terms of your overall cognitive abilities. “In early human groups, women typically collected plants and turned them into food while men hunted. To us, and it is just a suggestion, this brings up the possibility that there was some sexual division of labour in the Neanderthals and that is something most people did not think existed.”
New research into the health benefits of beetroot juice suggests it's not only athletes who can benefit from its performance enhancing properties – its physiological effects could help the elderly or people with heart or lung-conditions enjoy more active lives.
Beetroot juice has been one of the biggest stories in sports science over the past year after researchers at the University of Exeter found it enables people to exercise for up to 16% longer. The startling results have led to a host of athletes – from Premiership footballers to professional cyclists – looking into its potential uses. A new piece of research by the university in conjunction with the Peninsula College of Medicine and Dentistry has revealed the physiological effects of drinking beetroot juice could help a much wider range of people.
In the latest study, published in the Journal of Applied Physiology, the researchers looked at low intensity exercise and found that test subjects used less oxygen while walking – effectively reducing the effort it took to walk by 12%. Katie Lansley, a PhD student from the university's Sport and Health Sciences department and lead author of the study, said: “As you get older, or if you have conditions which affect your cardiovascular system, the amount of oxygen you can take in to use during exercise drops considerably. This means that, for some people, even simple tasks like walking may not be manageable. “What we've seen in this study is that beetroot juice can actually reduce the amount of oxygen you need to perform even low-intensity exercise. In principle, this effect could help people do things they wouldn't otherwise be able to do.”
When consumed, beetroot juice has two marked physiological effects. Firstly, it widens blood vessels, reducing blood pressure and allowing more blood flow. Secondly, it affects muscle tissue, reducing the amount of oxygen needed by muscles during activity. The combined effects have a significant impact on performing physical tasks, whether it involves low-intensity or high-intensity effort. So far the research on the impacts of beetroot juice has only been carried out on younger people who are in good health, but the researchers believe there is no reason why the effects of beetroot juice wouldn't help others. “While we haven't yet measured the effects on the elderly or those with heart or lung conditions, there is the potential for a positive impact in these populations which we intend to go on and investigate further,” Katie Lansley added.
Beetroot juice contains high levels of nitrate. The latest study has proved that this is the key ingredient which causes the increase in performance, rather than any other component of the beetroot juice. Professor Andy Jones, the senior scientist on the study and a pioneer of research into beetroot juice, said: “In this study, we were able to use – for the first time – both normal beetroot juice and beetroot juice with the nitrate filtered out. Test subjects didn't know which one they were getting. The drinks both looked and tasted exactly the same. Each time the normal, nitrate-rich juice was used, we saw a marked improvement in performance which wasn't there with the filtered juice – so we know the nitrate is the active ingredient.”
Individuals who drink three glasses of milk a day decrease their risk of cardiovascular disease by 18 percent, according to new research published in the American Journal of Clinical Nutrition.Researchers at Wageningen University and Harvard University examined 17 studies from the United States, Europe and Japan and found no link between the consumption of regular or low fat dairy and any increased risk of heart disease, stroke or total mortality. “Milk and dairy are the most nutritious and healthy foods available and loaded with naturally occurring nutrients, such as calcium, potassium and protein, to name a few,” said Cindy Schweitzer, technical director of the Global Dairy Platform. “It's about going back to the basics; maintaining a healthy lifestyle doesn't have to be a scientific equation.”
Schweitzer said during the past three decades as research sought to understand influencers of cardiovascular disease, simplified dietary advice including consuming only low fat dairy products emerged. However, in 2010 alone, a significant amount of new research was published from all over the world, supporting the health benefits of dairy. From dispelling the myth that dairy causes heart disease, to revealing dairy's weight loss-benefits, the following is a roundup of select dairy research conducted in 2010:
- U.S. researchers examined 21 studies that included data from nearly 350,000 and concluded that dietary intakes of saturated fats are not associated with increases in the risk of either coronary heart disease or cardiovascular disease. The study was published in the American Journal of Clinical Nutrition.
- A study published in the American Journal of Epidemiology examined 23,366 Swedish men and revealed that intakes of calcium above the recommended daily levels may reduce the risk of mortality from heart disease and cancer by 25 percent.
- An Australian study published in the European Journal of Clinical Nutrition concluded that overall intake of dairy products was not associated with mortality. The 16-year prospective study of 1,529 Australian adults found that people who ate the most full-fat dairy had a 69-percent lower risk of cardiovascular death than those who ate the least.
- A Danish study published in Physiology & Behavior concluded that an inadequate calcium intake during an energy restricted weight-loss program may trigger hunger and impair compliance to the diet.
- An Israeli study published in the American Journal of Clinical Nutrition showed that a higher dairy calcium intake is related to greater diet-induced weight loss. The study sampled more than 300 overweight men and women during two years and found those with the highest dairy calcium intake lost 38-percent more weight than those with the lowest dairy calcium intake.
The amount of dairy recommended per day varies by country and is generally based on nutrition needs and food availability. “In the US and some European countries, three servings of dairy foods are recommended daily, said Dr. Schweitzer.”
What did the research involve?
The researchers needed to obtain several sets of data to fill their model. Data for UK deaths from coronary heart disease, stroke and cancer were obtained from the Office for National Statistics, the General Register Office for Scotland and the Northern Ireland Statistics and Research Agency. Information on the population's intake of foods and nutrients was obtained from two sources: the average intake of fatty acids, fibre, and fruit and vegetables for 2005–7 was derived from the Expenditure and Food Survey, while estimates of salt intake came from the National Diet and Nutrition Survey, 2006.
The modelling also incorporated several meta-analyses of individual studies looking at diet and disease risk factors. The researchers looked at reviews that had pooled data from randomised trials, cohort studies or case-control studies, giving priority to meta-analyses of randomised trials. These different studies were combined in the model to calculate the change in risk of disease for an individual who changes his or her diet. To estimate the change in health outcomes with a change in diet at a population level, the model used the difference between current average consumption levels and recommended levels of different foods in the UK.
What were the basic results?
In a general summary of the main findings, the researchers calculated that:
About 33,000 deaths a year would be avoided if UK dietary recommendations were met. There would be a reduction in deaths from coronary heart disease of 20,800 (95% credible interval 17,845 to 24,069), a reduction of 5,876 for deaths from stroke (3,856 to 7,364) and a reduction of 6,481 for deaths from cancer (4,487 to 8,353). About 12,500 of these avoided deaths would be in people aged 75 or under. About 18,000 of the avoided deaths would be men and 15,000 would be women. More than 15,000 of the avoided deaths (nearly half the total figure) would be due to increased consumption of fruit and vegetables. Reducing average salt intake to 6g a day would avoid 7,500 deaths annually. The greatest number of deaths avoided would be in Northern Ireland and Scotland, whose populations are furthest from achieving dietary recommendations.
How did the researchers interpret the results?
The researchers say their study suggests that increasing average consumption of fruits and vegetables to five portions a day is the target likely to offer most benefit in terms of deaths avoided. They also say that reducing recommended salt levels to 3g daily and saturated fat to 3% of total energy would achieve a similar reduction in mortality.
They conclude that their calculations based on the Dietron model are robust, pointing out that their estimate of deaths avoided is lower than a previous government survey which calculated that 70,000 deaths a year could be avoided if government dietary recommendations were met. The estimates could be used in calculating the allocation of resources for interventions aimed at reducing chronic disease.
This well-conducted modelling study used various data sources to link consumption of different dietary components with disease risk factors (for example blood pressure, cholesterol and obesity) and subsequent mortality from coronary heart disease, stroke and cancer. The study supports previous research showing that diet plays a crucial role in health and that a diet with plenty of fruit and vegetables, fibre and low fat and salt levels can reduce the risk of chronic disease, in particular coronary heart disease. However, its predictions are made at the population level. A model such as this cannot predict individual risk, which will depend on many factors, including family history, smoking and other lifestyle habits.
It is important to note that the figures are based on the estimates and assumptions made when using a mathematical model, and not on reality. As the authors themselves note, the modelling technique they used may have led to “some degree of double counting” and that, therefore, their estimate of reduced mortalities if dietary recommendations were met is likely to be an overestimate. Also, the accuracy of the model depends to some extent on the quality of the meta-analyses that were included, and the quality of the individual studies that were pooled within these reviews in order to establish associations between diet and particular disease risk factors.
Overall, this study supports current dietary recommendations and even though it cannot predict how diet influences risk for individuals, it does indicate that keeping to dietary recommendations reduces the risk of disease.
Dietary recommendations include eating five portions of fruit and vegetables a day (about 440g) and 18g of fibre (provided by wholegrain foods and some fruit and vegetables). It is recommended that salt intake is limited to a maximum of 6g a day and that a third of total energy is provided by fats, with saturated fat comprising 10%. The researchers point out that in 2007, according to the estimated average intakes in the sources they used, none of the UK countries met these recommendations.