Non-Communicable Diseases III

Diet and Physical Activity-I

Two of the most important risk factors that have been identified for non-communicable disease are diet and physical activity. Indeed, they feature very prominently among the goals set by the World Health Organization and the United Nations for reducing NCD related premature mortality. We recognize of course that the world today sees two faces of malnutrition.

531 532 533 534 535First is the huge problem of undernourishment where we find a large number of children and young women in the developing countries having low body weight or anemia or even both. At the same time we are also see a rising burden of overweight and obesity across the world. Not just in the developed countries, but also in the developing countries. Interestingly, both of these problems while perceived as quite different from each other, have a profound impact on the risk of non-communicable diseases which can arise even from underweight or overweight. The whole idea that children are born small for size and underweight are much more susceptible to adult cardiovascular disease, diabetes, and some cancers was first proposed by Forstal and David Barker then in U.K. And this hypothesis known as the Barker hypothesis as acquireda great deal of evidence over the last 30 years. We know that children who are born with low birth weight, if they acquire what’s called rebound adiposity, that if they start gaining weight, even within the normal range, between the age of 2 to 12 years, especially between 2 to 6 years, they are much more likely to put on fat rather than muscle. And this is likely to result in early onset of adult diabetes, heart disease and even some cancers and reduce lung function. So we now recognize that there is a link even between under-nutrition and non-communicable disease. But when we look at the larger picture of what are the risk factors for disease and disability across the world according to the global burden of disease study and we take all diseases and all causes of death and all causes of disability into account we find that there are ten leading causes, almost all of them are related to non-communicable diseases, but the vast majority of them are related to diet and physical inactivity. Indeed, when you cluster all the risk factors responsible for death and disease which is avoidable across the world, then the diet and physical inactivity cluster is the largest cluster. So the good news is that we can actually modify much of this by altering the dietary patterns of people across the world and making them more physically active. Now when we look particularly at non-communicable diseases we recognize that apart from smoking and certain other risk factors like high blood pressure and cholesterol which of course are also related to diet and physical activity we find low intake of fruit and vegetables, high intake of unhealthy fats, low intake of nuts, low intake of fish, all of these have been recognized to be important risk factors for non-communicable diseases. And when we look at how diet can best prevent non-communicable diseases we can think of it in terms of what’s called primordial prevention. Preventing the acquisition of risk factors whether it is diabetes, high blood pressure, high cholesterol, or overweight. So if you prevent it in the first place by having a healthy diet across the life course, there can be nothing better. But even when risk factors have been acquired, a person has developed high blood pressure or diabetes or overweight or high cholesterol for that matter, we can actually reduce those risk factors substantially by what’s called primary prevention, effectively using diet and physical activity. But even people who have had a heart attack or a stroke can actually get much benefit from diet and physical activity and prevent a recurrence of heart attack or early death. So whether it is primordial prevention of risk factors or primary prevention by reducing risk factors before they get into disease, or secondary prevention of preventing recurrence of events, diet and physical activity have a potent influence in protecting us against non-communicable diseases. Now clearly we are looking at various elements of nutrition. Diet is what we eat, but nutrition is what we get out of it. Unfortunately most of nutrition science so far has focused on individual nutrients and occasionally on food items. So we have been talking about either saturated fat or monounsaturated fat or trans-fat or refined carbohydrate or we have been talking about other elements like antioxidants. All of them as though they were isolated in terms of their action on health. All of these need to be taken together, not merely as nutrients or food items, but as composite dietary patterns. But even for that, let’s look at the science behind it. Among the various types of fats we have the good fats, what have been called the good fats, the omega 3 fatty acids and the unsaturated fatty acids called monounsaturated and polyunsaturated fatty acids. Then there are the fats which have been considered bad, the saturated fatty acids as well as dietary cholesterol. Though the current evidence suggests that this may not be entirely true. Taken in moderation, these are actually helpful for building some of the essential body structures like cell membranes and hormones and so on. But taken in excess, they can also contribute excess calories. But the real ugly fats are the trans fats, or the partially hydrogenated fats which are not naturally produced, but are usually industrially hydrogenated fatty acids. Now the industrial hydrogenation is done in order to prolong the shelf life of these fats. But anything that lengthens shelf life unfortunately shortens human life. And this is very true of Trans fatty acids where a 2% increase in energy intake from trans fatty acids is associated with a 23% increase in the incidence of coronary heart disease or heart attacks. You can’t have a worse fat than that. Now there’s been a huge amount of debate about which type of fat and how much of fat and so on. But I think there is a reasonable consensus that has been built up now which says, it is not so much the quantity of fat that matters, it is the quality of fat that matters. Quantity does matter to the extent that you don’t want to take too many calories. But within that caloric limit it is the quality of fat that is much more important. You need more of monounsaturated and polyunsaturated fatty acids, less of saturated fats and certainly very little or none at  all of Trans fats. And there is that kind of consensus that’s been built up. One of the problems of course has been in trying to reduce the total amount of fat in the diet. Many people have advocated the introduction of high carbohydrates as a substitute for fat. That’s been a big mistake because introduction of carbohydrates to substitute fat actually increases certain types of abnormal fat patterns in the blood and also increases the risk of diabetes. So we can actually take fat, but prefer to take healthy fats rather than unhealthy fats. We recognize of course that omega 3 fatty acids are principally derived from fish, though they can also be produced from certain other fats that we can take in from some of the vegetables as well, particularly certain types of nuts and so on. And of course flax seed and others are sources. But mainly they’re derived from fish oils. Even as we are trying to increase the amount of healthy fats, we ought to pay attention to the carbohydrates, which have assumed a lot of importance recently, not only in the causation of diabetes, or increase in overweight but also in coronary heart disease. That refined carbohydrates are particularly dangerous and we need to take a lot more fiber through unrefined carbohydrates in our diet. Indeed, what’s called the glycemic load of the food has become very important. The carbohydrates in your diet, how quickly do they release sugar and how quickly does the sugar peak? That is what’s called the glycemic load. How much of sugar is released and how quickly? And that is the glycemic load which can actually cause overweight, obesity and increase the risk of heart attacks apart from the risk of diabetes. Now this can be offset of course by taking more of fruit and vegetables. Now salt is also a major issue that has been debated considerably. We don’t want to take too much excess salt in our diet and somewhere between five to six grams appears to be the optimal as recommended by the World Health Organization. But one of the things that people don’t seem to recognize very clearly is dietary sodium, the effect of which is on blood pressure and of course on stroke and heart attacks can be substantially countered by dietary potassium, which comes through fruit and vegetables, the natural sources.Therefore if you take more fruit and vegetables you are preventing high blood pressure, you are preventing stroke, you are preventing heart attacks. You are preventing a variety of cancers. And this is now emerging as one of the very protective elements in our diet and that’s what the global burden of disease studies says, that low intake of fruit and low intake of nuts, all of these protective elements in the diet is now a major cause of disease burden, especially through non-communicable diseases. Now we recognize that taking fruit and vegetables in a fair amount, particularly more than three times a day, preferably five times a day  can substantially reduce the incidence of stroke by 27% and lower the mortality due to stroke by 42%, reduce coronary mortality that’s due to heart attacks by 24%. Reduce overall cardiovascular mortality by 27% and lower all-cause mortality by 15%. Now if a single dietary item can change the disease burden so profoundly then there are public health implications that we have to make sure there is access to it. However we ought to be really looking at dietary patterns rather than looking at individual food items. And there have been several diets that have been studied like the Mediterranean diet, which has been quite celebrated now as being very protective against heart attacks and being very good for health. The DASH diet which looks at low sodium and a balanced diet with better fats and which reduces blood pressure. Then the Okinawa diet in Japan which has been attributed to be responsible for the high longevity in those populations. Again, a strong fruit and vegetable based diet. Low in unhealthy fats, high in fish. But the Mediterranean diet for example has a composite character. It’s rich in grains, fruit, vegetables, herbs, spices, nuts, beans, dairy food, seafood and healthy oils. Now even when you’re a non-vegetarian, for example, there is a simple rule to remember, fish is better than fowl and fowl is better than flesh. And if there’s a lot of red meat consumption, you’re in danger, but on the other hand, fish consumption is protective. Now we have seen that in a major secondary prevention trial of coronary heart disease in France that the risk of a second heart attack and sudden cardiac death was substantially reduced by a modification of the Mediterranean diet. But that led to further studies on primary prevention. Can we prevent the first heart attack with the Mediterranean diet? And it has been very clearly shown that in women, and, as well as in men, that the risk of getting a heart attack can be substantially reduced at the composite nature of the diet moves towards the full Mediterranean diet. More of the elements in your diet resemble that of the Mediterranean diet, the greater the protection from a heart attack. There has been a major study called the PREDIMED trial which has actually shown very clearly in Spain that if you have the Mediterranean diet with extra virgin olive oil, then the risk of heart attack and death actually substantially decrease and similarly we also see that if you actually add nuts, then also there is a substantial benefit. So the composite diet really matters in terms of protection. But we don’t have to borrow the Mediterranean diet everywhere in the world. What we are really aiming for is a prudent diet which resembles the Mediterranean diet but can be culturally and contextually adapted. For example, it’s been shown, even in the United States in large cohort studies that those who have a prudent pattern of diet will have a higher amount of vegetables, fruit, legumes, whole grains, fish and poultry. On the other hand the western pattern of diet classically consists of higher red meat, processed meat, refined grains, sweets and dessert, French fries, high fat dairy products. It has been shown, again, as I said, within large American cohorts that as you move towards a higher level of prudent diet from a very low level of prudent diet, you get a 30% lower risk of getting a heart attack or a cardiovascular death. And similarly if you move to a higher pattern of western diet from a low pattern of western diet, then you get a 64% higher risk of getting a heart attack or a cardiovascular death. So the dietary pattern matters very much and in each country we ought to be able to provide the population with dietary choices which will enable them to get their culturally appropriate fruit and diet. But this is becoming increasingly difficult. We are seeing vegetable oil consumption rising across the world. Now this may not be a bad thing in terms of providing energy to populations which are poor, but if the oils are unhealthy rather than healthy oils, if they´re mostly rich in trans fats and saturated fat, then actually they’re compounding the problem by creating non-communicable disease. And that’s where we ought to insure that the oils that are available are the healthier oils. Similarly, fruit and vegetable consumption across the world is fairly low, especially in low and middle income countries. In India for example, the per capita consumption of fruit and vegetables is a 130 grams per day as opposed to the WHO recommendation of 500 grams per day. So we need to correct this situation as well. And unfortunately when we look at the global production patterns we are seeing a fall in the availability of fruit and vegetables, now from a 22% shortage of supply of fruit and vegetables as compared to the need, by 2025, we will see a 34% shortage and by 2050 we will see a 43% shortage. So when we are looking at sustainable development we ought to be able to look at how best we can produce enough fruit and vegetables to meet the population needs and protect health. At the same time we are seeing a huge explosion in meat consumption and meat production. Red meat certainly is problematic from point of view of heart disease, obesity, cancers, but it also consumes a huge amount of grain because the animals are grain fed. And that also causes environmental problems in terms of a huge release of greenhouse gases from these grain fed cattle. But we ought to be able to really look at how we can balance our dietary patterns  by looking at agricultural livestock systems so that the healthier food options are available which are also environmentally friendly, rather than unhealthy options which are bad for health and bad for environment.



Citar este post
Pedro Pereira Leite (2015, 18 Maio). Non-Communicable Diseases III. Global Heritages. Recuperado em 13 de Junho de 2024, de https://doi.org/10.58079/p2ow

Pedro Pereira Leite

Researcher and professor. He had his PhD. on museology in 2011, with the title “Muss-amb-ike Homeland: The commitment on musicological process”, that was published in 2011. In 2012 he finishes a Post-PhD Research on "Biographical Glances: The intersubjectivity poetry on museology, at Lusófona University (Lisbon). Presently he is working in his Post PhD. Research about: “Global Heritages" with the aims to build a network on local cognizance and memory manager has a tool to build the will of action in 3 different communities, linked by past communed heritages.” He works at CES. He participates on different Research network, presented papers in national and international conferences, and had published books on research subjects.

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