Diet & Disease > Right diet keeps diseases away

Right diet keeps diseases away

By Rekha Naidu 

It is always better to prevent than to cure, especially where chronic diseases are concerned. The sad truth is, there is no cure for diabetes, high blood pressure, heart disease, osteoporosis and cancer. 

These non-communicable diseases are closely related to lifestyle and have major public health implications. 

One of the major concerns is that people are so absorbed with busy schedules that they tend to neglect their health until an illness strikes. Having regular health checks, especially if you have a family history of diabetes and/or heart disease, or if you are overweight, allows for early detection and prevention. These diseases can also be prevented by changes in diet and lifestyle. 

Common chronic diseases 
Diabetes is a common disease in Malaysia, but many still don't realise how dangerous it is. Often the terminology used "mild diabetes" gives the patient the wrong impression.

Diabetes occurs when our body cannot produce enough insulin, or cannot make use of insulin properly, to control the amount of sugar in our blood. It is referred to as the "mother of diseases", as it is related to a host of many other diseases and medical complications. 

Many dread hearing the words heart disease. Coronary artery disease (CAD) is the most common heart disease we have to watch out for.

CAD occurs when the arteries get clogged up, blocking blood flow to the heart, depriving it of oxygen. This causes ischaemic heart disease which can lead to a heart attack and even death. 

If the arteries to the brain are blocked, this results in a stroke. The disease, which used to affect mostly those over 50, is now prevalent among those in their 30s and 40s. 

Hypertension, or high blood pressure, is often called the "silent killer". Many people don't realise that they have it, and subsequently don't realise how it could damage their organs, especially the heart. 

High blood pressure may cause the walls of arteries to thicken. It could also accelerate the build-up of fatty plague within the artery wall. These arterial changes can lead to a restriction of blood flow and result in angina (chest pains or discomfort), heart attack or stroke. Hypertension is also linked to other clinical conditions such as kidney failure and blindness.

Osteoporosis is a condition where our bone mass falls too low and our internal structure becomes thin and weak. This causes our bones to break or fracture easily, especially at the wrist, hip and spine. Besides causing a lot of pain, disability and disfigurement, osteoporosis may also lead to death in the elderly. However, it can be prevented if we maintain healthy bones from a young age.

Probably the most dreaded of all chronic diseases is cancer. Cancer is a disorderly growth of our body cells. A clump of cancer cells is known as a growth or tumour, and if left untreated, it continues to grow and spread to other parts of the body. 

A cancerous tumour performs no useful function in the body, interferes with and steals nourishment from normal cells and is a danger to our lives. 

Diet-related risk factors 
The risk factors for these chronic diseases are mostly related to diet. Therefore, to prevent these diseases from occuring, we have to watch what we eat. 

Obesity is strongly related to chronic diseases and the possibility of early death. Overweight and obese individuals usually have high levels of triglycerides and LDL-cholesterol (also known as "bad" cholesterol), while having low HDL-cholesterol ("good" cholesterol). This increases the likelihood of clogged arteries which can result in heart attack and stroke. 

Obese individuals are three times more likely to have high blood pressure. It has also been found that 50% of Type 2 diabetics are obese. 

One of the main reasons for obesity is excessive intake of fat. Even if a diet high in fat does not lead to obesity, it can increase the risk of breast and prostate cancer. 

A high-protein diet, especially one rich with animal protein, can lead to high LDL-cholesterol levels and increase the risk of chronic diseases.

Too much protein can also induce the loss of calcium through the urine. The lack of calcium can thus lead to osteoporosis. A very-high-protein diet is especially risky for those with diabetes, because it can speed the progression of diabetic renal disease.

Contrary to popular belief, eating salty food does not cause hypertension. However, overweight people who take a high-salt diet are more likely to have hypertension than those who don't. Taking too much salt may increase the risk of stomach cancer, as well as aggravate the condition of someone who already has high blood pressure. Some experts believe that high consumption of preservatives could also be linked to increased risk of certain cancers.

While excessive intake of certain nutrients are bad, nutrient deficiency is also a proven risk factor. 

Those on low-carbohydrate diets are at higher risk of chronic diseases. This is because the fibre in complex carbohydrate foods can prevent heart disease and certain forms of cancer. 

The lack of certain vitamins can also increase the risk of chronic diseases. Firstly, lack of folate can increase homocysteine levels in our blood. Homocysteine is a compound that is produced when protein in food is broken down and metabolised. Certain theories suggest that high homocysteine levels may increase the risk of heart disease. Lack of vitamin B6 and B12 can also contribute to high homocysteine levels.

Some vitamins act as anti-oxidants. Oxidation of body cells is a normal occurrence, but it can be exacerbated through exposure to cigarette smoke, certain food and drinks. This oxidative damage can make us more vulnerable to diseases such as cancer.

Carotenoids are examples of compounds that are anti-oxidants. Some carotenoids also possess pro-vitamin A activities, i.e. they can be converted to vitamin A. Other carotenoids do not possess pro-vitamin A activities but they are known to possess anti-oxidant activities.

An example of this is lycopene. Lycopene is a red pigment found in watermelon, papaya and tomato, and is believed to reduce the risk of certain forms of cancer. 

Mineral deficiency is another risk factor. Calcium is crucial in maintaining bone strength. Therefore, calcium deficiency throughout childhood and adulthood will result in osteoporosis at a later age.

Foods rich in calcium can also prevent high blood pressure and certain forms of cancer, and also lower LDL cholesterol levels.

Phytochemicals, which are compounds found in plants, can also prevent chronic diseases. Examples of phytochemicals are flavonoids (found in fruits) and isoflavones (found in soy). 

We also have to watch out for carcinogenic foods. These are foods that contain cancer-causing agents. Examples of these include mouldy food (especially mouldy peanuts), charred meat, cured and smoked foods, and some spoiled foods. 

Over-consumption of alcohol can also increase the risk of cancer of the mouth and pharynx, larynx, oesophagus and particularly the liver. 

Rekha Naidu is a consultant dietitian and member of the Malaysian Dietitians Association.


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