How making the family connection could save your life
Knowing your family history can empower you to make crucial diet and lifestyle changes to protect your long-term health.
Check your family tree closely and you’ll probably find at least one major illness lurking in the branches. But does this automatically put you at high risk of developing it, too? A condition is suspected to be genetic if it crops up more often than you’d expect by chance. That’s generally two or more relatives with the same disease, especially if they’re diagnosed before the age of 50.
“We’re finding more and more illnesses – from cancer to diabetes – have a genetic element, so your family’s health history is certainly crucial when it comes to predicting your own future health,” says Dr Anand Saggar, consultant in clinical genetics. “I’d advise everybody to draw a simple family health tree so they can spot any recurring trends.
“But don’t panic! Even if you discover you carry a particular genetic mutation, you’ve only inherited a susceptibility to developing that disease – it doesn’t make it inevitable. Most diseases are triggered by a complex interaction of genes and lifestyle.”
Fortunately, that interaction means there’s plenty you can do to reduce your risk. Here are some of the ways you can minimise your risk of developing common medical conditions that often run in families.
Type 2 diabetes
You’re up to four times more likely to develop type 2 diabetes if a parent or sibling has it, compared to someone with no family history. So if there’s diabetes in your family, talk to your doctor about having a blood glucose (sugar) test. Also keep an eye out for the classic symptoms of tiredness, extreme thirst and the urge to urinate more frequently. On the plus side, according to Diabetes Australia, 60 per cent of cases of type 2 diabetes can usually be prevented with certain lifestyle changes so there are things you can do to help reduce your risk.
Reduce your risk – lose weight
Regardless of your genetic make-up, carrying too much weight is the biggest risk factor for type 2 diabetes. A 2010 study in Sweden found a high Body Mass Index (BMI) in men was the strongest predictor of who would go on to develop diabetes 10 years later, regardless of other factors. In fact, it’s thought that obesity accounts for 80–85 per cent of the overall risk of developing type 2 diabetes.
The good news is that a small change to your weight can make a big difference. It’s thought for every kilo of weight lost, the risk of developing type 2 diabetes is reduced by 16 per cent, and losing just 5–10 per cent of your current body weight can reduce your risk by 60 per cent. See p34 for more information about how to go about losing weight.
Reduce your risk – get moving
Many studies suggest regular exercise reduces the risk of diabetes by helping your body to deal with sugar in your blood more effectively – whatever your weight. And just eight minutes a week of intensive activity may be enough, according to a recent study published in BMC Endocrine Disorders. They found in men, short bursts of high-intensity exercise (four to six 30 second bursts of fast cycling) improved insulin sensitivity (or the body’s ability to control blood sugar) by nearly a quarter.
If a close relative younger than 60 has had a heart attack or a stroke you may have inherited a higher risk of the same. There are also many other factors that raise your risk of heart attack or stroke, including high cholesterol or blood pressure, being overweight, poor diet and being inactive.
“One common inherited condition that raises your risk substantially is Familial Hypercholesterolaemia (FH) – a gene alteration that causes very high cholesterol regardless of how healthy your diet is,” explains Dr Saggar. About one in every 500 people in Australia has FH. The problem is many people don’t know they have the condition, which puts them at high risk of having a heart attack.
Reduce your risk – know your numbers
“Everybody should ask their GP to check their cholesterol and blood pressure,” advises Dr Saggar, “especially if there’s heart disease in your family tree.” If your cholesterol is high, you will be encouraged to make changes to your diet and exercise routine. You may also be prescribed medication to lower your cholesterol.
Reduce your risk – cut out the bad stuff
Giving up smoking, losing excess weight (see below) and exercising regularly (at least 30 minutes on most days of the week) are important for lowering both cholesterol and blood pressure. It’s also essential to eat a ‘heart-healthy’ diet, so cut down on saturated fat and salt from processed foods, butter, cream and fatty meat. Instead, choose a balanced diet with fruit, vegies, legumes, whole grains and heart-healthy fats from olive oil, nuts and oily fish.
Reduce your risk – slash work stress
There’s increasing evidence that stress has a damaging effect on our hearts. One study from Denmark found women who described their job pressure as ‘much too high’ had a 50 per cent higher risk of ischaemic heart disease (restricted blood flow to the heart). Even those who only considered it ‘a little too high’ had a 25 per cent increased risk. So whether you enjoy yoga or yachting, it’s important to factor in some downtime for the sake of your health.
The good news is only around five per cent of cases of breast cancer and ovarian cancer are genetically linked. In these instances the cancer is caused by an inherited ‘faulty’ gene, specifically two genes called BRCA1 and BRCA2, that can be passed on from either parent. If you have two or more close relatives on the same side of the family who have been diagnosed with either cancer, then this may be the reason. Women carrying these mutations have an eight times higher risk of breast cancer and a 20 times higher risk of ovarian cancer. More common reasons cancer may run in the family are simply by chance or common exposure to risk factors such as sun exposure or diet.
Reduce your risk – lose excess weight
Scientists at Canada’s University of Toronto found young women aged 18–30 carrying BRCA1 and BRCA2 who lost at least 4.5kg more than halved their risk of developing breast cancer in their 30s and 40s. See box, left, for tips on losing weight.
Reduce your risk – review your diet
One of the easiest ways to lose weight and to reduce your risk of developing breast cancer (regardless of whether or not you carry the genetic mutation) is to eat a healthy balanced diet. According to research, changing to a healthier diet may prevent as many as a quarter of breast cancer cases. Make sure you include lots of fibre from fruit, vegies and whole grains, cut down on saturated fats found in fatty meats, full-fat dairy and processed foods and reduce the amount of alcohol you drink.
Reduce your risk – talk to your health professional
Talk to your health professional if you have a strong family history. They will be able to give you more personalised advice, refer you for genetic testing or to a family cancer centre to discuss your options about reducing the risk of developing the disease.
Family history is an important factor that increases the risk of bowel cancer. According to Bowel Cancer Australia, your risk of developing bowel cancer doubles if you have at least one first degree relative (parent, sibling or child) diagnosed at 55 years or older. Your risk increases three to six times if you have a first degree relative diagnosed younger than 55 years old or two first degree relatives diagnosed at any age.
Hereditary conditions called familial adenomatous polyposis (FAP) and hereditary non-polyposis colorectal cancer (also called Lynch syndrome) are responsible for about one in 20 cases of bowel cancer. If bowel cancer runs in your family, or you know you have either of these hereditary conditions in your family, it’s important to talk to your GP about regular screenings to pick up warning signs as early as possible.
Reduce your risk – know the symptoms
Look out for any change in your bowel habits, especially diarrhoea that lasts longer than a few days or any blood in your stools. See your GP immediately if you notice either.
Reduce your risk – go for wholegrain and high-fibre
Significant evidence shows high-fibre diets are associated with a lower risk of bowel cancer. This means eating plenty of fruit, vegies, legumes and in particular, whole grains and cereals. A review of 25 different studies published in the British Medical Journal found three serves of wholegrain foods each day can reduce the risk of bowel cancer by 20 per cent.
The Grains and Legumes Nutrition Council recommend we actually include 48g (four or more serves) of whole grains each day to get the most benefit.
Protect against bowel cancer with grains
APPROX. AMOUNT OF WHOLE GRAINS
Wholemeal bread (2 slices)
Wholegrain breakfast cereal (30–45g serve)
Porridge (1/3 cup raw rolled oats)
Brown rice (1 cup cooked)
Wholegrain pasta (1 cup cooked)
1 wholegrain muesli bar
Reduce your risk – choose your protein wisely
According to the World Cancer Research Fund, eating more than 500g a week of cooked red, and especially processed meat, such as bacon, ham, salami and sausages, increases your risk of bowel cancer. A study published in Archives of Internal Medicine found replacing just one serving of red meat with fish, chicken, low-fat dairy or wholegrain foods could reduce the risk of dying from bowel cancer by 7–19 per cent. So stick to the National Health and Medical Research Council’s recommendations of eating red meat three times a week and opt for poultry, fish and legumes more often instead.
Reduce your risk – boost your vitamin D
Having high blood levels of vitamin D is linked to a 40 per cent lower risk of bowel cancer, according to a large, recent study published in the British Medical Journal. Most of our vitamin D is made by exposing our skin to sunlight, so it’s worth following the Cancer Council guidelines and ensuring you spend a few minutes in the sun each day during summer (early in the morning or late in the day when the sun is less fierce) or a few hours during winter, particularly if you live in the southern states. Although you can’t meet your vitamin D needs through food alone, you can also choose to eat more vitamin D-rich foods. Try to include oily fish such as salmon, sardines, mackerel and herring, eggs, reduced-fat dairy, margarine and some other foods that are fortified with vitamin D.
Knowing about your family history means you can do more to protect yourself and help reduce your risk of health conditions, ranging from different types of cancer to heart disease. Having this knowledge gives you the tools to make healthy lifestyle choices that will have a positive impact on your future health – so you can lead the healthiest life you possibly can!
What is nutrigenetics?
Understanding the connection between genes and food has led to a new area of research and treatment called nutrigenetics. In the same way your genes may predispose you to certain illnesses, they can also play an important role in how well your body handles particular foods or nutrients.
Genetic variation is one of the reasons why certain diets work for some people but not others. New research has focused on the possibility of designing diets based on your specific genetic make-up. Nutrigenetic testing involves taking a sample of DNA (usually from saliva) and testing it for variations in our genes that may play a role in how our bodies respond to the food we eat. Based on these results, an eating plan can be recommended in the hope of reducing our risk of health problems. An example is a specific genetic variant that affects how your LDL or ‘bad’ cholesterol responds to eating fat, or how sensitive your blood pressure may be to eating sodium, thus affecting your risk of heart disease.
Nutrigenetic testing is now available in Australia through a small number of health professionals, including dietitians, GPs and pharmacists.
Visit www.daa.asn.au or ask your nearest Accredited Practising Dietitian for more information and advice.
Lose weight, cut your risk
The risk of many health conditions is increased when you’re carrying extra weight, so try the following easy steps:
Embrace the balanced plate at lunch and dinner! Fill half with vegies or salad (any vegie except potato, sweet potato or corn), one quarter with protein (meat, fish, poultry, legumes or dairy) and one quarter with carbohydrate (potato, sweet potato, corn, pasta, rice or bread).
Choose smaller plates and bowls to help you serve smaller portions. Try not to go back for seconds unless you’re really hungry and it’s been at least 20 minutes since you ate.
Check your snacks. Try keeping snacks to around 400–600kJ and only snack if you’re actually hungry, not because you’re bored, tired, stressed or due to routine.
Make small sustainable changes, rather than big changes all at once. Pick one small goal such as swapping your large coffee for a small one, or cutting back on soft drink and juice. Once you’ve got that goal mastered, start with a new goal.
Find ways to get exercise into your day. Aim to exercise for at least 60 minutes most days. Remember all of the movement you do during the day counts as well – even housework!
See an Accredited Practicing Dietitian for personalised advice. Visit www.daa.asn.au.