How the health of your sibling could affect you

When you were young, you shared toys and clothes, but now that you’re all grown up, research shows that you’ll be sharing health risks.

30 March 2007
by The Clicks Health Team

Having a sibling with certain medical conditions may be an important predictor of your own risks. According to Professor Alistair Hall, consultant cardiologist at Leeds University, the risks can be greater for siblings than those you inherit from your parents, because not only do you share 50 percent of your siblings’ genes, you also share similar lifestyle and environmental factors.

These influences can be as varied as your family’s habit of Friday takeaways, to the hormones you and your siblings were exposed to in your mother’s womb. ‘You can’t change your history, but if a sibling has a known health problem, there are genuine choices you can make to affect your future health for the better. It’s not the cards you are dealt, but how you play them that makes the most difference,’ he says.

Your siblings and heart disease

Lerato,* 35, never gave the health of her heart a second thought until a family tragedy struck four years ago, when her brother Themba* suffered a massive heart attack and died at the age of 27. “It came as a total shock to everyone because Themba thought he was fit and healthy. But after his death, it was discovered that his cholesterol levels were sky-high and that his arteries were 75-percent blocked,” she sadly recalls.

Lerato was told that having a brother with a history of heart trouble put her at higher risk too, so she didn’t waste any time getting her own heart health checked. “It’s a good thing I did, because I found out that my cholesterol was quite high. That was a big wake-up call for me and I became determined to change my unhealthy ways,” she says.

The first thing Lerato did was to cut out junk food. “I had a drawer full of chips, biscuits and chocolate. I threw all that away and started to eat more fruit, vegetables and wholemeal bread. I also joined a gym to use their fitness machines and go swimming.” Lerato’s outlook has changed since her brother’s death. “I’ve lost weight, and I’ve managed to lower my cholesterol levels from a high 7 down to a healthy 4. I don’t take any cholesterol medication – I’ve done it all by changing my bad habits. My brother helped me to see that life is short, and I want to make the most of it and stay around for my two children for as long as possible.”

What are the chances?

A recent study showed that having a brother or sister with a history of heart disease can increase your own odds of the disease by 45 percent. That’s akin to the danger of smoking five cigarettes a day. So if you have a sibling who has heart disease, get your cholesterol and blood pressure checked by your GP or at a Clicks Pharmacy clinic.

To keep your heart in tip-top shape, watch your weight and cut down on saturated fat from red meat, biscuits, cakes, chips and dairy products which can clog up your arteries. Eat more oily fish and five portions of fruit and vegetables a day. If you drink, do it sparingly. A glass of wine a day may be heart protective, but too much alcohol has the opposite effect. Above all else, if you’re a smoker, quit.

People who smoke have at least twice as great a risk of heart disease as those who don’t.

Your siblings and ovarian cancer

According to the Association for International Cancer Research, most women have around a one in 50 chance of developing ovarian cancer in their lifetime. But those with a sister with the condition face a four times higher risk – that’s four out of 50 – or a one-in-12.5 chance of developing the disease.

Sadly, 70 percent of all ovarian cancer is discovered at an advanced stage that does not respond well to treatment. But when it’s discovered early, there is an 85-95 percent five-year survival rate. So the key, if you know you are at higher risk, is to catch it early. Women who have a family history of the condition should ask their GP or gynaecologist about getting yearly internal trans-vaginal ultrasounds, because this is the best way to catch ovarian cancer early. Some women at high risk may also consider surgery to remove their ovaries.

Your siblings and diabetes

If you have a sibling or a parent with type-2 diabetes, you’ve got a one-in-three lifetime risk of developing the condition yourself. Research has pointed the finger at a number of genes, but the risks are highly influenced by how you live your life, so there’s lots you can do to keep your risk down even if you have a strong family history of diabetes.

For starters, keep your weight down. Over 80 percent of those with type-2 diabetes are overweight and the more overweight you are, the greater your risk. Watch for any symptoms so you can catch it early. These may include increased thirst, very frequent urination, fatigue, unexplained weight loss and genital itching or thrush. 

Your siblings and breast cancer

If you have a sister (or mother) diagnosed with breast cancer before the age of 40, then there may be a faulty gene in your family. Most cases of breast cancer happen by chance – only five out of 100 cases are related to a breast-cancer gene, but if you do carry it, then your lifetime risk of getting breast cancer is 80 percent. That means that up to four out of five women with a known breast-cancer gene fault will get breast cancer at some point in their lives. 

Breast self-examination and mammograms increase the chance of breast cancer being detected early enough to cure it. If a sister or mother has had early breast cancer, you may want to look into the possiblities of genetic testing to see if you are carrying the gene. Some women carrying the gene go so far as to choose to have both breasts removed and an immediate breast reconstruction to lower their risks. Or you may wish to enter a clinical trial using a hormone drug to prevent breast cancer.