p>Every aspect of health has a hereditary component. Who our parents are influences our personality and behavior and the probability of our developing diseases, such as cancer. So what about high blood pressure?

Until the recent decade, we had thought that high blood pressure was largely an inherited trait. After all, it was easy to identify families in which a significant percentage of family members in each generation had high blood pressure.

In support of the hereditary factor, Lewis Dahl, a scientist, bred laboratory animals with high blood pressure, proving that it can re- side in our genes. However, careful research has now proven that it is not simply a case of having high blood pressure–prone parents.

The majority of some populations never develop essential hyper- tension or common high blood pressure. (About 1 or 2 percent in any population develops secondary hypertension due to illness; when the illness clears up, the blood pressure returns to normal.)

We could erroneously assume those people are inherently resistant to high blood pressure, but if we follow people who emigrate from those societies into our society, about one-third of them will develop essential hypertension.

Therefore, we can conclude that there is an inherited susceptibility in some people, and the disease is triggered by something in the environment. Alcoholism is similar; the tendency is there in some people just waiting for the right circumstances, such as stress or depression.

With blood pressure, the environmental factors are food, lifestyle, and stress. After all, we control the environment inside our body with food and drink. In the case of essential hypertension, our cardiovascular system becomes what we eat.

Food and lifestyle go together. Excess calories usually lead to excess weight, and excess weight leads to poor exercise habits. A lack of exercise doesn’t dissipate the effects of stress, so they add to the growing problem.

Undissipated stress also leads to food and often alcohol abuse to relieve stress, which contributes to overweight and an imbalance in the dietary sodium-potassium ratio. All these environmental factors heaped on the wrong genetic background can send blood pressure soaring.

Although you can’t change your genetic composition, knowing where you stand is essential to how you approach diet, lifestyle, and personality. To have a better understanding of your task, you must conduct a family assessment to find out if you’re the first with high blood pressure or just one more in a long family history.

If you go through the genetic analysis in this chapter and conclude that you have an above average genetic risk, common sense indicates that you should take your high blood pressure very seriously and resolve to gain control.

How Do I Know If It's In My Genes?

Doing a family high blood pressure history is the only way to deter- mine your general genetic risk. It is not difficult, takes little time, and can be very interesting.

All you have to do is construct a family tree going back a generation or two. If possible, write the age at which a relative was diagnosed and two other facts about them: Were they overweight? Did they exercise regularly?

For an example, look at the sample family history in Table below.

Relatives	Blood Pressure	Weight
Siblings (and Self)
Brother (older)	H	OW
Brother (younger)	H	N
Sister (younger)	N	N
Self (Gene)	H	N
Percentage of high blood pressure	75% (3 out of 4)
Maternal Side
Grandmother	N	NA
Grandfather	H	NA
Great uncle	H	N
Great uncle	N	N
Great aunt	N	H
Mother	H	N
Aunt	N	N
Uncle	N	N
Uncle	N	N
Male cousin	N	N
Male cousin	N	N
Female cousin	N	N
Female cousin	N	N
Percentage of high blood pressure	23% (3 out of 13)
Paternal Side
Grandmother	H	NA
Grandfather	H	NA
Great uncle	H	N
Great uncle	N	N
Great aunt	H	N
Father	N	N
Aunt	H	N
Uncle	N	OW
Uncle	N	N
Uncle	N	N
Male cousin	H	N
Male cousin	N	N
Male cousin	N	N
Female cousin	H	N
Female cousin	H	N
Percentage of high blood pressure	53% (8 out of 15)

In reviewing Gene’s family, it appears that in recent generations about 30 percent of the family members have experienced high blood pressure. In a society where about 25 percent of men develop high blood pressure, Gene’s family has a greater than average risk.

You can construct a similar family tree in an afternoon by making some phone calls and sending some e-mails. Blood pressure is generally not something people are reluctant to discuss. Look over Gene’s family tree and make a few inferences.

Although there aren’t enough people in his family to draw hard conclusions, the history suggests the tendency is on his father’s side. Another factor is weight: high blood pressure consistently shows up among overweight members.

Again, a single family sample, though small, can be useful. It is clear that not everyone in Gene’s family gets high blood pressure. This suggests that the genetic link is not strong.

Indeed, it gives Gene a bright outlook and suggests that if he takes his health seriously, he’ll probably be able to control his blood pressure by diet and lifestyle. Suppose every male in Gene’s family had high blood pressure.

That consistency would indicate he has a harder, but not impossible, task. It might, however, be that he would never gain complete control and would always need medication.

What to Look For

In your own chart, look for patterns that suggest a cause for concern:

• Consistency. Is there a repeating pattern? A repeating pattern would be that over 30 percent in each generation developed high blood pressure, going through both parents and all grandparents, uncles, aunts, and cousins.

Ideally, you could trace back to great grandparents, great uncles, and possibly even their siblings. Search for patterns of several men or women in each family with high blood pressure.

• Excess weight and physical fitness. Does a pattern of obesity show up? How about fitness? Do people who stay fit get high blood pressure?
• Alcohol. Do heavy drinkers in the family get high blood pressure?

Does heredity mean you are fated to have high blood pressure? Absolutely not! Unequivocally, heredity is not even an excuse any longer. In high blood pressure, the hereditary tendency is not a firm trait like eye color.

It is simply a warning flag that says, “Take care of your body and everything will be just fine.” I like to put it in a more positive way: If you’ve inherited the tendency, you’re lucky because you know the boundary lines within which you must live. No need for you to experiment and search; you’re in control of your health!