Figure 18. Alcohol and Death. Alcohol has different effects on different causes of death. As alcohol intake increases, deaths from heart disease gradually decline, while deaths from accidents, liver disease, and other causes increase, slowly at first and then sharply at high levels of consumption. The result is a J-shaped curve, with the lowest mortality associated with moderate alcohol consumption and higher mortality associated with no drinking and with excessive drinking. The optimal range for an individual depends on age, sex, folic acid intake, and other factors, but is generally considered to be one to two drinks a day for men and no more than one drink a day for women.
For women, it is a little tougher to define moderate. Women, too, benefit from alcohol’s ability to raise HDL and prevent clot formation. But the Nurses’ Health Study and others have shown that two drinks a day increase the chance of developing breast cancer by 20 to 25 percent. This doesn’t mean that 20 to 25 percent of women who have two drinks a day will get breast cancer. Instead it is the difference between about twelve of every hundred women developing breast cancer during their lifetimes—the current average risk in the United States—and fourteen to fifteen of every hundred women developing the disease. This is not as huge a link as that between smoking and lung cancer, but it is still enough of an increase to be worrisome.
The degree of increased risk of breast cancer is directly related to the amount of alcohol consumed. With longer follow-up in the Nurses’ Health Study we detected a small increase in breast cancer even with one drink every other day.28 It doesn’t matter whether the alcohol comes from beer, wine, whiskey, or other alcoholic beverages.
Inconsistent evidence from large prospective studies of women show that the increased risk of breast cancer linked to drinking alcohol occurs mostly in women who don’t consume enough of the B vitamin known as folic acid. The same applies to colon cancer, with an increased risk occurring mainly among individuals with lower intakes of folic acid. So, as I discuss in chapter eleven, taking a multivitamin that contains folic acid is especially important if you drink alcohol.
For both men and women, even moderate drinking carries some risks. Alcohol can disrupt sleep. Its ability to disrupt judgment is renowned. Alcohol, particularly in higher amounts, interacts in potentially dangerous ways with a variety of medications, including acetaminophen, antidepressants, anticonvulsants, painkillers, and sedatives. It is also addictive, especially among people with a family history of alcoholism.
So who might benefit from a daily alcoholic drink? Alcohol offers little benefit and potential risks for a pregnant woman and her unborn child, a recovering alcoholic, a person with liver disease, and individuals taking one or more medications that interact with alcohol. It doesn’t benefit younger men and women, because their risk of heart disease is low and it isn’t possible to bank the benefits for the future. For a sixty-year-old man with high cholesterol whose father died of a heart attack at age sixty-one, a drink a day could offer some protection against heart disease that is likely to outweigh potential harm (assuming he isn’t prone to alcoholism).
The risk-benefit calculations are a bit more difficult for a sixty-year-old woman with a sister who has breast cancer. More than ten times as many women die each year from heart disease as from breast cancer—about 400,000 women a year from cardiovascular disease, compared with 40,000 a year from breast cancer. However, studies show that women are far more afraid of developing breast cancer than heart disease, something that must be factored into the equation. There’s a sound basis for this fear, given that deaths from breast cancer tend to be at a younger age than those from heart disease, and that we know more about ways to help prevent heart disease than breast cancer.
The so-called French paradox—the unexpectedly low rate of heart disease in France despite a typically high-fat diet—emerged from early studies suggesting that moderate alcohol consumption could prevent heart attacks and other heart disease. Some researchers suggested that red wine was the answer, something the wine industry heavily and heartily endorsed. But red wine wasn’t the only reason for lower heart disease rates in France. The overall diet and lifestyle in parts of the country, especially in the south, have much in common with other Mediterranean regions, and these almost certainly account for some of the protection against heart disease. More recent studies show that any alcohol-containing beverage offers the same benefits. Red or white wine, beer, cordials, or spirits such as gin or Scotch whiskey all seem to have the same effect on cardiovascular disease. Claims that the small amounts of resveratrol and other antioxidants found in red wine and grape juice prevent heart disease have yet to be proved; if they do indeed offer any extra benefit, it is likely to be small.
An individual’s drinking pattern seems to be more important than the type of alcoholic beverage. My colleagues and I looked at drinking habits among almost 40,000 men whose health and lifestyles we had been following for twelve years. Those who drank alcohol at least three days a week were 30 percent less likely to have had a heart attack than men who drank less than once a week. The type of alcoholic drink and whether or not it was consumed with meals had little effect on this association.29
When the alcohol–heart disease connection was in its early days, the standard caution most of us used in our scientific papers and when talking to reporters or the public was that no one should start drinking alcohol just for the heart benefits. Now that these benefits are well proven and durable, I offer these more concrete guidelines:
• If you don’t drink alcohol, don’t feel compelled to start: you can get similar benefits by beginning to exercise (if you don’t already) or boosting the intensity and duration of your activity.
• If you do drink alcohol, keep it moderate.
• A drink a day three or more times a week is far, far better for you than three or more drinks one day a week.
• If you are a man with no history of alcoholism who is at moderate to high risk for heart disease, a daily alcoholic drink may help reduce that risk.
• If you are a woman with no history of alcoholism, benefits of a drink a day may be counterbalanced by a modest increase in your chances of developing breast cancer. Getting enough folic acid (at least 400 milligrams per day) may reduce this increase in risk (see chapter eleven).
• Alcohol may be particularly beneficial if you have a low level of protective HDL cholesterol that just won’t budge upward with a healthy diet and plenty of exercise.
• Talk with your health care provider to help you weigh decisions about alcohol.
PUTTING IT INTO PRACTICE
What you drink over the course of the day and your lifetime can affect your health as much as what you eat. From a purely physiological point of view, you need to drink beverages to replace the water you lose. It makes the most sense to drink water when you have a choice. Other beverages are perfectly fine as long as they don’t add many calories to your diet.
• Hydration is a day-long process. Drink at least one glass of your beverage of choice with each meal, and one or more in between meals. Boost your fluid consumption if you are physically active or if you find yourself urinating infrequently.
• Drink sugar-sweetened beverages such as sodas, fruit drinks, and sports drinks only occasionally, if at all. Their liquid calories can help you unintentionally pack on extra pounds. Limit 100 percent fruit juices to one glass a day or, even better, eat the fruit whole instead of drinking its juice.
• Adults don’t need to drink milk. Think of it as an optional part of your diet, not something you need to drink two or three times a day.
• Coffee and tea are healthy beverages. Just don’t overload them with sugar, whipped cream, and other high-calorie additives.
• Keep alcohol consumption moderate. If you choose to drink alcohol, go easy—no more than one alcoholic drink a day for women, no more than two a day for men.
CHAPTER TEN
* * *
Calcium: No Emergency
FOR TWENTY YEARS THE “GO
T milk?” advertising campaign urged us to drink three glasses of milk a day. Celebrities ranging from pop stars Taylor Swift and Britney Spears to Olympian Kristi Yamaguchi, model Christie Brinkley, film director Spike Lee, the Simpsons—even Superman and Batman—have sported white milk mustaches to make us aware of the dangers of not getting enough calcium while showing us the way to combat our country’s “calcium emergency.”
Daily Calcium Intake: Too Much?
* * *
In the United States, the current recommended daily intake of calcium intake is:
Age
Milligrams/day
1–3
700
4–8
1,000
9–18
1,300
19–50
1,000
51–70 (men)
1,000
51–70 (women)
1,200
over 70
1,200
Source: Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes for Calcium and Vitamin D (November 30, 2010).
Most adults don’t need that much calcium, especially not from milk and other dairy foods, which also deliver unnecessary and often unhealthy extra saturated fat and calories.
This slick, highly successful campaign was sponsored by the National Dairy Council. Too bad that its message was wrong and it ran counter to good health. For starters, there isn’t a calcium emergency in the United States. In fact, Americans are near the top of the list for average daily calcium intake per person.
There’s no question that calcium is an essential part of a healthy diet. But milk and dairy foods aren’t necessarily the best way to get it. What’s more, getting too much calcium may be harmful to long-term health for most adults.
Nutrition experts worry about calcium because they worry about the prospect of developing osteoporosis, the gradual and insidious loss of bone that often comes with old age. In the United States, osteoporosis affects 10 million women and men. Each year it causes more than 2 million fractures, including more than 250,000 broken hips. Breaking a hip in old age can be disabling, even deadly: one-quarter of older people who break a hip die in the following year, often from complications caused by their injuries.
Calcium is a key element for building and strengthening bone. But there’s little evidence that boosting your calcium intake to the high level that is currently recommended will prevent broken bones. And all the high-profile attention given to calcium is distracting us from strategies that really work—like exercise, getting enough vitamin D and K, avoiding too much vitamin A, and taking certain medications.
As I describe in the next few pages, milk and dairy foods need not occupy a prominent place in your diet, nor should they be the centerpiece of the national strategy to prevent osteoporosis. Instead, the evidence shows that your dietary calcium should come from a variety of sources. And if you need more calcium, it’s best to get it from an inexpensive, no-calorie, zero-saturated-fat, easy-to-take supplement. Then you can look at milk and dairy foods as an optional part of a healthy diet and take them in moderation, if at all.
WHY YOU NEED CALCIUM
Your body contains roughly two pounds of calcium, about 99 percent of it locked into bone. Think of that calcium as the mortar that cements and solidifies the components that give bone its substance and strength. The rest of your calcium is dissolved in your blood and the fluid inside and outside cells. That dissolved calcium helps conduct nerve impulses, regulates your heartbeat, and controls other cell functions.
Like an obsessive remodeler, your body constantly builds up bone and tears it down. Early in life, building up dominates. Throughout midlife, the two processes generally balance out. Later on, though, demolition may outpace construction and lead to weak or broken bones.
Calcium in Foods
* * *
Food
Amount
Milligrams
% DR*
Total cereal
1 cup
1,000
83
Milk, skim
1 cup
299
25
Orange juice, calcium fortified
6 oz.
274
23
Tofu
1/2 cup
253
21
Yogurt, Greek
1 container
187
16
English muffin, whole wheat
1
176
15
Collard greens, cooked
1/2 cup
134
11
Soybeans, boiled
1/2 cup
130
11
Spinach, cooked
1/2 cup
122
10
Almonds
11/2 oz.
114
10
Whole wheat bread
2 slices
104
9
Mustard greens
1/2 cup
63
5
Figs, dried
4
56
5
Orange
1 medium
60
5
Swiss chard, boiled
1/2 cup
51
4
Kale, boiled
1/2 cup
47
4
Sweet potato, baked
1 medium
43
4
Butternut squash, baked
1/2 cup
42
4
Chickpeas, cooked
1/2 cup
40
3
Raisins
1/2 cup
41
3
Broccoli, boiled
1/2cup
31
3
Peanuts
11/2 oz.
39
3
Black turtle beans, boiled
1/2 cup
23
2
Green beans, boiled
1/2 cup
28
2
Brussels sprouts, cooked
1/2 cup
28
2
White bread
2 slices
26
2
Chocolate bar
11/2 oz.
10
1
Bulgur, cooked
1/2 cup
9
1
* Daily requirement based on 1,200 milligrams for a man or woman aged 50 years or older, but this is far higher than considered adequate by the World Health Organizaion.
Source: USDA National Nutrient Database for Standard Reference, Release 28, 2016, ndb.nal.usda.gov/ndb/foods.
Many factors influence bone remodeling. Putting a bone under repeated stress, like the stress of lifting a weight or carrying a body at a trot, triggers growth. Lack of stress, like sitting all day, leads to degeneration. Sex hormones such as estrogen and testosterone stimulate bone-building activity. The chaotic rush of these hormones during puberty sets off an adolescent’s growth spurt. Their loss later in life—a gradual ebbing away in men, a more abrupt cessation in women—nudges the balance toward bone loss, a shift that can be sudden and dramatic in women. The amount of calcium available to bone-building cells, called osteoblasts, also influences bone remodeling, as do the amounts of vitamins A, D, and K. But as I will describe shortly, exactly how much calcium you need each day is a very open question.
HOW MUCH CALCIUM DO WE NEED?
We don’t really know the healthiest, safest amount of dietary calcium. Different scientific approaches yield different estimates, so it’s important to consider all the evidence.
Daily calcium requirements are traditionally calculated using a balance study. This is a relatively straightforwar
d test: you assemble a group of volunteers, put them on a diet (or give them supplements) containing specific amounts of calcium for a few days or a few weeks, then measure the amount of calcium they excrete in their urine and stool. The balance point is the level at which calcium in equals calcium out. Balance studies show that about 550 milligrams of calcium a day is an optimal level for the mythical average adult.
Another route to estimating daily calcium requirements is called the maximal retention study. It, too, usually lasts only a few weeks. Volunteers take different doses of calcium and researchers try to determine the maximum amount of calcium their bodies (mainly their bones) can grab and hold on to.
Yet another piece of evidence comes from measurements of bone density using special X-ray machines before and after a year or so of calcium supplementation. These studies show an encouraging 1 to 2 percent increase in bone density. If that can be maintained for five or ten years, it would certainly help fortify the skeleton against future damage.
But there are problems with these studies. One has to do with the nature of bone itself. The small part of bone that is most able to grow and change, called the remodeling space, contains little calcium. If you greatly increased your calcium intake for a year or so—say, by drinking several glasses of milk a day or taking calcium supplements—this space would sponge up extra calcium. Your bone’s calcium content would increase by a small amount, about 1 to 2 percent, but only temporarily. After the first year, the filled-up remodeling space wouldn’t hold any more calcium, so continued calcium supplementation or a high-calcium diet would have little further effect on bone density. But it might affect other parts of the body. What’s more, any gains in bone mass would be lost when the higher calcium intake stops. This phenomenon—a small, short-term increase in the calcium content of bones with no further increase after a year or so—was confirmed in a 2015 meta-analysis of fifty-nine clinical trials of calcium intake from food or from supplements. The authors concluded that the very small increases in bone density would not translate into significantly fewer spine or hip fractures.1
Eat, Drink, and Be Healthy Page 25