One of the most common reactions to earnest recommendations that we overhaul our eating habits, from a diet based largely on red meat and highly processed foods to one more focused on vegetables, fruit and whole foods, is that we can never really be sure what's good for us. "Just wait," someone inevitably jokes. "Tomorrow they'll tell us that broccoli will kill us."
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Well, science has yet to suggest that. But it has delivered proof of the positive effect a societal change in diet can have on citizens' health.
The subjects of the study were the people of Cuba, who unknowingly took part in a large-scale study on the effect of lifestyle change during their country's extended economic downturn in the 1990s.
The economy began to collapse after the government of its state sponsor, the Soviet Union, fell in 1989. The Russian republic that emerged from the former regime soon ended its subsidies of cheap oil for Cuba. As Richard Schiffman reports in a fascinating new article in The Atlantic, the shift sent Cuba "into an economic tailspin from which it would not recover for over half a decade."
The effects were widespread. Most motorized agriculture and food distribution systems halted. The ongoing U.S. trade embargo, strengthened by Congress in 1996, further prevented the import of many drugs, manufactured goods and food products. "Cubans survived drinking sugared water and eating anything they could get their hands on," Schiffman writes, "including domestic pets and the animals in the Havana Zoo."
And yet the population's health actually improved, in some ways dramatically, according to a study recently released by researchers working in Cuba, Spain and the United States and published by the medical journal BMJ.
Researchers tracking the health of about 6,000 residents and analyzing national data compiled by the Cuban Ministry of Public Health found that mortality in the island country dropped during the depression. Death from cardiovascular disease fell by a third, and from adult-onset Type 2 diabetes by half. The rate of strokes was reduced, too.
Despite its economic struggles, Cuba maintained an effective health-care system. But the study found that it was not the doctors that kept citizens healthy but the lifestyle changes poverty forced on them.
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With public transportation largely idled by the gas crisis, more people walked and bicycled. Adults also ate less, losing an average 12 pounds as their daily calorie intake dropped from about 3,000 to between 1,400 and 2,400, according to the new research. Diets were transformed as well. Protein intake dropped an average of 40 percent as meat and dairy products became luxuries and families turned to de facto veganism, Schiffman reports, living off "what they could grow, catch and pick for themselves — including lots of high-fiber fresh produce and fruits, added to the increasingly hard-to-come-by staples of beans, corn and rice."
Cuba had gone green, even if unintentionally. With limited access to agro-chemicals, "farmers returned to the machetes and oxen-drawn plows of their ancestors," Schiffman notes. Community gardens flourished in major cities.
Cuba's state-controlled economy regained some of its footing in the late 1990s, due in large part to the support of oil-rich Venezuela. And as soon as cheap access to oil was restored, Cubans began exercising less and eating more. By 2011, the researchers found, the nation's obesity rate had almost tripled from its 1995 low. Diabetes and cardiovascular disease rates rose in lockstep with obesity and the national mortality rate returned to pre-downturn levels.
In an editorial accompanying the study in BMJ, Professor Walter Willett of the Harvard School of Public Health wrote: "Although the hardships experienced by Cubans in the 1990s were unfortunate, the present findings add powerful evidence that major population-wide benefits will be obtained rapidly by reducing overweight and obesity. To achieve this is perhaps the major public health and societal challenge of this century."
Schiffman joins Willett in wondering what the United States can learn from the Cuban experience as our own health care system struggles to manage soaring rates of Type 2 diabetes. The American Diabetes Association's chief medical officer, Dr. Robert Rattner, says 1 in 3 American adults could have the condition by 2050. Meanwhile, heart disease, which like diabetes is closely linked to a sedentary lifestyle and unhealthy diet, remains the leading cause of death in the United States.
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The authors of the Cuban study suggest that other countries seek to recreate the Caribbean nation's experience — without the economic downturn — through public health campaigns, redesigned public spaces, limits on unhealthy food and drink, especially for children, and taxes on sugary and fatty foods. They acknowledge, though, a troubling reality: "No country or regional population has successfully reduced the distribution of body mass index or reduced the prevalence of obesity through public health campaigns or targeted treatment programs."
In the absence of national initiative, it's up to each of us to do what we can to improve our own health. What can you do? Here are some fundamental steps that could boost your health and prolong your life. If enough of us adopt them, we may see a reduction in our national rates of diabetes and heart disease, and we'll ward off more cases of dementia, too:
- Eat healthier. The Mediterranean diet has been shown to help prevent 30 percent of heart attacks and strokes for people at high risk of those conditions. It features olive oil, fish, fruits, vegetables and unrefined grains. Wine, eggs and low-fat dairy products are allowed in moderation. One key to the diet's success is that it eschews highly processed snacks and prepared foods that are low on nutrients and high on additives. (Learn more about the three best ways to eat for a healthy heart.)
- Try vegetarianism. We saw the impact a meat shortage had on Cubans' health. Forgoing meat in this country is easier than ever as alternatives continue to improve and become more affordable. Becoming a vegan or vegetarian is no protection against obesity or metabolic syndrome if you continue to feast on processed foods low on fiber and loaded with fat and sugar. Focus on whole foods.
- Get moving. A sedentary lifestyle is one of the greatest health risks. Sitting for more than three hours a day can cut one's life expectancy by two years and the effects are not entirely offset by regular exercise. C. Everett Koop, a former surgeon general, recommended a minimum of 10,000 steps a day — about five miles. The federal Centers for Disease Control and Prevention advises all adults to get 150 minutes of moderate aerobic exercise a week. Barely half of us do either.
The Cubans, in a way, had good health forced on them. The discouraging news is that when it was no longer economically necessary to live a healthier, more active lifestyle, the population basically dropped it. Clearly the challenge for our country — to make such changes voluntarily and stick with them — is even more daunting.