Will a Pound of Bacon Really Make You Live Longer?

According to recently published research, there's a new longevity diet.

Posted Sep 21, 2017

Have recent headlines about how eating a high-fat diet may make you live longer changed your eating habits? Are you now breakfasting on three-egg omelets, a double side order of sausage, and a mound of well-buttered toast?  Have kale and quinoa been relegated to the hamster cage, and skinless chicken breasts passed over for chicken nuggets in the supermarket?

It would be understandable if you were now reconfiguring your diet. The media reports summarizing a study reported in Lancet were compelling: Populations consuming a diet high in fat had lower rates of deaths from cardiovascular disease such as stroke, heart attacks, and congestive heart failure, than populations consuming a high-carbohydrate, low-fat diet.

But before going to the Cheesecake Factory and ordering a particular pasta dish that, according to the Center for Science in the Public Interest, contains 2,310 calories and 79g of saturated fat, or to Buffalo Wild Wings for their Cheese Curd Bacon Burger with 1,950 calories and 53 g saturated fat, a few facts about the study ought to be considered. When we talk about low-fat diets, we are usually thinking of people in the states who are trying to avoid high-fat, high-cholesterol foods by eating lean protein, e.g., poached salmon, along with vegetables, fruits, and whole grains.

But would this represent the low-fat diets that the people in the multi-country study were consuming?

The study surveyed populations from middle-income countries such as Brazil, Argentina, and Turkey and also included poor countries such as Bangladesh, India, and Zimbabwe. Traditional diets among the poor in these countries are usually high in carbohydrates, e.g., white rice or cornmeal, because these are cheap foods. (Although recently the poor of some countries like Brazil fill up on sugary, high-fat snack foods rather than their traditional diet according to a recent article in the New York Times.) Foods higher in fat, namely meat, eggs, cheese, and dairy that have more nutrients, especially protein, are eaten infrequently because they are too expensive and/or scarce. Indeed, a recent CNN program on North Korea mentioned that most of the population lives on a very limited diet with rice as the staple, and high-protein, fat-containing foods like meat is eaten rarely. Is it not possible that those who did consume more fat were doing so by eating eggs, meat, and dairy products, thereby not living on boiled rice or yams and thus better nourished?

So how much fat were those on a high-fat actually eating? And how does it compare with our typical fat intake? Are we eating enough fat to prevent heart attacks?

The people in the high-fat group in the multi-nation study consumed on average 35 percent of their calories as fat. According to recent statistics from the Centers for Disease Control, we too consume on average about the same percentage of calories—34 percent—from fat. And some good news: current statistics on mortality indicates a significant decrease in death from heart disease in the U.S.

But before celebrating with a snack of fried butter to better keep away that heart attack, consider this statement from a study on rates of mortality from heart disease and cancer: “If current trends continue, cancer will become the leading cause of death by 2020.” And alas, high fat intake has been significantly associated with higher incidence of several cancers such as breast, colon, and prostate. For example, a sixteen-year study drawing on data from the Women’s Health Initiative compared the incidence of breast cancer among post-menopausal women who were on a low-fat diet  (20 percent of their calories came from fat) to women on a typical higher fat American diet. Women who followed the low-fat diet were less likely to develop breast cancer, and if they did so, die from it, than women who did not restrict their fat intake.

A similar relationship was found for lung and colon cancer.  High intakes of total and saturated fats (fat from meat, dairy, and eggs) were related to a higher incidence of lung cancer, and some studies showed that switching to unsaturated fat, for example using canola or olive oil rather than butter, decreased certain types of lung cancer.

Dietary fat also seems to have the same effect on colon cancer. In a recently published study, researchers from the Cleveland Clinic found that the growth of cancer stem cells, the cells that will develop into colon cancer, were enhanced by a high-fat diet. When they were able to identify, and then block, the action of a newly identified biochemical pathway leading to tumor growth … a high-fat diet had no effect on promoting colon cancer.  

As they say, there is no free lunch … and in this case, no very high-fat lunch that is free of possible health risks. Eventually, research will have even more information about how high-fat consumption affects cancer risk. And if they do, perhaps there will be drugs to block the route from eating pork rinds to breast and other types of cancer. But for now maybe it is still a good idea to follow the modified Jack Spratt diet rather than that of his wife:

“Jack Spratt would eat no fat, his wife would eat no lean, and between them they licked the platter clean.”

References

“Associations of fats and carbohydrate intake with cardiovascular disease and mortality in 18 countries from five continents (PURE): a prospective cohort study”, Mente, A., Zhang X., Swaminathan, S., et al: http://dx.doi.org/10.1016/S0140 736(17)32241-9.

Weir, HK, Anderson, R,, Coleman, King S, Soman A, Thompson T, Hong Y, et al. “Heart Disease and Cancer Deaths — Trends and Projections in the United States”2016: 1969–2020. Prev Chronic Dis 2016.

“Lower-fat dietary pattern and breast cancer mortality in the Women’s Health Initiative Randomized Controlled Trial”, Chlebowski, R., Aragaki, A., Anderson, G., et al, J Clin Oncol 2017.

“Dietary fat intake and lung cancer risk: a pooled analysis,” Yang, J., Takata, Y., Smith-Warner, S. et al J Clin Oncol 2017.