Leafy greens for the ladies: Follow a low-fat diet to lower disease risk

Low-fat diets are all the rage among fitness enthusiasts and health-conscious consumers looking to shed a couple of pounds. But scientists are now beginning to examine low-fat diets not for its reported weight loss benefits, but for its long-term effects on human health.

As part of a recent randomized controlled trial (RCT), a group of scientists from the Fred Hutchinson Cancer Research Center in Seattle led an investigation into the potential benefits of a low-fat diet in the long run outside of weight loss among women.

After a follow-up period of almost two decades, the scientists found that a low-fat diet corresponded to a significant reduction in deaths following breast cancer, the slower progression of insulin-dependent diabetes and a decreased risk of heart disease.

Low-fat diets have long-term health benefits

Few long-term intervention studies have made a causal connection between low-fat diets and certain health benefits. Moreover, existing studies on low-fat diets themselves offer conflicting results or correlational relationships between low-fat diets and certain health benefits at best.

For this recent RCT, Ross Prentice, a member of the Cancer Prevention and Biostatistics programs at Fred Hutch, led a team of scientists from medical schools and research institutes across the U.S. in an attempt to examine whether a low-fat diet could lead to positive long-term health outcomes in women.

The participants had been part of the Dietary Modification (DM) trial launched in 1993 as part of the Women’s Health Initiative (WHI). The WHI is a long-term national health study that focused on the prevention of heart disease, breast cancer, colorectal cancer and osteoporosis in postmenopausal women. Prentice had also been part of the WHI.

The DM trial involved a total of 48,835 participants aged 50 to 79. The participants had been assigned at random to follow either a low-fat diet or their usual diets from 1993 to 1998.

Prentice and his team then conducted two follow-ups: one after 8.5 years and another after 19.6 years. They found no significant outcome for breast cancer, colorectal cancer and coronary heart disease (CHD) during the first follow-up period but found groundbreaking ones during the second.

In particular, it appeared that following a low-fat diet rich in vegetables, fruits and grains for almost two decades led to a 15–35 percent reduction in deaths following breast cancer. However, the participants showed no significant improvements in colorectal cancer risk.

Prentice and his team also noted a 13–25 percent reduction in insulin-dependent diabetes incidence and a 15–30 percent reduction in CHD incidence among participants who had normal blood pressure levels at baseline.

According to Prentice, these findings support the role of nutrition in overall health. Their research also indicates that low-fat diets rich in fruits, vegetables and grains can have immense health benefits without causing adverse side effects, he added.

Moreover, unlike other intervention studies, the team’s research established a causal relationship between low-fat diets and the health benefits described. (Related: Low-carb versus the low-fat diet: Which one works better?)

This serves to further validate the long-term health effects of a low-fat diet outside of weight loss, said Garnet Anderson, a co-author of the study and the principal investigator of the Fred Hutch-based WHI Clinical Coordinating Center.

Tips on following a low-fat diet

Going low-fat is more than just cutting back on high-fat foods and processed foods. There are also some important guidelines to keep in mind to ensure that our bodies are getting more nutrients in place of those fats.

Here are some tips to keep in mind in following a low-fat diet, according to experts at the University of California San Francisco (UCSF):

1. Choose non-fat or fat-free products.
2. Opt for healthier oils like coconut oil and extra virgin olive oil.
3. Eat nuts in moderate amounts.
4. For meat, choose fish, chicken, grass-fed beef and lean cuts of pork. That being said, limit meat intake to no more than three servings a week.
5. Opt for non-fat milk or plant-based milk substitutes.
6. Eat a diverse range of fruits and vegetables.
7. Avoid high-fat snacks like cookies, pies and doughnuts.
8. Bake, boil or roast meats, and steam vegetables. Limit frying as much as possible.

Recent studies suggest that low-fat diets can lead to more than just weight loss in the long run. From a slower progression of diabetes to a reduced risk of breast cancer, low-fat diets can have far-reaching long-term benefits for human health.

Sources include:

ScienceDaily.com

Academic.OUP.com

UCSFHealth.org