Navigating beyond the fads for diets that can help fight disease

National Institutes of Health and National Cancer Institute at

By Sara Freund

The raw food diet promotes fruits, vegetables, nuts and seeds but rules out fish, a great source of healthy omega-3 fatty acids.

Juicing helps the body absorb nutrients more efficiently but the fiber from fruit and vegetable skin, essential for a balanced diet, is lost.

There are conflicting claims that coffee may pose an increased risk of cancer and red wine may help prevent it. The amount of information can be overwhelming especially when many experts disagree on the advice.

“There are certain things that classify a fad diet – it gets popular all of a sudden or it demonizes certain food groups and elevates others. Often they start with science and decent evidence but then take it to an extreme,” said Jean LaManita, a registered dietitian with extensive nutrition experience relating to cancer.

One example of this is the so-called alkaline diet. The research underpinning it shows that cancer cells can thrive in an acidic environment created in a lab setting.

The idea behind the alkaline diet is that by eating foods with high pH levels – alkaline levels –  such as spinach and broccoli, the body’s pH will rise enough to create an environment in which cancer cells are less likely to survive.

Acidity and alkalinity are measured by determining the pH level on a scale of 1-14. Honey has a low pH level meaning that it is acidic. Almonds have a very high pH level making them alkaline, which is the other end of the spectrum.

Healthy cells use oxygen for energy, and oxygen levels are higher in an alkaline environment. Cancer cells work differently. They generate energy through a process called glycolysis, which means that, instead of oxygen, cancer cells use sugar for energy.

“The reason people feel better on an alkaline diet is really because they are eating healthier overall. A lot of alkaline foods are healthy foods and leafy greens,” said registered dietician Torey Armul and spokeswoman for the Academy of Nutrition and Dietetics based in Chicago.

“I wouldn’t get too focused on the pH level or avoid acidic foods because ultimately our bodies control that very well,” Armul said.

Following the alkaline diet means sticking to vegetables, seeds and certain fruit, which are alkaline. It also means avoiding acidic foods such as sugar, coffee, and processed foods.

To determine a food’s pH level, scientists burn food in the lab and test the pH level of the ash. Citrus fruits are acidic but once burned, they produce an alkaline ash. So lemons and limes, even though they are acidic to start with, end up alkaline after digestion.

Choosing to focus on one of two healthy choices instead of the newest diet trend can help navigate the mountain of information.

“Looking at the key things all these cancer fighting diets have in common, it is to cut back on sugar, alcohol and processed foods. I think that’s a great bottom line you want to take away,” LaManita said.