Cancer is a leading cause of death worldwide, prompting extensive research into prevention and treatment strategies. Among environmental risk factors, diet has received considerable attention. In recent decades, the consumption of sugar-sweetened beverages (SSBs) and natural fruit juices has increased, leading to investigations into their effects on human health, especially concerning cancer. This article will delve into the current understanding of juice diets, their purported benefits, the potential risks, and the scientific evidence surrounding their role in cancer prevention and treatment.
The Appeal of Juice Diets
Juice diets, often involving the consumption of fresh fruit and vegetable juices, have gained popularity as a means to detoxify the body, stimulate metabolism, and potentially combat cancer. Proponents suggest that these diets address the root causes of cancer by eliminating toxins accumulated from environmental pollution and processed foods. The Gerson regimen, developed by Max Gerson in the 1940s, is a prime example of a strict juice diet. It emphasizes fresh fruit and vegetable juice, high carbohydrate and potassium, no sodium or fat, and low animal protein. The diet is often supplemented with digestive enzymes, coffee enemas, and various supplements.
Understanding Sugar-Sweetened Beverages (SSBs) and Cancer
The intake of sweetened beverages, including sugar-sweetened beverages (SSBs) and fruit juices, and their associations with cancer have received much attention. SSB consumption has increased worldwide, especially among adolescents. There is considerable evidence linking excessive consumption of SSBs to a wide range of health problems. Several studies have shown that consumption of SSBs was associated with a higher risk of type 2 diabetes mellitus, hypertension, cardiometabolic diseases, non-alcoholic fatty liver disease, and inflammatory disorders. The positive association between SSBs and obesity risk has also been reported. In terms of cancer, it has been shown that SSBs might affect cancer risk through chronic inflammation and hormonal imbalance. There might also be an indirect association between SSBs and cancer risk through obesity. Furthermore, SSBs consumption is associated with glycemic response, hyperinsulinemia, and higher levels of circulating insulin-like growth factor-I (IGF-I), which might be associated with cancer progression.
The Role of Fruit and Vegetable Consumption
While some studies suggest a link between SSBs and increased cancer risk, the consumption of whole fruits and vegetables generally shows a protective effect. A study examining data on nearly 9,000 women with breast cancer followed for up to 30 years found that those who consumed higher amounts of fruits and vegetables after their diagnosis were less likely to die during the study period than those with lower amounts of fruits and vegetables in their diets. High fruit and vegetable consumption, and high consumption of just vegetables, was associated with lower mortality from all causes-most women with breast cancer die from other causes. The study also observed that eating high amounts of blueberries was significantly associated with lower breast cancer-specific mortality, as well as all-cause mortality.
Fruits and vegetables consist of many components that may play important roles in decreasing mortality, such as anti-carcinogenic phytochemicals like beta-carotene. There is probable evidence that non-starchy vegetables and fruit combined DECREASE the risk of aerodigestive cancers overall (such as mouth, pharynx and larynx; esophageal; lung; stomach and colorectal cancers). Limited evidence suggests that fruit may DECREASE the risk of lung cancer (in people who smoke or used to smoke tobacco) and squamous cell esophageal cancer. Limited evidence suggests that non-starchy vegetables and fruit combined may DECREASE the risk of bladder cancer.
Read also: Explore the pros and cons of fruit juice detoxes.
Potential Risks of Juice Diets
Despite the potential benefits of fruit and vegetable consumption, juice diets are not without risks.
High Sugar Content
One surprising finding from the Harvard study was that high intake of fruit juices other than orange juice after diagnosis was associated with increased risk of death from breast cancer. The finding was particularly strong for apple juice and other juices. The high amount of sugar in apple juice compared to orange juice might be the reason. High blood glucose is associated with poor cancer prognosis, in part because tumors feed on glucose for rapid growth.
Lack of Fiber
Juicing extracts the juice from fruits and vegetables using a juicer or blender, but it separates the juice from the pulp. While many of the nutrients in fruits and vegetables can be passed through the juice (such as vitamin C), other nutrients, like fiber, cannot be consumed via juice. The average adult doesn’t consume nearly enough fiber each day, and therefore, does not need a digestive tract rest.
Gerson Therapy Risks
The Gerson therapy, a strict juice diet, has been associated with coma-inducing low levels of sodium. Case reports of deaths from repeated administration of coffee enemas indicate that the practice causes a dangerous decrease in serum electrolytes. The ease of absorption of the high volumes of raw fruit and vegetables in this diet is questionable, especially in patients with GI cancers or chemotherapy-induced mucosal damage. Common side effects include flu-like symptoms, loss of appetite, perspiration with foul odor, weakness, dizziness, cold sores, fever blisters, high fever, tumor pain, intestinal cramping, diarrhea, and vomiting. Campylobacterfetus sepsis caused by the liver injections was reported in 13 patients using the Gerson therapy between 1980-6; liver injections were subsequently eliminated from the regimen. Multiple seizures and hypokalemia leading to cardiorespiratory arrest, coma, and death were reported after excessive use of coffee enemas (1-4 per hour) for a number of days.
Misinformation and Unproven Therapies
Cancer patients are sometimes turning away from proven treatments in favour of unproven methods such as coffee enemas and raw juice diets amid an “alarming” increase in misinformation on the web. Some were dying needlessly or seeing tumours spread as a result. Several patients wanted an all-natural treatment approach after receiving treatment recommendations. They go online and search for something natural and they find a clinic in Mexico which promises an all natural treatment for cancer, which includes caffeine colonics, vitamin C infusions and other things. A few times, they didn’t come back, and then it was learned within nine months they tragically had died.
Read also: Juice Cleanse: Benefits and Risks
Scientific Evidence and Research
Despite proponents’ claims of recovery rates as high as 70-90 percent, case reviews by the NCI and New York County Medical Society in 1947 found no evidence of anticancer effects with the Gerson diet. There is no evidence to prove that Gerson therapy works as a cure for cancer. A review study in 2014 looked at 13 different cancer diets. The researchers looked at all the previous research on Gerson therapy. A study looked at the 5-year survival rate of 153 cancer patients. They found that there were higher survival rates in patients with melanoma, ovarian and colorectal cancer, who were undergoing Gerson therapy. This was compared to patients having other therapies. However, this study was done by the Gerson Research Organisation. The method they used is not reliable and flawed.
Specific Cancers and Sweetened Beverages
Data on the link between SSBs and specific cancers are conflicting. A meta-analysis of 27 observational studies reported a significant positive association between consumption of SSBs and risk of breast and prostate cancer. However, a meta-analysis and some observational studies reported that intake of SSBs was not significantly associated with pancreatic and colorectal cancers. This difference might be explained by the influence of IGF-I on the secretion of sex hormones. SSBs have an increasing effect on IGF-I levels. This hormone increases the risk of cancer development through increasing the levels of sex hormones like estrogen and testosterone. The increased levels of the mentioned hormone are the main risk factors for breast and prostate cancers, but not gastrointestinal cancers.
There is evidence indicating that a higher intake of SSBs among colorectal cancer patients increases the risk of death due to this cancer. For instance, based on a pooled analysis of two cohort studies [NHS and Health Professionals Follow-up Study (HPFS)], each 1 serving/day increase in SSBs was associated with a 59% higher risk of mortality from colorectal cancer. In another prospective cohort study from the Cancer Prevention Study-II (CPS-II), higher intake of SSBs was associated with increased risk of colorectal cancer mortality, which remained significant even after controlling for (BMI).
Carbonated Beverages and Cancer
Like the SSBs explained in the previous section, those carbonated beverages containing sugar may increase the risk of cancer and its mortality. However, in addition to sugar, other components in the carbonated beverages might be involved. One of these probable carcinogen compounds is 4-methylimidazole (4-MI) which is a by-product of the caramel process and coloring agent.
The Singapore Chinese Health Study showed that higher consumption of sugar-sweetened carbonated beverages was associated with an 87% higher risk of pancreatic cancer. A prospective cohort study on middle-aged and older Japanese individuals with stomach cancer indicated that frequent consumption of carbonated drink/juice significantly increased the risk of cancer mortality among women. Also, a population-based prospective study in South America showed that a higher intake of sugar-sweetened carbonated beverages was associated with an increased risk of breast cancer-related mortality among cancer patients.
Read also: Renal Diet Guide: Navigating Orange Juice Consumption
Interpreting the Data and Recommendations
While some elements of juice diets are healthy, it is not healthy if you are eating vast quantities of one food group in a certain way (juicing) without balancing it with other food groups. It can be harmful to people who are already weak and ill. Most Gerson therapists encourage people not to have chemotherapy while having their therapy.
No matter who you are or where you live, everyone can benefit by following one simple rule: eat more vegetables! While juicing can increase one’s intake of essential vitamins and nutrients, it cannot replace eating whole fruits and vegetables. Juice should be added to a diet in addition to full servings of fruits and vegetables. It is also essential to be selective with what goes into a juice.