Prostate cancer is an abnormal growth of cells in the prostate that form a tumor. The prostate continues to grow slowly throughout the man’s life and hormonal factors, in particular male hormones called androgens, are important factors in determining the size of the prostate and in stimulating the symptoms of BPH (benign prostate hyperplasia, which can be confused with prostate cancers). According to the American Cancer Society, men in the United States have a 14% risk of being diagnosed with prostate cancer during their lifetimes. However, there have been studies from other countries with a lower prevalence of the disease, such as Japan or Russia, which suggest that genetics is not the only factor that influences the incidence of prostate cancer. In fact, lifestyle habits such as a diet rich in fat and poor in fiber can increase the risk of suffering from prostate cancer. A healthy diet and correct habits will help you prevent prostate cancer and its complications.
If you are at risk for prostate cancer or are worried about it, you might be wondering if there are things you can do that might lower your risk. While there’s no sure way to prevent prostate cancer, there are things you can do that may help lower your risk. Some risk factors for prostate cancer are beyond your control – for example, your age, race, and family medical history. Other factors, however, can be changed through making healthy lifestyle choices that can help to prevent many types of cancer, including prostate cancer.
Overview of Prostate Cancer
There is currently no perfect method to diagnose prostate cancer. The prostate specific antigen (PSA) blood test and digital rectal exam can find many prostate cancers early, but have caused extensive overdiagnosis and unnecessary treatments. Though regular PSA blood tests and digital rectal exams are important tools for early prostate cancer detection, they reportedly miss from 20% to 25% of the cancers.
Prostate cancer is the most common cancer and the second leading cause of cancer deaths for men in the United States. Although most prostate cancers are diagnosed in men over age 65, the exact cause of prostate cancer remains unknown. However, excessive hormone levels, cigarette smoking, ultraviolet radiation, occupational exposure to heavy metals, and high-fat diets have been reportedly connected to the development of the disease. There are also some indications that African-American males may have a stronger genetic predisposition for prostate cancer than Caucasian males.
Significance of Lifestyle Factors
In recent years, research has focused on the potential role of lifestyle-related factors, including nutrition in managing risk of prostate cancer. Epidemiological studies, in particular, have increasingly generated some of the strongest evidence for possible associations between dietary habits and the risk of prostate cancer development and progression, especially towards high-grade prostate cancer. Data across numerous studies have suggested that frequent consumption of red meat is associated with elevated prostate cancer risk, whereas certain fruit and vegetables have favorable associations. Additionally, evidence suggests that a diet low in polyunsaturated fatty acids, selenium, and vitamin E may increase prostate cancer risk. This has generated consistent and systematic advice from researchers and health policymakers to consume diets that are high in fruit and vegetables and low in red meat and dairy. Furthermore, where higher risks are conferred by obesity and sedentary lifestyle, these lifestyle approaches and factors should generally be discouraged.
Prostate cancer has been ranked as the most common cancer among men worldwide. Recent epidemiological studies have revealed that a large part of prostate cancer cases can be prevented through changes in lifestyle factors, particularly those related to diet and nutrition. Similarly, the advice to increase consumption of fruit and vegetables is often some of the first lines of nutrition prevention towards prostate cancer, as the consumption of fruit and vegetables is associated with lower prostate cancer risk. Indeed, experimental studies have shown that certain food components may possess antineoplastic properties. While such food components are cost effective and readily available, clinical trials may provide further evidence to evaluate a promising role in the consultation rooms. It is warranted to conduct experiments using animal and human cellular model systems to gain insights into mechanisms linking diet to prostate cancer. In this review, evidence-based research on nutrition prevention of prostate cancer is presented and a discussion of future trends is included.
Understanding Prostate Cancer
Prostate cancer is the leading cause of cancer in men and is the second leading cause of cancer death in American men, with an estimated new case and death incidence of 275,500 and 26,730, respectively, in 2020. This high incidence leads to an increase in the death rate and a deterioration in the quality of life of males. However, the underlying cause of prostate cancer, whether genetic or environmental, has remained an ambiguous question, even though some factors such as age, race, genetics, and family history have been identified to increase the risk of prostate cancer. In view of the uncertainty of the causes behind the development of prostate cancer, it is necessary to understand the important lifestyle changes necessary to avoid the risk of prostate cancer.
The prostate gland is a part of the male reproductive organs situated beneath the urinary bladder and in front of the rectum. Prostate cancer can be defined as the condition when there is an abnormal and uncontrollable division of cells in the prostate, leading to the formation of a tumor in the affected gland. The tumor can either be malignant (cancerous) or benign (non-cancerous) and may interrupt the normal functioning of the prostate gland. The cells in an affected prostate gland can spread or metastasize from the prostate gland to other parts of the body, such as the lymph nodes, bones, lungs, and even the liver.
Risk Factors
The number of randomized prostate cancer prevention trials has increased in the last ten to 15 years. Results of these experimental studies suggest that medications can reduce prostate cancer incidence and mortality, but they also have serious side effects. It is therefore important to consider the existing knowledge of how lifestyle may affect cancer risk when making a decision on the best prevention strategy. The use of a randomized design to study the effect of lifestyle is not feasible for all exposures and in all study populations. Unfortunately, observational studies have significant drawbacks, including residual confounding, which can lead to misleading conclusions. However, under these circumstances, it is advisable to conduct further observational trials to test the association in different study populations and to conduct animal experiments and other laboratory tests to gain further insight into the observed biological association. Fashioning prevention strategies that target the identified risk factors for prostate cancer is essential. The ultimate risk for prostate cancer may be altered by employing a multi-pronged strategy targeting modifiable dietary and other factors acting on the individual and population level.
Prostate cancer, the second most deadly cancer in men, occurs primarily in the latter part of life. It is postulated that high fat consumption adversely alters relevant metabolic pathways and hormone levels. Using a preliminary cancer screen, we have previously found that reducing the level of dietary fat or increasing consumption of tomato and its products can alter the risk of prostatic malignancy. Recently, since tomatoes are the main dietary source of lycopene, a carotenoid with antiproliferative activity, a number of human studies have appeared on the potential anti-proliferative action of lycopene in prostate cancer. Some studies have suggested that the antioxidant and antiproliferative action of other carotenoids in the serum, rather than the action of lycopene alone, are associated with a reduced risk of prostate cancer. However, these findings remain contradictory as not all studies have found a protective role of carotenoids.
Lifestyle Factors and Prostate Cancer
Dietary habits are closely related to obesity. The Western diet is thought to lead to obesity, diabetes, and eventually PC. In the Western diet, the calories are densely packed and the foods often lack important nutrients and fiber, but contain large amounts of unhealthy fat, cholesterol, and sugar. However, the Mediterranean diet appears to reduce the risk of getting PC. The Mediterranean diet is a balanced diet with more whole grains, vegetables such as tomatoes and garlic, colorful fruits, unprocessed fish, olive oil, and red wine. The beneficial effects of the components of olive oil, like monounsaturated oleic acid, and chemical phenols of olive oil, are being actively studied. Experiments with PC xenografts suggest that olive oil phenols reduce PC cell growth. Further studies with men may give evidence about the benefit of olive oil. The continuous high intake of large amounts of red meat, processed meat, and unsaturated fat, which is related to the Western diet, is supposed to increase the phosphorylation of the insulin receptor. Signals like exhaustion of adenosine monophosphate-activated protein kinase (AMPK) in the Krebs cycle, to retrieve anabolic energy, dysregulate the AMPK-mTORC1-p70S6K pathway, and produce excessive ribosomal biogenesis. Excessive ribosomal biogenesis might also be stimulated by high levels of IGF-1. Increments in protein synthesis would then fuel fast PC cell growth. These diet-driven obesity-related signaling activities might be important links between PC and the above-described non-communicable diseases. PC may be the result of lifestyles that were imagined to be devoid of negative consequences.
In the era of uncertainty about PSA-based screening trials, the main recommendations focus on lifestyle. To prevent and decrease the progression of prostate cancer and other non-communicable diseases, a balanced diet and regular exercise is recommended. Excessive body fat and obesity are seemingly associated with the risk of developing aggressive PC and other non-communicable diseases. The association between these lifestyle factors modifying the high level of insulin and IGF-1 as powerful promoting factors for PC tumor growth is discussed. Lifestyles leading to other non-communicable diseases like unhealthy diets and excess body weight also modify chronic inflammation biomarkers which might promote PC tumor growth.
Dietary Choices
Dairy products contain a high amount of both saturated fats and calcium, which has been shown to increase the risk of prostate cancer. On the other hand, drinking milk may represent a transitory lifestyle and therefore may not affect the results if included in the study. It is also unknown if consuming dairy products on a regular basis reduces the risk or inhibits the development of prostate cancer. Other evidence suggests that milk may not have an effect on hormone levels. Therefore, prostate cancer progression or development would not be anticipated. Study data indicates that drinking or consuming dairy products may have caused certain genetic alterations, due in part to a tumor suppressor affecting the suppression of gender-targeting genes. When disrupted, this can increase the likelihood of prostate cancer. Investing in organic dairy products has a higher nutritional value, a health benefit, a sharp taste, passion from customers for healthier food and animal products, and offers a more natural way to reduce the risks associated with the most popular form of cancer, in which triggers include red meat and dairy.
Now let’s talk about what you are putting through your gastrointestinal system, contributing to increasing the risk of having prostate cancer. The following are just a few known factors that contribute: red meat, dairy products, and diets high in calories. Diets high in unsaturated and saturated fatty acids are related to increasing prostate cancer. In contrast, diets high in long-chain n-3 unsaturated fatty acids (like fish) are considered a protective factor. Recent data supports the following as beneficial for prostate cancer: lycopene, like that in tomatoes, cruciferous vegetables like broccoli or cauliflower, and the mineral selenium that occurs naturally in pork, beef, fish, and turkey. Soy isoflavones, which occur in soybeans, are useful in both curbing the enlargement of healthy cells in the prostate and preventing the spread of malignant cells.
Physical Activity
Moderate or vigorous physical activity, including brisk walking, reduces a man’s risk for the development and progression of lethal prostate cancer, but the potential for recreational activity to delay progression once disease has started is not confirmed. While physicians usually are in agreement that these findings, which have been accrued from many studies, are important, yet, few physicians ask their patients to make themselves accountable for these prime lifestyle changes. The benefits may be reaped when the physical activity level reaches a point that it becomes a habitual, regular part of a man’s life. In conclusion, it would be advised for men to be physically active throughout life.
Studies have investigated and confirmed that moderate to high physical activity is associated with a lower risk for developing prostate cancer. The value of regular physical exercise goes far beyond this. For men who adopt regular physical activity, the risk for more aggressive forms of prostate cancer, which are more likely to progress and spread to other organs, is reduced. This is even the case for men that achieve regular moderate levels of exercise. It should be emphasized that the exercise need not be extremely vigorous. Walking at an average pace, which is about 18 minutes per mile, is adequate. With the available data, it is concluded that the risk for advanced stages of disease at diagnosis is diminished for men who engaged in vigorous physical activity before diagnosis.
Maintaining a Healthy Weight
The first line of defense when it comes to losing weight is exercise, both aerobics and strength training. Beyond that, it is important to cut back on food intake. While many men seem baffled by how to lose weight, it is actually simple to grasp: one only has to eat a bit less every day than the body uses. However, do not let it become an obsession. Moderate weight lifting and aerobic exercises, most days of the week, are good solutions. Getting and staying physically active might help prevent prostate cancer. Some studies have found that men who exercise regularly have a slightly lower risk of getting prostate cancer, and others have found that men who are more active after being diagnosed actually live longer. Since exercise is already known to prevent heart disease and many other health problems, it seems worth trying.
Maintain a healthy weight. Being overweight seems to increase the risk of advanced prostate cancer. In one study of older men, being overweight seemed to increase the risk of prostate cancer that was likely to cause symptoms (more advanced). Doctors aren’t exactly sure why being overweight seems to affect the prostate, but they think it might involve the activity of hormones such as insulin or other substances in the blood. Whatever the reason, maintaining a healthy weight throughout life for those at risk or those who have already had prostate cancer is probably good for many reasons.
Other Lifestyle Considerations
Weight loss. Overweight men tend to harbor higher levels of various hormones associated with prostate cancer. Those with increased abdominal girth are even at greater risk. Today, many think of obesity as primarily a metabolic syndrome that can lead to heart disease, high blood pressure, and type 2 diabetes, but it is also a strong risk factor for prostate and some other cancers. Reducing fat can actually reduce serum levels of testosterone and estrone, both of which have been implicated in tumor growth. In fact, for some men diagnosed with prostate cancer, weight loss is considered part of standard treatment. It is believed that fat can convert the adrenal androgen precursor DHEA to testosterone. Epidemiologic evidence indicates that obesity is actually a worse type of risk factor compared to a diet high in fat. Weight reduction may even turn out to be essential in men with prostate cancer. The dietary recommendations discussed also promote weight reduction, for those in need of weight reduction.
Changes in lifestyle are some of the most difficult things to implement. No one ever said it was going to be simple. Nothing I am suggesting here is unattainable for anyone. Let me remind you that not dying from prostate cancer is my goal for your life. Good nutrition, regular exercise, and cancer are quite closely related. Even as a very old man, I do things to reduce the risk of cancer in my life. In fact, I do not remember a day that went by that I did not actively consider the choices that I made in relation to cancer prevention.
Smoking Cessation
If smoking cessation plays a role in the prevention of prostate cancer, some retrospective studies claim that people who quit smoking had an 18% lower risk of developing prostate cancer within five years, 20% after ten years, and 30 years after the cessation of smoking. In the study by Kenfield et al., a decline in the mortality of prostate cancer was observed five years after quitting smoking, demonstrating that the harmful effects of smoking on health can be reduced at any age by quitting smoking. According to the WHO, oncological cancers are quickly surpassed by cardiovascular diseases as the leading cause of tobacco-related mortality, and these data confirm how quitting smoking can significantly decrease this risk. Since age could be a factor that determines the prognostic value of smoking, further studies are needed to verify this hypothesis. Although smoking-related health problems can be reduced through smoking cessation, only a few patients use a patient-centered approach to encourage lifestyle changes.
The relationship between smoking and prostate cancer has not been examined extensively, but this association has been found in some studies of men of Afro-Caribbean descent. Cigarette smoke has many chemical carcinogens, which can easily access prostate tissue through the bloodstream and accumulate in it at higher levels than in any other tissue in the body. Moreover, smoking increases the risk of aggressive prostate cancer and the risk of recurrence after radical prostatectomy. Prostate cancer has been shown to be a tobacco-related tumor, and men who smoke do not react as well to therapy as men who do not smoke. Consequently, smoking cessation should play a greater role in the management of patients suffering from prostate cancer, as experts believe that four in ten cases of prostate cancer are caused by an incorrect diet and lifestyle choices such as smoking and the absence of physical exercise.
Alcohol Consumption
At present, the weight of the evidence is that alcohol has no appreciable effect on the development of prostate cancer. If anything, men who drink alcohol may be at somewhat lower risk of fatal advanced disease. Until more is known about alcohol and prostate cancer, the AICR strategy that men not drink alcohol to lower cancer risk has been withdrawn.
There are no consistent associations for prostate “cancer or fatal prostate cancer” and total alcohol consumption. The beneficial effect of alcohol on cardiovascular health is also questioned. Recent meta-analyses on alcohol and its health effects give little indication of increased risk of men with moderate alcohol consumption for selected diseases such as hypertension, digestive cancer, abdominal aortic aneurysm, type 2 diabetes and gallstone. However, alcohol increases the risk for pancreatitis and any alcohol increases the risk of cancer.
There are several studies that have looked at alcohol consumption as a possible way to increase the risk of prostate cancer. Specifically, associations between alcohol consumption and prostate cancer have been studied using different outcomes (diagnosis, recurrence and death) and at different time points (before, after and around the time of diagnosis).
Translating results on PSA testing and the potential benefits of lifestyle changes into the likelihood of reducing prostate mortality will help men better understand the importance of these activities. In particular, when communicating to men in the risk group with a PSA level of 3-9.9 ng/ml, it is necessary to focus on lifestyle changes, emphasizing one’s diet in relation to chronic diseases such as prostate cancer. Recommending dietary changes, especially those involving the inclusion of some animal products, are not only harmless but also help to reduce harmful effects, considering the population’s alarmist attitude towards diet quality.
Decision-making about the necessity of prescribing PSA testing and further treatment for a man’s good health and preferences is complicated by trade-offs between the real clinical benefits of preventive services and potential harms. Men have different opinions about the necessity of these manipulations; therefore, it is important to provide them with appropriate information to describe small changes in the risk level and the cumulative effect of the causation of a particular disease.