Lacto-ovo vegetarians are those who follow a plant-based diet along with dairy and eggs. Analysis of different population based studies indicate that adopting lacto-ovo vegetarian diets may have benefits in reducing the risk of specific cancer types such as gastro-intestinal cancers gallbladder polyps, colorectal cancer and breast cancer in certain populations including North-Indian women.
Can becoming vegetarian help us in reducing the risk of cancer?
This is one of the many questions we have ever since it has been established that consuming red and processed meat can increase the risk of cardiovascular diseases as well as different types of cancers.
One of the main reasons for these risks is the presence of high amounts of saturated fats in red and processed meat. However, we may also wonder whether a vegetarian diet can provide us all required nutrients that we generally get from non-vegetarian foods, as many of the non-vegetarian foods are an excellent source of proteins as well as various other vitamins and minerals including iron, zinc, Vitamin B12, Vitamin B3 (Niacin), Vitamin B6 and so on. In this blog, we will look into the different types of vegetarian diets and zoom into one of the many vegetarian diets – the lacto-ovo vegetarian diet.
Different Types of Vegetarian Diets
Recently, plant-based foods have been gaining popularity in the western world. When we hear of vegetarian diets, we usually assume a diet that is completely free from any foods obtained from the animal sources such as meat, fish, poultry, milk and milk products. However, this is not always true.
There are different types of vegetarian diets that are classified based on the foods we include and exclude in the diet. Some of the most common vegetarian diets are detailed below.
Vegan diets exclude any sort of foods from animal sources, which indicates that vegans do not include red meat, white meat, fish/seafood, poultry, eggs as well as dairy. Vegans may also exclude animal by-products such as gelatin and honey from their diet.
Lacto-vegetarians do not consume red meat, white meat, fish/seafood, poultry, eggs and those foods that contain them. However, lacto-vegetarian diets include dairy products, such as milk, yogurt, cream, butter and cheese.
Ovo-vegetarians do not consume red meat, white meat, fish/seafood, dairy and those foods that contain them. However, ovo-vegetarian diets include eggs.
Lacto-Ovo Vegetarian Diets
Lacto-ovo vegetarians do not eat red meat, white meat and fish/seafood. However, milk, milk products and eggs are allowed in lacto-ovo vegetarian diets. This is also one of the most common vegetarian diets.
Pescatarians usually include fish and sea food as part of their diet, and may not sound as a vegetarian diet. Hence this diet is also considered as a semi-vegetarian diet. Pescatarian diets do not include red meat, white meat or chicken.
Flexitarian diets are also semi-vegetarians diets. It is a plant-based diet which occasionally includes red meat, white meat, fish/seafood, poultry, eggs, milk and milk products in small quantities.
Health Benefits of Lacto-Ovo Vegetarian Diet
“Lacto” refers to Milk and Milk products and “Ovo” refers to eggs. Hence, as the name suggests, lacto-ovo-vegetarian diets are plant-based diets that exclude red meat, white meat and fish/seafoods but include milk, milk products and eggs. Due to their impressive health benefits, these days, a lacto-ovo vegetarian diet is chosen over a meat-based diet including red and processed meat that contains high amounts of saturated fats.
Some of the health benefits of lacto-ovo vegetarian diets include:
- Reduced rates of obesity
- Reduced risk of heart diseases
- Reduced rates of high blood pressure
- Reduced risk of diabetes
- Reduced risk of gallstone
- Lowers blood cholesterol levels
- Supports weight loss while maintaining a healthy weight
Since lacto-ovo vegetarian diet includes dairy and eggs, nutrients such as calcium, vitamin B12 and vitamin D can be easily obtained. However, those who follows a lacto-ovo vegetarian diet should also ensure that they include the right vegetarian sources such as pulses, soybean, tofu, walnuts etc to obtain the right amounts of nutrients like protein, iron, zinc and omega-3 fatty acids.
Lacto-Ovo Vegetarian Diets and Cancer Risk
Different studies have previously shown that consumption of red and processed meat may lead to different types of cancers due to the presence of high amounts of saturated fats. Hence, many people has put a deliberate effort to avoid these foods in their diet by adopting a lacto-ovo vegetarian diet. However, one may still wonder what the studies and evidence say about the association of lacto-ovo vegetarian diets with different types of cancers. In this blog, we have collated a list of such studies which evaluated the association between the two.
Lacto-Ovo Vegetarian Diet and Risk of Gallbladder Polyps
In a study published in 2019, the researchers from the Department of Family Medicine, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Taiwan evaluated the association of vegetarian diets, particularly the lacto-ovo vegetarian diet, with the development of gallbladder polyps (95% of gallbladder polyps are usually benign). Data for the analysis was obtained from a cross-sectional study which included 11,717 individuals who received a health checkup at Taipei Tzu Chi Hospital between October 2011 and October 2016. The prevalence of gallbladder polyps in this study group was 8.3%. The study gathered information on the dietary patterns followed by the participants and classified them as vegans (plant-based foods only), lacto-ovo vegetarians (consuming eggs or dairy products or both, but no other animal products), semi-vegetarians (consuming plant-based food with occasional meat products, no more than once a week) or omnivores (consuming both plants and animals). (Hao-Wen Liu et al, Ci Ji Yi Xue Za Zhi., 2019)
The study found that, compared to the omnivore group, the incidence of gallbladder polyps were significantly less common in the vegetarian groups including vegans, lacto-ovo vegetarians and semi-vegetarians. The study concluded that lacto-ovo vegetarian diets may have benefits in reducing the risk of gallbladder polyps.
Lacto-Ovo Vegetarian Diet and Risk of GastroIntestinal Cancers
In a study published in 2013, the researchers evaluated the association between different dietary patterns including non-vegetarians, lacto-vegetarians , pescatarians, vegans, and semi-vegetarian and the risk of overall cancer. The study used food frequency questionnaire based data of 69,120 participants from 38 U.S. states and Washington D.C. who were a part of a population based study among Adventist church members, named the Adventist Health Study-2. A total of 2,939 incident cancer cases were reported in the study.(Yessenia Tantamango-Bartley et al, Cancer Epidemiol Biomarkers Prev., 2013)
The study found that vegan diets may be associated with a significant reduction in overall cancer incidence in both genders combined and for female-specific cancers. The study also found that lacto-ovo vegetarians may be associated with a decreased risk of gastrointestinal cancers.
Lacto-Ovo Vegetarian Diet and Breast Cancer Risk
Study in North-Indian Population
In a study published in 2018, the researchers evaluated the association between Indian dietary patterns and the risk of breast cancer. The questionnaire based dietary data for the analysis was obtained from a multi-centre study that was conducted in the North Indian states of Punjab and Haryana, which included 400 women aged between 30 to 69 years of age with newly diagnosed breast cancer and 354 controls matched to the age and region of the breast cancer cases. Based on the diets followed, the participants were classified as non-vegetarians, lacto-vegetarians or lacto-ovo vegetarians. (Krithiga Shridhar et al, Int J Environ Res Public Health., 2018)
The study found that compared to both non-vegetarians and lacto-vegetarians, the risk of breast cancer was lower in those North-Indian women who followed a lacto-ovo vegetarian diet.
Study in low-risk population in the United States
In a study published in 2016, the researchers evaluated the association between dietary patterns and breast cancer risk. The study used food frequency questionnaire based data of 50,404 female participants (26,193 vegetarians) from 48 U.S. states and Washington D.C. who were a part of the Adventist Health Study-2 between 2002 and 2007. Based on the diet followed, the participants were classified as vegans, lacto-ovo vegetarians, pesco-vegetarians, semi-vegetarians and non-vegetarians. During a mean follow-up period of 7·8 years, a total of 892 incident cases of breast cancer were reported, which included 478 vegetarians. (Jason A Penniecook-Sawyers et al, Br J Nutr., 2016)
The analysis of data from this low risk American population found that following a vegetarian dietary pattern may not be associated with a reduced risk of breast cancer as compared with non-vegetarians. However, the researchers suggested that a reduced risk may be possible in vegans and may have to be further investigated.
Lacto-Ovo Vegetarian Diet and Colorectal Cancer Risk
In a study published in 2015, the researchers evaluated the association between vegetarian dietary patterns and colorectal cancer risk. The study used food frequency questionnaire based data of 77,659 Seventh-Day Adventist men and women from 48 U.S. states who were a part of the Adventist Health Study-2 between 2002 and 2007. Based on the diet followed, the participants were classified as vegans, lacto-ovo vegetarians, pesco-vegetarians and semi-vegetarians. During a mean follow-up of 7.3 years, 380 cases of colon cancer and 110 cases of rectal cancer were reported. (Michael J Orlich et al, JAMA Intern Med., 2015)
During the analysis of this cohort study, the researchers found that those groups who followed vegetarian diets had a combined reduced risk of colon and rectal cancers compared with non-vegetarians. Amongst vegans, lacto-ovo vegetarians, pesco-vegetarians and semi-vegetarians, a significant risk reduction for colorectal cancers was found in those who followed a pesco-vegetarian diet.
Different studies indicate that adopting lacto-ovo vegetarian diets may have benefits in reducing the risk of specific cancer types such as gastro-intestinal cancers, gallbladder polyps and breast cancer in certain populations including North-Indian women. However, the studies didn’t find any significant reduction in the risk of breast cancer in lacto-ovo vegetarians of a low risk population in the United States. The decrease in the risk of colorectal cancers in those who follow a lacto-ovo vegetarian diet also may not be as significant as compared with pesco-vegetarians. However, these studies do suggest that following a lacto-ovo vegetarian diet may be beneficial in reducing the risk of certain type of cancers.
Most of us do agree that vegetarians are generally more healthier than those who regularly follow a meat-based diet. However, there has to be a proper meal plan and a healthy balance of nutrients while choosing a vegetarian diet too. The vegan diet may be slightly better than lacto-ovo vegetarian diet in terms of reducing the risk of heart diseases, however, vegans may be deficient in vitamin B12, zinc and calcium. As lacto-ovo vegetarian diet includes milk, milk products and eggs, nutrients such as calcium, vitamin B12 and vitamin D can be easily obtained. At the same time, taking lots of milk and milk products may also lead to certain health issues. Hence, when designing a cancer patients’ diet, including the right foods and supplements in the right quantities ensuring a balanced diet becomes crucial.
One should also be careful while picking up pre-packaged foods for lacto-ovo vegetarians, as these may be highly processed with added sugars, calories and unhealthy oils that may not suit our health goals.
Cancer patients often have to deal with different chemotherapy side effects which affect their quality of life and look out for alternative therapies for cancer.Taking the right nutrition and supplements based on scientific considerations (avoiding guesswork and random selection) is the best natural remedy for cancer and treatment related side-effects.