Dairy foods contain a variety of nutrients, including vitamins, fatty acids, protein,
calcium, potassium, and in the U.S. they are often fortified with vitamin D. Low fat
dairy foods have been associated with lowered blood pressure, improved blood
lipid profiles, improved insulin resistance and lower incidence of diabetes. Milk
consumption is associated with an increased risk of prostate cancer, probably no
increased risk of endometrial (uterine) cancer, a reduced risk of colorectal cancer, and has been inconsistently associated with cardiovascular disease, and type 2 diabetes. Milk consumption does not appear to reduce the risk of
hip fractures.

A 2013 meta-analysis of 20 randomized trials showed a non-significant increase
in LDL-C with either higher intake of whole-fat dairy or low-fat dairy. A 2015
meta-analysis considering links between milk consumption and mortality found no
consistent association between milk consumption and all-cause or cause-specific
mortality. A 2016 meta-analysis found that total dairy products intakes have no
significant impact on increased all cancer mortality risk, but whole milk intake in
men contributed to significantly elevated prostate cancer mortality risk. The naturally
occurring hormones in milk may be the link between high consumption of
milk and any increased risk of cancer. A 2017 meta-analysis combining data from
29 prospective cohort studies demonstrated no association between dairy products
and cardiovascular and all-cause mortality.

A Swedish study found that mortality rates were up to nearly three times higher
among women with high consumption of milk who also had low consumption of
fruits and vegetables. A less pronounced increase in risk was found among men.
The authors consider that D-galactose is the component of milk that harms health
because it causes oxidative stress damage and chronic inflammation; and that the
antioxidants in fruits and vegetables mitigate that risk. One study found that the
replacement of 5% of energy intake from dairy fat with equivalent energy intake
from polyunsaturated fatty acid (PUFA) or vegetable fat was associated with a lower
risk of CVD, whereas a 5% energy intake substitution of other animal fat with
dairy fat was associated with a 6% increased CVD risk. In addition, the replacement
of dairy fat with high-quality carbohydrates from whole grains is associated with a lower risk of CVD.

A 2018 meta-analysis study (PURE) questions the long-standing dietary advice to
avoid full-fat dairy products in favor of non-fat or low-fat products. The PURE
study was conducted in 21, mostly low or middle-income countries. The study
found that over a nine-year follow-up, compared to no intake, two or more daily
servings of full-fat dairy foods were associated with a 22% lower risk of heart disease,
a 34% lower risk of stroke, and a 23% lower risk of death from cardiovascular
disease. In the PURE study, cheese or butter intake was not significantly associated
with decreased or increased risk. The relevance of the PURE study for North
America and Europe is questionable because dairy consumption and saturated fatty
acids intake in these regions is high compared to most of the regions of the world
in the study. In addition, the study did not adjust for socioeconomic variables, and
in many of the 21 countries, wealthier residents may have both higher consumption
of dairy and other foods and other factors that lead to better nutritional and health
status and lower death rates.
Neal Barnard has evaluated the health impacts of cheese, and warns against the
overconsumption of cheese, a high saturated fat, high sodium, high cholesterol,
calorie-dense food that he considers can be addictive. However, some research
suggests cheese has less impact on raising LDL-C than butter. Cheese is a fermented
dairy product, and, in a cohort study, total fermented food intake was not
found to be associated with mortality due to all causes. Some studies have found
a lower risk of CVD among high consumers of cheese, and a meta-analysis found
no significant association between cheese consumption and all-cause mortality.

The possible varying health effects of specific dairy foods such as milk, yogurt,
cheese, and butter have not been well established. The most that can be said is
that research on the links between dairy foods and health are inconclusive and are
still being investigated. Because low-fat and non-fat dairy has a lower content of
calories, SFA, and cholesterol than whole-fat dairy, they are recommended by most
dietary guidelines and scientific organizations. A future blog will discuss the role of dairy foods on osteoporosis.

This blog presents opinions and ideas and is intended to provide helpful general information. I am not engaged in rendering advice or services to the individual reader. The ideas, procedures and suggestions in that are presented are not in any way a substitute for the advice and care of the reader’s own physician or other medical professional based on the reader’s own individual conditions, symptoms or concerns. If the reader needs personal medical, health, dietary, exercise or other assistance or advice the reader should consult a physician and/or other qualified health professionals. The author specifically disclaims all responsibility for any injury, damage or loss that the reader may incur as a direct or indirect consequence of following any directions or suggestions given in this blog or participating in any programs described in this blog or in the book, The Building Blocks of Health––How to Optimize Your Health with a Lifestyle Checklist (available in print or downloaded at Amazon, Apple, Barnes and Noble and elsewhere). Copyright 2021 by J. Joseph Speidel,