Nutrition and cancer

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Nutrition and cancer

• Lecture 20
• April 6, 2009
• Dr. Quadro

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The leading causes of death in the United States
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Cancer

• Cancer is the 2nd leading cause of death in the
  US (after heart disease)
• 1 out of 4 Americans dies of cancer
• The risk of developing cancer can be reduced by
  changes in lifestyle.

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What is cancer?

• Cancer is the uncontrolled growth and spread of
  abnormal cells (cells do not die!).
• Cancer is the generic name for different
  diseases, usually classified according to the
  part of the body where it is first found.

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Types of Cancer

• Sarcoma- from connective tissues (muscle or
  bone). More common in younger people.
• Carcinomas- epithelial tissues (lung, breast,
  prostate, and colon). More common in older
  people.
• Leukemia- cancers of the blood or blood forming
  organs (bone marrow).
• Lymphomas- affect the lymphatic system. The
  lymphatic system is a group of vessels and nodes
  that act as the bodys filter. It prevents
  bacteria and foreign invaders from entering the
  bloodstream.

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Cell Theory

• 1) Every organism is composed of one or more
  cells.
• 2) A cell is smallest unit having the properties
  of life.
• 3) Continuity of life arises from growth and
  division of single cells.

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Cell

• Smallest unit of life.
• Can survive on its own or has potential to do so.
• Is highly organized for metabolism.
• Senses and responds to environment.
• Has potential to reproduce.

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Structure of Cells

• Plasma membrane
• Cytoplasm
• Nucleus (compartment where DNA is stored)

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What does a cell do?
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Cell Cycle
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What is cancer?

• Abnormal cell cycle regulation
• Not a single disease
• Many causes, Different details

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What is cancer?

• Cell proliferation
• cells division is out of control (cells divide
  too fast and/or at the wrong time/place)
• Apoptosis (programmed cell death)
• the self-destruct sequence of old or damaged
  cells fails

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What is cancer?
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Intestinal epithelium
Abnormal
Normal
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Causes of Cancer

• 80 are considered sporadic (not hereditary)
• Different types of cancer have different risk
  factors
• There are several risk factors
• Age- risk increases gt50
• Diet- high fat, high cholesterol diets

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Causes of Cancer

• Several risk factors (continue)
• Obesity- no clear reasons/link
• Cigarettes- increases lung cancer. Other tobacco
  products such as pipes and chewing tobacco,
  increase risk of mouth cancer.
• Long term exposure to chemicals- asbestos, radon
  and benzene.

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Causes of Cancer

• Several risk factors (continue)
• Exposure to high levels of radiation
• Harmful ultraviolet rays from the sun
• Some viruses- Hepatitis B, C, Human Papilloma
  Virus (HPV), Epstein-Barr (mononucleosis)
• Immune system diseases

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Causes of Cancer

• Hereditary
• Screenings are recommended for high risk
  families. One is considered at high risk if
  several relatives have had cancer or if someone
  in the family had cancer at a very early age.

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Carcinogenesis
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Carcinogenesis
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Carcinogenesis
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Diet and cancer

• Dietary factors act as
• -Initiators
• Promoters
• Anti-promoters

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Elevated serum vitamin D levels may help repress
development and progression of breast cancer
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Increased PCNA protein levels in prostate of
RBP-/- mice at 15 wks of age
p0.0004
weeks
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Where is the Colon? What does it do?
Colorectal cancer

• Stores mainly non-absorbed food, fiber and water
• Re-absorbs nearly all water
• Moves solid waste to the rectum where it is
  eliminated by defecation

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How does colorectal cancer develop?

• It begins as polyps (tiny abnormal growths on the
  inside walls of the colon or rectum).
• Polyps vary in size, from less than a millimiter
  to a few centimeters.
• Some polyps become cancerous after several years
  and should be removed to prevent development of
  colorectal cancer.

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X-Ray of Colon and Polyps
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Why the Concern?

• Leading cause of cancer-related death
• 4th-Worldwide
• 2nd- United States
• Why the difference between world and US ?

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What factors increase risk of developing
colorectal cancer?

• Poor Diet
• high fat
• high content of red meat
• high temperature cooking of red meats
  (heterocyclic amines and polycyclic aromatic
  hydrocarbon)
• low vegetables consumption
• high alcohol consumption
• low water consumption

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• Why does red meat consumption increase the risk
  of certain
• types of cancer?
• Higher fat content and antibiotics found in
  non-organic meat
• Presence of two chemicals produced when red meat
  is cooked to
• high temperatures.
• Production of heterocyclic amines (HCA) reaction
  occurs when red meat and any muscle meats are
  cooked above 150 C (regardless of whether it's
  fried, sautéed, grilled, or boiled). The higher
  the temperature the meat reaches, the more HCA's
  are produced. HCA's have been associated with a
  variety of cancers including colon cancer,
  pancreatic cancer, breast cancer, etc. Marinate
  your meat beforehand to substantially reduce HCA
  levels.
• adapted from www.ehow.com

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Why does red meat consumption increase the risk
of certain types of cancer? 2. Polycyclic
aromatic hydrocarbons (PAH) are formed primarily
when meat is grilled. Don't allow juices from the
meat to drip into your heat source, because they
form PAH, when they make contact. This chemical
will infiltrate your food during a flare-up. To
avoid this, always use a spatula or tongs to turn
your meat instead of piercing it with a fork. You
can also lay a piece of aluminum with holes on
your grate to keep meat from causing this
problem. Or you can choose a cheaper cut of meat,
or cook at a lower temperature, and that will
create less drip. Consider not serving meat, but
grilling vegetables instead. Make sure that your
grill is cleaned frequently, because what you
leave on the grill is high in HCAs if you have
cooked meat in the past. Be sure you scrape your
grill often with a wire brush to eliminate the
burned residue. adapted from www.ehow.com
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What factors increase risk of developing
colorectal cancer?

• Physical inactivity

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Why the Difference Between World and U.S. Rates?

• Colorectal Cancer has been called a Cancer of
  Economically Developed Countries
• Diet is different
• Physical activity is different

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Ways to Reduce Your Risk

• Regular moderate exercise
• Eat healthy diet
• Maintain proper weight
• Avoid smoking
• Limit alcohol use
• GET REGULAR SCREENING

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Ways to Reduce Your RiskHealthy
DietFive-A-Day is ? 5 servings of fruits
vegetables / dayThis can reduce your risk for a
number of diseases, not only colorectal cancer
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Ways to Reduce Your Risk

• Physical activity recommendations
• For 30 minutes
• At least 5 times per week
• At the pace of brisk walking

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Ways to Reduce Your Risk
Most important weapon in fight against cancer
SCREENING

• Prevention
• Finding polyps in the colon and removing them
  before they become cancerous
• Early detection
• Treatments are most affective when cancer is
  found early

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Who should be screened for colorectal cancer?

• EVERYONE aged 50 and older
• Women and men
• All races and ethnicities
• YOUNGER than 50 for those with a family history
  of colorectal cancer or colorectal polyps

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Who Is At Risk of Developing Colorectal Cancer?

• Men AND Women are at similar risk
• Risk increases with age (? 90 occurs in people
  aged 50)
• 85 of people with colorectal cancer had NO
  medical history related to colorectal cancer.

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AICRAmerican Institute for Cancer Research

• www.aicr.org